This book is DUB on the last date stamped below

 
 Abrasives & Abrasive Wheels 
 
 Their Nature, Manufacture and Use 
 
 A COMPLETE TREATISE ON 
 
 THE MANUFACTURE AND PRACTICAL USE OF 
 ABRASIVES, ABRASIVE WHEELS AND GRINDING OPERATIONS 
 
 INCLUDING 
 
 NATURAL AND ARTIFICIAL ABRASIVES, PRODUCTION AND PREP- 
 ARATION OF ABRASIVES, GRITS, GRADES AND BONDS, SHARPEN- 
 ING AND GRINDING STONES AND WHEELS, TESTING WHEELS 
 FOR EFFICIENCY, TRUING, REBUSHING AND INSTALLING 
 WHEELS, SAFETY DEVICES, AND DUST-COLLECTING SYSTEMS, 
 COMPLETE EXPOSITION ON SURFACE, EXTERNAL AND INTERNAL 
 GRINDING AND COMPREHENSIVE DATA COVERING THE PHYS- 
 ICAL AND CHEMICAL NATURE OF ABRASIVES IN GENERAL 
 
 BY 
 
 FRED B. JACOBS 
 
 A PRACTICAL HANDBOOK FOR ENGINEERS, FACTORY SUPERINTEN- 
 DENTS, FOUNDRYMEN, SHOP FOREMEN AND MECHANICS IN GENERAL 
 
 FULLY ILLUSTRATED 
 
 New York 
 
 The Norman W. Henley Publishing Company 
 
 2 West 45th Street 
 
 1919
 
 Copyrighted, 1919, by 
 The Norman W. Henley Publishing Company 
 
 Printed in U. S. A. 
 
 Printing Presswork and Binding by 
 Harper & Brothers, New York
 
 
 PREFACE 
 
 THE art of finishing metals by abrasion is one of the 
 oldest mechanical practices in existence, dating from 
 the time prehistoric man discovered that he could fashion 
 his wood and bone implements by rubbing them on rocks of a 
 gritty nature. 
 
 The grindstone is, without doubt, the oldest form of 
 grinding wheel known. With the early development of 
 the mechanical arts, it was discovered that a sandstone cut 
 in circular shape and mounted upon a revolving shaft, 
 showed higher efficiency than the side of a rock for sharpen- 
 ing and shaping various implements. It is definitely known 
 that grindstones, rotated by power, were used in the manu- 
 facture of armor as early as the year 1570. It is also 
 known that the emery deposits of the Grecian Archipelago 
 were known to the ancients and the value of this abrasive 
 recognized, as many writers of early days referred to emery 
 under various names. In considering some of the mechan- 
 ical achievements of the handicraftsmen who worked with 
 metals centuries before the Christian era, it is hard to 
 conceive how they attained so high a degree of perfection 
 without the use of an alumina abrasive for tool-sharpening 
 purposes. 
 
 While the practice of fashioning tools and implements by 
 abrasion is in all probability as old as civilization itself, 
 modern grinding, as we accept this term, is a compara- 
 tively recent development. About half a century ago, 
 the individual workman made his own grinding wheels of 
 glue and emery. 
 
 The first attempt at precision grinding consisted of finish- 
 ing the chilled iron calender rolls used in the paper-making 
 
 5
 
 PREFACE 
 
 industry. Owing to the hard nature of the material in 
 question, it was a long and tedious process to turn these 
 rolls accurately. 
 
 The development of the sewing-machine industry in the 
 New England States gave impetus to the development of 
 the grinding-wheel business. As a matter of fact, the first 
 attempts at cylindrical grinding, aside from roll grinding, 
 consisted of finishing parts of the Wilcox & Gibbs sewing 
 machine. The work was done by the Brown & Sharpe 
 Mfg. Co. 
 
 With the advent of the automobile industry, over twenty 
 years ago, the grinding-wheel business received a fresh 
 impetus as a rapid means was in demand for the accurate 
 finishing of parts. 
 
 Today, the modern grinding wheel is among the most 
 useful of modern shop accessories. Without it, it would be 
 impossible to maintain the present-day standard of rapid 
 production. In practically every line of metal working, 
 the grinding wheel plays an important part, its usefulness 
 ranging all the way from the rough grinding of castings and 
 forgings to the finishing of accurate surfaces, both plane and 
 cylindrical. 
 
 In presenting this work, the writer has taken great 
 precaution to make sure that every statement is authentic. 
 Aside from knowledge gained through many years as a 
 journeyman machinist, later supplemented with several 
 years' experience as a grinding-wheel salesman, many months 
 were spent in collecting data, verifying statements and 
 consulting reliable authorities, both in this country and 
 abroad. 
 
 The writer is indebted to the following manufacturers 
 and individuals who cheerfully answered numerous letters 
 and supplied valuable data and photographs: 
 
 Abrasive Co. The Carborundum Co. 
 
 American Emery Wheel Works Chicago Wheel & Mfg. Co. 
 
 The Blanchard Machine Co. The Cincinnati Milling Machine 
 
 Brown & Sharpe Mfg. Co. Co. 
 
 6
 
 PREFACE 
 
 The Cleveland Stone Co. 
 Cortland Grinding Wheel Corp. 
 Detroit Grinding Wheel Co. 
 Diamond Machine Co. 
 Parrel Foundry & Machine Co. 
 Metal & Thermit Corp. 
 H. G. Hammett. 
 Hampden Corundum Wheel Co. 
 The Heald Machine Co. 
 Frederick S. Jacobs, data on axe- 
 grinding. ' 
 Landis Tool Co. 
 
 Manufacturers Corundum Co., Ltd. 
 Minnesota Mining & Mfg. Co. 
 Newton Machine Tool Works. 
 Norton Co. 
 
 Norton Grinding Co. 
 
 Penton Publishing Co. 
 
 Pittsburgh Crushed Steel Co. 
 
 Pratt & Whitney Co. 
 
 Fred E. Rogers, editor emeritus of 
 
 Machinery. 
 
 Safety Emery Wheel Works. 
 Springfield Grinding Co. 
 Springfield Mfg. Co. 
 Sterling Grinding Wheel Co. 
 B. F. Sturtevant Co. 
 Superior Corundum Wheel Co. 
 United States Geological Survey. 
 Vitrified Wheel Co. 
 Waltham Grinding Wheel Co. 
 Wardwell Mfg. Co. 
 
 Permission to reprint material by the writer which had 
 been previously published, was granted by the following 
 publishers : 
 
 Penton Publishing Co., Marine Review. 
 McGraw Hill Co., American Machinist. 
 S. S. Smith Co., The Woodworker. 
 W. R. C Smith Publishing Co., Iron Tradesman. 
 Iron Age Co., The Iron Age. 
 
 The MacLean Publishing Co., Ltd., Canadian Machinery. 
 The Mines Publishing Co., Ltd., publishers of The Canadian Mining 
 Journal, gave permission to reprint material concerning corundum. 
 
 FRED B. JACOBS. 
 
 June, 1919.
 
 CONTENTS 
 
 CHAP. PAGE 
 
 PREFACE ix 
 
 I. NATURAL ABRASIVE SUBSTANCES Pages 13 to 36 
 
 Nature of natural abrasives Where found History of natural 
 abrasives Commercial application Sandstone Emery Corun- 
 dum Garnet Diamond Bort diamond Flint Quartz Nat- 
 ural sharpening stones Arkansas Washita Hindustan Tripoli 
 
 Pumice. 
 
 II. ARTIFICIAL ABRASIVES Pages 37 to 64 
 
 Various artificial abrasives Their physical and chemical properties 
 
 Their Commercial application Methods and processes employed 
 in the production of artificial abrasives Carborundum Alundum 
 Aloxite Boro- C arbone Oxalumina Adamite Crystolon, etc. 
 Relative hardness and abrasive efficiency of various materials 
 Artificial production of precious stones Their abrasive properties 
 Other artificial abrasives and their production Experimental 
 work Electro-thermic processes Production of rouge and crocus 
 Diamonds and crushed steel Angular grit. 
 
 III. THE MANUFACTURE OF GRINDING WHEELS .... Pages 65 to 82 
 Composition of grinding wheels Desirable and undesirable proper- 
 ties Bonds Shellac Rubber Fusible clays Silicate of soda 
 Vitrified wheels Method of oroducing vitrified wheels Puddled 
 process Pressed process Silicate wheels Shellac wheels Rubber 
 wheels Clay bond used in vitrified wheels Choice of bonding ma- 
 terial Wheel-turning Kiln used Heating of kiln and work 
 Cooling of kiln Dressing wheels Bushing wheels Speed tests for 
 wheels Elastic process Rubber process. 
 
 IV. ARTIFICIAL SHARPENING STONES Pages 83 to 87 
 
 Properties of artificial stones Carborundum stones Method of 
 manufacture Bond Grit Grade Finishing Combination 
 stones Carborundum rubs. 
 
 V. GRITS AND GRADES . . . ; Pages 88 to 96 
 
 Designation of grits and grades Mixed grits Grits of abrasive s 
 papers Standard grades Wheels Relation of speed to grade and 
 
 grit Wheel speeds for various operations. 
 9
 
 CONTENTS 
 
 CHAP. 
 
 VI. TESTING WHEELS FOR EFFICIENCY Pages 97 to 114 
 
 Selection of wheels Improper methods of testing Practical testing 
 methods Items to be noted in a wheel test How to figure result 
 Formula for finding volume of abrasive material in a wheel General 
 considerations Wheel tests. 
 
 VII. LABORATORY TESTS Pages 115 to 122 
 
 Apparatus and appliances used Limitations of laboratory tests 
 Factors to be considered Laboratory testing machine Data for 
 
 test Work used in testing. 
 
 VIII. GRINDING WHEEL vs. GRINDSTONES Pages 123 to 128 
 
 Advantages of natural and artificial abrasive used in wheels Early 
 
 use of grindstones Special work where grindstones are still em- 
 ployed Action of grinding wheel. 
 
 IX. THE ECONOMIC ADVANTAGE OF USING LARGE WHEELS . Pages 129 to 132 
 Factors to be considered in choosing a wheel Comparative price of 
 wheels of various sizes Advantage of large wheels in certain work 
 
 Why large wheels are more efficient. 
 
 X. TRUING DEVICES FOR GRINDING WHEELS Pages 133 to 138 
 
 Abrasive action Tools used in truing wheels Use of bort and 
 carbonado diamonds in tools Getting stones in tool Procedure in 
 truing wheels. 
 
 XI. RE-BUSHING GRINDING WHEELS Pages 139 to 141 
 
 Methods used in bushing wheels Tools employed Metals used. 
 
 XII. SUGGESTIONS TO FOLLOW IN ORDERING GRINDING WHEELS 
 
 Pages 142 to 144 
 
 Information to be given with grinding-wheel order Factor govern- 
 ing selection of wheels How to determine what kind of a wheel 
 should be used Ordering special wheels. 
 
 XIII. DESIGN OF DUST-COLLECTING SYSTEMS .... Pages 145 to 150 
 State law requirments Design of wheel hood General design 
 Size of exhaust pipe for different size wheels Elbows Collars 
 Method of erection Clean-out Fan Dust-collector Exhaust 
 systems. 
 
 XIV. SAFEGUARDING GRINDING WHEELS Pages 151 to 165 
 
 Why wheels break Cause of accidents How wheels are packed 
 
 and tested before leaving factory Wheel speeds Mounting wheels 
 properly What causes wheels to burst Safety flanges Work rest 
 Wheel guards Grinding on small wheels Precautions for the 
 workman. 
 
 10
 
 CONTENTS 
 
 CHAP. 
 
 XV. ABRASIVE PAPERS AND CLOTHS Pages 166 to 175 
 
 Abrasive substances used in making abrasive paper History of 
 abrasive paper How abrasive paper and cloth is manufactured 
 Grades of abrasive paper and cloth Finding percentage of iron in 
 garnet Testing garnet paper Paper and cloth abrasive discs-- 
 Testing discs for efficiency. 
 
 XVI. SURFACE GRINDING Pages 176 to 215 
 
 Finishing work by surface grinding Development of the surface 
 grinding machine Finishing locomotive guide bars Rotary 
 grinding fixture Wheel speeds Cuts Die grinding How dies 
 
 are held Grinding punches Care of wheels Magnetic chucks 
 Demagnetizes Proper wheel selection for surface grinding Types 
 of surface-grinding machines Standard wheel list. 
 
 XVII. CYLINDRICAL GRINDING Pages 216 to 242 
 
 Cylindrical grinders Operation of grinders Driving devices for 
 work Proper wheel speeds for various metals and work Traverse 
 feed Depth of cut Roughing and finishing cuts Sparking 
 Backrest and steadyrests Lubrication of work Lubricating com 
 pounds and mixtures Dressing and truing wheels while on the 
 grinder Chatter marks and their remedy Selection of proper 
 wheels for use on cylindrical grinders Universal grinders Grinding 
 tapers Various operations on universal grinder. 
 
 XVIII. INTERNAL GRINDING Pages 243 to 262 
 
 Internal grinding machines Internal grinding on universal grinder 
 
 Setting up universal grinder for internal work Grinding double 
 tapers Automatic grinders Grinding holes in spur and bevel gears 
 Chucks Wet and dry grinding Proper speeds Selection of 
 wheels Operating of cylinder grinders Cylinder grinding. 
 
 XIX. SPECIAL GRINDING OPERATIONS Pages 263 to 289 
 
 Grinding calender rolls Special grinding machines Roll grinders 
 
 and roll grinding Corrugating flour-mill rolls Grinding crank- 
 shafts Grinding cam shafts Locomotive valve gears. 
 
 XX. CUTTER SHARPENING Pages 290 to 307 
 
 Machines employed for cutter grinding Adjustments and attach- 
 ments on cutter grinders Grinding spiral cutters General opera- 
 tion of cutter grinders Selection of wheels Speeds Depth of cut. 
 
 XXI. SAW SHARPENING Pages 308 to 321 
 
 Band saws and circular saws Operation of band-saw sharpening 
 machine Sharpening band saws Grinding in new teeth Care of 
 machine Selection of wheels for saw gumming Machines for 
 sharpening cold saws Sharpening hack-saw blades. 
 
 ii
 
 CHAPTER ONE 
 
 NATURAL ABRASIVE SUBSTANCES 
 
 Nature of natural abrasives Where found History of natural abrasives 
 Commercial application Sandstone Emery Corundum Garnet 
 Diamond Bort diamond Flint Quartz Natural sharpening stones 
 Arkansas Washita Hindustan Tripoli Pumice. 
 
 NATURAL abrasives are being found in many parts of 
 the world. In a broad sense, the list includes all 
 minerals capable of abrasive action, but from a commercial 
 point of view, the principal natural abrasives are sandstone, 
 emery, corundum and garnet. The diamond is, of course, 
 a natural abrasive; indeed it is the hardest of all, but it is 
 needless to state that its rarity excludes it from the list of 
 commercial abrasive materials. 
 
 SANDSTONE 
 
 The first abrasive to be used in the form of a wheel was 
 in all probability sandstone. The use of a revolving stone 
 for sharpening purposes is so old that the beginning is 
 lost in antiquity. It seems reasonable to believe, however, 
 that the artificers of early civilization borrowed the idea 
 of a revolving sharpening stone from the crude mills used 
 many centuries ago for the grinding of grain. 
 
 Sandstone is a very curious mineral, indeed, as it consists 
 of uniform grains of sand (generally quartz with a small 
 percentage of feldspar and mica) firmly cemented together 
 with silica. Some varieties of sandstone, the Craigleith 
 stones used in the cut-glass industry for instance, are prac- 
 tically pure silica, this material often running as high as 
 98 per cent. Sandstone is found in many parts of the 
 
 13
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 world and in this country the most extensive deposits that 
 are worked for the production of grindstones are in Ohio 
 and Michigan. The Gray Canyon quarry at Amherst, 
 Ohio, is classed as the largest quarry in the world. Sand- 
 stones are of various colors, these being derived from 
 impurities that penetrated the mass during the formative 
 stage. Pure siliceous stones are white, or pale yellow in 
 cases where small quantities of iron oxide are present. A 
 red tinge is generally due to hematite, yellow to limonite, 
 green to glauconite, gray to clay and shale, and black, as 
 observed in black Graileith stones for example, to manganese 
 dioxide. 
 
 The average layman is of the opinion that all grindstones 
 are alike, but this supposition is erroneous for, in forming 
 the sandstone of which the grindstones of commerce are 
 made, it would appear that Nature anticipated the wants 
 of man by providing not only several grits to choose from, 
 but several grades as well. To insure an ample supply 
 of grits and grades, grindstone manufacturers generally 
 control holdings in various localities. 
 
 Before the advent of the grinding wheel, sandstone was 
 the only abrasive to be used in the form of a wheel. Its 
 use was, of course, limited, as practically the only grinding 
 done in the early manufacturing days consisted of tool 
 sharpening. Grindstones are used at present in large quan- 
 tities for sharpening edge tools, cutlery, etc., often in 
 preference to modern abrasive wheels. Many reasons for 
 this practice are explained later, under the heading, Grind- 
 stones Vs. Grinding Wheels. 
 
 EMERY 
 
 Emery, which in reality is an impure form of corundum, 
 has been known as an abrasive from very remote times. Its 
 value as an abrasive was known to the ancient Greeks/ 
 Dioscorides referred to it as a stone used in gem engraving. 
 Emery was also known to the Romans, Pliny and other
 
 EMERY 
 
 writers referring to it as naxium. There is also seme 
 authority for the statement that in the "adamant" of 
 the Old Testament, translated from the Hebrew, shamir 
 referred to emery ore. ^The principal emery deposits that 
 furnish the emery of commerce are located in Asia Minor, 
 in the basins of the Sarabat and Mender rivers. In the 
 Grecian Archipelago, the best known of these deposits are 
 located on the Island of Naxos, and in this country near 
 Chester, Mass., and Peekskill, N. Y. 
 
 Emery looks like iron ore, being of a dense, granular con- 
 struction. Its luster is metallic, while its color runs from 
 blue-black to black. It can truly be called a unique mineral, 
 as it is a mixture of alumina oxide and iron as magnetite 
 and hematite. At one time, all of the world's supply of 
 emery came from the Grecian Isles, principally Naxos, but 
 during the year 1847 Dr. J. Lawrence Smith located im- 
 portant emery deposits in Asia Minor. Dr. Smith's dis- 
 coveries proved to be of great benefit to the emery-consum- 
 ing trade owing to the fact that the price of emery was 
 materially reduced. Asia Minor or Turkish emery, as the 
 new material was called, at once became popular, as it 
 proved to be an efficient abrasive for many purposes. 
 
 Turkish emery always occurs in limestone or marble, 
 the deposits resting on gneiss, schist and mica slates, while 
 Naxos emery is generally found in limestone beds, being 
 associated with crystalline schists. One noticeable dif- 
 ference between the emery of the Grecian Archipelago and 
 that of Asia Minor is that in the former are numerous small 
 particles of mica which are seldom observed in the latter *- 
 
 The mining of both Turkish and Naxos emery is generally 
 carried on in a very primitive manner. Being near the sur- 
 face, the ore is easily removed as it is often present in loose 
 boulders. Masses that are too large for transportation to 
 the sea coast, are generally broken into fragments through 
 the process of heating them for a number of hours followed 
 by a sudden cooling with water. This causes the ore to 
 fracture in many places, and, by means of hammer blows, ^ 
 
 15
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 it is an easy matter to reduce the ore to pieces suitable for 
 transportation. The low cost of mining, together with 
 moderate transportation costs, accounts for the fact that 
 Turkish emery finds a ready sale in this country in competi- 
 tion with American emery. For the purpose of grinding- 
 wheel manufacture, however, *&axos emery is considered 
 superior to all other kinds as it is the hardest, toughest 
 and most uniform. The foregoing sounds like a broad 
 statement, to be sure, but it is the consensus of opinion 
 expressed by leading grinding-wheel manufacturers who 
 make wheels of emery. L 
 
 The discovery of emery in this country dates back to 
 about the year 1830, at which time a railroad was being 
 built from Boston to the Hudson River. In making a cut 
 near Chester, Mass., a deposit of emery ore was uncovered, 
 which, at the time, was taken for iron ore. As previously 
 stated, emery and iron ore resemble each other closely. 
 Blast furnaces were erected and provision made for working 
 the ore on a moderately large scale. At the first attempt 
 to smelt the ore, however, great difficulties were encountered 
 in separating the iron from the alumina and the deposits 
 were ultimately condemned as too refractory for practical 
 purposes. 
 
 The mine remained idle and almost forgotten for a num- 
 ber of years. In 1864 or thereabout, Dr. H. S. Lucas, 
 realizing the possibilities of working the deposits as a source 
 of abrasive supply to compete with the foreign product, 
 bought the property and began to successfully operate it 
 as an emery mine. Operations have been continued in 
 this district until the present day. The emery in question 
 is associated with amphibolite and serpentine, and, as the 
 veins of ore reach several hundred feet underground, it is 
 necessary to work them by extensive tunneling. 
 
 Mention should also be made of the emery deposits in 
 New York state in the vicinity of Peekskill. rhis emery, 
 which is called a spinel emery, does not occur in a continu- 
 ous vein, but in segregated masses, being associated with 
 
 16
 
 EMERY 
 
 morite rocks. In this ore spinel, which is magnesium 
 aluminate, MgAl 2 o 4 , furnishes the abrasive agent, since 
 spinel has a relative hardness of 8, as against 9, the hardness 
 of alumina, it is seen that spinel emery is somewhat softer 
 than other varieties of true emery. The value of spinel 
 emery should not be overlooked, however, as it furnishes 
 an efficient polishing material in cases where a very hard 
 and tough abrasive is not desired. 
 
 The specific gravity of emery varies in different speci- 
 mens from 3.7 to 4.3 and the percentage of alumina oxide 
 from 30 to 70. The abrasive power, sometimes called the 
 effective hardness, is not proportional to the amount of 
 alumina contained, being influenced to a great extent by 
 the proportions of other component parts in the form of 
 impurities such as silica, lime magnesia, etc., and the 
 structure of the grain itself. For the purpose of grinding- 
 wheel manufacture, the value of emery as an abrasive agent 
 is determined by the amount of alumina oxide present and 
 the toughness of the grain itself. ~^ 
 
 In common with other natural products, emery ore 
 varies in' a number of characteristics. This is true not 
 only of specimens from different mines, but of the product 
 of one mine as well. To market a high-grade emery, it is 
 necessary to pay especial attention to the selection and 
 grading of the crude ore, to which end the use of the micro- 
 scope cannot be recommended too strongly, as by this 
 means more can be learned of the quality of the emery 
 than by resorting to any other method, aside from the 
 actual working test of the finished product. 
 
 As emery may have a high percentage of alumina and 
 at the same time the ore may be so constituted that, after 
 crushing, the grains will seem to possess no cutting points. 
 Such an emery does not make a very efficient grinding 
 wheel. 
 
 Some specimens of emery crush up into the proper kind 
 of grains, as far as cutting points are concerned, but at the 
 same time nothing but fine grains are produced. Again
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 it is sometimes noticed that small flakes of mica are 
 scattered through the ore, which is sure to cause trouble 
 in the vitrifying process if the emery is used in the 
 manufacture of vitrified grinding wheels. It is readily 
 seen that an efficient abrasive cannot be made of an 
 emery ore selected at random. It is of the utmost im- 
 portance to know the nature of the grain to adapt the 
 same for a given abrasive purpose. 
 
 At one time, all grinding wheels were made of emery. 
 Of late years, however, corundum and the different artificial 
 abrasives are used. At the same time, notwithstanding 
 the efficiency of modern abrasives, the more ancient emery 
 wheel still has its field of usefulness, and, strange as it may 
 seem, on some classes of grinding, steel castings and heavy 
 malleables, for instance, emery wheels continue to show 
 the highest efficiency. This statement is not made thought- 
 lessly, but is the result of several years of observation spent 
 in representing grinding-wheel manufacturers. 
 
 From a theoretical point of view, it would seem that 
 abrasives containing a higher percentage of alumina than 
 is present in emery, would prove more efficient, regardless 
 of the nature of the work. Actual tests, however, have 
 proven beyond a doubt that for certain purposes the emery 
 wheel is still in a position to successfully compete with 
 artificial abrasives. This is explained in a subsequent 
 chapter. 
 
 Again, emery wheels are comparatively low in price, and 
 they find a ready market among consumers whose grinding- 
 wheel wants are few. A manufacturer who uses grinding 
 wheels intermittently, a few minutes at a time, is not con- 
 cerned whether or not the wheel shows the highest efficiency. 
 As long as it gives satisfaction, within certain limits, no 
 good reason is see'n why a higher price should be paid for 
 a more improved abrasive. 
 
 Another factor, that should be mentioned while consid- 
 ering the emery wheel, is that owing to the high percentage 
 of oxide of iron contained, this abrasive, grit for grit, leaves 
 
 18
 
 EMERY 
 
 a finer finish than any other abrasive material used in 
 grinding-wheel manufacture. Even on precision work, such 
 as gauge grinding and other similar operations, the emery 
 wheel still plays an important part and it is often the choice 
 of many engineers who know abrasives for their actual 
 worth. 
 
 Emery wheels, or emery stones, as they are termed in this 
 case, are also largely used for hulling oats and rice, taking 
 the place of the bed and runner natural stones as used in the 
 ordinary buhr mill. To whom the credit belongs for intro- 
 ducing the above stones, is not known for a certainty, but 
 experience has proven that the emery stone compares 
 favorably with the natural stones heretofore used for this 
 purpose. 
 
 Coarse emery is used in the form of bricks for rubbing 
 stone and various metals while the finer grades of emery 
 are made into sharpening stones, scythe stones, etc. Of 
 late years, however, artificial sharpening stones made of 
 electro-thermic abrasives (Carborundum, for example) have 
 largely replaced those made of emery. For a few specific 
 purposes, emery stones are still in use owing to the high 
 finish they produce. 
 
 v ln the form of grains and powders, emery is used for a 
 number of purposes such as finishing bevels on plate glass, 
 lapping hardened steel, polishing precious stones, etc., or, 
 in fact, for any purpose where a tough, durable abrasive in 
 grain form is desired. 
 
 Emery grain is also used to a great extent on polishing, 
 or set-up wheels, as they are termed, for finishing an end- 
 less variety of metal parts such as edge tools, cutlery, parts 
 of firearms, etc. Various kinds of emery act differently 
 on a polishing wheel and suitable grades for specific pur- 
 poses are generally chosen after careful experiment. One 
 reason why emery gives such good results on polishing 
 wheels is that its comparatively rough fracture presents 
 a good holding surface for the glue, which factor is not 
 true of many of the manufactured abrasives. Carborun- 
 
 19
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 dum, on account of its smooth, glassy surface, does not 
 form a very efficient abrasive to use on a polishing wheel. 
 
 Emery paper and cloth are used to a large extent in the 
 mechanical arts for smoothing and polishing small, intricate 
 parts of small machinery and instruments. 
 
 In the study of the occurrence of emery, we are con- 
 fronted with two very curious facts. First, emery is a 
 mixture of iron oxides and alumina and, second, this com- 
 position occurs in but few places in the world pin points 
 on the earth's surface, as it were. In American emery, Prof. 
 J. H. Pratt regards the alumina and iron oxides as basic 
 segregations from an igneous magma. This, of course, is 
 within reason since it is an accepted fact that the earth 
 was at one time a molten mass of elements, and as this 
 mass slowly cooled, the various elements combined and 
 sometimes segregated. What force of nature caused the 
 elements of iron and alumina to segregate together, in 
 practically the same manner, is beyond the knowledge of 
 the writer. 
 
 CORUNDUM 
 
 V 
 
 The name corundum was originally applied to the ruby 
 and sapphire of India, the word being derived from the 
 Sanskrit (kurminda) and literally means ruby. The variety 
 of corundum we are dealing with is called, by the older 
 mineralogists, impure corundum and comprises the numerous 
 varieties that are not transparent or perfect enough to be 
 used as gem stones. 
 
 Some thirty years ago, corundum was regarded as a 
 comparatively rare mineral, but at the present time it is 
 known to occur abundantly in several localities in this 
 country and in Ontario, Canada. In this country, it occurs 
 in igneous rocks, principally syenites, and in several gneisses 
 and schists. It also occurs in alluvium deposits in sands and 
 gravels. Canadian corundum occurs in nepheline syenite 
 associated with Laurentian gneiss. 
 
 Of the origin of corundum but little is known for a cer-
 
 CORUNDUM 
 
 tainty, as a study of his mineral calls for exhaustive research 
 work on the part of the geologist, who is sometimes reticent 
 when it conies to establishing hard and fast rules. Prof. 
 J. H. Pratt, who has made a deep study of the occurrence 
 of corundum, in this country and elsewhere, considers that 
 the corundum of North Carolina segregated from a molten 
 magma, the separation taking place at an early period of 
 consolidation. ^ 
 
 Canadian corundum has of recent years been regarded 
 as an essential rock constituent. Regarding the corundum 
 of Ontario, H. E. T. Haultain states that the corundum- 
 bearing rocks are not dykes, that they are not eruptive, 
 and that there is no sign of separation from magma. 
 
 The principal Canadian deposit of corundum occurs at 
 Craig Mountain, which is situated in Raglan Township, 
 Renfrew County, Ontario. In this country, corundum is 
 found in the following states: Maine, Massachusetts, 
 Connecticut, New York, Pennsylvania, Delaware, Virginia, 
 North Carolina, South Carolina, Tennessee, Georgia, Col- 
 orado, Montana, California and Idaho. 
 '"' Corundum is found in three different ways; block corun- 
 dum, crystal corundum and sand corundum. Under the 
 heading of block corundum, is included corundum found in 
 masses whether large or small. ( This is the most difficult 
 form of corundum to mine. Owing to its extreme hardness, 
 it is impossible to drill it for the purpose of blasting. Thus 
 it is not easily broken up. When block corundum is mixed 
 with foreign substances, such as feldspar, hornblende, etc., 
 it is often difficult to clean, whereas a block corundum 
 free from superfluous foreign matter makes an ideal ore, 
 provided the parting planes are -not too well developed. 
 The disadvantage of numerous parting planes is explained 
 later. 
 
 Corundum crystallizes in the rhombohedral division of 
 the hexagonal system and under the head of crystal corun- 
 dum is included all the crystal varieties of corundum 
 which occur in block corundum or % in sand or gravel. 
 
 21
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Some of these crystals take the form of a hexagon with a 
 prism at each end, in which case the crystal is termed 
 "barrel corundum." Many of these crystals are of no defi- 
 nite form, being enclosed in compact masses of surrounding 
 material. 
 
 Very small crystals and small grains are termed sand 
 corundum and often occur between a corundum-bearing 
 peridotite rock and the surrounding gneiss or schist. 
 
 Corundum possesses no true cleavage, but parting planes 
 are usually present along which the crystal fractures. How- 
 ever, if these planes are so numerous as to be present in 
 the small grains of abrasive material that constitute a 
 grinding wheel, a low abrasive efficiency will be the result 
 because the grains will readily fracture, thus breaking away 
 before becoming dull and useless. 
 
 An ideal corundum for an abrasive wheel is one wherein 
 the grains are free from parting lines, thus they will, on 
 becoming dull, break with the irregular to conchoidal frac- 
 ture, which is a characteristic of corundum. As a matter 
 of fact, all varieties of corundum have comparatively the 
 same degree of hardness, that is, from 8.8 to 9., but some 
 varieties are much higher in abrasive efficiency than others. 
 This is due to the fact that the parting planes are sometimes 
 too numerous as previously stated. This accounts for the 
 fact that some makes of corundum wheels are superior to 
 others. The only practical test for the abrasive efficiency 
 of a doubtful corundum is to make some sample wheels of 
 it and have them tested on actual work under every-day 
 working conditions. 
 
 From a theoretical point of view, corundum contains 
 but two elements, alumina and oxygen, its chemical formula 
 being A1 2 O 3 . Commercial corundum, as well as the gem 
 varieties, generally contains a trace of silica, ferric oxide 
 and combined water. The following table, which is taken 
 from Bulletin No. 269 of the United States Geological 
 Survey, gives the chemical analyses of several well-known 
 corundums.
 
 CORUNDUM 
 
 ANALYSES OF CORUNDUM 
 
 Locality 
 
 A1.0, 
 
 Per 
 Cent. 
 
 Fe 2 O 3 
 Per 
 Cent. 
 
 SiO 2 
 Per 
 Cent. 
 
 (H,0) 
 Per 
 
 Cent. 
 
 Insoluble 
 residue 
 Per 
 Cent. 
 
 Total 
 
 Analyst 
 
 Hastings County, 
 Ontario 
 Sapphire from India 
 Ruby from India . . . 
 Corundum Hill M ine , 
 N. Carolina 
 Laurel Creek Mine, 
 Georgia 
 
 96.92 
 97-Si 
 97-32 
 
 98.79 
 95-51 
 
 'i'8 9 
 1.09 
 
 -75 
 .88 
 
 0.80 
 
 I. 21 
 .90 
 
 i-45 
 
 2.43 
 
 .78 
 74 
 
 1-36 
 
 100. 71 
 
 IOO. 2C 
 99.62 
 
 100.22 
 
 98.58 
 
 Wells 
 Smith 
 Smith 
 
 Emerson 
 Emerson 
 
 
 
 
 
 Since corundum occurs more abundantly than emery, the 
 consumer of grinding wheels often asks why corundum 
 wheels command a higher price than wheels made of emery. 
 It is true that corundum deposits are numerous, but not 
 all of these corundums are of the correct structure for 
 grinding-wheel use, as above explained, and, again, co- 
 rundum goes through a comparatively expensive process 
 before it is fit for the grinding-wheel manufacturers. 
 
 It must be borne in mind that corundum, as it comes from 
 the mine, is not in a pure state, being mixed with other 
 minerals, such as feldspar, hornblende, margartite, mus- 
 covite, etc. Corundum is sometimes found in huge masses 
 weighing many tons and in cases of this kind, the elimi- 
 nation of the foreign matter is often a difficult problem. 
 Again, a corundum that is to be used in the manufacture 
 of vitrified wheels should be free from such substances as 
 mica, garnet and feldspar. Otherwise difficulties are sure 
 to be encountered in the vitrifying process. 
 
 In describing the methods used in mining and cleaning 
 corundum for the market, it may be well to first consider 
 the mines at Craigmont, Canada, as the methods and facili- 
 ties used there are generally acknowledged to be the most 
 up-to-date and practicable. 
 
 The above mine is worked by the Manufacturers Co- 
 23
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 rundum Company, Limited, and the following account of 
 the cleaning methods, etc., is taken from an article: "Co- 
 rundum at Craigmont," which appeared in the Canadian 
 Mining Journal under the date of August ist, 1907. As 
 this article was written by Mr. H. E. T. Haultain, who was 
 general manager of the company at the time, it is interest- 
 ing as well as authentic. 
 
 "The first discovery of corundum in Ontario was made 
 nearly thirty years ago on this Craig Mountain, then known 
 as Robillard's Hill, by Henry Robillard's daughter. As a 
 small child, she picked up and carried home a crystal that 
 'looked like a cruet stopper.' For years it remained as 
 an unnamed curiosity, but at the time of the phosphate 
 excitement, it was declared to be phosphate, and Robillard 
 and Fitzgerald located the ground as a phosphate mine. 
 
 "In 1896, Ferrier, of the Geological Survey, described the 
 presence of corundum in the neighboring township. Mining 
 operations were commenced in May, 1900, the ore being 
 transported in wagons half a mile to a small mill driven by 
 water power. In March, 1904, the present mill commenced 
 crushing. This mill is by far the largest corundum mill 
 ever built, and is the largest concentrating plant in Canada. 
 It has three divisions, the main mill, the grader, and the 
 finishing department. The latter is a comparatively recent 
 development. 
 
 " In the main mill, the rock is crushed on till 90 per cent. 
 of it will pass through a 2.5 millimeter hole, by means of 
 four rock breakers and five sets of rolls. It is concentrated 
 on 20 Overstrom tables; the concentrates, which contain 
 from 50 to 60 per cent, corundum, passing into bins for 
 drainage. 
 
 "In the grader, these concentrates are dried, passed over 
 magnetic separators, separated into 20 sizes, from 8 mesh 
 to 200 mesh, and still further subjected to concentration 
 on Wilfley tables and Hooper pneumatic jigs. The result- 
 ing product is again dried and again sized and passed into 
 bins, from which it is drawn off into zoo-pound bags. The 
 
 24
 
 CORUNDUM 
 
 run of bags each day is sampled by hand, every size by 
 itself, and these samples are carefully assayed, and accord- 
 ing to the assay results, the bags are stocked in the finishing 
 department. 
 
 "The finishing department performs three functions. It 
 thoroughly mixes the product so as to give a uniform ma- 
 terial complying closely with fixed standards. It re-screens 
 each size so as to eliminate the results of carelessness in 
 the grader. It automatically samples every lot of thirty 
 bags. 
 
 "The finishing foreman, knowing the assays of the con- 
 tents of his bags, mixes thirty hundredweight at a time 
 in a hopper. From this hopper, the corundum passes in a 
 thin, flat stream past a draft of air, which blows away the 
 mica. It then passes over a set of shaking screens, which 
 screen out both undersize and oversize particles and from 
 this it passes to a bin whence it is drawn off past an auto- 
 matic sampler direct into canvas bags, which are filled to 
 contain 100 pounds of corundum. 
 
 "The bags are then sewn up by machinery and marked 
 for size and lot number. The samples are tested by hand 
 screens for accuracy of sizing, by the eye for pyrites and 
 hornblende contents, by the magnet for magnetite contents, 
 and in the assay office for both corundum and iron content. 
 
 "On receipt of the assay results, the bags are marked G 
 or Gi, G grade being for silicate wheels and the polishing 
 trade, and Gi for the vitrified wheel trade. A sample 
 weighing about half a pound, representing each lot of 
 thirty bags, is stored for reference." 
 
 As before stated, corundum is found in many parts of 
 this country; one of the well-known mines is called the 
 Corundum Hill Mine. It is located in Macon County, 
 North Carolina. Corundum was discovered here in 1870 
 and mining operations were commenced a year later. This 
 corundum is found in a peridotite rock. The above mine 
 yields block, crystal and sand corundum having a high 
 abrasive efficiency in both silicate and vitrified wheels. 
 
 25
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 The corundum of this mine enjoys a wide reputation, in- 
 deed, one well-known manufacturer of grinding wheels ad- 
 vertises the fact that this brand of corundum is used. 
 
 Another famous mine, the Laurel Creek mine, is located 
 in Rabun County, Georgia. This corundum is also found in 
 peridotite and often in massive blocks, many of them weigh- 
 ing several hundred pounds. One mass of corundum taken 
 from this mine is reported to have weighed over 5,000 
 pounds. It is said that this mine has furnished the largest 
 masses of corundum ever mined in any locality. 
 
 An excellent grade of corundum is also found in Gallatin 
 County, Montana, where it occurs in a syenite rock. The 
 crystals are of all sizes up to eight inches long and some 
 have been found that weighed two pounds. Montana 
 corundum is being worked by modern methods. The 
 mills are equipped with up-to-date machinery. Several 
 grinding-wheel manufacturers have used this corundum, 
 reporting it as making an excellent grinding-wheel grade. 
 
 The above corundum deposits are mentioned because 
 they are well known to the corundum-consuming trade. 
 It must not be inferred from this, however, that excellent 
 grades of corundum are not found elsewhere in this country. 
 As a matter of fact, there are over 160 corundum deposits 
 that have been listed by geologists, many of them yielding 
 an excellent grade of material. 
 
 Abrasive engineers admit that corundum of the right kind 
 makes a very efficient grinding wheel for all purposes, with 
 the exception of materials of low tensile strength such as 
 cast iron, etc., and since corundum occurs so plentifully, 
 the question is often asked: why is it not used more ex- 
 tensively? This is at best a difficult question to answer, 
 but we may throw some light on the subject by considering 
 some facts that exist concerning the corundum industry. 
 
 To begin with, the older methods of preparing the abrasive 
 for the market were unsatisfactory; this resulting in an 
 imperfectly cleaned grain not wholly free from impurities, 
 for it is only within the. last few years, comparatively speak- 
 
 26
 
 CORUNDUM 
 
 ing, that modern appliances, such as used at the Canadian 
 mines, have been installed in this country. 
 
 In the old process of cleaning, the ore was crushed in rock 
 crushers and then re-crushed by passing it between a series 
 of rolls. The resulting grain was then washed in running 
 water, the corundum, being the heaviest, settled while the 
 lighter impurities were carried away. This, of course, 
 applied only to such substances as were not attached to 
 the grains of corundum themselves. The material was then 
 "scoured" by passing it through a machine not unlike a 
 screw conveyor and afterward re- washed. The grain then 
 received a further cleaning in a wet pan muller, which 
 consists of a revolving pan having a shaft over it carrying 
 two wooden rollers. The action of the muller caused the 
 grains to rub against each other, thus gradually wearing 
 away the impurities which were carried away by a stream 
 of running water. The material was then thoroughly dried 
 and sieved to the various commercial sizes. 
 
 The old process was expensive and uncertain as to re- 
 sults. Again, severe competition with artificial abrasives 
 began to creep in. The Carborundum Company was spend- 
 ing large sums of money int'oducing their product to the 
 manufacturing world and the Norton Company was not 
 far behind in extolling the merits of their artificial corundum 
 called Alundum. That it pays to advertise is an old and 
 true saying and artificial abrasives certainly have had the 
 advantage of wide publicity. Again, the artificial abrasives 
 were uniform, whereas corundum, when taken as a whole, 
 was not, since it was the product of many deposits, which 
 naturally varied to some extent. 
 
 It is the writer's opinion, given for what it is worth, that 
 corundum as an abrasive has been handled wrong from the 
 start. It has always been sold as a raw material, in com- 
 petition with emery at first and later in competition with 
 the artificial abrasives. The miners of corundum, even of 
 the very best qualities, were more than willing to sell their 
 product to all who wished to purchase, regardless of the 
 
 27
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 fact that not all manufacturers, a few years ago, knew how 
 to make the best quality of grinding wheels. 
 
 The writer fully realizes that it is a simple matter to say, 
 "I told you so," but, nevertheless he ventures the opinion 
 that if, upon the discovery of an exceedingly good quality 
 of corundum, the mine owners had gone into the wheel- 
 making business, absolutely controlling the sale of their 
 product and keeping the same up to a high standard, the 
 story of corundum could have been written differently at 
 the present time. 
 
 As a means of verifying the above statement, let us con- 
 sider The Carborundum Company for a moment. Suppose 
 they had been willing to sell their product to all wheel 
 manufacturers who cared to purchase. Would the carbo- 
 rundum grinding wheel hold the high position that it does 
 at the present day? Decidedly not. Carborundum wheels 
 of all kinds, good and bad, would have been on the market 
 and the result would have been that carborundum would 
 have lost favor in a great many cases. 
 
 Now it is a far easier matter to make a poor grinding 
 wheel than it is to produce a good one and here we have 
 the answer regarding corundum, an abrasive occurring 
 abundantly and possessing the highest abrasive qualities, 
 which now occupies an inferior position simply because 
 "too many cooks spoiled the broth." Everybody had 
 corundum wheels for sale wheels made of pure corundum 
 certainly. At the same time, however, some of this 
 "pure" corundum was unfit for wheel manufacture, while 
 in other cases corundum of the highest grade was given a 
 bad name because the actual value of the abrasive was 
 hidden in a poorly made grinding wheel. 
 
 How, then, should corundum have been handled? some 
 one is sure to ask. The answer is simple. As before stated, 
 the owners of a good corundum deposit should have en- 
 gaged in the wheel-making end of the business, given their 
 brand of corundum a good name, spent a hundred thousand 
 dollars in equipment, and several hundred thousand more 
 
 28
 
 DIAMOND 
 
 in advertising their product, and the business would have 
 developed itself. The sole ownership of a widely advertised 
 product is a gold mine in itself provided, of course, the 
 business is properly handled, and this is one factor that 
 has made manufactured abrasives rth distinctive names 
 so universally used. 
 
 Corundum is used for a number of purposes, and, in 
 comparing it with emery, it is a faster cutting abrasive 
 owing to its pure state. Corundum wheels are used prin- 
 cipally for steel grinding on both 'rough and precision work, 
 while corundum in grain and powder form is used for vari- 
 ous grinding and polishing operations. Sharpening stones 
 made of corundum are very efficient, while corundum- 
 coated paper and cloth are also put to a number of uses, 
 principally in the form of discs used on the disc-type of 
 grinder for finishing steel parts, both hard and soft. Taken 
 as a whole, corundum covers a wide field and by many it 
 is considered to be the best all-round abrasive known. 
 
 DIAMOND 
 
 Diamonds are divided into three groups, the transparent 
 and practically flawless varieties used as gem stones and im- 
 perfect stones called bort diamonds. There is also a black 
 diamond often called carbonado. The diamond has a specific 
 gravity of 3.50 and is the hardest substance known, being 
 placed at 10 on the mineralogist's scale. The diamond 
 crystallizes in the cubic system, generally taking the form 
 of an octahedron. 
 
 The fracture of the diamond is conchoidal and the crystals 
 invariably cleave along planes parallel to the octahedral 
 faces. Diamond cutters avail themselves of this character- 
 istic when reducing the stone to the best shape for cutting. 
 Of late years, however, a sawing process has been developed 
 which is said to be superior to the older method of cleaving 
 by means of a sharp blow. 
 
 The diamond is found in India, South America, South 
 29
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Africa, New South Wales, Borneo, and British Guiana. 
 At the present time, most of the diamond industry centers 
 in South Africa, the mines in this locality having been 
 worked since 1870. Previous to this time, diamonds were 
 found in alluvial deposits and in conglomerates, but in 
 the South African mines, the most famous of which are 
 the Kimberley and the De Beers mines, the diamonds are 
 found imbedded in a kind of blue clay in what are termed 
 "pipes." These are supposed to be filled-up craters of 
 long-extinct volcanoes. 
 
 Of the origin of the diamond but little is known, although 
 many eminent geologists have advanced well-grounded 
 theories concerning its formation, but, as the original con- 
 dition of the carbon, of which the diamond is composed, 
 remains a question, the genesis of the diamond is still un- 
 solved. 
 
 The De Beers Company mine many hundred thousand 
 dollars' worth of diamonds weekly and it is needless to state 
 that operations are conducted on a large scale, under the 
 supervision of the most able mining engineers available. 
 To get at the diamond-bearing blue clay, a shaft is sunk 
 several hundred feet into the earth just outside the pipe, 
 tunnels from this shaft running into the diamond-bearing 
 deposits. This material is hoisted to the ground above, 
 where it is spread out in large fields to allow the sun and 
 rain to crumble it to the extent of being easily washed. 
 This weathering process is materially aided by going over 
 the deposits occasionally with steam-plows. 
 
 The disintegrated soil is next washed in shallow cylin- 
 drical troughs wherein the diamonds are swept to the rim 
 by means of revolving toothed arms, the lighter material 
 escaping at the center. The findings are now concentrated 
 to separate the diamonds from hard foreign substances 
 and then a further separation is effected by passing the 
 concentrates over a greased surface. For some unaccount- 
 able reason, the greased surface holds the diamonds while 
 the other worthless materials escape. 
 
 30
 
 DIAMOND 
 
 It takes, on an average, four tons of blue ground to yield 
 one carat weight of diamond, and as the De Beers mines 
 often yield from three to four pounds of diamonds a day, it 
 is seen that an immense amount of blue ground has to be 
 worked. 
 
 The next step, and a very interesting one, is to sort out 
 the diamonds both for color and purity. The color runs 
 from clear white to black, a pale yellow being the most 
 common color. The only difference between a gem stone 
 and a bort diamond is that the former is practically flaw- 
 less and of good color, while the latter contains black specks 
 and other flaws, has no brilliancy and possesses an irregular 
 fracture. 
 
 It is needless to state that the diamond sorters are expert 
 at their work and they never let a gem stone pass for a bort. 
 As a matter of fact, dealers in bort stones look in vain for 
 a gem stone that might have missed the eye of the inspector, 
 but there is no record of their efforts being rewarded. 
 
 Aside from truing grinding wheels, bort diamonds are 
 used for many other purposes. In powdered form, they 
 are used for diamond cutting, this process being introduced 
 by L. von Berquen in the year 1476, for cutting and drilling 
 very hard substances, for certain kinds of delicate lapping 
 and grinding in watch factories and occasionally for very 
 minute turning operations in the watch or jeweler's lathe. 
 
 The process of converting bort diamonds into diamond 
 powder is simple, being carried out as follows: Several 
 bort stones are first crushed in a little mortar made especially 
 for this purpose and the material thus obtained is placed 
 in a quantity of the very best olive oil. The mixture is 
 thoroughly stirred and allowed to stand for five minutes. 
 The oil is then poured off and the diamond powder that 
 remains in the vessel is called No. o. The oil is now allowed 
 to stand for ten minutes and again poured off, the remain- 
 ing powder being known as No. i. To get the various 
 grades, the time limits used are shown in the accompanying 
 table.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Five minutes ...................... No. o 
 
 Ten minutes ....................... No. i 
 
 Thirty minutes .................... No, 2 
 
 One hour .......................... No. 3 
 
 Two hours ..... ................... No. 4 
 
 Ten hours ......................... No. 5 
 
 The oil is now allowed to stand until it shows clear, the 
 particles settling at the bottom being known as No. 6. 
 
 Carbonado, often called black diamond, is a form of 
 diamond found in Brazil, South America. It is of irregular 
 form and of a black, gray or brown color. It possesses no 
 cleavage and breaks with a granular fracture. Its specific 
 gravity is less than that of the true diamond. It is found 
 almost exclusively in the state of Bahia in what is called 
 cascalho, or diamond-bearing gravel. It is generally found 
 in small pieces, although occasionally a large piece is dis- 
 covered, the largest on record having a weight of 3,150 
 carats. 
 
 For truing grinding wheels, carbonado is superior to bort 
 diamond owing to the fact that absence of cleavage makes 
 the stone less liable to fracture. Thus carbonado is the 
 ideal form of diamond to use in rock drills and diamond 
 saws where the stone must withstand the impact of re- 
 peated shocks that would speedily ruin a bort stone. 
 
 GARNET 
 
 The name garnet is applied to a group of very closely 
 related minerals, some of which, in the pure varieties, are 
 used as gem stones. There are six kinds of garnet known 
 as follows: 
 
 Lime alumina garnet 
 
 Lime iron garnet 
 
 Lime chrome garnet ...................... Ca 3 Cr2Si 3 Oi2 
 
 Magnesia alumina garnet 
 Iron alumina garnet 
 Manganese alumina garnet 
 
 Garnet crystallizes in the cubic system, generally in 
 rhombic dodecahedra. It possesses an imperfect cleavage, 
 
 32
 
 GARNET 
 
 the parting lines running parallel to the dodecahedron. 
 Its hardness varies from 6.5 to 7.5 while its specific gravity 
 also varies to quite an extent, in different specimens running 
 from 3.4 to 4.3. 
 
 Garnet has been found in crystalline schists, gneiss, gran- 
 ite, metamorphic limestone, serpentine and volcanic rocks. 
 In this country, deposits are located in New York, New 
 Hampshire, Connecticut, Pennsylvania and North Caro- 
 lina. Large quantities of garnet are mined in New York 
 state, the deposits being located in the vicinity of the 
 Adirondack Mountains. This garnet, which occurs in 
 limestone and gneiss, is of the iron-alumina variety. It is 
 often called Almandine. The garnet of New Hampshire is 
 also of the above variety while North Carolina garnet occurs 
 in two forms, the iron-alumina and a subdivision called 
 rhodolite, which consists of two parts magnesia alumina and 
 one of iron-alumina garnet. 
 
 An excellent garnet, known to the trade as Spanish 
 mineral, is mined in Spain. This material is extensively 
 used in this country; in fact, one large manufacturer of 
 garnet paper uses it exclusively. There are no analyses on 
 record to establish the composition of this material, although 
 The United States Geological Survey informed the writer 
 that it is probably an iron-alumina garnet, or almandine. 
 
 Garnet is prepared for abrasive uses by crushing, concen- 
 trating and magnetic separation to remove the superfluous 
 iron oxide, after which it is graded into various commercial 
 sizes. As an abrasive for smoothing wood, garnet paper 
 and cloth enjoys great popularity, showing high efficiency 
 over ordinary sandpaper, especially on comparatively hard 
 woods, such as oak, cherry, maple, etc. It is not a suitable 
 abrasive for grinding-wheel manufacture, owing to its soft 
 nature, although it is sometimes mixed with corundum 
 in the manufacture of silicate wheels for such operations as 
 knife grinding. 
 
 The pure varieties of garnet are often cut as gem stones of 
 which there are many colors from deep red to light rose. 
 
 33
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Some of the finest garnet gem stones are found in loose 
 gravel in Macon County, N. C. 
 
 QUARTZ 
 
 Quartz is one of the most common of minerals and has 
 a wide distribution throughout the world. It is composed 
 of silicon dioxide, or silica SiO 2 . Aside from being an 
 essential constituent of some igneous rocks, as granite, it 
 occurs as sand and in crystals. Its specific gravity is 
 2.65 while its hardness is placed at 7 on Moh's scale. It 
 crystallizes in the trapezohedral-hemihedral class of the 
 rhombohedral division of the hexagonal system. In its pure 
 state, it forms many semi-precious stones such as the 
 amethyst, bloodstone, sardonyx and others. It has no 
 true cleavage and breaks with a conchoidal fracture. 
 
 As an abrasive, quartz has many uses. In grain form, 
 large quantities of it are used for plate-glass grinding and 
 in other forms of glass work. Glued on belts, it is used 
 for sanding implement and tool handles. Owing to its 
 hardness and sharpness, it is often used for sand blasting. 
 For sawing stone of the softer varieties, such as marble and 
 limestone, quartz forms a cheap and efficient medium. It 
 is not adapted to grinding- wheel manufacture although 
 it is sometimes mixed with other abrasives in making knife- 
 grinding wheels. 
 
 FLINT 
 
 Flint is a very hard, brown-colored stone being composed 
 principally of silica and having a specific gravity of 2.6. 
 Its fracture is conchoidal. It is one of the oldest known 
 minerals, being used by prehistoric man in the manufacture 
 of implements and weapons. It was once widely used for 
 striking fire and until the invention of the percussion cap 
 the flint-lock musket was used the world over. Thus it is 
 seen that this now little used material once played an 
 important part in shaping the destinies of nations. A 
 
 34
 
 NATURAL SHARPENING STONES 
 
 form of flint called flint-quartz is used in making the flint 
 paper of commerce which is more commonly spoken of as 
 sand-paper. In this country, the material in question is 
 mined in several places, the more important deposits being 
 in Maine, Maryland and Wisconsin. 
 
 NATURAL SHARPENING STONES 
 
 Under this heading are included all the natural stones 
 used, as hand stones, hones, etc., for various sharpening 
 operations. Sharpening stones are of very ancient origin, 
 specimens having been unearthed in Egypt dating back to 
 1500 B. c. Pliny, ^writing early in the Christian era, tells 
 of a stone from Crete used with oil and one from Naxos 
 used with water. The latter, in all probability, was noth- 
 ing more or less than a fragment of emery ore. The oldest 
 natural stone of modern civilization is the Turkey stone 
 mined in Asia Minor. This stone became popular over 
 one hundred years -ago and to some extent is used at the 
 present day. Other famous sharpening stones of a century 
 ago were the Belgian razor hone, which owes its abrasive 
 qualities to minute particles of garnet, and the German 
 water hone. Both of these stones are sold at the present 
 time. 
 
 The well-known Arkansas and Ouachita (Washita) stones 
 were discovered in Arkansas in the year 1815. These are 
 found in the foot-hills of the Ozark Mountains. There are 
 two varieties of Arkansas stones; hard Arkansas and soft 
 Arkansas. The former consists of 99^ per cent, pure 
 silica, being composed of very small particles of hexagonal- 
 shaped crystals to which it owes its cutting qualities. 
 This stone is widely used by watchmakers, engravers, tool- 
 makers, etc., for putting a very fine edge on cutting tools. 
 Soft Arkansas stones, although not as hard as the former 
 variety, are freer cutting, therefore they are the choice of 
 the carpenter, cabinet maker and pattern maker for putting 
 the correct cutting edge on chisels, plane irons, etc. 
 
 35
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Another famous natural stone is the Indian Pond scythe 
 stone, discovered in New Hampshire in the year 1821. 
 Upon this discovery was founded the well-known business 
 of the Pike Manufacturing Company, whose goods are 
 known to mechanics throughout the world. Several grades 
 of fine sandstone are used in making sharpening stones 
 for various purposes, scythe stones, axe stones, etc., large 
 deposits being located in Ohio. As a matter of fact, this 
 state furnishes many varieties of natural sharpening stones 
 such as the Hindustan, Queer Creek arid Chagrin Falls 
 brands. These are all excellent stones and find a ready 
 market for purposes to which they are adapted. 
 
 TRIPOLI 
 
 Tripoli is a trade name given to a yellowish abrasive 
 material which results from the leaching of calcareous 
 material from limestones and cherts. This material is also 
 often called rotten stone. It is found principally in Illinois 
 and Missouri. For abrasive purposes, it is used principally 
 for "cutting down" before polishing soft metals. It is put 
 on the market in the form of cakes, being mixed with tallow 
 and compressed. 
 
 PUMICE 
 
 Pumice is of volcanic origin, being an igneous rock which 
 was cooled so quickly that it did not have time to crystallize. 
 It sometimes contains impurities, such as feldspar and 
 hornblende, which diminish the general value of the 
 material as an abrasive, as the impurities leave deep scratches 
 owing to their hard nature. Natural pumice is found in 
 California, Kansas, Nebraska, Idaho, South Dakota and 
 Utah in this country while much of the imported article 
 conies from various islands in the Mediterranean Sea. 
 As an abrasive, pumice is used principally for very fine 
 varnish rubbing and in the manufacture of metal polishes. 
 
 36
 
 CHAPTER TWO 
 
 ARTIFICIAL ABRASIVES 
 
 Various artificial abrasives Their physical and chemical properties Their 
 commercial application Methods and processes employed in the pro- 
 duction of artificial abrasives Carborundum Alundum Aloxite Boro- 
 Carbone Oxalumina Adamite Crystolon, etc. Relative hardness and 
 abrasive efficiency of various materials Artificial production of precious 
 stones Their abrasive properties Other artificial abrasives and their 
 production Experimental work Electro-thermic processes Production 
 of rouge and crocus Diamonds and crushed steel Angular grit. 
 
 UNDER this heading can be included all grinding and 
 polishing materials produced by the arts of man; the 
 most commonly used being divided into two classes, carbide 
 of silicon abrasives, the original of which is Carborundum, 
 and artificial corundum, which material, in the form of 
 precious stones, has been made for more than seventy years. 
 
 In reality, the artificial corundum of today, sold under va- 
 rious trade names, such as Aloxite, Alundum, Boro-Carbone, 
 Oxalumina, etc., is an indirect outgrowth of the experiments 
 of other days, wherein scientific investigators had to con- 
 tent themselves with making artificial rubies and sapphires, 
 while vainly striving to produce the artificial diamond. 
 
 To class rouge and crocus as abrasives may seem rather 
 far fetched on first thought, but it must be borne in mind 
 that while these materials are used for polishing purposes 
 only, their mission is accomplished through abrasion, since 
 the finest mechanically finished surface possible to produce, 
 when viewed under a powerful microscope, is seen to consist 
 of a multitude of fine scratches. 
 
 Crushed steel and chilled iron are abrasives in the true 
 sense of the word. The former is used for grinding and the 
 
 37
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 latter for sand blasting, which is a process of removing 
 superfluous material by abrasive action. 
 
 Carborundum is undeniably the best known and, for 
 many purposes, the most useful of all the artificial abrasives; 
 indeed, it is often called the father of them all, since its 
 introduction into the mechanical world gave electro- 
 chemical engineers an impetus to produce competitive 
 material. 
 
 For the sake of clearness, the various well-known artificial 
 abrasives will be considered in chronological order, Car- 
 borundum being at the head of the list as it was the first 
 artificial abrasive to be recognized commercially. 
 
 CARBORUNDUM 
 
 Carborundum is a trade name given to carbide of silicon, 
 a substance discovered during the year 1891 by Edward G. 
 Acheson. It can truly be called the most unique of all 
 abrasives as it has never been found in nature, therefore 
 it is not an imitation of nature's work, but a distinct creation 
 in a class by itself. It is a chemical combination of the 
 two elements carbon and silicon, its chemical formula 
 being SiC. 
 
 The raw materials entering into the manufacture of 
 Carborundum are coke, sand, salt and sawdust. Coke 
 supplies the element carbon, while the element silicon is 
 derived from the sand. The object of the sawdust is simply 
 to make the mass porous, thereby permitting the gases 
 generated during the burning operation a free passage to 
 the open air. The object of the salt is to eliminate im- 
 purities such as iron, etc. As the salt volatilizes; it im- 
 pregnates the whole mass, taking up impurities in the form 
 of chlorides. 
 
 The Carborundum furnaces used at the present time are 
 fifty feet long, ten feet wide, and five feet high. The 
 original furnaces, however, were somewhat smaller. Both 
 types are of open construction, the sides and ends being
 
 CARBORUNDUM 
 
 built of brick. The end walls are approximately two feet 
 thick, through which run the terminals for the electric cur- 
 rent. These terminals are made of carbon rods three feet 
 long and three inches in diameter, arranged parallel in 
 bundles of sixty, the spaces between the rods being packed 
 tightly with graphite. At the outer ends of the rods, 
 copper terminals are let in, which, in turn, are connected 
 to a large copper cap. Current is supplied by means of 
 cables from overhead bus bars. 
 
 In charging the Carborundum furnaces preparatory to 
 burning, a mixture of thirty-four parts coke, fifty-four 
 
 Fig. i. Carborundum furnace charged with raw material, ready for burning. 
 
 parts sand, ten parts sawdust and two parts salt is used. 
 The materials are thoroughly mixed and brought to the 
 furnaces by means of mechanical conveyors. Enough of 
 this mixture is placed in the furnace to bring the upper 
 layer level with the ends of the electrodes. A trench is now 
 made between the terminals, wherein a core of granulated 
 coke is laid. The object of the coke is to allow a free pas- 
 sage for the electric current. More of the material is now 
 introduced and built up in the form of a mound as shown 
 in Fig i. 
 
 39
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 An alternating current of 190 volts and 6,000 amperes 
 is now turned on. As the mass heats, the resistance to the 
 current gradually diminishes, and after about four hours' 
 operation, it remains constant at 125 volts and 6,000 
 amperes. The sawdust, of course, burns away first, after 
 which carbon monoxide is given off. This burns freely at the 
 sides and top of the furnace with a yellow flame. As the 
 process of burning progresses, the mass shrinks somewhat, 
 which necessitates adding more raw material. Occasionally 
 the phenomenon of "blowing" occurs, which makes the 
 furnace look not unlike a miniature volcano. This is caused 
 by an over-charge of gas suddenly igniting and bursting 
 through the top crust of the charge. After a period of 
 about thirty-six hours, the burning operation is completed. 
 Several furnaces are in the process of burning at the same 
 time, being started at intervals of a few hours apart. The 
 object of this is to insure constant production as well as 
 the economical use of current. The current is carefully 
 watched, at all times by an electrical engineer especially 
 trained on electric-furnace work. This is quite essential, 
 otherwise a uniform product would be an impossibility. 
 
 After the burning is completed, the furnace is allowed to 
 cool for twenty-four hours, after which it is broken open, 
 ^he top crust, which is in a comparatively unaltered state, 
 is removed, exposing a layer of amorphous carbide of sili- 
 con under which lies the pure crystallized Carborundum. 
 Next comes a mixture of Carborundum and graphite and, 
 last of all, the core. The intense heat, estimated at ap- 
 proximately 7,500 Fahrenheit, transforms the core into 
 practically pure graphite. The amorphous carbide of sili- 
 con previously mentioned was at first considered of no 
 value and consequently thrown away. Later scientific in- 
 vestigation, however, showed that it possessed a high 
 refractory value. At the present time it finds a ready 
 market as a refractory material for lining furnaces subjected 
 to high heats of long duration. 
 
 The Carborundum crystals, while well developed, are 
 40
 
 CARBORUNDUM 
 
 not regular in appearance, some being hexagonal and others 
 rhombohedral. The crystals have no lines of cleavage, 
 breaking with a distinct crystalline fracture, invariably 
 leaving sharp cutting edges. 
 
 Carborundum crystals are of various colors, being truly 
 beautiful from an artistic point of view; coal black, deep 
 brown, light green, pale blue, deep blue a'nd purple are all 
 intermingled in a gorgeous riot of colors seldom equaled in 
 nature. In the early days of the industry, green Carbo- 
 rundum predominated and at present many are of the opin- 
 ion that green Carborundum is superior in cutting qualities 
 to specimens of other colors. Actual tests, however, con- 
 ducted by abrasive engineers, have proven beyond all reason- 
 able doubt that the above theory is absolutely groundless, 
 the color being the result of oxidation. 
 
 On Moh's scale of hardness, Carborundum is placed be- 
 tween nine and ten. It is probably nearer ten than nine 
 as Carborundum has been known to scratch rubies, sapphires, 
 and diamonds. Compared with other abrasives, Carbo- 
 rundum is comparatively light, its specific gravity being 
 approximately 3.18. This factor should not be under- 
 estimated since the centrifugal force of a revolving body 
 is proportional to the square of the velocity. Thus, wheels 
 running at the high speeds recommended in present-day 
 grinding practice are under a severe centrifugal strain, 
 and it is apparent that the lightest abrasive makes the safest 
 wheel. 
 
 Fig. 2 gives a good idea of the appearance of Carborundum 
 as it comes from the furnace, the photograph being taken 
 after the outer layers and core had been removed. As this 
 material looks like the products of the mine and quarry, the 
 question is sometimes asked, "Why is carbide of silicon not 
 found in nature?" The only reasonable answer the writer 
 can give is that the degree of heat at which both carbide of 
 silicon and graphite are formed is so near the same temper- 
 ature that nature seemed content to produce graphite alone. 
 
 An interesting feature of the production of Carborundum, 
 41
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 from the electrical engineer's point of view, at least, is the 
 form of circuit breaker used in making and breaking the 
 heavy current. As this amounts to 750 kilowatts it is seen 
 that the ordinary form of contact switch would be destroyed 
 in short order. To overcome this difficulty, a special circuit 
 
 Fig. 2. How Carborundum looks as it comes from the furnace. 
 
 breaker of the water-regulator type is used. This consists 
 of a number of iron plates working in a salt-water solution. 
 
 Thejarge masses of crystals produced in the Carborundum 
 furnace are reduced in crushing machines of the dry-pan 
 muller type, illustrated in Fig. 3. Under the weight of 
 the rolls (two tons each) and the rotary motion of the pan 
 (thirty revolutions per minute), the Carborundum masses 
 are rapidly crushed to small crystals. These range all the 
 way from very coarse to an impalpable powder. Although 
 the crushing rolls are made of manganese steel, they do not 
 last long, owing to the abrasive action of the Carborundum 
 grains, a pair lasting but six months at the longest. 
 
 Carborundum as it comes from the furnace is impreg- 
 nated with a small amount of iron oxide taken from the 
 sand and other minor impurities derived from the coke. 
 To eliminate these the crystals are transferred to wooden 
 vats, lined with lead, where they are lixiviated with strong 
 
 42
 
 CARBORUNDUM 
 
 sulphuric acid. The crystals are next washed in long 
 wooden troughs, the washing being passed through settling 
 tanks which help to separate the grains from the fine powder. 
 The crystals are now thoroughly dried by coke fires, after 
 
 Fig. 3. Muller type of crusher used in preparing Carborundum. 
 
 which they are ready for "grading," or "screening," as this 
 operation is sometimes termed. 
 
 The screening machine, as shown in Fig. 4, consists of a 
 series of screens set on a slight incline with their ends meet- 
 ing. The fine screens are made of a superior quality of 
 milling silk, while the coarser type are made of brass wire. 
 The Carborundum grains are fed on the screen at the high 
 end, and a vibratory motion, imparted to the screen frame, 
 causes them to journey downward. In passing over the 
 screens, they find an outlet suitable for their size. After 
 passing through the screens, the grain flows into receptacles 
 placed under the delivery openings as the illustration shows. 
 The screens vary from six meshes to the inch to two hundred 
 and twenty meshes to the inch. 
 
 Owing to the abrasive action of the grain the screens 
 wear readily. Thus care has to be exercised to insure uni- 
 form grading. This is accomplished by frequently testing 
 
 43
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 samples that have passed through the several screens in 
 testing machines carrying master screens. When the grains 
 are out of grade, it is a sign that the screen through which 
 it passed has worn to the extent of warranting renewal. 
 
 Fig. 4. Screening machines used in grading Carborundum. 
 
 This is promptly attended to and all over-size material 
 regraded. 
 
 It is not practicable to grade Carborundum finer than 
 two hundred and twenty by the screening method. There- 
 fore another method is used for grading the powders as they 
 are termed. In this system the fine powder is carried by a 
 stream of water through a series of settling tanks. In pass- 
 ing through the tanks, one after another, the heavier 
 grains sink. Thus, the last tank contains nothing but the 
 very finest powder. At the works of The Carborundum 
 Company, the following grains and powders are carried in 
 stock: 6, 8, 10, 12, 14, 16, 20, 24, 30, 36, 40, 50, 60, 70, 80, 
 90, 100, 120, 150, 180, 220 and powders F, FF, FFF. 
 
 44
 
 CARBORUNDUM 
 
 Carborundum is very hard, exceedingly sharp, and when 
 made into grinding wheels, it furnishes a highly efficient 
 abrasive for the grinding of materials of comparatively 
 low tensile strength, such as gray iron, chilled iron, brass, 
 bronze, marble, pearl, bone, horn, etc. In grain and pow- 
 der form, Carborundum is extensively used for lapidary 
 work, valve grinding, plate-glass beveling, stone finishing, 
 etc. It is sometimes used on "set up" wheels for polishing 
 cast iron, but owing to the fact that considerable skill is 
 required, both in preparing the glue and in covering the 
 wheels, the above practice has not become universal. 
 
 Carborundum coated paper and cloth enjoy an immense 
 sale in the boot-and-shoe industry, where they are used 
 for such operations as fore-part buffing, heel breasting, 
 heel scouring, etc. In the wood-working industries, how- 
 ever, Carborundum paper does not show efficiency over 
 flint and garnet paper as its sharp nature causes the coated 
 paper to fill up very readily. 
 
 In the leather-manufacturing industries, Carborundum 
 is used in a barrel-shaped wheel form, for the "wet wheeling " 
 of leather, as this operation on skins is termed. In grain 
 form, it is used on a special shaped cylinder for "buck- 
 tailing," while in the form of paper and cloth, it is used for 
 various finishing operations. 
 
 It is often stated that Carborundum will not grind steel 
 economically, but this statement is erroneous. At one 
 time The Carborundum Company sold a large number of 
 wheels to the lumber industry for saw gumming. As a 
 matter of fact, this is an operation calling for a very cool 
 and rapid-cutting wheel. The writer has used Carborundum 
 wheels for the cylindrical grinding of cold rolled and ma- 
 chine steel with excellent results. Not only did the wheels 
 produce an excellent finish, but they were very uniform in 
 grade, a feature not at all common some ten years ago. 
 The writer has seen Carborundum wheels used for auto- 
 mobile crank-shaft grinding by one of the largest manu- 
 facturers in the Middle West. The results were satisfac- 
 
 45
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 tory, Carborundum being preferred to all other makes of 
 wheels. 
 
 It must be considered that the above instances happened 
 some years ago, before the high development and accurate 
 grading of manufactured alumina abrasives, which at the 
 present time show higher efficiency on steel grinding than 
 is possible to attain with Carborundum. The above state- 
 ments are made simply to show that at one time in the his- 
 tory of grinding, Carborundum held its own on steel. 
 
 Why, then, does not Carborundum, which is acknowledged 
 to be the hardest and sharpest of all abrasives, both natural 
 and artificial, show high efficiency on steel grinding? This 
 is, at best, a hard question to answer and one upon which 
 opinions are at great variance. The writer's opinion, based 
 upon many years of observation, close study, and prac- 
 tical application, is that if Carborundum was not quite so 
 hard, and broke with a conchoidal instead of a crystalline 
 fracture, it would eventually drive the alumina abrasives 
 out of the market. 
 
 The above opinion can be called pure speculation without 
 a suitable hypothesis, therefore it is open to question. 
 However this may be, it is set down for what it is worth, 
 for opinions, no matter how theoretical they may appear, 
 possess some merit, at least until they have been dis- 
 proved by actual demonstration, and as it is an impossi- 
 bility to produce the type of Carborundum described, the 
 above theory may be as rational as any other. 
 
 The name Carborundum is registered as a trade mark, 
 thus it is the sole property of The Carborundum Company. 
 It, however, grinding wheels are made of Carborundum, 
 no matter by whom, they can lawfully be sold as genuine 
 Carborundum wheels. 
 
 OTHER CARBIDE OF SILICON ABRASIVES 
 
 A carbide of silicon abrasive called " Carbosolite " is made 
 in Germany. It has been sold in this country to a limited 
 
 46
 
 ARTIFICIAL CORUNDUM 
 
 extent, chiefly in the granite-finishing business. It is 
 mostly of a dark-gray color and it is not considered as pure 
 as Carborundum. Aside from the granite trade, a limited 
 amount of this material is made into grinding whe^s. 
 
 Crystolon is a trade name given to a carbide of silicon 
 abrasive made by Norton Company at their electric- 
 furnace plant in Chippawa, Canada. It is made by practi- 
 cally the same method used in producing Carborundum; 
 the same raw material forming the ingredients. It was 
 first puu on the market about seven years ago, and at 
 the present time it enjoys a large sale, both in the form of 
 wheels and grain. 
 
 The Abrasive Company of Philadelphia market grinding 
 wheels made of carbide of silicon, calling the same "Elec- 
 trolon." This material is an electric-furnace product, being 
 made of selected materials, the grain being specially treated 
 before being incorporated into grinding wheels/ This ma- 
 terial was first put on the market during the year 1914 
 and it is considered by many large consumers of grinding 
 wheels to be a very efficient abrasive. 
 
 ARTIFICIAL CORUNDUM 
 
 As stated at the beginning of this chapter, artificial 
 corundum has been produced for more than seventy years 
 and in considering the subject in the abstract, a little light 
 thrown on the experimentalists of other days may not be 
 out of place at the present time. 
 
 It is a well-known fact among those conversant with the 
 values of precious stones that a true Oriental ruby, of fine 
 color and flawless, is worth more, carat for carat, than 
 the finest diamonds of Brazil or South Africa. The term 
 ruby is often misconstrued to embrace the spinel or balas 
 ruby. Indeed, the famous "ruby" set in the Maltese cross 
 in front of- the imperial state crown of England is in reality 
 a spinel. It is, of course, possible for experts to readily 
 distinguish the difference between true and spinel rubies, but 
 
 47
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 since the ruby is nothing more or less than pure crystallized 
 alumina, colored with a small quantity of chromium, it is 
 evident that a laboratory product of the above materials 
 is a true synthesis of the ruby. It is as much entitled to the 
 name as the choicest specimens of nature from the Mandalay 
 district of Upper Burma, where the finest rubies have been 
 found. 
 
 In the year 1837, M. A. A. Gaudin successfully made 
 true rubies by fusing alum in a carbon crucible at a very 
 high temperature, a little chromium being added to impart 
 the desired color. The rubies, while of a very small size, 
 hardly visible to the naked eye, proved that it was within 
 the means of science to produce corundum artificially. 
 
 J. J. Ebelmen's experiments during the year 1847 resulted 
 in the artificial production of the white sapphire and rose- 
 colored spinel. The process consisted of fusing the desired 
 constituents at high temperature in boracic acid. He also 
 produced the ruby by using borax as a solvent. 
 
 Not until the year 1877, however, was it proved possible 
 to produce crystallized artificial alumina of a size suitable for 
 cutting into small stones, the process being the result of 
 experiments on the part of E. Fremy and C. Feil. The 
 process used was as follows : By the fusion of lead oxide and 
 alumina in a fire-clay crucible, lead aluminate was formed. 
 Silica enters into the composition of fire clay, and under 
 the influence of high temperature, the silica of the crucible 
 gradually decomposes the lead aluminate, forming lead 
 silicate, which remains in a liquid state while the alumina 
 crystallizes as white sapphire. By mixing in a small amount 
 of chromium, rubies were formed. The experiments of 
 Sainte-Claire Deville, Caron, Eisner, Debray, and De 
 Senarmont, too lengthy to be described fully here, did 
 much toward reducing the art of producing artificial corun- 
 dum to an exact science. 
 
 So much for the experimentalists of other days. They 
 did not attempt to produce artificial corundum for abrasive 
 purposes, to be sure, such a possibility being undreamed of 
 
 48
 
 ARTIFICIAL CORUNDUM 
 
 in their day. The fact remains, however, that their investi- 
 gations were of value as by their means it was shown con- 
 clusively that it was possible to produce artificial corundum. 
 
 One of the first inventors to achieve success in the manu- 
 facture of an artificial abrasive of the alumina type was 
 Franz Hasslacher of Frankfurt-on-Main, Germany. As 
 stated elsewhere, emery contains a high percentage of iron 
 oxide, which possesses no abrasive value, and aside from this 
 fact most specimens of emery are hydrous, often containing 
 as high as 5 per cent, of combined water, which causes trouble 
 in the kilns where wheels, in which this emery is incor- 
 porated, are made by the vitrified process. The above- 
 named inventor was granted a patent for changing natural 
 emery into iron-and-water-free corundum (German patent 
 No. 85,021, issued Nov. 20, 1894), the method of procedure 
 being as follows: 
 
 Crushed emery ore and charcoal or coke are first mixed 
 together, the percentage of the latter being equal to the 
 proportion of iron oxide contained in the emery ore. This 
 mixture is then placed in an electric furnace, an illustration 
 of which is shown in Fig. 5. The furnace consists of fire- 
 brick walls (A) , supported by the uprights (H) , the electric 
 current being transmitted by the carbons (C) . 
 
 In charging the furnace the opening at the bottom (D) 
 is closed by means of a glass plate (P) and the furnace filled 
 with the emery-and-coke mixture until the top of the mass 
 is level with the center of the carbons. The carbons are 
 placed about i-> inches apart, the space between them 
 being packed with a few lumps of coke. The furnace is 
 now completely filled and heaped up as shown at (S). 
 
 An alternating current of 300 amperes at a pressure of 
 no volts is now turned on, under the influence of which 
 the pieces of coke between the carbons are brought up to 
 incandescence, which causes the surrounding emery to 
 assume a molten state. The pieces of coke are soon ab- 
 sorbed and an electric arc established between the terminals, 
 the presence of which is proven by a loud buzzing sound. 
 
 49
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Carbon monoxide gas escapes through the mass, burning 
 with a blue flame. The presence of this gas indicates that 
 the iron oxides are in the process of reduction. A large 
 mass of molten emery soon forms about the electrodes, 
 
 Fig. 5. Hasslecher's furnace for making artificial corundum. 
 
 the furnace walls being protected by the surrounding, un- 
 melted material as the illustration shows. When a suf- 
 ficient amount of emery has been melted, the glass plate 
 fuses, causing the emery to run through to the floor in a 
 dazzling, white-hot stream. 
 
 At this point, the top crust is broken in, whereat the 
 descending crust of emery cools the molten emery around 
 the opening, causing the same to close. The furnace is 
 then charged again and the process continued. In about 
 fifteen minutes, the molten emery again breaks through. 
 Thus the process can be continued as long as convenient. 
 
 The resulting product is fairly well crystallized alumina, 
 running from white to blue in color, possessing a luster 
 not unlike that of quartz. This material, being free from 
 iron, possesses a higher abrasive efficiency than emery 
 and for some purposes it gives excellent results. It has been 
 
 5
 
 ARTIFICIAL CORUNDUM 
 
 used in this country to quite an extent, but at the present 
 time, and in fact for the last fifteen years, it has not been able 
 to successfully compete with American-made products. 
 
 Another process for making artificial alumina was patented 
 by Dr. G. Dollner of Rixdorf, Germany (German patent 
 No. 97,408, issued Feb. 28th, 1897). The method is quite 
 simple and easily carried out, consisting of mixing crushed 
 aluminum with oxides, peroxides and other metallic com- 
 pounds with oxygen. This mixture, when ignited, owing to 
 the high combustion temperature of aluminum, reacts in an 
 endothermic manner causing the formation of oxide of alumina. 
 This phenomenon is accompanied by the separation of the 
 metals, the oxides and peroxides of which were used. 
 
 In the reaction, the oxide of alumina is brought to a 
 state of fusion, and, on cooling, it is characterized by extreme 
 hardness. In his patent specifications, the inventor claims 
 that this material is of a degree of sufficient hardness to 
 replace diamonds for technical purposes, and further states 
 that it is superior to other artificial abrasives as by this 
 process grinding wheels can be prepared in solid blocks 
 that is a grinding wheel produced without a bonding 
 material. Whether or not this has been carried out suc- 
 cessfully the -writer cannot state. Even if it were possible, 
 however, such a wheel would be of one grade only, thus 
 its field of usefulness would be limited. 
 
 It may be well at this time to consider an abrasive called 
 Corubin, which is a by-product resulting from the manu- 
 facture of chromium by the Goldschmidt Thermit alumino- 
 thermic process. The above process is one for making 
 metallic chromium through endothermic action, the slag or 
 by-product of which forms an excellent abrasive material 
 as the following analysis shows. 
 
 Chromium 13 . 2 per cent. 
 
 SiO 2 3.08 " 
 
 A1 2 O 3 71-65 " 
 
 Fe 2.00 " 
 
 CaO Trace 
 
 MgO 1.35 "
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 From the above, it is seen that this material is composed 
 chiefly of alumina and chromium, the percentage of alu- 
 mina being high enough to form an efficient abrasive, while 
 the amount of chromium contained renders the abrasive 
 very hard and tough. 
 
 In the manufacture of other metals by the Goldschmidt 
 Thermit process, other slags are obtained being only slightly 
 inferior in abrasive efficiency to Corubin. The writer is 
 informed on good authority that these abrasives are giving 
 satisfaction, owing to the fact that several thousand tons 
 of them are sold annually to responsible abrasive-wheel 
 manufacturers in this country. Large quantities of Corubin 
 are used abroad in the manufacture of lenses, wherein the 
 abrasive is used to grind the glass, and in other abrasive 
 work. 
 
 That the experimentalists made great strides in perfect- 
 ing methods for the manufacture of artificial abrasives 
 (after Acheson and The Carborundum Company proved to 
 the world that there was a ready market for an artificial 
 abrasive) no one will deny. The artificial corundum made 
 previous to the year 1900, however, was incomplete in 
 that it lacked what we term at the present day abrasive 
 temper. We all know that high-carbon steel, or tool steel 
 as it is called, possesses a valuable characteristic inasmuch 
 as it can be made exceedingly hard by heating it red hot 
 and suddenly cooling it by immersion in water, or a brine 
 solution. Further, by tempering it, or drawing the color 
 as the smith says, we get various degrees of temper for in- 
 numerable purposes; a very hard steel for razors, a some- 
 what softer material for machine reamers, softer still for 
 lathe, tools, and yet softer for cold chisels and axes. 
 
 A piece of tool steel that has been hardened but not drawn, 
 is very brittle, thus its field is limited. For an illustration, 
 a lathe tool, a pair of scissors, or an axe thus treated would 
 be useless the lathe tool would crumble away as soon as 
 it was brought in contact with the piece of work to be turned, 
 the scissors would break the first time they were dropped 
 
 52
 
 BAUXITE 
 
 on the floor, while the axe would fly to pieces at the first 
 stroke of the woodsman. Thus, it is seen, that the character- 
 istic of temper is what gives tool steel its immense value 
 in the arts and sciences. 
 
 To complete the parallel we will now consider artificial 
 corundum, which, as originally made, was very hard and 
 useful in a limited field only. It is evident that if means 
 could be found whereby the temper of the material in 
 question could be controlled, its usefulness would be in- 
 creased a thousandfold. 
 
 This has been successfully accomplished and the credit 
 is due to an American, Charles B. Jacobs (no relation to 
 the writer), who in the year 1900 obtained a process 
 patent for manufacturing an abrasive from bauxite and 
 tempering the same to a degree of hardness suitable for 
 abrasive purposes. Briefly stated, Mr. Jacobs' process con- 
 sists of fusing bauxite in an electric furnace of the arc type 
 and cooling the resultant alumina oxide in a manner to 
 impart the desired degree of temper. 
 
 Before considering Mr. Jacobs' process, it will be of ad- 
 vantage at this point to touch briefly on the material bauxite 
 as we will have occasion to refer to it several times later. 
 
 BAUXITE 
 
 Bauxite is a clay-like mineral, or rather a combination of 
 minerals, containing among other constituents alumina 
 oxide, iron oxide, silica and titanic acid. It is taken to be 
 a decomposition product of igneous rock. It was first dis- 
 covered in France as long ago as the year 1821 by P. 
 Berthier, who called it alumina hydratee de Beaux. The 
 present name of bauxite was given to the material in ques- 
 tion by E. H. Sainte-Claire Deville in 1861. The name 
 was derived from the village of Les Beaux in Southern 
 France where the material was first observed. 
 
 Bauxite is never found in a crystallized state, but always 
 as a clay-like earth. Its color varies from light yellow to 
 
 53
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 deep red. The material, while always impure, contains a 
 high percentage of alumina oxide. Hence its value as a 
 raw material for the manufacture of an alumina abrasive 
 claimed the attention of abrasive manufacturers some 
 years ago, when a substitute for natural alumina abrasives, 
 that is to say emery and corundum, was seriously given 
 consideration. 
 
 In this country, bauxite is found in Georgia, Alabama 
 and Arkansas. In these localities, the material in question 
 is generally associated. with limestone and its origin is at- 
 tributed to the action of solutions of aluminum sulphate 
 on limestone. 
 
 CHARLES B. JACOBS' PROCESS 
 
 Mr. Jacobs' electric furnace for carrying out his process of 
 converting bauxite into artificial corundum is shown in 
 Fig. 6. It consists of a rectangular casing (i) with a slop- 
 ing top, at the apex of which is an opening (2) which serves 
 the double purpose of charging the furnace and carrying 
 off the volatile matter of the charge. The furnace casing 
 is constructed with a sheet-iron shell (3) which is lined with 
 fire brick (4), which serves as a non-conducting material 
 in regard to electricity as well as heat. Next to this, are 
 laid carbon bricks (5). 
 
 The hearth of the furnace consists of a cast-iron plate 
 (6) lined first with ground lime (7) and then carbon bricks 
 
 (8) laid in the lime. The hearth is mounted on a screw 
 
 (9) by means of which it can be lowered or raised at will. 
 By lowering the hearth during the furnace run, in a gradual 
 manner, a thick body of the fused material is obtained. 
 
 Over the earth are mounted four pairs of carbon electrodes 
 
 (10) between which the electric arc is produced. The fur- 
 nace is supported by cast-iron legs (n). These are of suffi- 
 cient height to allow the hearth to be lowered clear of the 
 bottom of the furnace. It is seen that the two outside pairs 
 of electrodes are away from the furnace walls; the object 
 being to keep the walls clear of fused material. The hearth 
 
 54
 
 CHARLES B. JACOBS' PROCESS 
 
 Fig. 6. Jacobs' artificial corundum furnace. 
 55
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 is left free to move up and down in the furnace. An 
 opening is made in one side of the furnace to permit 
 of inspection should occasion require and also to provide 
 means of introducing a stirring rod. The opening is closed 
 by the plug (12). 
 
 Mr. Jacobs' process of converting bauxite into artificial 
 corundum is as follows: The first step is to calcine the raw 
 material, the object of which is to drive away as much 
 moisture as possible. This saves undue expenditure of cur- 
 rent and wear on the electrodes. The hearth is now raised 
 until it occupies a position one inch below the electrodes, 
 each pair of which is placed in contact, and the furnace 
 filled with the calcined bauxite.' Current is now turned on 
 and the electrodes pulled apart, causing electric arcs to be 
 set up between them. The bauxite fuses under the intense 
 heat and the alumina contained therein runs down on the 
 hearth, which is lowered about two inches per hour. This 
 results in a quiet pool of melted alumina oxide which cools 
 and solidifies in crystalline form while the furnace hearth 
 descends. During the process of fusion, the impurities in 
 the raw material are volatilized, in which condition they 
 escape through the opening at the top of the furnace. 
 
 Regarding the temper of the material, Mr. Jacobs has 
 the following to say: "The nature of the product may be 
 varied by the slow or rapid cooling of the fused mass, so 
 as to obtain a product of the same degree of absolute 
 hardness, but of varying toughness, and consequently 
 varying abrasive power, by the slow or rapid lowering of 
 the hearth. The more slowly the product cools, the better 
 defined will be its crystallization and the greater its tough- 
 ness and abrasive power. The nature of the product may 
 also be varied by agitating the mass while cooling, as by a 
 poker or stirring rod inserted through the hole normally 
 closed by plug 12, and thus disturbing its natural tendency 
 of crystallization, producing thereby a finer grain of crys- 
 talline structure than when the material cools without 
 disturbance." 
 
 56
 
 ALUNDUM 
 ALUNDUM 
 
 Alundum is a trade name originated by Norton 
 Company and is applied to an alumina abrasive manufac- 
 tured under the above-described patent. However, the 
 process has been modified somewhat as shown by the fol- 
 lowing account of the same by Richard G. Williams, Me- 
 chanical Engineer and Special Investigator of Norton 
 Company, in a paper presented at the thirty-first general 
 meeting of the American Electrochemical Society held in 
 Detroit, Mich., May 2 5, 1917. 
 
 "The raw material must necessarily be a substance high 
 in aluminum oxide. The most satisfactory material is a 
 high-grade bauxite, although satisfactory abrasives are 
 being made from other materials, such as low-grade bauxite 
 and emery. Aluminous abrasives are made in the arc type 
 of furnace. These furnaces often consist of a wrought-iron 
 shell, or some form of pot, lined with carbon. The electrodes 
 are suspended in the pot and then lowered to the bottom 
 of the furnace, a train of graphite or fine coke placed be- 
 tween the electrodes, the current turned on and an arc 
 suitable for fusing is available as soon as the train of graphite 
 or coke has volatilized. 
 
 "Before fusion in the electric furnace, the bauxite receives 
 a calcining treatment to drive off 30 per cent, of combined 
 water. Suitable chemicals are mixed with the calcined ore 
 in order to facilitate the removal of such materials as iron 
 and silicon. Furnaces of three-ton capacity consume between 
 650 and 700 horse power and it takes approximately 24 hours 
 for a furnace run. After the run is completed, the shell 
 is stripped off or the furnace sides removed and the pigs 
 allowed to cool. When the pigs have cooled to a sufficient 
 temperature, they are broken up by sledge hammers into 
 pieces convenient for putting through a large jaw crusher. 
 This operation reduces the material to pieces about the 
 size of a man's fist, and in this condition the abrasive is 
 sent to the grinding-wheel factory for further treatment." 
 
 57
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Alundum, as put on the market, consists of two kinds; 
 ordinary Alundum and white Alundum. White Alundum 
 makes an almost white wheel when bonded by the silicate 
 process and a deep red-colored wheel when the vitrified 
 process is employed. White Alundum is designated by 
 the prefix 38. A 60 grit wheel made of white Alundum 
 is marked 3860. Ordinary Alundum is used for general 
 steel grinding on both rough and precision work, while 
 white Alundum is used principally for grinding such ma- 
 terials as high-alloy steels and general precision tool-room 
 grinding. 
 
 ALOXITE 
 
 Aloxite is the trade name of an alumina abrasive manu- 
 factured by The Carborundum Company. It is made from 
 bauxite in an electric furnace of the arc type. The Car- 
 borundum Company's Aloxite plant is located at Sarran- 
 colin, a small town in the province of Hautes Pyrenees in 
 Southern France, so as to be near an adequate supply of 
 the raw material. As a precautionary measure, however, 
 several furnaces are operated at the Niagara Falls plant. 
 
 An Aloxite furnace is quite a simple affair, consisting of 
 an outer shell resting on a base, and two electrodes for sup- 
 plying the current. The outer shell is water-cooled, but does 
 not have a refractory lining as the charge forms this itself. 
 It is placed on wheels to facilitate moving it from under 
 the electrodes when the burning operation is completed. 
 
 In charging the furnace, the bottom is first lined with a 
 mixture of carbon and tar. Next a layer of bauxite is in- 
 troduced and the electrodes lowered until they rest on the 
 bauxite. A path of graphite is now laid between the elec- 
 trodes, the object being to form a free passage for the cur- 
 rent. As soon as the charge is in a molten state, however, 
 it forms a good conductor in itself. The current is now 
 turned on and the bauxite brought to a molten state. An 
 alternating current of 6,000 amperes at a pressure of 100 
 volts is used. 
 
 58
 
 ALOXITE 
 
 As soon as the first layer of bauxite is in a molten state, 
 another layer is introduced, the electrodes raised, and this 
 layer melted. This process is continued until the furnace 
 is full, which requires about thirty-six hours. During the 
 melting process, the oxide of iron and silicon in the raw 
 material unite in the form of ferro silicon, thus practically 
 freeing the alumina from all impurities. As a matter of 
 fact, Aloxite runs about 97 per cent, pure alumina. The 
 ferro silicon, being heavier than the alumina, sinks to the 
 bottom of the furnace where it is easily disposed of. Several 
 furnaces are operated at the same time, the object being 
 twofold; that is, to produce a large supply of material and 
 to keep the current consumption as uniform as possible. 
 
 After the furnace has cooled sufficiently, the outer shell 
 is removed, exposing the Aloxite ingot. Two of these are 
 shown in Fig. 7. The ingots are first broken into pieces 
 
 Fig. 7. Aloxite ingots as they come from the furnace. 
 
 of about fifty pounds weight by means of a heavy breaker 
 of the skull-cracker type. The pieces thus obtained are 
 next crushed in an ore crusher of the type illustrated in 
 Fig. 8. Two crushers are employed, the first one being set 
 to produce lumps about as large as a man's fist while the 
 second crusher breaks them still smaller. The Aloxite lumps 
 are now passed through a magnetic separator which re- 
 
 59
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 moves any lumps of silicon which may have clung to the 
 ingot. A roller-type crusher is next used which completes 
 the crushing operation. Aloxite is screened in the same 
 manner as Carborundum and the numbers of the grades 
 and powers are identical. 
 
 Aloxite is very tough and possesses what might be termed 
 a well-regulated temper. The grains are hard enough to 
 
 I II 
 
 Fig. 8. Ore crushers used in preparing Aloxite. 
 
 cut rapidly, yet not so tough that they will not fracture 
 when dull. The temper of the grain is under control, thus 
 a uniform abrasive is the result. In color, Aloxite is of a 
 purplish blue and its formation is distinctly crystalline, 
 as Fig. 9 shows. 
 
 Aloxite is adapted for all kinds of steel grinding, especially 
 on precision work such as surface grinding, cylindrical 
 grinding, cutter and reamer sharpening, special grinding 
 operations such as crank-shaft grinding, wherein it is ab- 
 solutely essential that the corner of the wheel hold a well- 
 defined radius for some time, and for the general , grinding 
 of high-speed and alloy steels. As a substitute for emery 
 cloth, Aloxite-coated cloth has found favor with many 
 manufacturers of motor-cars and other products. Aloxite 
 
 60
 
 WERLEIN'S ARTIFICIAL ABRASIVE 
 
 grain is also being used for many grinding and polishing 
 operations heretofore done with emery grain. In the cut- 
 glass industry, Aloxite wheels are used for finishing the 
 beautiful and intricate cuts seen on the best ware, having 
 
 Fig- 9- Aloxite as it is formed in the furnace. 
 
 to a great extent taken the place of the black Craigleith 
 natural stones which were used for this purpose for many 
 years. Aloxite has been on the market since 1909. 
 
 WERLEIN'S ARTIFICIAL ABRASIVE 
 
 A comparatively recent patent (French patent No. 
 430,932, issued Aug. 28th, 1911) for the manufacture of an 
 artificial abrasive has been granted to Ivan Werlein of 
 Seine, France. It is an electric-furnace product composed 
 of alumina and silicon. In his patent specifications, the 
 inventor states: "This alumina and silicon compound 
 produced at high temperature may be obtained in various 
 ways. For instance, a mixture of 80 to 95 parts of alumina 
 and 5 to 20 parts of silicon is melted in an electric furnace. 
 
 61
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 When the mass has reached about 2,888 to 3,000 C. it is 
 kept at that temperature for about 20 minutes and then 
 cooled." 
 
 The writer has never seen this abrasive, therefore he 
 is not in a position to comment on its merits. From its 
 composition, however, it would appear to have some of 
 the characteristics of Carborundum combined with those 
 of the various alumina abrasives. Just what such an abrasive 
 would accomplish, judging from an American efficiency 
 standpoint, is a question of conjecture and to the best of 
 the writer's knowledge, this abrasive has not as yet claimed 
 the attention of American abrasive engineers. 
 
 BORO-CARBONE 
 
 Boro-Carbone is an artificial alumina abrasive made in 
 an electric furnace of the arc type by a process somewhat 
 similar to that used in the manufacture of Aloxite and 
 Alundum. It contains a high percentage of alumina oxide 
 with a small amount of impurities. In color, this abrasive 
 varies from a milky white to a light blue and its crystal- 
 lization is very pronounced. 
 
 Boro-Carbone is made in France, the raw material being 
 bauxite, and in one respect it enjoys a unique reputation 
 in that it is the only foreign abrasive that has been success- 
 fully able to compete with American-made products. To 
 be sure, Aloxite might be called a foreign abrasive, but in 
 the strictest sense of the word, this is a fallacy, as it is a 
 product of American engineering talent, originating at 
 The Carborundum Company's Niagara Falls plant. 
 
 The sale of Boro-Carbone is controlled in this country 
 by the Abrasive Company of Philadelphia, Pa., to whom 
 is really due the credit of perfecting this abrasive to a point, 
 where it could compete with American-made products. It 
 was put on the market in 1912 and at the present time en- 
 joys a large sale, being adapted for all kinds of steel grinding. 
 The Abrasive Company state that the temper of Boro- 
 
 62
 
 OXALUMINA 
 
 Carbone can be varied according to the kind of grinding it 
 is to do. 
 
 OXALUMINA 
 
 Oxalumina is a name given to a manufactured abrasive 
 of the artificial alumina type by. the Cortland Grinding 
 Wheel Corporation. Physically, it is composed of micro- 
 scopic crystals of alumina; chemically, it contains about 
 98 per cent, of aluminum oxide. It is prepared by fusing 
 and refining various alumina-bearing clays and ores in 
 carefully regulated furnaces. The resulting mass is properly 
 cooled, then crushed and graded for use as an abrasive. 
 This abrasive is widely advertised and sold in competition 
 with other American artificial abrasives principally for pre- 
 cision grinding operations. 
 
 ADAMITE 
 
 This material is an electric-furnace product made in 
 Austria. It contains approximately 80 per cent, alumina 
 oxide. It is dark blue to black in color, being of a compact, 
 well crystallized nature. It is a very tough abrasive and 
 by some American grinding-wheel manufacturers it is used 
 to a limited extent in the manufacture of very durable wheels. 
 
 ROUGE AND CROCUS 
 
 Both of these materials are made by the same process, 
 which consists of calcining sulphate of iron in crystal form. 
 The sulphate of iron crystals are subjected to high tempera- 
 ture in crucibles and the powder that forms at the bottom 
 is crocus, while that at the top is rouge. These materials 
 differ in color, rouge being red while crocus is purple. 
 These materials are used in buffing and polishing operations. 
 
 DIAMOND CRUSHED STEEL 
 
 This material is manufactured by the Pittsburgh Crushed 
 Steel Company of Pittsburgh, Pa. It is made of crucible 
 
 63
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 steel, subjected to a special treatment, after which it is 
 crushed and graded into the following sizes: 4, 6, 8, 10, 
 12, 14, 16, 18, 20, 30, 36, 40, 50, 60, 70, 90, 120, 150, 170, 190, 
 200. The sizes from 60 to 200 inclusive are known to the 
 trade as Diamond Steel Emery. 
 
 The material in question is a new departure in abrasives; 
 a scientifically prepared material designed to replace emery 
 for grinding operations on granite, onyx, marble, brick, 
 glass, etc., or in fact for any purpose wherein an abrasive 
 is used in grain form. As this material has three important 
 characteristics; hardness, sharpness and toughness, it should 
 prove a very durable grinding agent in cases where a rolling 
 and crushing action is present. 
 
 Crushed steel is not an ideal abrasive to employ in grind- 
 ing-wheel manufacture inasmuch as its tough nature tends 
 to prevent the grains from fracturing upon becoming dull. 
 
 ANGULAR GRIT 
 
 This is another abrasive material made by the above 
 concern, being used in the place of sand for sand-blasting 
 operations. It is a crushed chilled-iron product marketed 
 in the following sizes : 10, 12, 20, 30, 40, 60, 90. This ma- 
 terial is, without doubt, an excellent medium to use for 
 sand blasting as the individual grains have a number of 
 cutting points and the material does not break away, or 
 pulverize, as quickly as sand, thus reducing the objection- 
 able factor of dust to a minimum.
 
 CHAPTER THREE 
 
 THE MANUFACTURE OF GRINDING WHEELS 
 
 Composition of grinding wheels Desirable and undesirable properties 
 Bonds Shellac Rubber Fusible clays Silicate of soda Vitrified 
 wheels Method of producing vitrified wheels Puddled process Pressed 
 process Silicate wheels Shellac wheels Rubber wheels Clay bond 
 used in vitrified wheels Choice of bonding material Wheel-turning 
 Kiln used Heating of kiln and work Cooling of kiln Dressing wheels 
 Bushing wheels Speed tests for wheels Elastic process Rubber 
 process. 
 
 A GRINDING wheel consists of two parts the abrasive 
 'f\ material that does the cutting and a suitable bonding 
 material to hold the countless grains of which the wheel is 
 composed in a solid mass. Grinding wheels for some pur- 
 poses, such as the rough grinding of heavy gray-iron cast- 
 ings, should be hard and compact, to resist undue wear. 
 A cylinder wheel designed for a vertical spindle surface 
 grinding machine, such as the Pratt & Whitney Company 
 manufacture, must be open and porous to insure free cutting. 
 Thus it is seen that the dressing action which a particular 
 work has on the wheel in any given operation must be given 
 consideration in the manufacturing process. 
 
 The two kinds of wheels above mentioned are at extremes, 
 but in the making of wheels for various other purposes, 
 equally important factors must not be overlooked. As an 
 illustration, wheels for various tool and cutter sharpening 
 operations must be very cool cutting, while wheels for such 
 special grinding operations as crankshaft finishing are re- 
 quired to hold their peripheral shape for a reasonable length 
 of time; otherwise more time would be consumed in keep- 
 ing them in proper condition than would be spent in actual 
 production. 
 
 65
 
 AB^SIVES JtfrD ABRASIVE WHEELS 
 
 Some years ago, when grinding wheels were used only 
 for a few simple operations such as tool sharpening and 
 general grinding, simple "rule of thumb" manufacturing 
 methods answered very well. At the present day, however, 
 owing to keen competition and the high standard required 
 by modern efficiency engineers, grinding- wheel manufac- 
 ture is fast becoming an exact science, as it were, wherein 
 the manufacturer studies the requirements of his customers 
 and perfects his production methods to a point where only 
 the highest quality of goods receive the final inspector's 
 approval. 
 
 When we speak of the bond of a grinding wheel, we refer 
 to the material used to hold the grains in the wheel together. 
 In the vitrified bond, the binding medium is a high grade of 
 kaolin, or other refractory or fusible clays, the process of 
 vitrification taking place in a kiln patterned after a pottery 
 kiln. In the elastic bond, a good grade of shellac is em- 
 ployed, while in the rubber bond, the particles of abrasive 
 material are held together by vulcanized rubber. In an- 
 other process, silicate of soda, sometimes called waterglass, 
 is used. All these bonds possess merit for specific purposes, 
 but as a matter of fact the majority of grinding wheels in 
 use at the present time are made by the vitrified process. 
 This bond is used so much more extensively than the others 
 that it is possible to obtain with it a greater range of grade 
 than is possible with other wheels. Again, years of ex- 
 perience, to say nothing of costly laboratory experimenta- 
 tion, have proven that the bond of a grinding wheel is 
 always a detriment to fast cutting, but as a bond of some 
 kind is, of course, a necessity the one that will produce 
 the least friction and at the same time produce the desired 
 grade is always preferable. Thus, the vitrified bond has 
 been found by practice to be the best adapted for the ma- 
 jority of purposes. 
 
 For the sake of clearness, all the above methods of wheel 
 manufacture will be considered separately. The selection 
 of correct bonding materials and the perfection of the various 
 
 66
 
 THE VITRIFIED PROCESS 
 
 processes involved is the result of many years of research 
 work and close study on the part of ceramic engineers and 
 experts on abrasives. 
 
 THE VITRIFIED PROCESS 
 
 As before stated, in the vitrified process, the binding 
 material is a good grade of kaolin, or other refractory or 
 fusible clay, which comes to the grinding-wheel manufac- 
 turer in carload lots, just as it is taken from the earth. 
 By means of standardized formulas, the chemist tests this 
 material to make sure that it comes up to a predetermined 
 standard. Otherwise several thousand finished wheels might 
 prove to be absolutely worthless. Further to test the value 
 of the bonding material, several small wheels and briquets 
 are made up and run through the kilns to make sure that 
 the material in question stands a satisfactory heat and 
 resistance test. 
 
 The foregoing may seem to the layman like an elaborate 
 procedure for the testing of a carload of clay, but eternal 
 vigilance is the watchword of the grinding-wheel manufac- 
 turer who desires to get new trade and successfully hold it 
 against competition. After it has been assured that the 
 bonding material is up to the correct standard, it is care- 
 fully ground and thoroughly dried and sifted. 
 
 The hardness, or resistance to wear, in a grinding wheel 
 is determined by the percentage of bond used with a cer- 
 tain amount of abrasive material. A hard wheel has a 
 heavy bond, while in a soft wheel, the percentage of bond- 
 ing material is less. To adapt an abrasive to many different 
 kinds of work calls for a variety of bonds, the most common 
 being the close tough and close brittle, open tough and open 
 brittle. It must also be borne in mind that bonds are em- 
 ployed to produce texture between these extremes. The 
 standardization of grinding-wheel bonds is the result of many 
 years of research work and actual experimentation. It is 
 needless to state that bond mixtures are kept as close secrets. 
 
 67
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 In the manufacture of vitrified grinding wheels, there are 
 three methods used in mixing the abrasive material with 
 the bond; dry mixing, wet mixing and a combination of 
 both these methods. A dry mixed wheel is made by what 
 is known as the pressed process while a wet mixed wheel is 
 made by the puddled method. In a puddled and pressed 
 wheel, a combination of both mixing methods is employed. 
 
 In making wheels by the pressed process, the first step 
 is to determine the correct proportions of grain and bonding 
 material by weight, after which the mixture is dampened 
 a little and tumbled about in a tumbling barrel for a few 
 hours. The object of this procedure is twofold; to mix 
 the materials thoroughly and to surround each individual 
 grain of abrasive material with a matrix of bonding mixture, 
 to hold it in place in the finished wheel. 
 
 The mixed material now goes to the press room to be 
 formed into wheels. In this department are a number of 
 hydraulic presses, some of them capable of exerting a pres- 
 sure of 5,000 pounds per square inch. The process of 
 pressing a wheel is quite simple and easily carried out. An 
 operator carefully weighs out the correct amount of mixture 
 and places it in a steel mold of the desired size. After 
 leveling the mixture carefully, a cover that fits the bore of 
 the mold is placed on the wheel mixture and the mold placed 
 in position over the ram of the press. With his eye on the 
 pressure gauge, the operator opens the water inlet and as 
 the ram rises under the water pressure, and as the hand 
 of the pressure gauge mounts upward a crunching sound 
 is heard as the enormous pressure exerted by the water is 
 transmitted to the wheel in process of formation. When 
 just the exact pressure required is recorded by the gauge, 
 the operator opens the release, the ram descends and the 
 mold is removed. The pressed wheel is now taken from 
 the mold, ready for the vitrifing kiln. 
 
 Wheels made by the pressed process are very compact 
 but not necessarily hard. As an illustration, a Carborun- 
 dum wheel in O grade, G2 bond is a pressed wheel, al- 
 
 68
 
 - THE VITRIFIED PROCESS 
 
 though it is six grades softer than an I grade wheel in B6 
 bond, which is a puddled wheel. On the other hand, a 
 Carborundum wheel in BI6 bond, which is made by the 
 puddled process, is very hard but not as compact as an I 
 grade wheel in G6 bond which is a pressed wheel, and 
 although six grades softer, it is more compact: It is seen 
 that the object of making wheels by the pressed process is 
 to make them compact, which characteristic is to be de- 
 sired in wheels for a variety of grinding purposes. 
 
 In making wheels by the puddled process, the correct 
 proportions of grain and bonding material are agitated for 
 several hours in mechanical mixers as shown in Fig. 10. 
 
 Fig. 10. Mixing the materials to form puddled wheels. 
 
 The mixture is then poured into a sheet-iron mold and 
 thoroughly dried by steam heat. After drying sufficiently, 
 which consumes several weeks for very large wheels, the 
 embryo wheel is placed on what is termed a shaving machine, 
 an illustration of which is shown in Fig. n. This machine 
 is constructed on the principle of a potter's wheel, consisting 
 of a revolving circular table upon which the wheel is placed, 
 and a cross-slide over which travels the head carrying the 
 tools used in shaping the wheel. 
 
 69
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 The process of turning the wheel to the correct size and 
 shape, and boring the hole for the lead bushing, is com- 
 paratively simple although considerable skill is required in 
 turning wheels of irregular shape, such as certain wheels 
 for special tool grinders, cup wheels, large cylinder wheels, 
 
 Fig. II. Shaving grinding wheels preparatory to vitrifying. 
 
 recessed wheels for cylindrical grinding, etc. The wheel- 
 shaving operator is a skilled artisan in his particular line 
 of work, prosecuting his work by means of a blue print, or 
 other drawing, and obtaining the necessary dimensions by 
 means of scales and calipers such as are used by the machinist. 
 The next step consists of vitrifying the wheels. The 
 vitrifying kilns used by grinding-wheel manufacturers are 
 patterned after those used in the pottery industry for 
 vitrifying china and earthenware. They are approxi- 
 mately sixty -feet high and sixteen feet in diameter, being 
 constructed on what is called the down-draft principle. 
 A secondary interior wall is built inside the kiln, coming to a 
 
 70
 
 THE VITRIFIED PROCESS 
 
 crown about twenty feet from the kiln floor. The heat is 
 so distributed that it circulates freely in all parts of the 
 kiln interior, finding an outlet at the bottom. 
 
 The wheels, as they come from the press and puddling 
 rooms, are placed in earthenware receptacles technically 
 termed sagers, a few of which are shown at the left-side 
 foreground of Fig. 12. As the wheels are in what is termed 
 
 Fig. 12. Loading a grinding- wheel kiln. 
 
 a "green" state, care is necessary in handling them. To 
 insure even bedding in the sagers, the wheels are placed on 
 a layer of sand. Several small wheels are loaded in one 
 sager but with medium-sized wheels, say 12x2, one to a 
 sager is considered sufficient. Wheels 14 inches in diameter 
 and over are piled one over the other in sectional sagers, 
 each wheel being bedded in sand. 
 
 An interior view of a grinding-wheel kiln is shown in 
 Fig. 13, wherein several piles of sagers are shown in the 
 background. After the kiln is completely filled, the door 
 is sealed tight and the kiln is ready for firing. To correctly 
 burn a kiln of grinding wheels is an operation calling for 
 long practice. It consists of bringing the kiln up to the 
 correct heat, keeping it there for the necessary period and 
 
 7 1
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 then letting it cool gradually. Too much heat would result 
 in over-burning, the effect being the destruction of the bond, 
 leaving it in a burnt-up or honeycombed condition, while too 
 little heat would produce an under- vitrified wheel. Again, 
 if the kiln is brought up to full heat too rapidly, wheels 
 
 Fig. 13. Interior of a grinding- wheel kiln. 
 
 having hard and soft spots are liable to result. Further, 
 if the kiln is allowed to cool too rapidly 75 per cent, of its 
 contents will come out in a cracked state, being absolutely 
 of no value, for, unlike the good housewife's pie-crust, 
 grinding wheels cannot be worked over again. 
 
 Arranged around the base of the kiln, are approximately 
 ten fire boxes, the fuel used being a good grade of either 
 anthracite or bituminous coal. Two fires are started at a 
 time and allowed to burn for some time, after which two 
 more are started at regular intervals until all are burnr'ng. 
 The kiln is now brought up to the first, or red heat, which 
 takes fifteen hours. The heat is gradually increased until 
 the kiln is at what is termed the "low melting point." 
 Tests are frequently made by means of sets of pyrometric 
 cones which, are inserted in the kiln through test holes. 
 There are several of these test holes in every kiln arranged 
 at regular intervals and it is important that the readings of 
 each test hole tally, otherwise it is a sign that the heating is 
 uneven. The test cones are made of clays having different 
 melting points. Three cones having different melting tem- 
 peratures are placed on one base. When the first one melts 
 nd topples over, it is a sign that the kiln is at "red heat." 
 
 72
 
 THE VITRIFIED PROCESS 
 
 The next one succumbs at low melting point and when the 
 third one wilts under the heat, it signifies that the kiln is 
 up to full heat or a trifle higher than 2,500 Fahr. A set of 
 the cones used is illustrated in Fig. 14. For many years, the 
 pyrometrical cone was the only means used for determining 
 the heat of the kiln. Of late years, however, owing to the 
 
 Fig. 14. Pyrometric cones used for measuring degree of temperature in 
 grinding-wheel kilns. 
 
 high degree of perfection reached in the manufacture of 
 various types of pyrometers for accurately determining high 
 temperatures, the latter are now used in connection with the 
 former in grinding-wheel kiln burning. 
 
 After the kiln has reached full heat, it is sealed up and 
 allowed to cool for several days. As much care has to be 
 exercised in cooling the kiln as in heating it, for sudden or 
 uneven cooling would bring about disastrous results to the 
 contents. It takes three days to load a kiln, five days to 
 burn it, a week is allowed for cooling and three days for 
 unloading. Small wonder, then, that the grinding-wheel 
 manufacturer cannot ship special wheels a few days after 
 the order for the same has been entered. Burning a kiln of 
 grinding wheels is an operation that cannot be carried on 
 too carefully, as a slight error in judgment is sufficient to 
 turn success into failure. The men who have charge of this 
 important work become skilled through long experience, and 
 it is needless to state that they are numbered among the 
 grinding-wheel manufacturer's trusted employees. 
 
 From the kilns, the grinding wheels go to the sorting room 
 73
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 where they are sorted according to size, grit and grade. 
 The grits and grades are determined by markings scratched 
 on the wheels while in the "green" state, before vitrifying. 
 The wheels are next inspected for soundness by tapping them 
 with a light hammer. A sound wheel will emit a faint, bell- 
 like tone when tapped, this tone having a distinct reverbera- 
 tion, whereas a cracked wheel gives out a dead sound in 
 which no reverberation is detected. 
 
 The wheels that pass this inspection go to the lathe room, 
 where they are faced and edged. The type of lathe used 
 for facing is not unlike an ordinary engine lathe with the 
 possible exception that the former is slightly heavier than 
 the latter. The wheel is firmly gripped in a universal chuck 
 and a cut taken over one side, bringing the surface as near 
 to a true plane as possible within practical limits. The 
 wheel is now reversed in the chuck and the other side faced, 
 care being exercised to make sure that the sides are parallel ; 
 otherwise the wheel might be out of balance, which feature 
 is to be avoided. 
 
 For facing large wheels, star-toothed dressers of the type 
 familiar to every mechanic are used. These are mounted 
 in suitable holders which are gripped in the tool post. For 
 fine, comparatively small wheels, diamonds mounted in 
 copper bars are used. Being in constant use, these stones 
 soon wear out; thus the diamond bill of the grinding- 
 wheel manufacturer amounts to a large sum annually. 
 
 After being faced, the wheels are ready for the first in- 
 spection for grade. This operation is done by hand as 
 shown in Fig. 15. The instrument used looks not unlike 
 a short, wide screw-driver mounted in a heavy handle. To 
 determine the grade, the operator depends wholly on his 
 senses of hearing and touch, which, through constant prac- 
 tice, are very reliable. The testing is done simply by 
 gouging into the wheel in several places, noting the sound 
 given out and feeling the amount of resistance met in separat- 
 ing the particles of abrasive from the bond. 
 
 Constant practice makes these operators very expert, 
 74
 
 THE VITRIFIED PROCESS 
 
 especially in grading medium hard, medium and medium 
 soft wheels. With the very hard wheels, however, it is 
 almost impossible to make an impression with the grading 
 tool. In this case, the operator relies almost wholly upon 
 the sound emitted. Several mechanical means have been 
 
 Fig. 15. Grading grinding wheels by the hand-test method. 
 
 devised for grading grinding wheels, but as yet not one has 
 been perfected that is as reliable as the simple hand-grading 
 tool in the hands of an expert. 
 
 The next step is to provide the wheels with lead bushings. 
 In this operation, the wheel is held in a special fixture which 
 locates it centrally. A mandrel of the desired size is now 
 inserted and the space between the mandrel and the grind- 
 ing-wheel hole filled with molten lead. As soon as the lead 
 cools sufficiently, the bushing is stamped with the grit and 
 grade, and, in the case of Carborundum wheels, the bond 
 also, as a means of permanent identification. This practice 
 originated with The Carborundum Company, and it is need- 
 less to state that it fills a long-felt want as the consumer 
 has at hand a reliable guide in duplicating a successful 
 wheel. 
 
 75
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 The next operation is to true the periphery of the wheel. 
 This is done by men called wheel edgers. The wheels are 
 mounted on heavy grinding stands and the edging done by 
 means of star-shaped dressers fed by hand. Diamonds 
 are used on the smaller and more delicate wheels. The 
 grinding-wheel stands are equipped with guards to eliminate 
 danger from flying fragments in case a wheel should hap- 
 pen to burst, and the workman's health is also taken into 
 consideration as an efficient exhaust system is provided to 
 carry away the dust. 
 
 The wheels are now ready for another important oper- 
 ation, that of balancing. Owing to the high speed at which 
 they are operated, it is very necessary for grinding wheels 
 to be in almost perfect running balance. Carefully worked- 
 out tables, prepared by the engineering department, show 
 the exact amount any size of wheel can be out of balance, 
 and all wheels failing to come up to this predetermined 
 standard are rejected. 
 
 The balancing is done by mounting the wheel on an arbor 
 which is placed on balancing ways. If a heavy side is in 
 evidence, a weight of the required number of ounces allowed 
 on this particular size of wheel is clamped on the periphery 
 opposite the heavy side. If this weight fails to counter- 
 balance the wheel, it shows that the wheel is out of balance 
 to the extent of warranting rejection for the particular 
 size in question, although it can be turned smaller when, 
 in all probability, it will pass a satisfactory test. It is very 
 necessary that the balance of wheels intended for precision 
 grinding be almost perfect ; otherwise accurate work on the 
 part of the grinding-machine operator is sometimes im- 
 possible. 
 
 Owing to the fact that grinding wheels are used under 
 various conditions, some of which are far from ideal, 
 chances for serious accidents owing to the bursting of the 
 wheel must be guarded against by the manufacturer who 
 aims to market reliable goods. To this end, grinding wheels 
 are given a speed test before going to the shipping-room. 
 
 76
 
 THE VITRIFIED PROCESS 
 
 As the centrifugal force of a body moving with different 
 velocities in the same circle is proportional to the square 
 of the velocity, it is evident that if the velocity is doubled 
 the centrifugal force will be four times as great. Thus it 
 is seen that if a wheel is speeded fifty per cent, faster than 
 the recommended operating speed, the centrifugal force 
 would be twice as great. The Carborundum Company 
 make a practice of speeding all wheels above eight inches 
 in diameter seventy per cent, higher than the recommended 
 operating speed. After this test, it is safe to assume that 
 the wheel is sound and when used under the proper oper- 
 ating conditions the danger of breakage is practically nil. 
 
 The speed-testing machines consist of substantial grinding- 
 wheel stands equipped with variable-speed counter-shafts 
 for increasing and decreasing the speed as desired, accurate 
 tachometers for registering the number of revolutions, and 
 stout, iron-bound oak boxes surrounding the wheels to 
 retain the fragments in case a wheel fails to withstand the 
 speed test. Two testing machines are shown in Fig. 16. 
 The tests are conducted in a very deliberate manner by 
 men whose integrity can be depended upon and at the com- 
 pletion of each day's work these men subscribe and swear 
 before a notary public to the tests they have made. The 
 number and conditions of each test are kept in a book pro- 
 vided for this purpose and a certificate is attached to the 
 tested wheel, showing both the test speed and the recom- 
 mended operating speed. 
 
 Accidents caused by grinding-wheel imperfections are 
 indeed very rare. The writer has personally investigated 
 many cases of broken grinding wheels and has yet to find 
 a case where the accident was caused directly by imper- 
 fections in the manufacture of the wheel. That all grinding- 
 wheel manufacturers intend to market dependable wheels is 
 borne out by the following paragraph taken verbatim from 
 The Carborundum Company's Number Five catalogue. 
 
 "In May, 1902, the Association of German Engineers 
 began an exhaustive series of speed tests of abrasive wheels. 
 
 77
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 These tests were conducted by Professor Griiber of the 
 Technical High School, Dresden. All manufacturers were 
 invited to submit a 2o-inch wheel to be speeded until it 
 burst. About sixty wheels, including almost all standard 
 makes, were tested in this manner. The result, as a whole, 
 
 Fig. 1 6. Speed-testing grinding wheels for safety. 
 
 demonstrated the entire safety of all makes of wheels when 
 properly used; for, while the proper operating speed for a 
 2o-inch wheel is 955 revolutions per minute, the poorest 
 record made by any wheel tested was 2,615 revolutions 
 per minute before bursting. The regular grade of Car- 
 borundum wheel tested made 4,340 revolutions per minute 
 before bursting, which was the best record made by any 
 wheel tested." 
 
 The above statements bear out the writer's opinion, i. c., 
 73
 
 THE SILICATE PROCESS 
 
 that the specific gravity of Carborundum, being less than 
 that of other abrasives, makes it a very efficient and safe 
 wheel. 
 
 THE SILICATE PROCESS 
 
 In making wheels by the silicate process, silicate of soda 
 and the abrasive material are first mixed together in the 
 proper proportions in mechanical mixers. This mixture is 
 then tamped by hand in iron molds. The operation of 
 tamping the mixture calls for a high degree of skill, thus 
 the work can only be intrusted to experienced men. Ma- 
 chines have been devised for tamping silicate wheels, but 
 the mechanical process does not produce as satisfactory 
 results as are obtained with the hand-tamping process. 
 Why this is so is a matter of conjecture. Nevertheless, the 
 fact remains that hand-tamped wheels are turned out in 
 large lots daily by grinding- wheel manufacturers. 
 
 On first thought, it would appear that silicate wheels 
 could be readily pressed in molds by the same process used 
 in making pressed vitrified wheels as heretofore explained. 
 This method has been the basis of lengthy experiments 
 without tangible results, the product always showing in- 
 ferior in actual tests. 
 
 The process of hand tamping is comparatively slow and 
 laborious as it has to be done in a thorough manner, but when 
 properly carried out excellent wheels are the result. After 
 tamping, the wheels are baked slightly under low heat, 
 which sets the bond. For many years it was considered an 
 impossibility to make Carborundum wheels by the silicate 
 process, inasmuch as the glassy nature of this abrasive 
 and the same characteristic in the bonding material, after 
 baking, did not form a good contact. Of late years, how- 
 ever, this difficulty has been overcome. 
 
 Silicate wheels are very close in texture and they are 
 successfully used on grinding operations where a compact, 
 but at the same time a comparatively free cutting wheel 
 is desired. For tool grinding in the machine shop, saw 
 
 79
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 gumming and knife grinding in wood-working establish- 
 ments and on other operations of like nature, silicate wheels 
 are successfully used. Again, the silicate process is exten- 
 sively used by small grinding-wheel manufacturers who 
 have not the facilities for turning out vitrified wheels in 
 large lots. Further, an inferior abrasive, one containing 
 an excess of mica or garnet, for instance, can be used in 
 the manufacture of silicate wheels, whereas these impuri- 
 ties would ruin a vitrified wheel. Inasmuch as the silicate 
 process is of short duration, hurry orders for grinding wheels 
 can be filled in far less time than is required to make them 
 by the vitrified process. This factor is, of course, worth 
 consideration in a few specific cases. 
 
 In the early days of the grinding-wheel industry, the 
 silicate process was quite popular owing to the fact that 
 wire-web wheels, wherein a screen of brass wire was in- 
 serted, were considered as an ample safeguard against 
 accidents. At the present day, however, owing to the 
 high development of the vitrified process and the subse- 
 quent safety of the finished product, there is no logical 
 excuse for using silicate wheels purely as a matter of safety. 
 
 THE ELASTIC PROCESS 
 
 In making wheels by the elastic process, wherein the 
 binding medium is shellac, the first step is to melt the shel- 
 lac, which is afterward cooled and broken into lumps. 
 The lumps are next finely ground and the proper propor- 
 tions of shellac and abrasive mixed together. This mixture 
 is then transferred to a hot mold and thoroughly melted 
 under pressure. A slight baking in specially constructed 
 ovens completes the process. 
 
 Shellac -bonded wheels are very cool cutting, imparting 
 a high degree of finish to the work, and, owing to the firm 
 nature of the bonding material, they are the safest form of 
 wheel to use for any purpose. This bond is especially de- 
 sirable for comparatively thin wheels as used for grinding 
 
 80
 
 THE RUBBER PROCESS 
 
 out slots, fine saw gumming, marble coping, etc. Small, 
 delicate cup and dish wheels, as used for certain kinds of 
 cutter sharpening in the machine shop, are generally made 
 by the shellac process. For the finish grinding of the large 
 calender rolls used in paper making, the shellac bond is the 
 accepted favorite, owing to the high degree of finish im- 
 parted. Hones of various shapes used in polishing marble 
 are also made by this process. 
 
 The layman is inclined to associate shellac with the 
 sticky variety used in liquid form' by the pattern maker 
 and other wood workers and therefore is sometimes in- 
 clined to think that a grinding wheel bonded with this 
 material would soon fill up, and consequently refuse to cut. 
 Actual tests, however, have proven beyond all doubt that 
 the shellac-bonded grinding wheel is very free cutting; 
 probably owing to the fact that the heat used in baking 
 brings about a chemical change in the bond which elimin- 
 ates the tendency of the material to retain the minute 
 particles removed from the work by the action of abrasion. 
 
 THE RUBBER PROCESS 
 
 In cases where grinding wheels are subjected to very severe 
 strains, especially when very thin wheels are used, the 
 rubber process makes a very satisfactory wheel. Many 
 years ago, before the present-day state of perfection in 
 grinding-wheel manufacture, large wheels were made by 
 the rubber process, and in a very few cases, there is a demand 
 for these wheels at the present time. The majority of 
 rubber wheels used today, however, are comparatively thin 
 ones used for such purposes as grinding slots in cast-iron 
 stove doors, sawing stone, etc., or in fact for any operation 
 where an exceedingly durable wheel is desired. 
 
 The process of making rubber bonded wheels is quite 
 simple, consisting of passing carefully selected crude rubber 
 and abrasive material between steam-heated chilled iron 
 rolls. The material is passed and re-passed until all the 
 
 81
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 abrasive material is thoroughly imbedded in the rubber. 
 When the required amount of material is worked up, the 
 Operator scribes a circle of the desired diameter on the 
 sheet of material with a pair of dividers, cuts the outline 
 thus made with a sharp knife, punches a hole in the center 
 of the disc and the wheel is ready for the final process, that 
 is vulcanizing the rubber. This is done in a small furnace, 
 electrically heated, and takes but a short time
 
 CHAPTER FOUR 
 
 ARTIFICIAL SHARPENING STONES 
 
 Properties of artificial stones Carborundum stones Method of manufac- 
 ture Bond Grit Grade Finishing Combination stone^-Carboran- 
 dum rubs. 
 
 to. 01 mar 
 i&s Carb 
 
 " 
 
 ARTIFICIAL sharpening stones have been on the mar- 
 ket for many years, dating from the time when the 
 early grinding-wheel manufacturers put them on the market 
 in small lots. It is a fact that when any abrasive material 
 is crushed, much of the same is reduced to a fine powder, 
 which is of no value in the manufacture of grinding wheels. 
 Thus, one reason for the introduction of artificial "sharpening 
 stones in competition with the natural product was that the 
 grinding wheel and abrasive manufacturer sought a market 
 for the fine grains that otherwise have but little market 
 value. 
 
 Artificial sharpening stones possess one merit that should 
 not be undervalued, in that they are generally very uniform 
 in grit and grade. Absence of hard and soft spots is an- 
 other good characteristic which is not always present in 
 natural stones. Any good abrasive material can be made 
 into sharpening stones, but the artificial abrasives seem to 
 hold the preference, owing to their purity and uniformity as 
 compared to natural abrasives. 
 
 The first artificial abrasive to be put. on the market in the 
 form of sharpening stones was Carborundum. During the 
 last few years, the demand for these stones has advanced 
 by leaps and bounds, so to speak, two reasons being assigned 
 for this. First, they are carefully made by skilled workmen, 
 which procedure always results in a superior product, and, 
 
 83
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 again, they are universally advertised, being on sale in 
 every town and city throughout the civilized world. Over 
 a million and a quarter of Carborundum sharpening stones 
 are sold annually in more than one hundred and fifty dif- 
 ferent sizes, styles, etc. 
 
 Carborundum sharpening stones are made in vitrified 
 bond by the pressed process, the principle being the same 
 
 Fig. -1 7. Finishing Carborundum sharpening stones on rotary laps. 
 
 as employed in making pressed wheels, with the exception 
 that the work is carried on on a smaller scale. Great care is 
 exercised in molding the stones. Careful workmen deter- 
 mine the amount of grain and bond mixture by weight; 
 thus, exactly the same amount of material is incorporated 
 into all stones of a given size. This material is evenly dis- 
 tributed in the mold, otherwise the finished stone would 
 have what is technically termed "heavy spots." Again, 
 the amount of pressure exerted on the mixture after the 
 mold is placed in position in the hydraulic press must be 
 
 84
 
 ARTIFICIAL SHARPENING STONES 
 
 watched carefully, otherwise the finished product would 
 vary in grade. As the stones are very delicate in the 
 "green" state, and thus easily damaged, it is necessary to 
 handle them carefully. They are loaded ;n sagers and 
 vitrified by the same process and in the same kilns used 
 in the manufacture of vitrified Carborundum wheels. 
 Carborundum sharpening stones are made in three grits, 
 
 Fig. 1 8. Part of the specialty department at The Carborundum Company's 
 
 plant. 
 
 namely, coarse, medium and fine. The coarsest grain is 
 used in number 120, while number 180 is used in medium 
 stones. Fine stones are made in F, FF, and FFF powders. 
 A superfine powder called 6o-minute powder (so called 
 because it takes 60 minutes to settle in water) is used in 
 making several very fine stones. 
 
 Large flat stones are made in G 7 bond for fine grits and 
 in G-5 bond for coarse grits. For other stones, points, 
 sticks, etc., G-i2 bond is used. For making razor hones 
 and other fine instrument stones a special bond is used to 
 give the desired hardness, the nature of this bond being 
 a trade secret. 
 
 85
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 In making combination stones, that is, stones composed of 
 two grits, fine on one side and coarse on the other, two 
 methods are used. One method is to level the fine mixture 
 in the mold and over this place the coarse mixture, both 
 being pressed together. The other method consists of 
 cementing two finished stones, a coarse one and a fine one, 
 together. 
 
 After the stones come from the vitrifying kilns, they are 
 
 Fig. 19. A few varieties of Carborundum sharpening stones. 
 
 carefully inspected for imperfections such as cracks, burned 
 spots, etc., arid all imperfect specimens thrown aside. The 
 stones which pass this inspection go to the finishing de- 
 partment, where skilled artisans rub them smooth on hori- 
 zontal rubbing beds, or rotary laps. The abrasive used 
 in tliis operation is Carborundum grain mixed with water. 
 This operation is shown in Fig. 17. 
 
 The stones are now transferred to the specialty depart- 
 ment, where they are carefully buffed, cleaned, inspected 
 and packed in boxes and display cases. A view of this 
 department is shown in Fig. 18. As before stated, Car- 
 borundum sharpening stones are made in upwards of one 
 hundred and fifty different styles, being used for a diversity 
 of purposes too numerous to mention here. Some of the 
 well-known varieties are shown in Fig. 19. 
 
 A form of stone technically called a "rub" is much used 
 for smoothing castings, marble, granite, cement, etc. These 
 are made in the same manner as sharpening stones, with 
 the exception that the grits are coarser and no extra finish 
 is imparted after they come from the vitrifying kilns. 
 
 86
 
 ARTIFICIAL SHARPENING STONES 
 
 Considerable skill has been developed in the manufacture 
 of Carborundum sharpening stones 'and rubs, through the 
 study of proper bonding materials, methods of manufac- 
 ture, etc., thus the finished products are very uniform and 
 do not vary to any noticeable extent.
 
 CHAPTER FIVE 
 
 GRITS AND GRADES 
 
 Designation of grits and grades Mixed grits ^rits of abrasive papers- 
 Standard grades Wheels Relation of speed to grade and grit Wheel 
 speeds for various operations. 
 
 THE grit, or grain as it is sometimes called, of a grinding 
 wheel alludes to the size of the particles of abrasive 
 material of which it is composed. Thus, a wheel in 24 grit 
 is made up of particles of abrasive material that were 
 separated from the mass that passed over the grading ma- 
 chine by a screen having 24 meshes to the linear inch. 
 It is sometimes erroneously stated that the particles of 
 grit composing a 24-grain grinding wheel are 1/24 inch in 
 diameter. This is not true, because the size of the wire of 
 which the screen is made must be taken into consideration. 
 Therefore, if the screen was made of very coarse wire, 
 the particles of grit passing through it would be somewhat 
 finer than those passing through a screen having the same 
 number of meshes per inch but made of finer wire. 
 
 Grinding-wheel grits are referred to as straight, mixed, 
 combination and combination mixed. A straight grit is 
 one wherein the abrasive is of one size only; thus if 40 grit 
 was used the wheel would be a 40 straight grit. For con- 
 venience, the word ''straight" is generally omitted in 
 speaking of a straight grit wheel. When a 40 grit wheel is 
 ordered, it is understood that a straight grit is required. 
 
 A mixed grit is one composed of two or three different 
 kinds of abrasive materials. Thus, a wheel designed for 
 grinding steel castings, for an illustration, made of a mix- 
 ture of emery, corundum and adamite, would be a mixed- 
 grit wheel. 
 
 88
 
 GRITS AND GRADES 
 
 By a combination grit, which term is sometimes errone- 
 ously used to designate a mixed grit, is meant a combina- 
 tion of various-sized grits, scientifically selected, and in- 
 corporated into one wheel. A combination mixed grit is 
 one wherein two or more abrasives are used, the grains 
 being of different sizes. 
 
 A wheel composed of a combination of 24, 36 and 80 
 grit is known as a 24-combination grit. Successful grit 
 combinations are standardized only through long experi- 
 ment and actual tests, and the grin ding-wheel manufacturer 
 generally keeps them secret. The Norton Company make 
 many combination grits, referring to them simply as 24 
 combination, 36 combination, etc. The Carborundum Com- 
 pany, who have investigated the theory and practical 
 results derived from combination grits in a very thorough 
 manner, have originated a simple means for designating 
 their grit combinations, which is of great benefit to the cus- 
 'tomer in re-ordering. They use a number of grit combina- 
 tions designated i, 2, 3, 4, etc. This number is annexed 
 to the grit number, thus a 365 combination grit has 36 
 grain for its base while 5 stands for the combination number. 
 
 For certain operations, combination grits offer decided 
 advantages. On cylindrical grinding, for instance, a wheel 
 in a combination grit with a comparatively coarse base, 
 24 to 36, cuts very fast and at the same time leaves a smooth 
 finish, leading to the deduction that the coarse grains 
 remove material rapidly, while the finer grains impart the 
 desired finish. On certain operations where a very durable 
 wheel is required, on car-wheel grinding, for example, a 
 combination grit gives entire . satisfaction, showing high 
 efficiency over a straight grit used for the same purpose. 
 
 Manufacturers of abrasive paper and cloth designate the 
 different grits by numbers: i, 1-1/2, 2, 2-1/2, etc. At one 
 time, the various grits used by different manufacturers 
 varied to quite an extent even though they were designated 
 by the same number. This often led to confusion and some- 
 times enabled one manufacturer to gain an unfair ad- 
 
 89
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 vantage over another. For instance, a certain manufac- 
 turer of garnet paper uses a specified size of grain which he 
 calls No. 1-1/2. A competitor uses a slightly coarser grain 
 which he, too, designates as No. 1-1/2, and while the sizes 
 of the two grains are so near alike that detection with 
 the naked eye is impossible, it often happened that the 
 manufacturer using the coarser grain was enabled to show 
 a slight efficiency over his competitor, the consumer in the 
 meanwhile being ignorant of the fact that the grains were 
 not the same. To eliminate' misunderstandings among the 
 consumers, and to bring competition to a fair basis, the 
 majority of abrasive paper and cloth manufacturers of the 
 present day use the same sizes of grains for each grade. 
 Thus 2-1/2, for an illustration, designates a grain that has 
 passed through a standard sieve, the mesh of which has 
 been agreed upon. 
 
 In chinking of the various grit numbers used to designate 
 the sizes of abrasive papers and cloths, it is sometimes 
 advantageous to know how they compare with the grain 
 numbers commonly used in sizing abrasive materials. The 
 following table is authentic and up to date, being recently 
 furnished by The Carborundum Company. 
 
 Carborundum. Flint. Ga net. Emery. Aloxite. 
 
 FF 
 F 
 
 220 
 
 i 80 3/0 4/0 3/0 3/0 
 150 3/0 2/0 2/0 
 
 I 2O 2/O O O 
 
 100 O 2/0 100 100 
 
 90 1/2 O 1/2 1/2 
 
 80 I I 
 
 7O 1-1/2 1-1/2 
 
 60 I 1/2 2 2 
 
 50 1-1/2 1 
 
 40 2 1-1/2 2-1/2 2-1/2 
 
 36 2-1/2 2 
 
 30 2-1/2 3 3 
 
 24 3 3 3-1/2 3-1/2 
 
 20 3-1/2 3-1/2 
 
 90
 
 GRITS AND GRADES 
 
 By the expression "grade" we refer to the relative hard- 
 ness of a grinding wheel. In the early days of the grinding- 
 wheel industry, a few grades sufficed. These were known 
 generally as medium, medium hard, hard, medium soft and 
 soft. As the industry grew, however, and the grinding 
 wheel became adapted to a diversity of operations, closer 
 and more accurate grades were required which led to the 
 adoption of somewhat elaborate grade scales. A grade is a 
 certain value, within very close limits at least. An L grade 
 wheel offers the same resistance to disintegration by means 
 of the hand-grading tool as the grinding -wheel manu- 
 facturer's master block in the same grade. By way of 
 explanation, it may be well to state that all reliable grinding- 
 wheel manufacturers have a set of master grade blocks as 
 standards. These are carefully made from the correct 
 proportions of grain and bond to form the various grades, 
 and are referred to as a check in determining the actual 
 grade of doubtful wheels. Thus an M grade wheel made 
 by a reliable manufacturer is not somewhere between L 
 and M or M and N in which case it might be a de-grade. 
 De-graded wheels are used in some cases, to be sure, but 
 they are made as such. The Carborundum Company make 
 three de-grades: G plus, H plus, and I plus. 
 
 The various grinding-wheel manufacturers use different 
 markings to designate their various wheel grades. Some 
 use the letters of the alphabet (not always arranged the 
 same) while others use numbers, including whole numbers, 
 mixed numbers and fractions. All grinding-wheel manu- 
 facturers have comparative grade lists, the object of which 
 is to show the difference between their grades and those 
 of their competitors. The writer has, from time to time, 
 examined and compared many of these grade lists and, 
 unfortunately, they vary to such an extent that it is an 
 impossibility to state for a fact which one is absolutely 
 correct. 
 
 To compile a comparative grade list that would satisfy all 
 grinding-wheel manufacturers, and, at the same time, im- 
 
 91
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 part reliable information to the layman, the writer used the 
 following method in arranging the list here given. Taking 
 Norton Company's grade list as a basis, a chart was drawn 
 up on tracing paper including the letters used, with spaces 
 between each for de-grades. A number of blue prints were 
 made from this chart, one being sent to every prominent 
 grinding-wheel manufacturer in this country with the request 
 that they fill in on the same, their wheel grades, showing 
 the comparison with Norton Company's grading. Many 
 complied with the request, while some declined, and the chart 
 in question was compiled from the date thus obtained. 
 Inasmuch as every individual grinding-wheel manufacturer 
 knows more about his own grades than does his competitors, 
 and supplied his wheel grades in comparison to a given 
 standard, in this case Norton Company's grading, it is safe 
 to assume that a comparative grade scale compiled in this 
 manner is as reliable as it is possible to arrange the same. 
 
 The grinding-wheel manufacturers who use the letters 
 of the alphabet in regular order as a grade scale designate 
 the letter M as showing their medium grade. This has led 
 many technical writers who are not conversant with the 
 grinding-wheel industry to show the comparison between 
 Carborundum and Alundum wheels with the two M's 
 together. This is a fallacy, as The Carborundum Com- 
 pany's M grade is equal to Norton Company's K, which 
 brings the L's of both grade scales together. While both 
 The Carborundum Company and Norton Company con- 
 sider their respective M grades as medium, they do not 
 agree as to what constitutes a medium grade. 
 
 It is to be regretted that the various grinding-wheel 
 manufacturers do not standardize on a universal grade 
 scale, which procedure, it is needless to state, would elim- 
 inate much confusion. In all probability they will never 
 agree on a universal grade scale, the nature of which would 
 cause them to abandon their gradings for a standard already. 
 
 92
 
 GRITS AND GRADES 
 
 II 
 
 i 
 
 si 
 
 Waltham Grinding Wheel Co. 
 (Silicate Process) 
 
 II 
 
 1 
 
 ? 
 
 Vitrified Wheel Co. 
 Westfield Mass, 
 
 Superior Carborundum Wheel Co. 
 Waltham.Mass. 
 
 1 
 
 s 
 
 If 
 1 
 
 1 
 
 
 
 p 
 
 L Safety Emery Wheel Co. 
 Springfield.Onio 
 
 i 
 
 Sf 
 
 1 
 
 ^ 
 
 f 
 
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 Detroit. Mich. 
 
 S 
 
 Cortland Grinding WheelCord 
 
 1 
 
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 ff 
 
 1 
 P 
 
 IThe Carborundum Company^ 
 Niagara Falls.N.Y. 
 
 fi- 
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 1 
 
 i 
 
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 1 
 
 | COMPARATIVE GRADING VITRIFIED AND SILICATE WHEE 
 
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 93
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 in use, but perhaps if they all agreed to adopt a universal 
 grade scale, the nature of which would cause every manu- 
 facturer to discard his present grade scale and adopt a new 
 one, the change might be brought about. 
 
 By referring to the bottom of the comparative grade 
 scale here shown, it is seen that the writer has had the pre- 
 sumption to take a step toward standardizing wheel grades. 
 Figures i to 22 are used, a space being left between each 
 for de-grades. Thus The Carborundum Company's G-plus 
 grade would be designated 13 plus. A leading grinding- 
 wheel manufacturer, with whom the writer had some cor- 
 respondence regarding wheel grades, has the following to 
 say concerning a standard grade list: "Nevertheless, go 
 ahead. We will never get anywhere unless some one makes 
 the attempt." If a universal grade scale is to be adopted 
 eventually, the one shown has merit in one respect that 
 should not be undervalued; that is to say, it would require 
 each manufacturer to discard his present grade scale, put- 
 ting all on the same level. In this case, no one manufac- 
 turer would be in a position to 'state that other manufac- 
 turers adopted his grade scale because it was the most com- 
 prehensive, or because he was regarded as the leading grind- 
 ing-wheel manufacturer. 
 
 It is often stated on good authority, that it is impossible 
 to arrange a grade scale which is absolutely reliable in all 
 respects and cases. In a measure, the above statement is 
 correct, owing to the fact that the abrasive efficiency of 
 wheels of the same grade, but made of different abrasives, 
 or combinations of different grits, is not always the same. 
 For an illustration, a Carborundum wheel in 20 grit, G-plus 
 grade, is universally acknowledged to be highly efficient 
 for grinding gray iron castings. Now if we should test an 
 Alundum wheel in Q .plus, which corresponds in grade to 
 Carborundum G plus, the latter would prove low in abrasive 
 efficiency because Alumdum is an alumina abrasive not 
 adapted for grinding materials of low tensile strength. 
 Again, suppose we had a wheel made of pure corundum in 
 
 94
 
 GRITS AND GRADES 
 
 46 grit, M grade, vitrified bond and tested it in competition 
 with a wheel made of the same material, in the same grit 
 and grade, bonded by the silicate process. In this case, we 
 would find that the wheel made by the vitrified process would 
 show the highest efficiency, inasmuch as the silicate bond 
 is closer ; thus making the wheel more compact and less 
 free in cutting. Further, if we should test a wheel in a 
 combination grit against one in a straight grit, both being 
 of the same material in a like grade, one will show high 
 efficiency over the other. However, let it be assumed that 
 several manufacturers agreed to make a 24 x 3 wheel in 
 20 grit, 13 universal grade for the purpose of grinding drop 
 forgings, and let it be further assumed that they used the 
 same material, which could be corundum from one mine, 
 Aloxite, Alundum, Boro-Carbone, or in fact any standard 
 abrasive. In this case, it is very probable that the abrasive 
 efficiency of the several wheels would be so close that it 
 would require the services of an expert abrasive engineer to 
 accurately determine which wheel really was the most efficient. 
 It may seem out of place ' to many to consider wheel 
 speeds in connection with grades, but, as a matter of fact, 
 one bears on the other to a remarkable degree, as shown 
 in the data supplied by the Abrasive Company in another 
 chapter. Let it be assumed that we are using a wheel 
 made of artificial corundum for grinding the flash marks 
 from drop forgings, running the same at a peripheral speed 
 of 5,000 feet per minute, and that the wheel seems to wear 
 readily. We state at once that the wheel is too soft. How- 
 ever, if we speed up the wheel slightly, say to a peripheral 
 speed of 5,300 feet per minute, it seems to appear harder, 
 for while it cuts just as good as it did previously, it does 
 not wear away so readily. Again, if at a surface speed of 
 5, ooo* feet per minute the wheel glazed and refused to cut, 
 the objection could be overcome by reducing the speed 
 slightly. In other words, it is a good rule to speed up a 
 wheel that appears soft and to decrease the speed of one 
 that seems to be unduly hard. 
 
 95
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 From the foregoing, it is seen that speed has everything 
 to do with, what the writer will call for want of a better 
 expression, the running or working grade. As wheels wear 
 away, their speed should, of course, be increased slightly 
 to keep them working at their maximum efficiency. It is 
 not always possible to do this, however, and hundreds of 
 thousands of grinding wheels are worn out prematurely. 
 
 To overcome this difficulty by providing a constant work- 
 ing grade, regardless of the peripheral speed, an American 
 inventor recently obtained a patent on a grinding wheel 
 having a gradually increasing grade from the periphery to 
 the hub. Thus as the wheel wears, its hardness at the 
 periphery keeps increasing, which offsets the tendency to 
 wear away rapidly, owing to the reduced surface speed. 
 Wheels made by this process should be productive of 
 economical results. 
 
 For different grinding operations, wheel speeds vary 
 to quite a remarkable degree. The following table shows 
 the speeds generally recommended for various grinding 
 operations. 
 
 Cylindrical grinding. 
 
 Surface grinding 
 
 Automatic knife grinding 
 Automatic knife grinding 
 
 Drill grinding 
 
 Tool grinding (dry) 
 
 Tool grinding (wet) 
 
 Cup wheels in general . . . 
 
 General grinding 
 
 Set-up polishing wheels. . 
 Vulcanite wheels 
 
 5,000 to 7,000 feet 
 4,000 to 5,000 
 2,500 (disc wheels) 
 2 ,000 (cup wheels) 
 4,000 to 4,500 
 4,000 
 3>500 
 
 3,500 
 5,000 
 7,500 
 
 10,000 
 
 minute
 
 CHAPTER SIX 
 
 TESTING WHEELS FOR EFFICIENCY 
 
 Selection of wheels Improper methods of testing Practical testing methods 
 Items to be noted in a wheel test How to figure result Formula 
 for finding volume of abrasive material in a wheel General considerations 
 Wheel tests. 
 
 MANUFACTURERS who use grinding wheels in large 
 * T * quantities are desirous of getting the most efficient 
 wheel for a specific purpose. To determine which is the 
 most efficient abrasive or make of wheel, and, further, 
 what grit and grade of any particular make of wheel is the 
 most desirable to use for a predetermined purpose, is not 
 an offhand procedure. Results that can be relied upon 
 are arrived at only by carefully conducted tests arranged 
 along practical lines. Grinding-wheel manufacturers are 
 frank to admit that there is no absolute rule for the selection 
 of grits and grades as the following, which appears on page 
 96, 1916 edition of Norton Company's catalogue, plainly 
 states: "Conditions under which grinding wheels are used 
 vary to such an extent that no absolute rule can be given 
 for selecting the right grades for the work." 
 
 Because a certain kind of wheel gives entire satisfaction 
 in one plant, is no indication that it will do equally well in 
 another shop, even though the work is identical in both 
 cases. The reason for this is that local conditions generally 
 have to be taken into consideration and as they often can- 
 not be altered, it is best, when practicable, to test trial 
 wheels on actual routine work under the supervision of 
 careful and painstaking efficiency engineers who have some 
 knowledge of abrasives and grinding practice. 
 
 To give a trial wheel to the grinder with the injunction : 
 07
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 "Here, Bill, try this wheel and see what you think of it," 
 is one way of testing a trial wheel and a practice that is 
 too prevalent with many grinding-wheel consumers. Bill 
 may have the best intentions in the world, but it requires 
 more than good intentions to test a grinding wheel to 
 determine its actual worth. He uses the wheel for a day 
 or so, maybe a week, and then forms a decision which may 
 or may not be correct. He is not to blame in nine cases 
 out of ten if his verdict is incorrect because the actual user 
 of grinding wheels, on rough operations at least, has but 
 little use for mathematics, therefore he is at a loss to form 
 an accurate decision regarding actual cost of production. 
 In his opinion, the wheel may be a good one or a poor one. 
 Unless the wheel shows a remarkable saving in grinding 
 time, his decision is liable to be a guess pure and simple 
 and it may be influenced by a deep-rooted prejudice in 
 favor of a certain make of wheel. He may use a trial wheel 
 for a few weeks and report that he sees no apparent saving, 
 and if the wheel in question happens to be a comparatively 
 high-priced one, the test is ended then and there. 
 
 On the other hand, if the wheel was tested according to 
 common-sense methods the production department would 
 have actual figures to show the purchasing department 
 regarding the actual earning power of the wheel. There 
 are over twenty grinding-wheel manufacturers in this 
 country and they all make reliable products. They have 
 brought the grinding-wheel industry to its present high 
 state of development through tireless and painstaking effort, 
 being ready at any time to make special wheels for trial 
 purposes for any operation that appears practicable. Since 
 they are ever ready to help the manufacturer in reducing 
 his production costs, why should not the manufacturer 
 meet them half-way by giving trial wheels a fair and im- 
 partial test? 
 
 The average manufacturer is broad-minded; he is gen- 
 erally willing to grant the grinding-wheel salesman a 
 courteous interview and often orders trial wheels for test 
 
 98
 
 TESTING WHEELS FOR EFFICIENCY 
 
 purposes. After the wheels have been tested, however, it 
 is seldom that the salesman who supplied them is able to 
 get an accurate report of their performance. Unless the 
 saving is readily apparent, as in testing Carborundum against 
 emery for cast-iron grinding for instance, the trial wheel 
 is in many cases reported as showing no saving as com- 
 pared with the wheels regularly used. 
 
 A report of this kind, lacking in figures to verify it, is 
 unsatisfactory to all parties concerned. The consumer does 
 not know for a certainty whether the wheel tested actually 
 did or did not show efficiency; the salesman is at a loss 
 to make an intelligent report to his employer; while the 
 grinding-wheel manufacturer, although compelled to ac- 
 knowledge defeat in the specific case in question, js justified 
 in forming the conclusion that his wheel was not given a 
 fair test since no figures were submitted to verify the 
 unsatisfactory report. 
 
 In analyzing the above case, we must admit that the 
 salesman exercised the talents of his profession in getting 
 permission to submit a sample of his product for test pur- 
 poses, while the grinding-wheel manufacturer did his part 
 in supplying a test wheel made to meet the grinding con- 
 ditions as specified on the salesman's trial order. The 
 consumer, however, to state the case in plain English, 
 condemned the wheel without furnishing any figures to 
 substantiate his claim. 
 
 A few cases have been called to the writer's attention 
 wherein a trial order was given solely for the purpose of 
 getting rid of a persistent salesman and an unsatisfactory 
 report submitted to discourage further effort on the sales- 
 man's part. A procedure of this kind is unjust and not in 
 accordance with good business ethics. To give the majority 
 of successful manufacturers credit, however, we are safe 
 in stating that cases like the above are happily not common. 
 
 We certainly are not justified in condemning all manu- 
 facturers at large for their apparent lack of interest in 
 grinding-wheel tests, and the only reason the writer can 
 
 99
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 assign for this state of affairs is that the average manufac- 
 turer is not an abrasive engineer, therefore he lacks tech- 
 nical knowledge of grinding wheels and often does not use 
 the practical methods employed by the abrasive efficiency 
 engineer in determining the actual earning power of a 
 grinding wheel. In conducting a grinding-wheel test em- 
 bracing wheels of several makes, or a few wheels of the same 
 make in different grits and grades, it is a waste of time to 
 attempt to state from observation alone which is the most 
 efficient wheel. A careful record of each wheel should be 
 kept and reliable figures submitted to use in comparing 
 the different wheels. 
 
 To illustrate the principle of practical wheel testing as 
 graphically as possible, it may be well to consider a few 
 practical tests. Where a large number of comparatively 
 
 Fig. 20. Ideal shape of castings for testing economy of wheels. 
 
 small pieces are ground, we have ample opportunity to 
 determine the actual earning power of the grinding wheel 
 by considering the following factors: Time consumed, 
 number of pieces ground, value of abrasive material used 
 and the cost of labor. By comparing the amount of work 
 produced with the actual cost involved, we readily determine 
 the actual grinding cost per thousand pieces. This is what 
 
 100
 
 TESTING WHEELS FOR EFFICIENCY 
 
 interests the successful manufacturer actual production 
 costs. What the grinding wheel is made of does not matter 
 as far as he is concerned; if wheels made of river sand 
 bonded with molasses showed the greatest earning power 
 he would accept them just as readily as he does the com- 
 paratively high-priced products of the electric furnace. 
 
 In Fig. 20 is shown an ideal casting for making an effi- 
 ciency test. It is of malleable iron weighing 10-1/2 oz., 
 and the only grinding necessary is at the base to remove 
 the sprue left when the casting was knocked off the gate. 
 Let it be assumed that we are to test a 1 6 x 2 wheel for 
 grinding these pieces. The' workman is given the wheel 
 together with an unlimited supply of castings and the test 
 conducted for a period of fifty hours. At the end of this 
 time, we might have a report like the following: Number 
 of pieces ground 2,000, time consumed 50 hours, weight 
 of wheel after test 30 Ibs. In the meantime, we have 
 drawn up a form like the following to aid us in determining 
 the grinding cost. 
 
 Part tested Rocker arm short bracket 
 
 Make of wheel Duplex 
 
 Size 16 x 2 
 
 Grit 20 
 
 Grade Q 
 
 Bond Vitrified 
 
 Cost $6.63 
 
 Weight 34 Ibs. 
 
 Cost per pound $00.195 
 
 Operating speed 1,200 R.P.M. 
 
 Material ground Malleable iron 
 
 Length of test 50 hours 
 
 Workman's name G. Harris 
 
 Workman's rate $0.25 per hour 
 
 Number of pieces ground 2,000 
 
 Cost of labor $i 2.50 
 
 Weight of wheel after test 30 Ibs. 
 
 Pounds of abrasive used 4 
 
 Value of abrasive used $0.78 
 
 Tota cost of gr'nding $13.28 
 
 Cost per thousand pieces $6.64 
 
 Cost per piece $0.00664 
 
 101
 
 ABRASIVES .AND ABRASIVE WHEELS 
 
 Here we have sufficient data to satisfy the most critical 
 efficiency engineer. Nothing is contained in the above that 
 is superfluous; in fact every item is for a distinct purpose. 
 The total grinding cost means something because it repre- 
 sents actual dollars and cents that have been expended on 
 a certain operation. How much better it is to have a 
 statement like the above than to rely upon the foreman's 
 statement that a certain wheel cuts good and that one of 
 them lasts the operator three months. This statement 
 conveys no real information as regards actual production 
 costs. Suppose, for the sake of an argument, that he tried 
 another make of wheel which lasted only two months. 
 He would, in all probability, condemn it as too short- 
 lived, never taking into consideration that a practical test 
 as outlined above might prove that it actually reduced 
 grinding costs while it lasted. The first cost of a grinding 
 wheel is of no consideration; it is its earning power that 
 should be known to be appreciated. To illustrate the 
 point clearly, let us consider a cheap wheel. 
 
 As in the previous test, we will use a 16 x 2 wheel, but 
 of such a quality that it can be purchased at a rock-bottom 
 price of $4.54. Owing to the low price of the wheel, it 
 naturally follows that it cannot be made of a very expensive 
 abrasive, the ultimate result being that it is slow cutting 
 when compared with wheels that bring better prices. As 
 before, the workman is given an unlimited number of cast- 
 ings, the wheel weighed, and the test run for fifty hours. 
 At the expiration of the test, we might have the following 
 report: Number of pieces ground 1,500. Time consumed 
 50 hours. Weight of wheel after test 28 pounds. From 
 this report we proceed as before and draw up a summary. 
 
 Part tested Rocker arm short bracket 
 
 Make of wheel Complex 
 
 Size 16 x 2 
 
 Grit 20 
 
 Grade Q 
 
 Bond Vitrified 
 
 Cost $4.54 
 
 102
 
 TESTING WHEELS FOR EFFICIENCY 
 
 Weight 34 Ibs. 
 
 Cost per pound $0.13325 
 
 Operating speed 1,200 R.P.M. 
 
 Material ground Malleable iron 
 
 Length of test 50 hours 
 
 Workman's name G. Harris 
 
 Workman's rate $0.25 per hour 
 
 Number of pieces ground i;5o 
 
 Cost of labor $12.50 
 
 Weight of wheel after test 28 Ibs. 
 
 Pounds of abrasive used 6 
 
 Value of abrasive used $0.7995 
 
 Total cost of grinding $13.2995 
 
 Cost per thousand pieces $8.866 
 
 From this test, it is seen that it cost more to use the cheap 
 wheel than it did to use the moderate-priced one. As a 
 general thing the purchasing agent sees the first cost only, 
 and as long as he can keep his purchases at a low figure he 
 is not concerned with actual operating expenses in the 
 production department. In due justice to the purchasing 
 agent, however, he should not be blamed for buying at 
 as low a cost as possible when the shop management is not 
 armed with figures to show actual grinding costs for dif- 
 ferent operations. It is the purchasing agent's duty to 
 buy standard goods at the best prices obtainable and it is 
 up to the shop to test the material purchased to see that 
 it is efficient. 
 
 In carrying the test farther, let it be assumed that we have 
 bought a high-priced wheel for test purposes, the same 
 costing us $9.27 or over twice the price paid for the wheel 
 previously tested. It is tested in the same manner as the 
 previous wheels and the following report submitted: Num- 
 ber of pieces ground 3,000, time consumed 50 hours, weight 
 of wheel after test 25 Ibs. As before we draw up a summary 
 from the report. 
 
 Part tested Rocker arm short bracket 
 
 Make of wheel Simplex 
 
 Size 16 x 2 
 
 Grit 20 
 
 103
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Grade : . H pi. 
 
 Bond Vitrified 
 
 Cost $9.27 
 
 Weight 34 Ibs. 
 
 Cost per pound $0.2726 
 
 Operating speed 1,200 R.P.M. 
 
 Materia' ground . Malleable iron 
 
 Length of test 50 hours 
 
 Workman's name G. Harris 
 
 Workman's rate $0.25 per hour 
 
 Number of pieces ground 3,000 
 
 Cost of labor $12.50 
 
 Weight of wheel after test 25 Ibs. 
 
 Pounds of abrasive used 9 
 
 Value of abrasive used $2.4534 
 
 Total cost of grinding $14.9534 
 
 Cost per thousand pieces $4.9844 
 
 It is seen that by using a first-class abrasive we have 
 actually reduced our grinding cost, although the first cost 
 of the wheel was over twice that of the wheel previously 
 tested and the wear per week is 50 per cent, greater. 
 
 If a wheel seems to wear rapidly there is no cause for 
 alarm, for it must be borne in mind that the ideal grade of 
 grinding wheel for a specific operation is of just the correct 
 degree of hardness to allow the particles of abrasive material 
 to be pulled from the bonding material as soon as they have 
 lost their cutting power. A hard wheel will last longer 
 than a soft one, to be sure, but at the same time its earning 
 power is greatly reduced, as it is slow cutting. It is a very 
 good plan to determine the earning power of a wheel before 
 condemning it for .wearing out too rapidly. There is, of 
 course, a limit beyond which we cannot go in installing 
 comparatively soft wheels for rough work. If the wheel 
 is too soft, the grains of the abrasive will be pulled from the 
 bonding material before accomplishing a fair amount of 
 work. Instead of removing metal from the work, we are 
 truing off the grinding wheel. 
 
 That a softer grade will oftentimes accomplish more work 
 on a given operation' is a fact known to every grinding- 
 wheel salesman, and the following incident which carre to 
 
 104
 
 TESTING WHEELS FOR EFFICIENCY 
 
 the writer's notice, may be of interest while considering this 
 factor. The work in question consisted of cast-iron cream- 
 separator frames which were ground all over with the object 
 of preparing an even surface for the painter. Here it was 
 necessary to go over the surface of the casting carefully, 
 and as this was somewhat of a tedious operation at best, 
 a free cutting wheel, which would enable the operator to 
 finish a frame in the quickest possible time, was very much 
 desired. 
 
 With the work in question, the operator had been using 
 Carborundum wheels 8 in. dia., i in. face, 30 grit, G pi. 
 grade in V A bond. The output with this wheel was 
 thirty castings per day. One day, one of The Carborundum 
 Company's efficiency engineers investigated the operation 
 and induced the management to try wheels of a softer grade, 
 stating that, while the softer wheel would not last as long, 
 it would materially increase production while it lasted. 
 The result was that wheels in 30 grit H pi. grade were tried 
 out and, much to the operator's surprise, he was enabled 
 to finish fifty castings per day. 
 
 Assuming that we were conducting a test of this kind today 
 we would use a day's wage of $3.00 as a basis on which to 
 conduct our cost test. In finishing thirty castings per day, 
 our grinding cost for labor would be ten cents per casting 
 as against six cents per casting when fifty are ground per 
 day. Thus, it is seen that an actual saving of 40 per cent, 
 in production cost is accomplished through a little experi- 
 ment in changing the grade of the wheel. 
 
 A slight change in grade often makes a great difference, 
 as the above-mentioned test illustrates, and another simple 
 experiment along the same lines, that came to the writer's 
 attention a few years ago, may be of interest. In any 
 farming country may be found blacksmiths and others who 
 net quite a sum annually grinding plow points during the 
 plowing season. The operation is simple, consisting of 
 grinding the plow point until it is sharp. To the city-bred 
 man it may seem laughable that the point of a plow has to
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 be sharp, but such, nevertheless, is well known by those 
 who have had occasion to guide a plow. 
 
 The man in question used a Carborundum wheel in 20 
 grit, G pi. grade and V A bond with which he could grind 
 forty plow points per day, netting him $8.00. He was 
 dubious about trying a softer wheel, claiming that $8.00 
 per day was a nice little sum in itself and that it was some- 
 times a good plan to let well enough alone. However, he 
 was induced to try a wheel one grade softer, that is H pi., 
 with the result of grinding sixty points per day, netting him 
 $12.00. It is seen that by using a wheel more adapted for 
 his work he put $4.00 extra in his pocket daily during the 
 plow-point grinding season. 
 
 Now the business of grinding plow points in a country 
 cross-roads shop may not amount to much in itself, but 
 that is not the point. The lesson is here: If one man, 
 who knows but little of efficiency from the average manu- 
 facturer's point of view, can put an extra $4.00 in his pocket 
 every day, using one wheel only, the same being graded 
 properly, what are the possibilities for saving with the 
 manufacturer whose grinding- wheel bill, and subsequent 
 grinding costs, runs into big figures? The possibilities for 
 saving are enormous. 
 
 The tests so far considered have dealt only with com- 
 paratively light work, but from this it^rnust not be inferred 
 that accurate tests for production costs cannot be conducted 
 on heavy work. Car-wheel grinding furnishes an ideal 
 means of determining the efficiency of a grinding wheel 
 on heavy work, and the following test, which came to the 
 writer's notice a few years ago, embodies all the data 
 necessary for computing the actual grinding cost per wheel. 
 
 The work consisted of grinding the small fins left by the 
 molds on Barr contracted chilled-iron car wheels, often used 
 on freight cars. The work was done on a car- wheel grinder, 
 of regular pattern, and the wheel used was Carborundum 
 18 in. dia., 4-1/4 in. face, 166 grit, G pi. grade and V A 
 bond. The average grinding time was 50 seconds per 
 
 1 06
 
 TESTING WHEELS FOR EFFICIENCY 
 
 wheel and in 72 working days of ten hours each, the wheel 
 was reduced to a diameter of 11-3/4 inches. If the wheel 
 had been used constantly, ten hours per day, it would have 
 ground 8,640 car wheels. This is, of course, a theoretical 
 calculation as a certain amount of time was consumed in 
 taking the car wheels to and from the grinder and in mount- 
 ing them for the grinding operation. As it was, 6,343 car 
 wheels were actually ground during the test of 72 days. 
 
 Let us assume that the operator of the car- wheel grinder 
 receives $2.50 per day, and proceed to ascertain our grind- 
 ing cost per wheel. As 72 x 2.50 = 180, we have a cost of 
 $180.00 for labor. A Carborundum wheel 18 x 4-1/4 
 inches costs $13.07, but in the case in question it was not 
 completely worn out, therefore we will compute the actual 
 cost of the abrasive used. Instead of considering the 
 number of pounds of abrasive used we will, for the sake of 
 variety, use another method of figuring the cost of a partial 
 wheel by ascertaining its volume in cubic inches and sub- 
 tracting the number of cubic inches in the worn portion 
 of the wheel, which will give us the number of cubic inches 
 actually used in grinding the 6,343 car wheels. Knowing the 
 volume of the new wheel and its value it is an easy matter 
 to find the value per cubic inch and also the value of the 
 amount of abrasive used. 
 
 To find the volume of an 18 x 4-1/4 grinding wheel, 
 we can use the following formula, in which V stands for 
 volume, D for diameter, W for width, while the decimal 
 .7854 is a constant. 
 
 V = .78 54 xDxW 
 
 Thus, .7854 x 1 8 x 18 x 4-1/4 = 1,044.3168 cubic inches, 
 which is the volume of an 18 x 4-1/4 wheel. 
 
 Again, .7854 x 11-3/4 x 11-3/4 x 4-1/4 = 445.0026 cubic 
 inches, which is the volume of a 11-3/4 x 4-1/4 wheel. 
 
 Further, if 1,044.3168 cubic inches of material cost $13.07, 
 ore cubic inch will cost $0.01251. 
 
 By subtracting 445.0026 cubic inches from 1,044.3168 
 cubic inches, we have 599.2905 cubic .inches as the amount 
 
 107
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 of material used. Multiplying this amount by the cost 
 per cubic inch, we have $7.4971 or the actual cost of 
 abrasive used. Adding this to $180.00, our labor cost, we 
 have a total cost of $187.4871. 
 
 We will call our cost $187.50 for convenience in figuring, 
 and dividing this amount by 6,343, the number of car 
 wheels ground, we find an actual grinding cost of $0.02956 
 per wheel or $29.56 per thousand wheels. It is seen that 
 by using a simple practical method it is possible to accurately 
 determine the grinding cost under everyday working con- 
 ditions. It is reliable figures of this kind that the manufac- 
 turers desire. 
 
 In grinding comparatively large work, it is possible to 
 determine the grinding cost while working on an individual 
 piece, as the following report on the grinding of a large 
 chilled-iron roll, by Mr. J. H. Hollinger, of The Landis 
 Tool Company, published in the Oct. 26, 1911, number of 
 the American Machinist, graphically illustrates. 
 
 "I have ground a chilled cast-iron roll 20-3/16 inches 
 diameter by 28 inches long on a Landis 20x96 inch roll 
 grinder, removing 1/4 inch from the diameter of the body 
 only. Surface speed of roll, roughing 52-1/2 feet, finishing 
 521/2 feet; traverse of wheel for each revolution of the 
 work, 7/8 inch; wheel feed at each reversal, 0.006 inch 
 for roughing; o.ooi inch for finishing. The roll was ground 
 with a 22-9/16x2 inch Carborundum wheel having an 8- 
 inch hole, 403 grit, P grade, O F bond, running at 925 
 revolutions per minute, 5,472 surface feet and it was re- 
 duced in diameter 19/32 inch, which represents a cost of 
 90 cents. This wheel wore just fast enough to keep itself 
 sharp and, for roughing, was only dressed once with a 
 diamond. Time for grinding the roll to a smooth finish, 
 good enough for hot rolling, 4 hours; total cubic inches 
 removed, 221 ; cubic inches removed per minute to finished 
 surface, 0.92 inch. The motor used on this work was a 
 variable speed 25 horsepower. Average horsepower con- 
 sumed, 21." 
 
 108
 
 TESTING WHEELS FOR EFFICIENCY 
 
 In the above report it is seen that Mr. Hollinger has 
 embodied all the data necessary for computing an accurate 
 grinding cost, which is quite essential when testing wheels 
 on large work. It is needless to state that comparatively 
 long grinding operations on large pieces are expensive and 
 without accurate data, compiled by one who understands 
 the art of grinding thoroughly, it is an impossibility to de- 
 termine the actual cost. 
 
 The operation shown in Fig. 21, furnishes another in- 
 stance wherein the grinding cost can be computed through 
 
 Fig. 21. Grinding long shafting used in textile machinery. 
 
 working on one piece. The work in question consists of 
 actually grinding long shafting used in textile machinery. 
 The shafting comes slightly oversize and after being centered 
 is kept in racks and ground as needed. With shafts of the 
 same length and with a like amount of material to remove, 
 it is obvious that a record of the grinding cost for each size 
 can be kept. When another make of wheel is to be tested, 
 it is a simple matter to determine its earning power by 
 
 109
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 noting the length of time taken to remove a certain amount 
 of material and the wheel wear meanwhile. 
 
 Still another instance where the grinding cost can be 
 computed while working on one comparatively large piece 
 is shown in Fig. 22. In this case, the work consists of 
 grinding locomotive guide bars to produce a smooth and 
 
 Fig. 22. Grinding a locomotive guide bar. 
 
 true surf ace for the cross-head gibs to slide upon. Different 
 types of locomotives have various kinds of guide bars, 
 but with the kind shown four constitute a set. Thus, to 
 determine the grinding cost, all that is necessary is to 
 measure the thickness of the wheel with a pair of calipers 
 before and after grinding the four bars and taking note of 
 the time consumed in the grinding operation. The actual 
 grinding cost is arrived at by adding the labor cost and 
 value of abrasive material used. In tests of this kind, it is 
 truly surprising how some makes of wheels show remarkable 
 
 no
 
 TESTING WHEELS FOR EFFICIENCY 
 
 saving in grinding costs over others. Thus the man who 
 thinks that it is not worth while to test grinding wheels for 
 efficiency is often needlessly grinding away dollars, so to 
 speak, instead of removing metal in the most efficient man- 
 ner possible. It must be borne in mind that grinding 
 operations on large work are expensive at best and too 
 much cannot be said in favor of making accurate tests 
 to determine actual grinding costs. 
 
 On certain classes of grinding of an automatic or semi- 
 automatic nature, wherein the actual time of contact be- 
 
 Fig. 23. Type of chain links finished by semi-automatic grinding. 
 
 tween the wheel and the work does not vary, the efficiency 
 of the wheel can be determined by considering one factor 
 only, that is the actual number of hours it lasts. The 
 operation of grinding chain links of the kind illustrated in 
 Fig. 23 furnishes an excellent means of determining the earn- 
 ing power of a grinding wheel by considering its life only. 
 Chain links of this kind are used for transmitting power, 
 
 .in
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 conveying material, etc., and are made in various sizes from 
 small ones approximately an inch long to large sizes a foot or 
 more in length. The smaller sizes are cast from a gated 
 pattern and the object of the grinding is to remove the gate. 
 This gate is shown on the top of the link illustrated in Fig. 23. 
 The means generally provided for this work are shown 
 in Fig. 24, wherein A is the grinding wheel revolving as 
 shown by the arrow and B the drum for carrying the links 
 
 Fig. 24. Principle involved in grinding chain links. 
 
 which are placed by hand in depressions, or pockets, pro- 
 vided to accommodate them. This drum revolves quite 
 slowly in the direction shown by the arrow. The object 
 of the slow motion is to give the wheel ample time to grind 
 away the gate. The operator places the links in the pockets 
 by hand and as the drum revolves they are brought in 
 contact with the wheel. Means are provided for moving 
 the shaft carrying the drum toward the wheel as it wears 
 away, which is, of course, necessary in producing uniform 
 work. As the speed of the drum is always constant, it is
 
 TESTING WHEELS FOR EFFICIENCY 
 
 evident that the life of the wheel is the chief factor to con- 
 sider, as a comparatively soft wheel would wear away very 
 rapidly without performing its full quota of work and during 
 its life would require almost constant attention in keeping 
 the drum in proper relation to the periphery of the wheel: 
 
 Fig. 25. Semi-automatic machine for rounding the backs of pearl buttons. 
 
 On the other hand, the wheel should not be too hard or 
 it would glaze very readily, refuse to cut, and in some cases 
 a fractured wheel would result. In testing wheels on work 
 of this kind, it is a good plan to begin the test with com- 
 paratively soft wheels, taking note of the amount of links 
 of a given size ground during the life of the wheel. Harder 
 wheels are then tried and the hardest wheel that will cut 
 satisfactorily without constant glazing is the one that should 
 be selected.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Another case wherein the efficiency of the wheel is de- 
 termined by its life is illustrated in Fig. 25. The machine 
 shown is of semi-automatic construction and is designed 
 for rounding the backs of pearl-button blanks. As the illus- 
 tration shows, the operator has a box of button blanks 
 and places them one at a time in the chucks which au- 
 tomatically grip them and carry them under the wheel 
 shown at the right. The face of the wheel is slightly con- 
 caved and as the chucks revolve on their axes, as well as 
 traveling in a circle, the blanks are given the desired 
 rounded shape as they pass under the wheel. Provided 
 the blanks are ground in a satisfactory manner, that is, 
 without burning them, the wheel that will last the greatest 
 number of working days is considered the most efficient. 
 Tests of the above kind are, of course, easily conducted as 
 they consist simply of selecting a wheel that will do the 
 work in a satisfactory manner and noting how long it will 
 last. 
 
 From the foregoing, it is seen that there are three practical 
 methods used for testing the efficiency of a grinding wheel. 
 
 1. A definite time test wherein the wheel is used for a 
 specified number of hours ; the grinding cost being computed 
 by adding the value of the abrasive used to the labor cost ; 
 from which the grinding cost per piece or per hundred or 
 thousand pieces is computed. 
 
 2. The individual piece test, wherein the grinding time 
 and cost of abrasive is noted while working on one piece 
 of comparatively large work. 
 
 3. The life of wheel test in which the amount of grinding 
 is noted during the whole time the wheel is in service. 
 
 All the above tests are practical, and can be relied upon 
 to give accurate production costs on a variety of work; 
 both of a rough and precision nature. 
 
 Grinding-wheel tests should, of course, be conducted by 
 responsible men and the data regarding the performance of 
 each wheel should be kept accurately, otherwise the tests 
 will be of no practical value. 
 
 114
 
 CHAPTER SEVEN 
 
 LABORATORY TESTS 
 
 Apparatus and appliances used Limitations of laboratory tests Factors 
 to be considered Laboratory testing machine Data for test Work 
 used in testing. 
 
 THE simple methods used in testing grinding wheels on 
 actual work, as described in the previous chapter, 
 can be used only in cases where there are comparatively 
 long runs of routine work. In many instances, however, 
 the work is of such a nature that it is an impossibility to 
 secure enough like pieces on which to test the efficiency of a 
 particular wheel. This is often true in gray iron, brass, 
 steel and malleable iron foundries, to say nothing of the 
 innumerable manufacturing plants where a diversity of 
 cylindrical grinding is done. 
 
 By means of simple appliances, as described in this 
 chapter, however, it is possible to obtain absolute knowledge 
 of the abrasive efficiency of any grinding wheel on practically 
 any kind of material. The value of these laboratory tests 
 should not be under-estimated as they give the efficiency 
 engineer knowledge of the actual worth of different abra- 
 sives and different makes of wheels without resorting to the 
 production department for data. 
 
 On cylindrical grinding especially, owing to the many 
 factors to be considered while testing wheels on actual 
 work, such as depth of cut, work speed, feed, etc., it is a 
 difficult matter sometimes to determine which is the better 
 wheel to use. Again, operators of cylindrical grinding 
 machines are sometimes unduly prejudiced in favor of one 
 particular make of wheel, often flatly refusing to be con- 
 
 "S
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 vinced that other grinding-wheel manufacturers, also, make 
 dependable wheels. Other factors also, the nature of 
 which it is not necessary to state here, sometimes unduly 
 influence grinding-machine operators, or even department 
 heads to whom is sometimes left the selection of grinding 
 wheels. It is seen that laboratory tests can be relied upon 
 as a sure means to the desired end; that is, to ascertain 
 beyond reasonable doubt the actual abrasive efficiency of 
 all wheels offered for test purposes. 
 
 A given number of cubic inches of abrasive material 
 incorporated into a grinding wheel will, at a given surface 
 speed, remove a definite amount of metal. This is the 
 hypostasis upon which laboratory tests, to determine the 
 abrasive efficiency of grinding wheels, are based. 
 
 In Fig. 26 is illustrated a simple testing machine for 
 determining the efficiency of grinding wheels used for such 
 
 Fig. 26. Laboratory grinding-wheel testing machine for testing grinding 
 wheels used in hand-grinding operations. 
 
 purposes as grinding castings and forgings, general grinding 
 in the machine shop, tool grinding, or, in fact, for any pur- 
 pose where the work is held in contact with the wheel by 
 hand. 
 
 This machine consists of a substantial base (A) upon 
 116
 
 LABORATORY TESTS 
 
 which is mounted a swing frame (B) carrying the grinding 
 wheel (C). The pulley (D) on the jack shaft (E) is driven 
 from an overhead countershaft of the variable-speed type, 
 while the pulley (F) on the wheel spindle (G) is driven by 
 the pulley (H). 
 
 The work to be tested is shown at (J), consisting of a 
 bar one inch square held in the anvil (K) by means of a set 
 screw. The grinding wheel is always 1 2 inches in diameter 
 with a one-inch face. The machine should be very rigid to 
 absorb vibration, for, with a lightly constructed machine, 
 vibration is sure to be present, which would cause chatter- 
 ing, thus preventing the end sought to determine the 
 efficiency of the grinding wheel under normal conditions. 
 The wheel spindle is 2 inches in diameter while its pulley 
 is 6 inches in diameter with a 4-inch face. Both pulleys 
 on the jack shaft are 12 inches in diameter. 
 
 Power is transmitted by means of three-inch double-ply 
 leather belt. The object of the ribs on the swing frame and 
 the rib on the base is to make the construction as rigid as 
 possible for the reason previously stated. 
 
 The swing frame should be counter- weighted by means of 
 a weight attached to a cord passing over over-head pulleys. 
 This cord is fastened to the rod at the front end of the swing 
 frame. The counter-weight should be just heavy enough 
 to cause the grinding wheel to exert a pressure of 10 pounds 
 on the work, this being the average pressure exerted in 
 hand-grinding operations. The pressure is determined by 
 fastening a spring balance suspended from the ceiling to 
 the eye on the swing frame directly over the spindle. 
 
 A little experimentation with a machine of this kind is 
 sure to disclose startling results regarding the efficiency 
 of different grinding wheels. Some wheels will be found to 
 cut readily, holding their shape well, while others prove to 
 be comparatively slow cutting. The wheels should all be 
 run at the same speed, 1,592 R. P. M. being the correct 
 speed for a 1 2-inch wheel, the above number of revolutions 
 per minute giving a peripheral speed of 5,000 feet per 
 
 117
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 minute, which surface speed is considered correct for hand- 
 grinding operations. If the speed is retained constant at 
 1,592 R. P. M. and the same pressure exerted in all tests 
 (10 pounds) it follows that all wheels tried are given a fair 
 and impartial test since they are tried under the same con- 
 ditions. 
 
 The test bar should, of course, be made of the same ma- 
 terial on which the grinding wheel is used on actual pro- 
 duction work. The wheel, after being carefully weighed, 
 is placed in position on the spindle and carefully trued by 
 means of the dresser shown in Fig. 27, which consists of a 
 
 
 r-\rv 
 
 
 So| 
 
 : Rfff] t f 
 -j{tj|jl 
 
 -LH_HJ-L 
 
 Fig. 27. Star-wheel dresser for use with testing machine. 
 
 few star-wheel cutters mounted in a holder which fits the 
 hole in the anvil. The test bar is now placed in position 
 and the test conducted for one half -hour. At the expiration 
 of this period, the number of cubic inches of material ground 
 away are noted and the wheel taken off and weighed to 
 determine the weight of abrasive material used. This should 
 be done on a sensitive scale which accurately registers 
 ounces. 
 
 It is evident that the wheel which will grind away the 
 greatest amount of material in a given time, with the least 
 amount of loss to the wheel itself, is the most efficient 
 wheel to use for the purpose in question. In ordering 
 wheels for test purposes on a machine of this kind, it is 
 
 118
 
 LABORATORY TESTS 
 
 best to get at least two from each maker. The performance 
 of each wheel should be carefully noted and in comparing 
 wheels of different makes, the most efficient of each is 
 considered. The records of all tests conducted should be 
 kept in a book provided for the purpose and, after a few 
 weeks of experimenting the manufacturer should have at 
 his disposal authentic data relating to the performance of 
 many wheels. The records should be kept on a form like 
 the following: 
 
 Make of wheel, 
 
 Cost, 
 
 Grit, 
 
 Grade, 
 
 Bond, 
 
 Diameter, 
 
 Face, 
 
 Weight, 
 
 Cost per lb., 
 
 Material tested, 
 
 Grinding pressure, 
 
 Wheel speed, 
 
 Length of test, 
 
 Weight of wheel after test, 
 
 Wheel loss, 
 
 Cubic inches of material removed, 
 
 Grinding cost per cubic inch. 
 
 Remarks. 
 
 It is readily seen that it is a more simple matter to de- 
 termine the abrasive efficiency of a grinding wheel on a 
 machine of the above kind than it is to conduct a long test 
 in the shop. Again, the results derived from these tests 
 can be relied upon as the testing can be done under the 
 direct supervision of the efficiency engineer, who cannot 
 always spare the time personally to superintend a long 
 test on actual work in the production department. 
 
 The machine shown in Fig. 28 is designed to test wheels 
 as used for cylindrical grinding. It consists of a solid base 
 (A) carrying a wheel spindle (B) on which is mounted a 
 wheel 12 inches in diameter with a i-inch face and 5 -inch 
 
 119
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Fig. 28. Laboratory grinding-wheel testing machine for testing grinding 
 wheels used in cylindrical grinding operations.
 
 LABORATORY TESTS 
 
 hole. This wheel is a regular stock size as it fits several 
 cylindrical grinding machines. 
 
 The piece to be tested consists of a disc (C) 2 inches in 
 diameter, i inch wide with a 3/4-inch hole. It is made of 
 the material upon which it is desired to test the wheel and 
 is fastened in place on the work spindle (D) by means of the 
 nut (E) which holds the piece against a shoulder on the 
 work spindle. The work spindle is mounted on the swing 
 frame (F). 
 
 The work is kept in contact with the wheel by means of 
 the weight (G) on the lever (H). The weight is adjusted 
 to make the wheel spark heavily as it does on regular pro- 
 duction work when working at its maximum limit. The 
 same amount of pressure should be used in testing all wheels 
 otherwise a fair decision is not possible. 
 
 A diamond mounted in the holder (J) which fits the slide 
 (K) at the back of the machine is for the purpose of truing 
 the wheel. The testing can be done either wet or dry. The 
 machine shown is designed for dry testing, but with the 
 addition of a hood to cover the wheel and a pipe to supply 
 water at the point of grinding contact, tests in wet grinding 
 can be conducted. 
 
 The tests are carried on in the same manner as those just 
 described with a view to determining which is the fastest 
 cutting wheel with the least amount of wear. As previously 
 stated, it is often a difficult matter to determine the actual 
 efficiency of a wheel used for cylindrical grinding owing to 
 the many factors to be considered. With a machine of this 
 kind for conducting comparative tests, however, wherein 
 the factors are simplified as much as possible, tangible 
 results are possible in a very short time without the neces- 
 sity of interrupting the regular work in the grinding de- 
 partment. 
 
 The manufacturer who wishes to reduce his grinding costs 
 will do well to conduct a few simple tests as outlined in this 
 and the previous chapter. The results of the tests should be 
 carefully noted for future reference, and by testing different
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 makes of wheels and different grits and grades of the same 
 make, economical results in the production department are 
 sure to follow. It costs comparatively little to test grinding 
 wheels when the work is undertaken in the right way and 
 the actual saving in dollars and cents that results from 
 reliable tests makes it worth while to conduct them.
 
 CHAPTER EIGHT 
 
 GRINDING WHEEL VS. GRINDSTONES 
 
 Advantages of natural and artificial abrasive used in wheels Early use of 
 grindstones Special work where grindstones are still employed Action 
 of grinding wheel. 
 
 AS previously stated in another chapter, the grindstone 
 ** is the oldest form of grinding wheel known, being at 
 one time exclusively used for all grinding operations. When 
 the grinding wheel made of emery was first put on the 
 market, some forty years ago, it did not readily meet with 
 favor in the manufacturing world owing to many dis- 
 advantages. In the first- place it was often dangerous; 
 being liable to burst from centrifugal strain without a mo- 
 ment's notice and, again, the high speed at which it was run, 
 together with the low abrasive efficiency of the grinding 
 material used, caused it to draw the temper of edge tools 
 unless great care was exercised in the grinding operation. 
 The grinding-wheel industry of today being in its infancy, 
 grinding-wheel manufacturers faced a serious problem in 
 finding a market for their goods. 
 
 While the old-fashioned emery wheel of previous days 
 did not successfully compete with the grindstone, in the 
 edge tool, saw, file and other industries it began to be used 
 for many operations heretofore accomplished by the slow 
 hand method of filing. As a matter of fact, it was common 
 practice to file all kinds of castings as late as twenty-five 
 years ago, but as experience proved that the emery wheel 
 furnished a more rapid means, together with the fact that 
 emery-wheel manufacturers began to seriously consider the 
 factor of safety, the grinding wheel slowly advanced in 
 
 123
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 favor. In the year 1878, Mr. Hart of Detroit obtained a 
 novel patent on a grinding wheel containing a wire web, 
 the object of which was to prevent the fragments of the 
 wheel from flying in case it burst. This was readily ac- 
 cepted as a great improvement, which indeed it was, and 
 the grinding-wheel business thereby received a remarkable 
 impetus. 
 
 With the general introduction of corundum in the early 
 eighties, grinding wheels began to be used for other pur- 
 poses aside from rough grinding owing to the fact that 
 a cooler cutting wheel could be made by substituting 
 corundum for emery. Thus corundum wheels found a 
 limited market for certain tool-grinding operations hitherto 
 done on the grindstone. 
 
 With the adoption of cylindrical grinding machines for 
 finishing hardened parts of machinery, the grinding-wheel 
 business was established on a firm basis owing to the fact 
 that the cylindrical grinder furnished a sole means for a 
 desired end; that is, doing work that could not be done 
 either with the file or grindstone. With the improvement 
 of cylindrical and other precision-grinding machinery, the 
 grinding-wheel industry has kept pace; abrasive wheels 
 being used at the present day for thousands of manufacturing 
 operations. 
 
 Strange as it may seem, however, the modern grinding 
 wheel has not wholly replaced the grindstone for certain 
 operations owing chiefly to the cheapness of grindstones 
 and to the manner in which they act on the work with which 
 they are brought in contact. 
 
 A grindstone is run at a comparatively slow peripheral 
 speed, so slow that it will not throw water from its surface. 
 In the grinding operation, particles of quartz are torn from 
 the stone and these floating in the surface water present a 
 planing action on the work, often with a shearing cut as 
 the particles of quartz are dragged under the piece being 
 .ground. Any mechanic realizes that a shearing cut is very 
 effective and this peculiarity of "grindstone action," as it 
 
 124
 
 GRINDING WHEEL VS. GRINDSTONES 
 
 is termed, together with the fact that quartz in itself is a 
 very efficient abrasive for some classes of work, accounts 
 for the fact that the old grindstone is still in favor in cer- 
 tain phases of work. 
 
 At the present day, grindstones are used for a number of 
 surfacing operations such as grinding the sides of saws, 
 grinding file blanks, surfacing plows, axe grinding, etc. 
 Large numbers of grindstones called pulp stones are used 
 in preparing wood pulp for paper manufacturers. In this 
 particular field, the grinding wheel cannot, or, at least, has 
 not been able to compete successfully owing to the low initial 
 cost of grindstones and to the fact that grinding wheels 
 do not prepare the material in % the desired manner to suit 
 American paper manufacturers. In the Scandinavian coun- 
 tries, however, a special form of manufactured grinding 
 wheel is used for pulp grinding, but these same wheels 
 do not find favor in this country. 
 
 In the manufacture of files, the grindstone is still used 
 in large quantities owing to the fact that it leaves just the 
 proper kind of surface for the tools that cut the file teeth. 
 Numerous experiments have been tried to develop a 
 grinding wheel to do this class of work successfully, but to 
 the best of the writer's knowledge no success has been 
 attained. 
 
 That the grindstone still shows efficiency on certain 
 classes of work cannot be doubted and as an illustration 
 of this we can consider the subject of axe grinding. As they 
 come to the grinding room, axes, like other products of 
 the forge, are in a rough state and the operation of grinding 
 them smooth before they are tempered is termed by the 
 axe manufacturer "press grinding" or "pressing." A press 
 in this case is nothing more or less than a stout iron bar 
 to hold the axe firmly against the stone, pressure being ap- 
 plied by means of a foot-operated treadle. 
 
 The stones used for this work are six feet in diameter 
 and twelve inches thick, costing at a fair market price, 
 $25.00 each. One of these stones lasts approximately three 
 
 125
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 weeks, during which time it grinds 3,500 axes. Considering 
 ten hours as a day's work, it is seen that the operation 
 of rough grinding one axe consumes three minutes. Now 
 there are a good many square inches on the surface of an 
 axe and any abrasive whatsoever that will do this work 
 in the short time of three minutes is efficient to say the 
 least. The cost of abrasive material used per axe is less 
 than one cent, being approximately 7/10 of a cent. 
 
 If we invest our $25.00 in a grinding wheel we can, at a 
 fair market price, purchase a wheel 30 inches in diameter 
 with a 2-1/2 -inch face, one 24 inches in diameter with a 
 3-1 /2-inch face, or one 20 inches in diameter with a 5-1/4- 
 inch face. A grindstone 6 feet in diameter with a 12 -inch 
 face, contains 48,858 cubic inches, whereas a typical grinding 
 wheel that can be purchased for the same price, a 30 x 2-1/2 
 for an illustration, contains but 1,767 cubic inches. Thus 
 it is seen that a decided factor is in favor of the grindstone ; 
 that is, its low cost per cubic inch. It naturally follows 
 that a grinding wheel to compete with a grindstone on the 
 work in question must be highly efficient owing to the fact 
 that its cost per cubic inch is much greater. Again we 
 must not lose sight of the fact that it takes a very fast- 
 cutting grinding wheel to surface an axe in three minutes. 
 
 However, notwithstanding that grindstones are cheap 
 and efficient, the grinding wheel is gradually creeping into 
 the axe industry, owing to the fact that its adoption offers 
 advantages that cannot be had while using grindstones. 
 A prominent axe manufacturer with whom the writer has 
 had some recent correspondence regarding the grinding 
 wheel in the axe factory, has the following to say in favor 
 of the grinding wheel. 
 
 "Our general opinion is that grinding- wheel grinding is 
 as economical in labor cost and abrasive cost as wet-stone 
 grinding, but the collateral advantages of the grinding- 
 wheel grinding throw the advantages strongly in favor of 
 this method. Grinding-wheel grinding takes up much less 
 space, requires less power and permits better working con- 
 
 126
 
 GRINDING WHEEL VS. GRINDSTONES 
 
 ditions because the grinding wheels can be used with ex- 
 haust hoods to carry off the dust, and even if they are used 
 wet the water can be confined; whereas with wet grinding 
 with large grindstones, the men are constantly wet and the 
 department cannot be kept either clean or sanitary." 
 
 Abrasive engineers and grinding- wheel .salesmen are prone 
 to discuss the possibilities of the grinding wheel wholly 
 replacing the grindstone in various manufacturing pursuits. 
 As a matter of fact, the above theme has been discussed 
 more or less ever since the grinding wheel first made its 
 appearance nearly fifty years ago. Notwithstanding that 
 the grindstone is entirely different in grinding action from 
 the grinding wheel, the latter is slowly gaining in favor 
 owing to the rapid strides made in abrasive engineering, 
 and in considering future possibilities in fields now oc- 
 cupied by the grindstone, we are confronted with two 
 vital factors. 
 
 First, the grindstone is a natural product; thus it cannot 
 be altered it must be accepted just as nature formed it, 
 millions of years ago when the earth was young. Different 
 degrees of hardness and variations of the size of the quartz 
 grain of which the stone is composed can be had, to be sure, 
 but neither the abrasive itself, nor the natural bonding ma- 
 terial that holds the innumerable grains of which the 
 grindstone is composed can be changed by the arts of 
 man. 
 
 Second, the grinding wheel can be made to differ in quite 
 a number of ways to suit varied grinding conditions. It 
 Can be composed of various kinds of abrasives bonded 
 together by many different means. Again, it can be coarse 
 or fine, hard or soft, compact or open, brittle or tough. In 
 fact the abrasive engineer of the present time first studies 
 the work to be performed and then makes a wheel to suit 
 the requirements, and in cases, where the experimental 
 wheel fails to come up to his expectations, he profits by the 
 failure and tries again. 
 
 By this method, and this method only, the grinding 
 127
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 wheel has been adapted to purposes undreamed of a few 
 years ago, comparatively speaking, thus it is reasonable to 
 assume that the knowledge of future years will produce a 
 grinding wheel that will eventually replace the grindstone 
 just as artificial abrasives have practically replaced the 
 emery wheel of yesterday.
 
 CHAPTER NINE 
 
 THE ECONOMIC ADVANTAGE OF USING LARGE WHEELS 
 
 Factors to be considered in choosing a wheel Comparative price of wheels 
 of various sizes Advantage of large wheels in certain work Why large 
 wheels are more efficient. 
 
 'T'HOSE who purchase grinding wheels have probably 
 * noticed that the grinding- wheel salesman seems anxious 
 to sell large wheels^ that is 16 x 2 inches or over. This is 
 not always because the salesman wishes to write up a 
 "nice order," as it were. Contrary to this, he generally 
 has his customer's interests in mind and realizes that there 
 is true economy in using comparatively large wheels, as the 
 following figures show. The wheel sizes and list prices 
 are taken from the standard grinding-wheel list and a 
 perusal of the same shows that the cost of grinding wheels, 
 per cubic inch, in most instances, decreases as the size 
 increases. 
 
 There are some exceptions to this rule, however, for, as 
 the data shows, a 24 x 4-inch wheel costs more per cubic 
 inch than a 20 x 3 -inch wheel. It is well for the purchasing 
 agent who wishes to buy as economically as possible to 
 figure carefully the cost per cubic inch of the various-sized 
 wheels that he buys to ascertain whether or not he is buy- 
 ing to advantage. 
 
 The greatest difference in cost per cubic inch is found 
 in wheels below 20 inches in diameter. With wheels larger 
 than this the cost difference per cubic inch is not so great, 
 and in some instances there is no decrease in cost per cubic 
 inch with an increase of size. As an illustration, a 30 x 4- 
 inch wheel costs just as much per cubic inch as a 20 x 3 -inch 
 
 129
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 wheel, while the cost per cubic inch of a 60 x 8 -inch wheel 
 is only slightly less than that of a 30 x 4-inch wheel. 
 
 Size 10 x 1-1/2 
 
 List price $10.20 
 
 Area in cubic inches 117.81 
 
 Cost per cubic inch $00.0871 
 
 Cost per hundred cubic inches $8.71 
 
 Size 12x2 
 
 List price $16.70 
 
 Area in cubic inches 226.20 
 
 Cost per cubic inch $00.0738 
 
 Cost per hundred cubic inches $7.38 
 
 Size 16 x 2-1/2 
 
 List price $3 2.40 
 
 Area in cubic inches 502.65 
 
 Cost per cubic inch $00.0645 
 
 Cost per hundred cubic inches $6.45 
 
 Size 20 x 3 
 
 List price $58.00 
 
 Area in cubic inches 942.48 
 
 Cost per cubic inch $00.0615 
 
 Cost per hundred cubic inches $6.15 
 
 Size 24 x 4 
 
 List price $i 13.00 
 
 Area in cubic inches 1,809.56 
 
 Cost per cubic inch $00.0624 
 
 Cost per hundred cubic inches $6.24 
 
 Size 30 x 4 
 
 List price $174.00 
 
 Area in cubic inches 2,827.44 
 
 Cost per cubic inch $00.0615 
 
 Cost per hundred cubic inches $6.15 
 
 Size : '. 60 x 8 
 
 List price $1,358 
 
 Area in cubic inches. . 22,619.20 
 
 Cost per cubic inch $00.060 
 
 Cost per hundred cubic inches $6.00 
 
 The advantage of using comparatively large wheels is 
 shown in the following comparison : Let it be assumed that 
 a concern uses two hundred 12 x 2-inch grinding wheels 
 
 130
 
 ECONOMIC ADVANTAGE OF USING LARGE WHEELS 
 
 annually. At a fair market price these wheels would cost 
 $835.00. The two hundred wheels contain 45,240 cubic 
 inches, and in using them until they are four inches in 
 diameter, 40,214 cubic inches of material are actually used 
 while 5,026 cubic inches are discarded in the stubs, which 
 represent an actual cost of $92.47. 
 
 If 24 x 4-inch wheels were used in place of the 12 x 2 -inch 
 wheels, twenty-five will contain 45,239 cubic inches which 
 is practically the cubical contents in inches of the two 
 hundred 12 x 2 -inch wheels. Twenty-five 24 x 4-inch wheels, 
 bought at the same discount that applied to the 12 x 2 -inch 
 wheels, would cost $706.25. In using the wheels to a 
 diameter of 8 inches, practically the same amount of abra- 
 sive material is used as heretofore, that is 40,213 cubic 
 inches, and in comparing the two prices it is seen that there 
 is an actual saving of $128.75. The twenty-five 8 x 4-inch 
 stubs contain 5,026 cubie inches and represent an invest- 
 ment of $70.40 against $92.47, the cost of the stubs of the 
 12 x 2-inch wheels. Thus another saving, amounting to 
 $14.07 is effected. 
 
 Another point that should not be overlooked In consider- 
 ing large wheels is that a pair of comparatively large wheels 
 mounted on a heavy grinding stand are more free from 
 vibration than small wheels mounted on light stands. 
 
 If we take an ordinary machinist's hammer and beat a 
 piece of steel with it for a few seconds, the face of the 
 anvil, for instance, both the hammer and the anvil become 
 slightly heated, owing to the fact that the energy of the 
 blows has been transformed into heat. Consider for a 
 moment the wasted energy expended by a vibrating grinding 
 wheel traveling at a peripheral speed of 5,000 feet per 
 minute. Here the same principle above explained holds 
 true even if the grinding wheel vibrated but very little. 
 
 A grinding wheel should generate as little heat as possible; 
 the wheel that vibrates while in use is very inefficient 
 because some of the energy that should be expended in 
 removing metal is used in generating useless heat.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 As the surface of a grinding wheel presents thousands 
 of cutting points to the work, it is evident that the surface 
 having the most points to present to a given piece of work 
 will last the longest without becoming dulled, or glazed. 
 In considering a 14 x 2-inch wheel in 20 grit, we have a 
 cutting surface of 87.9648 square inches and allowing 400 
 cutting points to the square inch the sum of these equals 
 35,185. On the other hand, a 2 4 x 3 -inch wheel has a cutting 
 surface of 226.1952 square inches containing 90,478 cutting 
 points. It is plainly seen that the latter is bound to remain 
 in cutting condition longer than the former. 
 
 Why is it then, that many manufacturers persist in using 
 comparatively small grinding wheels mounted on light 
 stands? In the first place, small grinding-wheel stands are 
 cheap to install and the wheels for the same are not an 
 expensive item when bought a few at a time. There is, of 
 course, a place for the small grinding wheel, but for the 
 average jrun of general work, snagging castings and forgings, 
 tool grinding, etc., it is false economy to use wheels smaller 
 than 20 inches in diameter. An ideal size to use for any 
 of the above purposes is 30x4 inches, but outside of the 
 plow industry, this size is little used. The cheapest 
 course in the long run is to consign the small grinding-wheel 
 stands to the scrap heap and install larger ones; and in 
 the meanwhile the consumer of grinding wheels should be 
 educated to the fact that small wheels are expensive at any 
 price.
 
 CHAPTER TEN 
 
 TRUING DEVICES FOR GRINDING WHEELS 
 
 (Reprinted from The Iron Age.) 
 
 Abrasive action Tools used in truing wheels Use of bort and carbonado 
 diamonds in tools Getting stones in tool Procedure in truing wheels. 
 
 RINDING wheels are in reality cutting tools re- 
 volving at high speed whereby countless sharp points 
 remove minute chips by what we call, for want of a better 
 term, the action of abrasion. In the strictest sense of the 
 word, this is not correct because the word abrasion means 
 to wear or rub, whereas a modern grinding wheel actually 
 removes material, be it hard or soft, by a cutting instead 
 of a wearing action. To obtain the best results, the in- 
 numerable cutting points on the surface of the wheel should 
 be kept sharp and the periphery concentric with the spindle ; 
 otherwise the efficiency of the wheel is materially lowered. 
 In this chapter, a few simple methods for truing grinding 
 wheels will be briefly considered. 
 
 The tools used for this purpose are of two kinds, diamonds 
 and ordinary emery-wheel dressers. There are two varieties 
 of diamonds used, that is to say bort stones, many of 
 which are nearly white in color, and a black variety called 
 carbonado or black diamond. Bort stones are compara- 
 tively inexpensive when compared with black diamonds, 
 but they are not so hard and consequently are shorter lived. 
 It is, therefore, more economical to use black diamonds. 
 Both varieties are sold by the carat and can be bought loose 
 or already mounted in steel or copper holders. The majority 
 of manufacturers prefer to buy loose stones, as by this 
 method flaws are more readily detected, and since the stones
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 are never guaranteed it is important to see that only good 
 specimens are selected. 
 
 The operation of setting the stones is comparatively 
 simple and can be intrusted to any tool maker who has the 
 reputation of being a careful workman. In setting a stone, 
 all workmen do not proceed along the same lines, but the 
 following method, which is used by many tool makers, is 
 simple and satisfactory. First, select a drill of the same 
 size as the stone. This is readily accomplished by passing 
 the stone through the holes in an ordinary drill gauge. As 
 stated before, both steel and copper holders are used, but 
 in actual practice the latter makes the better holder for 
 two reasons. First, it is very malleable and thus is easily 
 worked, and also copper is an excellent conductor of heat 
 and readily absorbs superfluous heat, thereby tending to 
 
 m 
 
 Fig. 29. First step in mounting the diamond. 
 
 Fig. 30. The metal in position over the stone. 
 
 Fig. 31. The finished setting with the superfluous metal removed. 
 
 Fig. 32. Special type of diamond holder. 
 
 prevent overheating the stone, which sometimes causes it to 
 fracture. The rod should be about six inches long and of 
 the correct diameter to fit the holder of the machine where 
 it is to be used. A hole is drilled in the end of the rod 
 deep enough to bury the stone, as shown in Fig. 29. The 
 next step is to force over the metal over the edges of the 
 stone firmly in place. This s done with a light hammer 
 and a small staking chisel, The result is shown in Fig. 30. 
 
 i34
 
 TRUING DEVICES FOR GRINDING WHEELS 
 
 Care should be exercised as a diamond is quite brittle and 
 easily broken by a chance blow. The completed setting 
 is shown in Fig. 31, the superfluous metal having been 
 turned away. Some tool makers prefer to braze the stone 
 in position, and while this method no doubt holds the stone 
 firmly in place, the heat necessary to melt the spelter is 
 liable to crack the stone. However, as the method of braz- 
 ing stones in place is often used by reliable manufacturers 
 there certainly is some authority for employing it. The 
 process consists of filling the hole about half full of spelter 
 and flux, and when this has reached a molten state, the 
 stone is pressed in place, which causes the spelter to rise 
 in the hole, thus forming a matrix that grips the stone 
 firmly. " It may be well to add that the work should under 
 no circumstances be cooled in water, as the sudden contrac- 
 tion of the diamond will in many cases cause it to fracture. 
 
 Even the hardest stones will wear flat in time. It is' 
 necessary to reset them occasionally, which brings a new 
 cutting edge in position. This is done by turning the stone 
 upside down or canting it sideways. The holder shown in 
 Fig. 32 accomplishes this in a very simple manner. It 
 consists of an auxiliary plug in which the stone is mounted, 
 fitting a hole, the axis of which is at a slight angle with that 
 of the main holder. The plug is held in place by means of 
 a set screw. When the stone becomes flattened, the plug 
 is turned slightly, which brings a new cutting edge in posi- 
 tion. This device is covered by patent and it is not public 
 property. 
 
 Care should be exercised while using a diamond as an 
 undue strain caused by gouging it into the wheel often re- 
 sults in tearing the stone from its setting, in which event 
 it is generally lost. In truing wheels on cylindrical grinding 
 machines, water should always be used to keep down fric- 
 tional heat and several light cuts are to be preferred to a 
 few heavy ones. It is hardly necessary to state that the 
 tool should never be guided by hand as it is impossible 
 to do a satisfactory job in this manner. Nearly all grinding 
 
 135
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 machines are equipped with suitable holders to accommodate 
 truing devices and they should always be used. 
 
 The device illustrated in Fig. 33 is excellent for truing 
 wheels used on surface-grinding machines. It is very 
 
 Fig- 33- Simple device for truing wheels on surface grinders. 
 
 simple, consisting of a diamond set in a holder 1-1/2 inches 
 long, which is fastened in a block of cast iron by means of 
 a set screw. It can be used on. a magnetic chuck or clamped 
 
 Fig. 34. Device for truing wheels on cutter grinding machines. 
 
 in a vise. For truing wheels on various types of cutter- 
 grinding machines, an angle iron, as shown in Fig. ^54, 
 . 136
 
 TRUING DEVICES FOR GRINDING WHEELS 
 
 gives good results. The diamond holder is fastened by 
 means of a set screw and the angle iron is clamped to the 
 platen of the machine by a strap, bolt, or other convenient 
 means. 
 
 We are sometimes inclined to look askance at ordinary 
 emery-wheel dressers in connection with wheels for precision 
 
 Fig- 35- Grinding- wheel dressers mounted in a special holder for truing 
 wheels used on cylindrical grinding machines. 
 
 grinding, but under certain limited conditions they are 
 productive of excellent results. In ordinary cylindrical 
 grinding, it is customary to rough out several hundred 
 pieces before taking any finishing cuts, and as we are re- 
 
 Fig. 36. Truing device for use on large vertical spindle grinding machines. 
 
 moving stock only, paying absolutely no attention to finish, 
 .all that we desire is a fast-cutting wheel. In cases of this 
 kind, a few emery-wheel dresser cutters mounted in a 
 holder, as shown in Fig. 35; will prove a revelation to the
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 man who has never used them. They keep the wheel rough 
 and free cutting, which is just the condition required. 
 
 For truing the wheels used on large vertical spindle 
 surface-grinding machines, a holder, as shown in Fig. 36, 
 will be found a valuable accessory. It should be provided 
 with slots for clamping it in place. On the magnetic chuck, 
 however, the force of the magnetism is sufficient to keep 
 the holder in place. 
 
 It must be borne in mind that emery-wheel dressers 
 are practicable for roughing wheels only, but when we 
 stop to consider that even a comparatively small diamond 
 costs several dollars, whereas a set of emery-wheel dressers 
 can be purchased for a few cents, their merits are well worth 
 consideration.
 
 CHAPTER ELEVEN 
 
 RE-BUSHING GRINDING WHEELS 
 
 (Reprinted from Canadian Machinery.) 
 
 Methods used in bushing wheels Tools employed Metals used. 
 
 MANY large manufacturing concerns use a number of 
 grinding wheels in various departments for rough 
 grinding of castings and general purpose work. As the stands 
 upon which these wheels are used are generally of different 
 makes and sizes, it is not uncommon for the diameters of 
 the wheel ends of the spindles to vary from 1/16 to 1/4 
 inch or 'more. Thus, while 1 6 -inch wheels might be used 
 in several departments, it is necessary to carry a super- 
 fluous stock to accommodate the various sized spindles. 
 To overcome this difficulty, many manufacturers make a 
 practice of re-bushing their grinding wheels as occasion 
 requires, thereby eliminating the necessity of carrying in 
 stock individual grinding wheels for each department where 
 the sizes of the wheel spindles vary. The wheels are or- 
 dered with the proper size arbor hole to fit the largest spindle, 
 and with facilities easily procured they can be readily re- 
 bushed to fit the other sized spindles at slight expense. 
 
 The following method for performing the work in question 
 necessitates but a slight outlay for equipment and the results 
 will be found to be satisfactory. The necessary tools are a 
 cast-iron disc or plate as shown in Fig. 3 7 and several plugs 
 of the same diameter as the various arbors on which the 
 wheels are mounted. The plate should be as large in diam- 
 eter as the largest wheel used, and, for the sake of illustra- 
 tion, the plate shown is 20 inches in diameter. It has three
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 feet cast on it, which allows level setting on an uneven 
 surface, should occasion require. 
 
 The rough casting is mounted in a large lathe chuck and 
 the face turned off, after which a 3/4-inch hole is bored and 
 reamed in the center. The next step is to turn several 
 grooves 1/4 inch apart. These can be cut with an ordinary 
 
 Fig. 37. Appliance for re-bushing grinding wheels. 
 
 threading tool, and are used to set the grinding wheel 
 central while re-bushing its hole. Two heavy lines are next 
 scribed on the disc 90 apart, and near these lines the 
 circles are stamped i, 2, 3, 4, 5, 6, etc. Several plugs are 
 now made with one end to fit the hole in the disc, while the 
 diameters of the large ends should be o.oo2-inch larger 
 than the arbors on the grinding-wheel stands. This slight 
 clearance is sufficient to allow the wheels to slip on freely. 
 The large portion of the plugs should be one inch longer 
 than the thickness of the grinding wheels. Thus, if wheels 
 
 140
 
 RE-BUSHING GRINDING WHEELS 
 
 with a 2 -inch face are used, the plugs should be 3 inches, 
 as shown in the cut. 
 
 In re-bushing a grinding wheel, the first operation is to 
 cut out the original lead bushing with a compass saw. 
 By making two cuts diametrically opposite one another, 
 the bushing is easily removed by means of a few light taps 
 with a hammer. The wheel is now laid on the disc and 
 carefully arranged in the center by means of the nearest 
 circle to its periphery. A plug of the correct size is next 
 inserted and the new bushing cast in place. Lead is the 
 best material for this purpose, although any scrap stock 
 of low melting point such as solder, die-casting metal, etc., 
 will answer the purpose equally well. 
 
 The operation of re-bushing wheels is so simple that any 
 boy or handy man can do the work in a satisfactory manner, 
 while the cost of the necessary outfit should not exceed 
 twenty dollars.
 
 CHAPTER TWELVE 
 
 SUGGESTIONS TO FOLLOW IN ORDERING GRINDING WHEELS 
 
 Information to be given with grinding-wheel order Factor governing selec- 
 tion of wheels How to determine what kind of a wheel should be used 
 Ordering special wheels. 
 
 '"T'HE majority of grinding-wheel manufacturers include 
 * in their catalogues a list of various grinding operations, 
 together with the grits and grades generally recommended 
 for the different work. The object of these lists is to guide 
 the purchasing agent in the selection of grinding wheels for 
 various purposes. 
 
 An order for grinding wheels should, of course, give the 
 diameter, thickness, size of arbor hole and quantity desired 
 and, in case of a repeat order, the grit and grade. Other- 
 wise it is a good plan to refer to the tables previously men- 
 tioned or give with the order full and complete information 
 describing how, and for what purpose, the wheel is to be 
 used. This information is of great value to the grinding- 
 wheel manufacturer in filling the order intelligently, and 
 also it is the means of saving much valuable time as un- 
 necessary correspondence for the purpose of gaining full 
 information is thereby eliminated. 
 
 There are indeed many factors governing the proper selec- 
 tion of grinding wheels as the following data, furnished the 
 writer by the Abrasive Company of Philadelphia, plainly 
 illustrate. It is with pleasure that the writer incorporates 
 this material in his work as it states fully just how the grind 1 
 ing-wheel manufacturer views an order for grinding wheels 
 that he may fill the same correctly, thereby being assured 
 of future business. 
 
 142
 
 SUGGESTIONS IN ORDERING GRINDING WHEELS 
 
 "In order to obtain the best results, it is necessary to 
 furnish full information to the wheel manufacturer. 
 
 "It is true that the size is generally given, but it is also 
 necessary to know the kind of material to be ground, how 
 the work is applied to the wheel and whether the same is 
 edge or surface contact. In describing the class of materials 
 to be ground, it is necessary to cover the point fully, or best 
 results will not be obtained, no matter whose make of 
 wheel is used. 
 
 " It is necessary to know the type of machine on which the 
 wheels are to be used, whether the same is of the bench, 
 floor, swing frame, flexible shaft or cylindrical type. 
 
 " When possible, give the make of the machine. It is im- 
 portant to know the construction, whether light, or heavy 
 and rigid, for the following reasons: A heavy machine 
 will absorb vibration and for this reason a softer grade 
 of wheel may be used, thereby increasing production, 
 whereas a harder grade wheel would be required for the 
 same work on a light machine, due solely to the construc- 
 tion of the machine. If the machine is light and vibrates, 
 production is sacrificed on account of the necessity of fur- 
 nishing a harder grade wheel. 
 
 " Strong rigid machines, set on firm foundations, allow the 
 grade of wheel to be used that will produce the best results. 
 
 "To determine the proper grit and grade, it is necessary 
 to know the kind of material to be ground. With this in- 
 formation, the correct abrasive can be selected. If steel, is 
 it hard or soft? If malleable iron, is it hard or annealed? 
 If iron, is it cast, wrought or chilled? In the grinding opera- 
 tion, it is necessary to know whether there is line or surface 
 contact. To describe fully what we mean, the following 
 illustration will suffice: If the operation was grinding 
 balls, there would be line contact, and, in such a case, 
 it would be necessary to furnish a hard grade wheel. If 
 the operation was internal grinding, there would be a 
 large surface contact, thereby requiring a softer grade 
 wheel, and in most cases a coarser grit.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 "Whether the work is to be ground wet or dry largely 
 determines the grade of wheel to be furnished. In many 
 cases, a harder grade of wheel can be used if the grinding 
 is done wet, as this practice prevents the work from over- 
 heating. 
 
 "Wheels are, under ordinary conditions, recommended to 
 run 5,000 to 5,500 surface feet per minute, although in 
 many kinds of grinding, they should be run much slower. 
 If a wheel is too hard for the operation, good results can 
 often be obtained by reducing the speed, and if too soft, 
 this condition may be rectified by increasing the speed. 
 It is seen, therefore, that wheels at slow speeds tend to 
 act softer, whereas wheels at high speeds appear to act 
 harder. In stating the speed, the number of revolutions 
 per minute should be given. Wheels used on cylindrical 
 grinders are operated at about 5,500 peripheral feet per 
 minute, while for automatic knife grinding, they are run 
 as slow as 2,500 feet per minute surface speed. It is seen, 
 therefore, that speed plays an important part in a successful 
 grinding operation. 
 
 " If the operation for which wheels are to be ordered is 
 cylindrical grinding, the diameter of the pieces to be ground 
 should be given, also the R. P. M. of the work. This en- 
 ables the grinding-wheel manufacturer to determine the work 
 speed. It is also necessary to know the quality of finish de- 
 sired, as this is largely determined by the grit of the wheel. 
 
 "If the operation is surface grinding, the speed in linear 
 feet should be given. It is important also to know the table 
 traverse, or cross feed, which is the speed with which the 
 wheel is fed across the work. 
 
 " If the wheel is other than regular, a blue print or sketch 
 should accompany the order. Oftentimes the work to be 
 done is of a special nature, thus a sketch of the work will 
 also materially aid in the proper selection of the wheel. 
 The user who is careful to give required information is 
 generally the one who is getting the best results from his 
 grinding wheels." 
 
 144
 
 CHAPTER THIRTEEN 
 
 DESIGN OF DUST-COLLECTING SYSTEMS 
 
 (Reprinted from American Machinist.) 
 
 State law requirements Design of wheel hood General design Size of 
 exhaust pipe for different size wheels Elbows Collars Method of 
 erection Clean-out Fan Dust-collector Exhaust systems. 
 
 TN the majority of states where manufacturing is carried 
 1 on to any extent, laws have been passed compelling the 
 manufacturer to equip grinding and polishing departments 
 with a suitable system for carrying away the dust. The 
 different state laws vary greatly as to what constitutes an 
 effective dust -collecting system; some being very rigid, while 
 others are quite liberal. 
 
 This legislation is good for several reasons. In the first 
 place, it protects the workman's health. The removal of 
 dust from any manufacturing plant affords better fire pro- 
 tection. It saves quite an amount of material in cases 
 where brass, copper, nickel or other comparatively valu- 
 able metals are ground or polished. It is a fact that in 
 many cases where dust-collecting systems have been in- 
 stalled, enough metal has been saved in the course of a few 
 years to offset the cost of the installation. 
 
 The first point to consider in any dust-collecting system 
 is the design of the hood that covers the wheel. Fig. 
 38 illustrates an effective hood,, made by the B. F. 
 Sturtevant Co., Hyde Park, Mass. The lower part of 
 the hood forms a receptacle for containing the heavier 
 part of the material removed from the work, and is
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 provided with a swing clean-out gate. It is important 
 to collect as much metal and abrasive as possible in the 
 hood, as this saves wear on the piping, fan and collector. 
 By referring to Fig. 39, it is seen that the hood in ques- 
 
 Fig. 38. Wheel hood designed for catching dust. 
 
 tion is hinged on one side to facilitate the removal of 
 the wheel as occasion requires. 
 
 The size of the branch pipes connected to the hoods is 
 determined by the size of the wheels used. The following 
 table gives the general rules recommended by the Sturte- 
 vant Company. These are general and open to modification 
 in cases of special or wide-faced wheels. 
 
 146
 
 DESIGN OF DUST-COLLECTING SYSTEMS 
 
 Pipe Sizes Wheel Sizes 
 
 2 inch 4 inch. 
 
 3 inch 4 to 6 
 
 3>2 inch 8 to 10 
 
 4 inch , 1 2 to 16 
 
 4K inch 18 
 
 5 inch 20 
 
 6 inch 22 to 26 
 
 The elbcws used in connecting the branch pipes with the 
 main pipe collars are generally made in four sections for 
 45 elbows as shown in Fig. 40 A. This design allows a 
 
 Fig- 39- Wheel hood in opened position. 
 
 comparatively smooth interior, thus reducing friction to a 
 minimum. As a further means of reducing friction, the 
 radii of all elbows should at least equal the diameter of the 
 pipe, and should exceed this when it is practical to have 
 them do so. 
 
 The collars that connect the branch pipes with the main 
 U7
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 pipe should intersect at an angle of 45, or less, when 
 measured from the center line of the main pipe. A greater 
 angle than this creates unnecessary friction, which impairs 
 
 Fig. 40. Piping details for dust-collecting system: "A," elbow joint; 
 "B," cap cleanout; "C," main pipe joint; "D," main pipe cleanout. 
 
 the effectiveness of the system, and throws an unnecessary 
 load on the fan. 
 
 The main pipes should be placed on the floor or between 
 the ceiling and floor when possible. By referring to Fig. 41, 
 which is a plan and end elevation of an exhaust system in- 
 stalled in a manufacturing plant, it is seen that the area 
 of the main pipe increases for every two branch pipes 
 added. This is essential in maintaining a uniform draft. 
 
 Without doubt, the ideal main pipe would be one having a 
 constant taper from end to end. Such a pipe, however, 
 would not be practical to construct, and, furthermore, 
 would be unnecessarily expensive. The general rule, which 
 by the way, is sometimes open to change, is to have the 
 main pipe sections 25 per cent, larger than the sum of the 
 openings that lead to it. Thus, in Fig. 41, the section 
 marked A should be 25 per cent, larger than the combined 
 areas of the two. branch pipes opening into it. Section B 
 should be 25 per cent, larger than the combined areas of its 
 
 148
 
 DESIGN OF DUST-COLLECTING SYSTEMS 
 
 branch pipes, plus the area of section A, and so on. From 
 this, it is seen that there is always a 25 per cent, increase 
 to insure cutting down the air resistance to a minimum. 
 
 The joints of the main pipe should be formed as shown 
 in Fig. 40 C the straight line always being at the lowest 
 
 Fig. 41 . Plan and end elevation of a dust-collecting system. 
 
 point. This is important, as it helps to keep the pipe free 
 from obstructions. 
 
 A cleanout should be placed in every section of the 
 main pipe, also at every elbow. This should be as air-tight 
 as possible. Fig. 40 D illustrates the type of cleanout 
 used for this purpose. It consists simply of a slide conform- 
 
 149
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 ing to the curve of the pipe. The length of the slide should 
 be twice its width to avoid cramping. 
 
 A cap cleanout, as shown in Fig. 40 B should always be 
 located at the end of the main pipe. This type of cleanout 
 is sometimes seen in main pipes. This, however, is poor 
 practice as it has a tendency to interrupt the free passage 
 and force of the draft, thus forming a pocket where ob- 
 structions collect. 
 
 In exhaust systems, for removing dust from grinding and 
 polishing wheels, it is the generally accepted practice to 
 place the fan between the work and the dust collector. In 
 some cases, however, the collector is located between the 
 work and the fan. Sometimes two collectors are used, one 
 on the intake and one on the exhaust side. 
 
 Where it is practicable to do so, the fan should be placed 
 reasonably near the work, to avoid a long intake pipe. It 
 should also be near the ceiling to avoid taking up valuable 
 floor space. 
 
 The size and speed of the fan determine the velocity of 
 the draft, which should be sufficient to raise a column of 
 water i>^ to 2 inches in a U-shaped tube at the point of 
 weakest suction, which is farthest away from the fan. The 
 amount of suction stipulated in some of the recently passed 
 state laws is in excess of these figures, although the suction 
 above stated is sufficient for the exhaust system in question. 
 
 Exhaust systems, as applied to grinding and polishing 
 wheels, are designed to carry away the dust, and to deposit 
 it at a. convenient point. The collector is usually placed 
 out of doors, but it should be within a reasonable distance 
 of the fan to avoid a long exhaust pipe.
 
 CHAPTER FOURTEEN 
 
 SAFEGUARDING GRINDING WHEELS 
 
 (Reprinted from The Iron Age.) 
 
 Why wheels break Cause of accidents How wheels are packed and tested 
 before leaving factory Wheel speeds Mounting wheels properly What 
 causes wheels to burst Safety flanges Work rest Wheel guards 
 Grinding on small wheels Precautions for the workman. 
 
 WHEN we stop to consider that grinding wheels are 
 used under all sorts of conditions, both good and bad, 
 it is evident that serious accidents are bound to happen if 
 precautions for proper safeguarding are not taken. From 
 the writer's practical experience with grinding wheels, 
 covering a period of many years, and from observation of 
 the conditions under which grinding wheels are used in 
 practically every -branch of manufacturing, it is his opinion 
 that fully 95 per cent, of the accidents due to the breakage 
 of grinding wheels are wholly uncalled for and could be 
 avoided by a little precaution on the part of both employer 
 and employee. 
 
 The following is a list of the principal causes of grinding- 
 wheel failures which will be explained, each cause being 
 taken up separately for the sake of convenience. 
 Imperfect wheels. 
 Abnormal wheel speeds. 
 ' Faulty mounting of wheels. 
 Lack of attention to work rests. 
 Loose-wheel spindles. 
 
 The reliable manufacturer of grinding wheels, whose 
 products are to be found in every city and town in the 
 country, spares no expense to make sure that only perfect 
 wheels are placed on the market. This has been explained
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 under the head of grinding-wheel manufacture, and no 
 further comment is necessary. 
 
 Extreme care is also exercised in packing wheels for ship- 
 ment that accidents in transit may be avoided. The larger 
 wheels are packed in individual boxes with sawdust. The 
 smaller wheels, or rather comparatively thin wheels, receive 
 the added protection of corrugated strawboard. Before a 
 wheel is mounted for use, it should be lightly tapped with 
 a small hammer. If it emits a bell-like sound, it is safe. 
 If it gives out a dull sound, it should be condemned as un- 
 safe. Accidents through defective wheels are, happily, very 
 rare. 
 
 Reliable makers of grinding wheels always mark on the 
 tags of regular wheels the proper operating speed, and the 
 consumer, or in the case of a large concern, the millwright 
 and the mechanical engineer, should pay a little attention 
 to this important detail. The proper operating speed for 
 a common wheel in vitrified or silicate bond is 5,000 feet 
 per minute. This is a safe speed and it is productive of 
 economical results. The thin, special wheels made by the 
 vulcanite and shellac processes, can be run much faster 
 with perfect safety, owing to the strong nature of the bond. 
 As a matter of fact, a vulcanite wheel has to be run at a 
 high peripheral speed to show efficiency. 
 
 There are several reasons why grinding wheels are over- 
 speeded. Indifference on the part of the millwright who 
 installed the grinding stand is sometimes the cause. Not 
 having just the proper- sized pulley for the line shaft, he 
 is likely to substitute a different size, often larger than is 
 called for, which of course overspeeds the wheel. Many 
 grinding-wheel stands are equipped with a two- or three- 
 step cone, the object being to speed up the wheel as it 
 wears down. Neglecting to shift the belt to its lowest 
 speed after installing a new wheel, results in overspeeding. 
 While grinding-wheel stands of the above type are no doubt 
 very convenient as regards speed adjustments, they are, 
 at the same time, a source of constant danger, as an in-
 
 SAFEGUARDING GRINDING WHEELS 
 
 different or, in some cases, a green workman is liable to 
 shift the belt to suit himself, ignoring limits of safety. 
 
 A safe and, at the same time, an economical way to use 
 ordinary wheels, and one that is giving entire satisfaction 
 in some of our largest manufacturing concerns, is to always 
 buy wheels of a given size. When new, these wheels are 
 mounted on a stand, the spindle of which runs at the proper 
 speed for the diameter of the wheel. As soon as the wheels 
 are worn down, say 2 inches, they are placed on another 
 stand running at a higher speed and so on until the wheel 
 is worn down to a stub. The above, of course, applies only 
 to wheels having a constant grade from periphery to hub. 
 Wheels having an increasing grade from the outside to the 
 hole, as explained elsewhere, do not require speeding up 
 as they wear away. 
 
 In mounting a grinding wheel, the lead bushing should 
 slip readily over the spindle. If the bushing is a little small, 
 as it sometimes is, the defect can be readily remedied 
 by means of a bearing scraper or an old file. The operator 
 who neglects this simple precaution and mounts a wheel 
 by forcing it on the spindle, is taking a chance of meeting 
 with a serious accident, as tight wheel bushings are the 
 source of the majority of accidents. 
 
 The reason for this is quite apparent, as lead, the material 
 with which grinding wheels are bushed, expands readily 
 from heat. When the wheel spindle runs warm, as it in- 
 variably does after being in use a few hours, the spindle 
 expands a little from the heat. The lead bushing readily 
 absorbs a part of the heat which expands it several thou- 
 sandths of an inch, owing to the fact that lead has a high 
 co-efficient of expansion. The expansion of the lead throws 
 an undue stress on the wheel, which, added to the stress 
 to which the wheel is subjected from centrifugal force, 
 is sufficient to cause it to burst. 
 
 Wheel flanges should be at least one-third of the diameter 
 of the wheel, and should always be recessed as shown in 
 Fig. 42. Plain flanges, as shown in Fig. 43, are dangerous,
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 as they do not always grip the wheel properly, a slight 
 crowning of either wheel or flange being sufficient to cause 
 them to grip the wheel near the arbor only. Fig. 44 illus- 
 trates another source of trouble caused by wheel flanges 
 
 Fig. 42. Proper design of wheel flanges. 
 
 Fig. 43. Incorrect in design as recesses are absent. 
 
 Fig. 44. Fruitful cause of accidents two flanges of different sizes on one 
 
 wheel. 
 Figs. 45 and 46. Two types of safety flanges. 
 
 belonging to different grinding stands becoming mixed. 
 The outer flange being smaller in diameter than the inner 
 one, brings an undue side strain on the wheel. 
 
 Two types of safety flanges are shown in Figs. 45 and 46. 
 While flanges of this type will prevent a split fragment of a 
 wheel from flying, their use is not at all common. As a 
 matter of fact, the average manufacturer considers them a 
 nuisance. Generally speaking, safety flanges are not neces- 
 sary with wheels made by a reliable maker, properly mounted 
 and run at the speed recommended. 
 
 When the nature of the grinding will permit, it is a good 
 plan to use wheels without a work rest. On compara- 
 tively heavy work, however, a rest is, of course, necessary 
 as the workman has to utilize his strength in holding the 
 work to the wheel. Rests are also necessary on tool-
 
 SAFEGUARDING GRINDING WHEELS 
 
 grinding wheels, and other wheels used for general purposes. 
 It is with the last two classes of wheels that accidents occur 
 by getting the work caught between the wheel and the rest. 
 This generally results in a broken wheel and consequent 
 
 Fig. 47. Sharpening a counterbore on an unguarded wheel. 
 
 injuries to any one who happens to be in the path of the 
 flying fragments. The only way to avoid accidents is to 
 keep the wheel true and the rest adjusted closely within 
 1/32 inch of the face of the wheel. In justice to the manu- 
 facturer, it should be stated that accidents of this kind 
 are in nearly every case caused by carelessness on the part
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 of the operator. His common sense and mechanical instinct 
 should tell him that he is taking desperate chances in 
 allowing a wide gap between the wheel and the work rest. 
 
 Loose wheel spindles often cause wheels to break as they 
 allow the wheel to run out of balance and also make it 
 
 Fig. 48. Sharpening the peripheral teeth of a milling cutter on an 
 unguarded wheel. 
 
 impossible to keep the rest adjusted close to the wheel. 
 Babbitt metal, even of the highest quality, is cheap as com- 
 pared to the consequences of injuries, and this is one reason 
 why the spindles of grinding-wheel stands should be re- 
 babbitted as soon as they show noticeable signs of wear. 
 
 Many states have passed laws requiring manufacturers 
 to equip the grinding wheels used in their plants with guards, 
 the object being to keep the pieces of the wheel from flying 
 
 156
 
 SAFEGUARDING GRINDING WHEELS 
 
 in case of accident ; not to keep sparks out of the operator's 
 eyes as one might judge from the flimsy guards sometimes 
 seen over grinding wheels! While wheel guards are not 
 necessary where reliable wheels, properly mounted, are in 
 
 Fig. 49. Sharpening the side teeth of a milling cutter on an unguarded 
 wheel. 
 
 operation, their use is to be strongly recommended as they 
 are the direct cause of preventing many fatalities from ac- 
 cidents caused by carelessness on the part of the operator. 
 It is, however, not practicable to use guards over the 
 smaller wheels used for cutter sharpening, and other work of 
 like nature. Figs. 47, 48 and 49 illustrate cutter-sharpening
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 operations, and to place guards over these wheels would 
 be an impossibility, as the size of the wheels and their rela- 
 tive position to the work are different with every operation. 
 Accidents with wheels of this kind are so rare as to cause 
 no comment. There are two reasons for this: First these 
 
 Fig. 50. Correctly guarded surface grinding wheel. 
 
 small wheels are comparatively strong for their size, seldom 
 breaking unless injured by being dropped; and again there 
 is no reason for standing directly in their path. 
 
 The photographs referred to were taken by the writer 
 for advertising purposes. In each case the operator was 
 
 158
 
 SAFEGUARDING GRINDING WHEELS 
 
 asked to assume a working position, nothing being said 
 about standing out of the path of the wheel. However, the 
 operator is out of the path of the wheel in each case, and 
 as he assumed this position naturally, one would infer that 
 a skilled mechanic prefers to keep out of the path of cutter 
 grinding wheels. As a matter of fact he does not because 
 
 Fig. 51. Guarded wheel on a Brown & Sharpe surface grinder. 
 
 he is afraid of the wheel breaking but because he has learned 
 from experience that to stand directly in the path of an 
 unguarded wheel nearly always results in particles of the 
 abrasive getting in the eyes; which in some cases requires 
 the services of a skilled surgeon to remove. 
 
 Figs. 50 and 51 illustrate two types of surface grinding 
 wheels, each of which is protected by a suitable guard. 
 Guards over wheels used for surface grinding' are generally 
 considered necessary, the reason for this being that surface 
 grinding wheels frequently break as they are of a soft, open 
 bond. With guards of the types shown in the illustrations,
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Fig. 52. Sheet-metal wheel and spindle guard. 
 
 Fig. 53. Wheel and belt both guarded. 
 .160
 
 SAFEGUARDING GRINDING WHEELS 
 
 serious accidents are an impossibility. With the modern 
 cylindrical grinding machine, accidents from wheel breakage 
 are almost impossible as the wheel is always protected by 
 a heavy guard. While the operator generally stands di- 
 rectly in front of the wheel he runs no chance of being in- 
 
 Fig. 54. Sheet-metal wheel guard arranged for adjustment. 
 
 jured, as it would be practically impossible for a piece of the 
 wheel to strike him. Machines of this kind are never 
 used without wheel guards. In fact, a guard on a cylin- 
 drical grinding machine is a necessity in keeping water from 
 flying all over the shop, as this class of grinding is invariably 
 done wet. 
 
 Figs. 52 and 53 are from photographs taken in the shops 
 of two well-known railroad companies. By referring to 
 Fig. 52, it is seen that the guard, which is made of sheet metal 
 of sufficient thickness to withstand the shock of the wheel 
 fragments in case of accident, is also provided with a hood 
 to cover the projecting threaded end of the spindle. The 
 object of this hood is to prevent the workman's clothing 
 
 161
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 from being caught. While the workman in this illustration 
 is grinding a comparatively small piece of work, he is taking 
 no chances as the work rest is placed close to the wheel. 
 
 The tool grinder shown in Fig. 53 is of a type often seen 
 in railroad shops. It is provided with a heavy hood; the 
 work rest is properly adjusted, and a guard is provided to 
 prevent the workman's clothing from being caught in the 
 
 Fig- 55- Novel form of sheet-metal wheel guard. 
 
 driving pulley. The reason that railroad-shop employees 
 are so adequately guarded against accidents lies in the fact 
 that the shop foreman and master mechanics in charge 
 are fair-minded, conscientious men who have gradually 
 worked up from unimportant positions to positions of trust 
 and who, therefore, consider the workman's welfare from 
 their own actual shop experience. 
 
 Fig. 54 illustrates another tool-grinding wheel that is 
 properly guarded. The hood, which is made of i /4-inch 
 sheet metal, is. securely bolted to the frame of the machine 
 and is provided with an adjustment which allows it to be 
 moved towards the wheel as the wheel is reduced in diam- 
 eter. This is of importance as a guard should be placed 
 
 162
 
 SAFEGUARDING GRINDING WHEELS 
 
 reasonably close to prevent the wheel fragments from fly- 
 ing in case of breakage. The work rest in this instance is 
 placed close to the wheel. Although the machinist in this 
 illustration is standing in front of the wheel, he is taking 
 
 Fig. 56. These guards are inadequate and invite" disaster. 
 
 no chance as it would be impossible for a section of a wheel 
 guarded in this manner to get away from the hood. The 
 guard over the driving pulley deserves mention. It is 
 made of i-i /2-inch iron pipe and covered with heavy wire 
 netting. 
 
 Two sheet-metal guards are shown in Fig. 55. They are 
 easily removed when it is necessary to change wheels, as 
 
 163
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 the guard in the foreground shows. The working position 
 of the guards is shown by the guard in the background. 
 These guards are adjustable and can be moved toward the 
 face of the wheels. They are novel in construction, the 
 body being cut from one piece of heavy sheet metal. 
 
 Figs. 56 and 57 illustrate a wholly inadequate type of 
 grinding- wheel guards that are, unfortunately, in common 
 
 - 57- This guard is too flimsy to stop flying- wheel fragments in case of 
 an accident. 
 
 use. While guards of this kind are often passed by factory 
 inspectors who are lacking in practical knowledge, they are 
 worse than no guards at all, as a section of a burst wheel 
 would crumple them up like so much cardboard. 
 
 In cases where grinding wheels burst, resulting in fatali- 
 ties, it is sometimes a difficult matter to determine who is 
 at fault, the employer or the employee. Is it justice to 
 
 164
 
 SAFEGUARDING GRINDING WHEELS 
 
 compel a manufacturer to pay heavy damages for fatalities 
 brought about (as they often are) by wanton carelessness 
 on the part of the operator? If the employer neglects to 
 have adequate guards placed over grinding wheels, where 
 there is a law requiring him to do so, it would seem that he 
 was criminally negligent in cases where fatalities result 
 from the bursting of grinding wheels. However, let it be 
 assumed that the wheel is properly guarded and that the 
 operator himself removes the guard for some reason and 
 by so doing is injured. Should the employer be compelled 
 to pay damages in this case? Assuming that one operator 
 removes a wheel guard and neglects to replace it, another 
 operator being injured on the same wheel a short time after- 
 ward, who is to blame in this case, the operator who re- 
 moved the guard, the operator who afterward used the 
 wheel without the guard or the employer who was ignorant 
 of the whole proceeding? These are, of course, questions 
 for the courts to decide, and decisions in cases of this kind 
 are not easily reached by any means. 
 
 In questions where the safety of employees is concerned, 
 labor and capital should co-operate. The working-man 
 should bear in mind the fact that it is an impossibility for 
 him to earn a living without assuming some risk, and where 
 the employer provides all possible safeguards against acci- 
 dents, the employee should see to it that these safeguards 
 are not removed or destroyed.
 
 CHAPTER FIFTEEN 
 
 ABRASIVE PAPERS AND CLOTHS* 
 
 Abrasive substances used in making abrasive paper History of abrasive paper 
 How abrasive paper and cloth is manufactured Grades of abrasive 
 paper and cloth Finding percentage of iron in garnet Testing garnet 
 paper Paper and cloth abrasive discs Testing discs for efficiency. 
 
 ABRASIVE papers and cloths, the abrasive coating of 
 ** which is emery, Carborundum, garnet, flint, Aloxite, 
 etc., are to be found in practically every branch of manu- 
 facturing from the small country planing mill or machine 
 shop to the immense furniture factory or automobile plant. 
 Large quantities are also consumed by tanneries and other 
 leather workers. Comparatively little seems to be known 
 concerning the manufacture of these staple articles, save 
 from the meager accounts given now and then by salesmen. 
 
 All abrasive papers and cloths are made in the same man- 
 ner, with the exception of abrasive discs, which will be 
 considered later. We can explain the process followed by 
 taking up the subject of garnet paper. 
 
 While the use of abrasive materials dates from remote 
 times, the use of coated paper and cloth is a comparatively 
 modern innovation. Some two hundred years ago it was 
 common practice for New England cabinet makers who 
 lived near the seacoast to use the dried skins of dogfish 
 and sharks for smoothing wood. Any one who has had 
 occasion to deal with the above-named fish in the live state 
 will admit that their skins are excellent abrasives in a literal 
 
 * The above chapter is a consolidation of two articles: "Abrasive Paper 
 and Cloth," originally published in The Iron Tradesman, and "The Selection 
 of Garnet Paper," which first appeared in The Wood Worker, to which the 
 writer has added some further material concerning the testing of abrasive 
 discs. 
 
 166
 
 ABRASIVE PAPERS AND CLOTHS 
 
 sense, as a single indiscreet rubbing contact, on the naked 
 arm, for instance, invariably draws blood in a dozen places. 
 However, as our forefathers could not always take the time 
 to go shark fishing when the stock of this "natural abrasive" 
 ran low, necessity prompted them to invent a substitute 
 which resulted in the abrasive paper and cloth of the present 
 day. 
 
 As near as we can ascertain, emery cloth and sand-paper 
 were invented about two hundred and fifty years ago, the 
 process of manufacture being very primitive, consisting of 
 coating the backing with glue,, liberally covering it with the 
 desired abrasive, shaking off the superfluous material and 
 hanging the sheets up to dry. 
 
 Wonderful improvements have been made in the manu- 
 facture of abrasive papers and cloths, the slow hand methods 
 of a few generations ago being superseded by the modern 
 coating machine, which turns out material by the mile. The 
 process is practically the same for both paper and cloth 
 backing and can be described as follows : The web of paper, 
 traveling at high speed, passes under a printing attachment 
 which imprints the brand, number, etc., at regular intervals. 
 Next it passes through a series of rollers wherein the top 
 side is given a coat of glue, which is distributed in much the 
 same manner that ink is applied to the type in a large print- 
 ing press. The glue-coated paper now passes under a 
 large hopper from an opening in the base of which the grain 
 flows in a steady stream, just a little wider than the width 
 of the paper being run. The amount of running grain is 
 regulated to allow slightly more to flow than will stick to 
 the paper, the superfluous material being carried away by 
 mechanical means, the exact nature of which most manu- 
 facturers wish to keep to themselves. By means of two 
 endless chain belts, carrying cross sticks at regular intervals, 
 the paper is caught up in long loops and carried to another 
 coating machine where the sizing, or upper coating of glue, 
 is applied. This covers the upper surface of the grain, and 
 as it unites with the lower coat to a certain extent each 
 
 167
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 grain is firmly embedded in a matrix. The paper is now- 
 caught up on more sticks, where it travels up and down the 
 long drying room, the process of drying being hastened by 
 carefully regulated blasts of warm air. The paper finally 
 reaches the winding machine, where it is wound in rolls of 
 about four feet in diameter. From there, it goes to the 
 storage room, where it is thoroughly aged before being sent 
 to the cutting room. It is of the utmost importance to 
 age the paper before putting it on the market, as green 
 paper, as it is termed by the manufacturer, is very short 
 lived, owing to the fact that the glue is not set sufficiently 
 to hold the grain firmly in place. 
 
 From the store room, the rolls go to the cutting room, 
 where they are prepared in marketable sizes, consisting of 
 9x11 sheets, in quires and reams, and 5o-yard rolls of 
 various widths. Emery cloth is sold in 9x11 sheets and in 
 rolls 9, 1 8 and 27 inches wide. The grits run from crocus 
 to 3-1/2. Emery paper is sometimes sold in rolls, but 
 there is more demand for this material in sheet form. 
 Carborundum paper can be bought in both rolls and reams 
 in all grits from 20 to F F. As this material is used ex- 
 tensively in the boot and shoe industry for heel scouring, 
 heel breasting and fore-part buffing, it is also cut in odd sizes 
 and shapes to fit various machines used for the above pur- 
 poses. Carborundum cloth can be had in all grits from 
 4-1/2 to F F in 9, 18 and 24 inch rolls or 9x11 sheets. 
 
 There are four kinds of garnet paper, known to the trade 
 as follows: Finishing paper, used for rubbing varnish, 
 which is made in all grits from i to 6/0; double-faced 
 finishing paper, in the same grits, which is coated on both 
 sides and stripped apart as needed, the grits being the same 
 as for ordinary finishing paper; cabinet paper (ordinary 
 sheet garnet paper) in numbers from 3-1/2 to 6/0, and roll 
 paper in numbers 3-1/2 to 4/0. Roll paper is furnished in 
 standard widths of 18, 24, 30, 36, 40, 42 and 48 inches. 
 Garnet cloth is always run in rolls of 28 inches wide, but 
 can be had in any desired width. The bulk of garnet paper 
 
 1 68
 
 ABRASIVE PAPERS AND CLOTHS 
 
 is used in the wood-working industries, but it also furnishes 
 an excellent material for finishing comparatively soft 
 metals such as aluminum, copper, very soft brass, etc. 
 Ordinary sand-paper is made in the same sizes and numbers 
 as garnet paper and is used principally for smoothing com- 
 paratively soft woods. In ream form, it is sold in every 
 hardware and general store throughout the civilized world 
 to customers who desire a few sheets at a time. 
 
 Abrasive paper and cloth are also made in disc form for 
 finishing metals on the disc type of grinder. As the back- 
 ing of this material is very heavy, and the coating extra 
 thick, it is not practicable to run it off in mile lengths, thus 
 it is coated in long strips of approximately 200 feet. After 
 drying, the discs are cut from the strips by means of heavy 
 dies in a hydraulic press. Some makers have processes for 
 coating discs after they are cut to shape, the Besley discs 
 with the spiral groove being a good example of this practice. 
 The majority of these special methods are covered by patent. 
 
 Contrary to the general impression, there is very little 
 profit in the manufacture of abrasive paper and cloth. This 
 statement is not made at random, simply for the sake of 
 filling up space, but from actual observation of the manu- 
 facture of the products in question. Therefore the writer's 
 advice to the consumer who aims to use efficient material is 
 to purchase standard priced goods. Owing to the fact that the 
 margin of profit is small, the maker cannot cut prices to any 
 extent and supply high-quality material at the same time. 
 
 The superintendent and the purchasing agent of any 
 concern where garnet paper is used to any extent, are fre- 
 quently interviewed by garnet-paper salesmen. As the 
 salesman's duty is to sell goods, each and every one, of 
 course, has just the material that will surely reduce produc- 
 tion costs. Thus the question arises: "Whose paper is the 
 most efficient ?" It is impossible to answer this question off- 
 hand, but there are a few simple tests that any manufacturer 
 can make in his spare time, and the data thus obtained is 
 reliable. 
 
 169
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Any one who is conversant with the working of a three- 
 drum sander realizes that a machine of this type calls for a 
 paper with a very strong backing; otherwise the paper is 
 liable to tear before the grain is worn to a point of useless- 
 
 Fig. 58. Simple device for testing the strength of abrasive papers. 
 
 ness. To test the strength of the backing we can proceed 
 as follows: First a frame as shown at (A) Fig. 58 is sus- 
 pended from a convenient overhead timber. The cross 
 
 170
 
 ABRASIVE PAPERS AND CLOTHS 
 
 piece should be about five feet from the floor. A common 
 wood clamp (B) is fastened to the cross piece by means 
 of another clamp (C). The tray (D) is suspended from the 
 clamp (E) by means of short ropes (G) and two wire hooks (F) . 
 (H) is the sample of paper to be tested. This is cut length- 
 wise from a roll of paper and should be about 9 inches long 
 and exactly i inch wide. The ends of the paper should 
 extend about 2 inches in the jaws of the clamps, which must 
 be fastened securely. 
 
 The next step is to place weights, one at a time, on the 
 tray until the paper breaks; pieces of babbitt metal are 
 excellent for this purpose. By weighing the amount of 
 metal necessary to break the paper, we readily ascertain the 
 breaking strain per linear inch. It is evident that the 
 paper which supports the greater weight is the strongest. 
 The results of these tests should be entered in a note-book, 
 giving the make of paper, mn number, grit number, and 
 date of the test. It is a well-known fact that all garnet- 
 paper salesmen lay great stress on the strength of their 
 papers, but the practical man who takes the time to make 
 the simple test here described, between several makes of 
 papers, can readily determine for a certainty which is the 
 strongest. Furthermore, the simple appliance used (which 
 costs practically nothing) is as efficient for all practical 
 purposes as the expensive paper-testing machines used by 
 the paper manufacturers. 
 
 Oxide of iron, an impurity which is often present in garnet v 
 is a detriment to fast cutting, and it generally indicates that 
 the grain was not properly cleaned. To determine the 
 amount of this impurity, a square foot of unused paper should 
 be boiled for an hour or so in a clean receptacle; this will 
 detach the grain from the backing. The grain thus ob- 
 tained is carefully washed and dried, then spread out on a. 
 piece of paper and carefully gone over with an ordinary 
 horseshoe magnet, which readily attracts the grains contain- 
 ing any amount of oxide of iron. These are placed in a little 
 pile, and when the operation is complete, we have two.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 samples of grain one containing iron and another free from 
 this impurity. 
 
 To obtain the percentage of iron, we must measure each 
 pile by volume. This can be done with any small re- 
 ceptacle; an empty 38-caliber cartridge shell will answer 
 the purpose very well. Suppose we find ninety shellfuls 
 of grain that was unattracted by the magnet and ten that the 
 magnet picked up. In this case, it is evident that the grain 
 contains 10 per cent, of iron. If subsequent tests of grain 
 taken from another make of paper yield 15 per cent, of iron, 
 it is apparent that the first sample was of better quality. 
 The results of these tests should also be entered in the note- 
 book for future reference. 
 
 To test the working efficiency of any make of paper is also 
 a comparatively simple operation. Here we can use what 
 the salesman terms a "fifty fifty" test. Let it be assumed 
 that we are using belts 18 feet long. We can make up a 
 belt composed of 9 feet of one make of paper and 9 feet 
 of another make. It is obvious that the paper that gives 
 out first is of the poorer quality. A test of this kind causes 
 the salesman who supplied the paper of poorer quality to 
 scratch his head in perplexity. On these occasions it is 
 up to the salesman to frame a good excuse or retire from the 
 field as gracefully as possible. We can use the same kind 
 of a test on the drum sander, provided it is of the type that 
 takes straight paper that is, not wound on the drums 
 spirally. By covering half of each drum with one make of 
 paper and the other half with another make, we can soon 
 arrive at a definite conclusion. 
 
 The tests here described, which are not known to every 
 user of garnet paper, were brought to the writer's notice 
 while traveling as a salesman for one of the leading garnet- 
 paper manufacturers and the data obtained from them 
 can be relied upon. Any garnet-paper salesman can cite 
 numerous instances where his goods have won out over 
 those of his competitors, but he always keeps quiet con- 
 cerning the instances wherein he has failed. This is one 
 
 172
 
 ABRASIVE PAPERS AND CLOTHS 
 
 reason why it is a good plan for the consumer to work out 
 his own tests in his own plant, ever bearing in mind the 
 fact that crucial tests should result in cold, hard figures 
 that have been obtained through actual common-sense tests. 
 
 The practice of disc grinding has become quite common 
 during the last fifteen years and has led disc manufacturers 
 to supply their products in many different abrasives and 
 combinations of abrasives for various purposes. Flint, 
 quartz, garnet, emery, corundum, Carborundum, Crystolon, 
 Aloxite, Alundum and Adamite are the principal abrasives 
 employed for disc grinding. 
 
 Notwithstanding this formidable array, the selection of 
 suitable discs is a simple operation compared with the selec- 
 
 Fig. 59. Gas-burner parts finished by disc grinding. 
 
 tion of grinding wheels. Grinding wheels are made in many 
 different degrees of hardness to suit various classes of work. 
 With grinding discs, however, the factor of grade as applied 
 to grinding wheels is wholly eliminated. All that is neces- 
 sary, is to select an abrasive that proves satisfactory, the 
 character of the finish desired determining the grain of the 
 disc.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 To illustrate the principle used in testing discs for ef- 
 ficiency, we can consider the pieces shown in Fig. 59, which 
 are gas-burner parts, made of cast iron, measuring 5 inches 
 in diameter. The finished surfaces measure 3/8 inch across 
 and the grinding is done from the rough, the object being 
 to make a good joint in the shortest possible time. The 
 grinding operation is shown in Fig. 60. 
 
 Here it is seen that the pieces to be ground are held by a 
 retaining ' device and also that they are weighted. The 
 
 Fig. 60. Grinding gas-burner parts on a horizontal disc-grinder. 
 
 object of the weights is to insure a good contact. The 
 final finishing is sometimes done by hand as shown. 
 
 To determine the grinding cost with a given make of disc, 
 it is only necessary to note the cost of the disc, its life and 
 the number of pieces ground. From this data the grinding 
 cost per hundred pieces is easily computed. 
 
 To obtain the best results, the abrasive must, of course, 
 be suited to the work, and while it is a well-known fact that 
 flint and quartz are suitable for soft wood, garnet for hard 
 wood, emery for rough-steel grinding where a durable disc 
 is required, corundum, Aloxite and Alundum for steel, and 
 
 i74
 
 ABRASIVE PAPERS AND CLOTHS 
 
 Carborundum and Crystolon for cast iron, the actual selec- 
 tion is often controlled by the makers as the majority of 
 them designate their discs by numbers, preferring to keep 
 the actual character of the abrasives to themselves. The 
 object of this practice is to enable the disc manufacturer 
 to be reasonably sure of securing repeat orders, relying on 
 the consuming trade to order by number. This method is 
 not without advantage to the consumer, as it enables him 
 to order the material desired without having to resort to a 
 list of abrasives, which, at best, are confusing to those not 
 engaged directly in the abrasive lines. 
 
 Modern disc grinding is a comparatively new branch of 
 engineering practice, and when we stop to consider that it 
 originated from a sheet of sand-paper glued to a wooden 
 disc for the convenience of the wood-worker, the present- 
 day possibilities of this class of grinding reflect no small 
 degree of credit on the experimenters who made this practice 
 a commercial possibility.
 
 CHAPTER SIXTEEN 
 
 SURFACE GRINDING 
 
 Finishing work by surface grinding Development of the surface grinding 
 machine Finishing locomotive guide bars Rotary grinding fixture 
 Wheel speeds Cuts Die grinding How dies are held Grinding 
 punches Care of wheels Magnetic chucks Demagnetizes Proper 
 wheel selection for surface grinding Types of surface-grinding machines 
 Standard wheel list. 
 
 MANY years ago, after the grinding wheel became a 
 commercial possibility, one of the first uses to which 
 it was put, aside from tool grinding, was a simple kind of 
 surface grinding called in shop language "spot grinding." 
 
 This operation, while comparatively simple, is productive 
 of accurate results and is used at the present time in finishing 
 certain kinds of gauges and other work where extreme 
 accuracy as regards parallelism is desired. The operation 
 is illustrated in Fig. 61. The operator is grinding a die by 
 passing the work back and forth under the wheel. If the 
 plane upon which the work slides is a flat surface, it follows, 
 that true planes will be ground on the work. 
 
 Fig. 62 illustrates a set of accurate size blocks as used by 
 tool-makers and machinists who work to close limits. After 
 hardening, gauges of this kind are often finished parallel 
 by spot grinding, leaving a very small amount for final 
 lapping on each surface. The amount left for the final 
 finishing is generally 0.0002 inch on each surface. 
 
 At the top of the illustration is shown the fixture used for 
 holding the blocks while grinding. This consists of a flat 
 base equipped with two pinch clamps for firmly holding the 
 work and forcing it downward at the same time. The slat 
 
 176
 
 SURFACE GRINDING 
 
 Fig. 61. Spot-grinding a blanking die. 
 
 A0BML 
 
 :#. t *^| 
 
 Fig. 62. Accurate size blocks finished by spot grinding and fixture for 
 holding them in the grinding operation.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 seen at the front is for the accommodation of the micrometer 
 so that the operator can measure the work without taking 
 it out of the fixture. 
 
 Fig. 63 illustrates a tool-maker's square, the base of which 
 was finished by spot grinding. The wheel marks are plainly 
 seen on the work. The wheel marks left by this process 
 are very slight and a true surface is assured if the operator 
 takes time enough to pass all parts of the surface under the 
 
 Fig. 63. Spot-ground tool-maker's square. 
 
 wheel several times, in fact until the wheel sparks but 
 faintly. In Fig. 64 is shown a cylinder and steam chest for a 
 model marine engine. The top of the cylinder, the top and 
 bottom surfaces of the steam chest and the under surface of 
 the steam chest cover were finished by spot grinding with 
 the object of making a steam-tight joint without using 
 packing. 
 
 The few illustrations shown will bring to the mind of 
 the practical mechanic numerous instances where spot 
 grinding can be used on work where accurate surfaces are 
 necessary. The process is simple and can be carried out on 
 any machine equipped with a grinding wheel and a table. 
 The wheels used for this operation should be medium soft 
 in grade. The grit used depends on the finish desired. 
 For die grinding, as shown in Fig. 61, a grit as coarse as 36 
 
 178
 
 SURFACE GRINDING 
 
 can be used, while for size-block grinding, wheels as fine 
 as 80 grit give good results. 
 
 Another early adaptation of surface grinding consisted of 
 finishing locomotive guide bars after they were hardened. 
 Formerly, guide bars were invariably made of wrought iron 
 and case hardened to insure them against wear. As may 
 
 Fig. 64. Cylinder and steam chest for model engine on which the flat sur- 
 faces were finished by spot grinding. 
 
 be imagined, these pieces were often sprung in hardening, 
 thus means were sought for correcting this error. 
 
 An early-developed machine for guide-bar finishing is 
 shown in Fig. 65. This is not a grinding machine in the 
 strictest sense of the word because it carries a circular lead 
 lap instead of a grinding wheel. The work is securely 
 held by the clamps shown on the platen and automatically 
 fed back and forth past the circular lap which is charged 
 with emery or other abrasive material. The roll seen at the 
 extreme right of the platen is for the purpose of charging 
 the lap. 
 
 The slide that carries the lap spindle is actuated by 
 means of the handwheel which is plainly shown, while the 
 wedge seen under the lap-slide ways is for the purpose of 
 setting the lap square with the work. Lapping guide bars 
 is a slow operation at best, but it is productive of excellent 
 results. 
 
 Of late years, machines of this type have been equipped 
 with grinding wheels in place of the lead lap. The writer 
 
 179
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 observed such a machine modified in this manner at the 
 Baldwin Locomotive Works, Philadelphia. The wheels used 
 were Aloxite in shellac bond. 
 
 The machine just described is the forerunner of the pres- 
 ent-day face-grinding machine, or side surf acer as it is often 
 called. The side surfacer was first extensively used for 
 grinding locomotive guide bars, but of late years it has been 
 
 Fig. 65. Locomotive guide-bar lapping machine. 
 
 adapted to a large variety of surface-grinding operations. 
 A modern face-grinding machine is illustrated in Fig. 66. 
 This machine is a product of the Diamond Machine Co., 
 Providence, R. I. It carries a ring wheel 30 inches in 
 diameter, 6 inches wide with a 26-inch hole. This gives a 
 working surface of 2 inches. The wheel is mounted in a 
 substantial chuck, the body of which is cast iron; turned 
 all over to insure a perfect running balance. The body 
 of the chuck is tapered on the outside and is slotted so that 
 it may be readily compressed by means of a steel ring 
 which is drawn up on the. taper by means of bolts. The 
 chuck is equipped with a backing plate, back of the wheel. 
 The object of the backing plate is to bring the wheel face 
 forward as it wears away. By this arrangement, the wheel 
 can be used down to a thickness of 1-1/4 inches with perfect 
 safety. Chucks of this kind also insure the wheel against 
 flying in case it is accidentally fractured. The machine is 
 equipped with a circulating pump which floods the work 
 
 180
 
 SURFACE GRINDING 
 
 with water, the object being to carry away dust and to 
 keep down frictional heat. 
 
 The operation of grinding guide bars is comparatively 
 simple. The work is strapped to the platen of the machine 
 
 Fig. 66. Modern face grinding machine or side surfacer. 
 
 as shown in Fig. 67 and automatically fed back and forth 
 under the wheel until the desired finish is acquired. 
 
 New guide bars, as they come from the planer, are 
 generally finished by grinding as the grinding wheel imparts 
 a smooth surface for the cross-head gibs to slide upon. If 
 the work is planed with a coarse feed, which leaves deep 
 tool marks, so- much the better, because this condition helps 
 to keep the wheel true and free cutting. 
 
 By the time a locomotive comes to the shop for a general 
 overhauling, the guide bars often require refinishing, owing 
 to the fact that the pressure brought to bear on them through 
 the cross heads, by the action of the main rods, wears them 
 out of a true plane. This wear, in some cases, is as great as 
 
 181
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 1/32 inch. They are carefully lined up on the platen of 
 the guide-bar grinder and ground until the wearing surface 
 presents a true plane. Guide-bar grinding is one of the 
 first instances where the grinding wheel showed a distinct 
 saving over other methods in the railroad shop. 
 
 In considering side surfacing in general, it should be 
 borne in mind that machines of this type cannot "hog of!" 
 stock as rapidly as can a planer or miller. On certain oper- 
 
 Fig. 67. Locomotive guide bar in position for grinding. 
 
 ations, however, the side surfacer shows high efficiency 
 over machines equipped with cutting tools. 
 
 In Fig. 68 is shown a variety of work that is admirably 
 adapted for finishing on the side surfacer. The pieces shown 
 are flasks, flask sides, heads, cases, covers, hoods, lathe 
 legs, columns, guards, etc. From the design of these pieces, 
 it is readily seen that they do not lend themselves readily 
 to milling or planing operations. It is on work of this kind 
 that the side surfacer shows efficiency. In finishing work 
 of this kind on the miller or planer, it is necessary to strap 
 the pieces securely in place. Pieces of comparatively thin 
 section are often sprung out of shape by this procedure, 
 caused by the strains, set up in clamping, adjusting them- 
 selves after the clamps are released. 
 
 On the side surfacer, conditions are more favorable be- 
 cause work does not have to be held as securely for grind- 
 ing operations as it does when it is to be finished with 
 
 182
 
 SURFACE GRINDING 
 
 cutting tools. Where work is to be finished regularly on 
 the side surfacer, a smaller allowance for finishing is recom- 
 mended which causes quite an annual saving in metal at 
 the foundry. 
 
 A rotary grinding fixture designed for use on a side 
 surfacer is illustrated in Fig. 69. This is a self-contained 
 unit driven by a 3/4-horsepower motor running at a speed 
 of i, 800 revolutions a minute. Power is transmitted to 
 
 Fig. 68. Type of pieces readily ground on the side surfacer. 
 
 the chuck spindle through a chain drive and a worm and 
 worm wheel. A clutch is provided to throw the power in 
 or out and a crank in the foreground is for rotating the 
 spindle by hand, as occasion requires. 
 
 This fixture was designed for finishing work that here- 
 tofore was done in the lathe and it is readily seen that if 
 the fixture is properly aligned on the platen of the machine, 
 surfaces that are square with the spindle of the attachment 
 will result. Finishing the faces of round work by this 
 method offers the advantage of combining the roughing 
 
 183
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 and finishing operations, to say nothing of imparting an 
 excellent finish. 
 
 Side surfacers are now used by many of the leading 
 automobile manufacturing concerns for finishing a diversity 
 
 Fig. 69. Rotary grinding fixture for use on the side surfacer. 
 
 of pieces. In Fig. 70 is shown the operation of facing 
 gear-case covers. These are made of aluminum and 3/32 
 inch is allowed for finishing. As the illustration shows, 
 four covers are set on the machine at one setting, being 
 held in special fixtures. 
 
 184
 
 SURFACE GRINDING 
 
 An interesting grinding operation is illustrated in Fig. 71. 
 This work consists of finishing aluminum crank cases for 
 airplane engines. The work is clamped in special fixtures 
 and 1/8 inch is allowed for finishing. The surfaces thus 
 
 Fig. 70. Finishing gear-case covers on the side surfacer. 
 
 finished require no scraping and in assembling they are 
 put together with a thin paper gasket and shellac. 
 
 A piece difficult to machine by ordinary methods is 
 illustrated in Fig. 72. This is a gear-case cover used on 
 tractors. It is held in the fixture shown and rapidly finished 
 in a satisfactory manner. 
 
 To successfully finish work on the side surfacer is not a 
 difficult operation if the operator pays due attention to a 
 few simple factors. The wheel should be run at the speed 
 recommended by the grinding-machine manufacturer. In 
 the case of the 3o-inch wheel on the machine shown in 
 Fig. 66, the correct speed is 500 revolutions per minute. 
 Plenty of water should be used as this keeps down the 
 frictional heat and aids materially in imparting a good 
 finish. Also, the wheel should be kept "sharp" by frequent 
 
 185
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Fig. 71. Surfacing airplane engine-crank cases on the side surfacer. 
 
 Fig. 72. Grinding a gear-case cover on the side surfacer. 
 186
 
 SURFACE GRINDING 
 
 dressing, preferably with an ordinary wheel dresser of the 
 star- wheel variety. The correct table speed for side sur- 
 facing depends on the amount of material to be removed. 
 The machine illustrated in Fig. 66 is equipped with three 
 table speeds of 10, 17 and 22 feet per minute respectively. 
 A slow speed should be used when taking heavy cuts, other- 
 wise the wheel is not given a chance to cut properly. In 
 taking light finishing cuts, a fast table speed can be used to 
 advantage. After the wheel has ceased to spark heavily, 
 it is a good plan to let the work feed past the wheel several 
 times without further cross feeding, especially with work 
 of comparatively thin section. This practice produces 
 accurate results as any undue pressure caused by the 
 grinding-wheel which might spring the work is automatically 
 avoided. 
 
 In selecting wheels for the side surfacer, it should be 
 borne in mind that no one wheel can be depended upon to 
 produce efficient results on all classes of work. Wheels 
 made of carbide of silicon abrasives give excellent results 
 for the surface grinding on cast iron, but they cut slowly 
 and cause undue heating when used on steel. For malleable 
 iron, steel castings or pieces made of machine steel, alumina 
 abrasives should be selected. All grinding-wheel manufac- 
 turers carry wheels in stock for the grinding machines in 
 question, but in ordering wheels, the manufacturer should 
 state clearly for what purpose and under what conditions 
 the wheels are to be used. This information enables the 
 grinding-wheel manufacturer to make the proper selection. 
 
 DIE GRINDING 
 
 Die grinding is one of the earliest and, at the present day, 
 one of the most common practices. When we stop to con- 
 sider the numberless articles seen in the home, office, and 
 factory that are the products of punches and dies, it is 
 readily seen that die grinding is a very important branch 
 of present-day machine-shop practice. 
 
 187
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 As previously stated, dies are often ground by spot 
 grinding as shown in Fig. 61 and this practice produces 
 good results where the die grinding is of an intermittent 
 nature. The wheel used for this work, assuming that the 
 die is made of hardened steel, should be made of an alumina 
 abrasive, and should be run at a surface speed of approxi- 
 mately 5,000 feet per minute. The grade should be medium 
 soft and, for ordinary purposes, 36 grit gives good results. 
 Where an extra-nice finish is desired, on small dies for 
 example, a wheel in finer grit can be used to advantage. 
 
 As Fig. 6 1 shows, the work is ground dry. For this 
 reason, the cut taken is generally comparatively light, 
 about o.ooi inch. The work seldom becomes unduly heated 
 owing to the fact that the platen of the machine absorbs 
 the heat from the die nearly as fast as it is generated. 
 Punches are ground in the same manner as dies with the 
 exception that they must be held in a special holder in 
 cases where their shanks are made integral. 
 
 The use of the machine jusc considered is somewhat 
 limited, as it produces flat planes only, whereas many kinds 
 of dies, especially those used for punching comparatively 
 thick metal, should be ground to give a shearing cut. To 
 accomplish this it is necessary, from a practical point of 
 view, to utilize a machine on which the work can be firmly 
 fastened and fed back and forth under the wheel. 
 
 The machine illustrated in Fig. 73 is a Brown & Sharpe 
 number 2 surface grinder a machine that is widely used for 
 sharpening dies and for the general run of surface-grinding 
 work. It will accommodate work 18 inches long, 6 inches 
 wide and 9-1/2 inches high when using a wheel 7 inches in 
 diameter. The longitudinal travel of the platen is controlled 
 by dogs that actuate the reversing lever and the platen 
 saddle can be fed in from o.ooi to 0.009 inch at each reversal 
 of the platen. 
 
 The simplest manner in which to hold a die for grinding, 
 in cases where a flat surface only is desired, is to grip it in 
 the vise with which the machine is provided. This practice, 
 
 188
 
 SURFACE GRINDING 
 
 however, is not always productive of the best results 
 because it is sometimes almost impossible to hold the work 
 level in this manner. 
 
 For this reason, many mechanics prefer to strap the die 
 directly to the platen of the machine, as illustrated in Fig. 
 
 Fig. 73. Brown & Sharpe automatic surface grinder. 
 
 74. If the bottom of the die is ground flat after hardening, 
 it is obvious that this surface can be used for locating in 
 subsequent grinding operations to bring about accurate 
 results. In Fig. 74, A is the die, B the platen of the surface 
 grinder, C the grinding wheel, D the straps that grip the 
 work, and E the backing straps against which the straps D 
 bear. The straps D act as pinch clamps and their downward 
 thrust seats the die firmly against the platen of the machine. 
 
 189
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Where comparatively thick metal is to be pierced, it is 
 common practice to shear the face of the die as shown in 
 Fig. 75, wherein A is the die, B the punch, and C the metal 
 to be pierced. The double taper imparted to the face of 
 
 Fig. 74. Holding a blanking die in position for grinding. 
 
 the die allows it to cut the metal with a shearing action 
 which relieves the punch press of considerable strain. 
 
 A fixture for holding dies that are to be ground with a 
 sheared face is illustrated in Fig. 76. This consists of a 
 base casting (A) and a die holder (B). The holder swivels on 
 
 n 
 
 Fig- 75- Blanking die with a sheared face. 
 
 the pin (C) and is locked in the desired position by the bolts 
 (D). One of the lugs on the base is graduated in degrees 
 for ready setting as shown at (E). The recess in the holder 
 is machined at an angle to correspond to that of the die 
 
 190
 
 SURFACE GRINDING 
 
 which facilitates ready setting. This fixture is easily made 
 by any tool-maker of ordinary ability and its use saves con- 
 siderable time that is usually spent in setting up by other 
 methods. 
 
 Punches are ground in the same manner as dies, with the 
 exception that other means are usually employed in locating 
 them on the grinding machine. A punch that is set in a 
 holder having a flat upper surface, the upper member of 
 a sub-press for instance, is readily ground by strapping 
 it directly to the platen of the grinding machine. Many 
 punches, however, are made with integral taper shanks, 
 
 Fig. 76. Fixture for holding dies while grinding sheared faces. 
 
 thus, means must be provided for locating them. The 
 simplest method consists of a square block of cast iron, 
 generally machined all over, with a taper hole bored through 
 it to accommodate the punch shank. A block of this type 
 is illustrated in Fig. 77, wherein A is the block, B the punch 
 to be ground, C the grinding wheel and D the straps that 
 hold the block in place on the grinding -machine platen. 
 These are finger straps and holes are drilled in the block to 
 accommodate them. 
 
 By referring again to Fig. 75, it will be seen that the 
 punch will punch out a comparatively flat piece as its cutting 
 surface is flat, while the stock that is perforated will be 
 distorted to a certain extent by the action of the die face. 
 In some instances, w r e do not care whether the punches are 
 flat or not, as in perforating operations where the punchings 
 constitute the scrap, but we do desire to preserve a flat 
 surface on the stock that is perforated. 
 
 191
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 In this case, the punch is ground to give the shear instead 
 of the die. The lower part of the punch holder shown in 
 Fig. 77 is machined to accommodate the fixture shown in 
 Fig. 76. This is for the purpose of grinding sheared faces 
 on punches, the punch block being held in the position 
 
 
 i r 
 
 
 ifii 
 
 i A 
 
 c& 
 
 D ^ 
 
 s\ 'r-. 
 
 C . D 
 
 1 1 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 Fig. 77- Fixture for holding tapered-shank punches for grinding. 
 
 usually occupied by the dies, and the base of the fixture 
 swiveled to impart the desired shear to the punch. 
 
 Die grinding in itself is a comparatively simple operation 
 that does not call for the services of a skilled tool -maker. 
 As a matter of fact, at the present time, die grinding is 
 done in many plants by women who do not pretend to 
 be skilled mechanics. All that is necessary is to understand 
 the fundamental principles of surface grinding and to exer- 
 cise due care to see that the depth of cut and the cross 
 feed is not heavy enough to cause the wheel to burn the 
 edges of the die. 
 
 In ordinary die grinding, if done dry, which is the usual 
 custom, the depth of cut should be from o.ooi to 0.002 inch 
 and the cross feed o.oio inch for each reversal of the platen. 
 This is a general rule. 
 
 The wheels used for die grinding should be made of 
 alumina abrasives and they should be quite soft and coarse. 
 
 192
 
 SURFACE GRINDING 
 
 Grades 3, 4 and 5 in the writer's proposed grade scale are 
 generally furnished in grits from 36 to 46. 
 
 At the first sign of glazing, the wheel should be trued with 
 a diamond tool. The easiest method for truing the wheel 
 on a surface-grinding machine is to clamp the diamond 
 tool in the vise with which the machine is equipped, and 
 feed the diamond past the wheel by means of the cross 
 feed. 
 
 Die grinding is sometimes done wet, which practice, of 
 course, expedites production as the water keeps down the 
 f fictional heat. In wet grinding, both the depth of cut and 
 the amount of cross feed can be materially increased. The 
 machine illustrated in Fig. 73 can be equipped with a wet- 
 grinding attachment wherein water is supplied to the wheel 
 by means of a special wheel guard, through piping, by a 
 centrifugal pump immersed in a tank supported by a bracket 
 from the floor. The water is caught by a work tank pro- 
 vided with a hood and splash guards and returned to a 
 settling pan through a flexible discharge pipe. 
 
 On the larger types of surface-grinding machines, the work 
 should 'be ground wet under practically all conditions. The 
 reason for this lies in the fact that the comparatively large 
 wheels used create more friction in proportion than do smaller 
 ones. A surface-grinding machine of the type in question 
 having provision for an ample water supply, is illustrated 
 in Fig. 78. Machines of this type give excellent results on 
 heavy die work such as sections of large blanking dies, 
 which, owing to their nature, cannot be made from a solid 
 piece of steel, and for grinding large sub-press dies such as 
 are used for blanking armature discs. These large surface- 
 grinding machines give economical results as the depth of 
 cut and the traverse feed can be materially increased when 
 compared with smaller surface-grinding machines. This is, 
 of course, owing to the heavier construction throughout and 
 also to the fact that a larger wheel is used. Surface grinding 
 in general was given a decided impetus some 25 years ago 
 by the introduction of the magnetic chuck, by means of
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 which flat work is readily located for grinding. The mag- 
 netic chuck offers the additional advantage of holding flat 
 work securely without danger of springing. 
 
 Fig. 78. Surface-grinding machine having provision for wet grinding. 
 
 A magnetic chuck made by the Heald Machine Co. is 
 illustrated in Fig. 79. It has a working surface 13 inches 
 long and 6 inches wide, and is equipped with vertical ad- 
 justable side and end stops for locating the work. These 
 prevent the thrust of the grinding wheel from forcing the 
 work off the chuck. The front edge of the working surface 
 is provided with a T slot, the object of which is to accom- 
 modate stops, fingers, retainer strips, etc., according to 
 the nature of the work handled. 
 
 Figs. 80 and 81 illustrate special types of magnetic chucks 
 designed by the Heald Company. The one shown in Fig. 
 80 has a taper base which is adjustable for finishing tapered 
 work such as keys, wedges, etc. The base plate is pivoted 
 at the left-hand end and has an adjusting screw, clamping 
 
 194
 
 SURFACE GRINDING 
 
 Fig- 79 Heald magnetic chuck for use on the surface grinder. 
 
 Fig. 80. Heald magnetic chuck with adjustable taper base. 
 
 Fig. 8l. Heald magnetic chuck with adjustable swivel base. 
 195
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 bolt, and graduations at the right-hand end. The gradua- 
 tions show the taper in degrees and in inches per foot. This 
 chuck is also provided with a swivel adjustment for grinding 
 compound angles. 
 
 The chuck shown in Fig. 81 has a swivel base, the axis of 
 which runs lengthwise through the cencer of the chuck. 
 The swivel plate is provided with trunnions which are clamped 
 to hold the chuck at the angle desired. This is indicated 
 by graduations at the right-hand end. The base plate is 
 in one casting which supports the chuck at both ends. 
 Thus the outfit is self-contained. 
 
 Both these chucks lend themselves admirably to a diver- 
 sity of tool-room and other work which otherwise would 
 require special fixtures or setting-up devices. 
 
 A properly designed and constructed magnetic chuck 
 should demagnetize as soon as the current is turned off, 
 but to assist in the removal of work having comparatively 
 
 IFig. 82. Demagnetizing switch for use with magnetic chucks. 
 
 large contact surfaces, a demagnetizing switch is of great 
 assistance. This is due to the fact that after the current 
 is turned off, the work retains a certain amount of mag- 
 netism. To offset and neutralize this force, a demagnetizing 
 switch as shown in Fig. 82 is employed. This device is 
 fitted at one end with contact points which close the circuit 
 and magnetize the chuck for operation. At the opposite 
 
 196
 
 'SURFACE GRINDING 
 
 end, it is provided with contact points having a reversing 
 spring for demagnetizing purposes. By throwing the handle 
 to the left, the chuck receives the current permanently 
 and by throwing it to the right, making only an instant's 
 contact between the blades of the switch, the demagnetizing 
 effect is produced. After this, the work can be removed 
 readily from the face of the chuck. 
 
 AJ1 work that is ground on a magnetic chuck is bound to 
 retain a smal 1 amount of magnetism which often proves 
 
 Fig. 83. Heald demagnetizer. 
 
 detrimental, owing to the fact that small particles of metal 
 are thereby attracted. Magnetized pieces are readily 
 demagnetized by the device shown in Fig. 83. The steel 
 plates seen at the top of the case are the poles of magnets 
 contained in the box. These electro-magnets are energized 
 by connecting to an alternating-current circuit. The rapid 
 reversals of polarity produced by this kind of current, 
 remove all traces of magnetism by simply passing the work 
 a few times across the steel plates. 
 
 In installing and operating magnetic chucks, two im- 
 portant factors should be borne in mind. First, the voltage 
 for which the chuck is wound should correspond to the 
 voltage in the circuit to which the chuck is to be connected. 
 If the voltage in the line is too high for the chuck, the latter 
 will be burned out and if the voltage is too low, the chuck 
 will not retain the work. 
 
 Second, magnetic chucks cannot be operated on alternat- 
 197
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 ing current because the rapid reversal of polarity produced 
 by such currents gives the poles or magnets of the chuck 
 no permanent holding power. Thus, in cases where direct 
 current is not available, it should be generated by a small 
 generator driven by the line shafting. 
 
 Fig. 84. Grinding work with irregular contour on the surface grinder. 
 
 A Brown & Sharpe surface grinder equipped with a mag- 
 netic chuck is illustrated in Fig. 84. It is seen that the 
 pieces ground are of irregular shape and it is on work of this 
 kind in particular that the magnetic chuck shows efficiency 
 when used on the surface grinder. The pieces shown enter 
 into the construction of shoe machinery, which is very 
 
 198
 
 SURFACE GRINDING 
 
 accurate work. These pieces are cast iron, the limit of 
 variation allowed being 0.0002. The wheel used in this 
 case is Carborundum 241 grit, M grade. 
 
 The ordinary run of surface grinding, as far as the method 
 of procedure is concerned, does not differ materially from 
 die grinding. With some classes of surface grinding, how- 
 ever (tool-room work for an illustration) more care has to 
 be exercised to insure accuracy. Accurate surface grinding 
 on machines of the type under consideration, depends a 
 great deal on the "sizing power" of the wheel. 
 
 Let it be assumed that a tool-maker grinds a piece 4 inches 
 long and 3 inches wide, locating the work on the magnetic 
 chuck. He rough grinds both sides with a fairly coarse 
 cross feed and then takes a finishing cut over one side with 
 a finer feed. The work is then turned over and a finishing 
 cut taken over the other side. If the wheel is sizing prop- 
 erly, that is, holding its shape and size, within close limits, 
 the variation in the work should be very slight. In many 
 cases, the work will be slightly tapered from o.ooi to 0.002 
 inch owing to the fact that the wheel wore away gradually 
 while the cut was being taken. 
 
 The remedy for this is to true the wheel carefully and to 
 see that a very slight depth of cut is used for finishing, not 
 over 0.0005 inch. If, under this condition, the work still 
 finishes tapered, the error is due to two causes. Either the 
 wheel is too soft or it is run at too low a peripheral speed. 
 
 With machines having no provision for increasing the 
 spindle speed as the wheel wears down, wheels often ap- 
 pear soft after they are half worn out owing to the fact 
 that the peripheral speed is lowered considerably. The 
 remedy in this case is to discard the wheel and mount a 
 new one that is of the proper size. In nine cases out of 
 ten, the new wheel will be found to size in a satisfactory 
 manner. For this reason, it is poor economy sometimes 
 to attempt to use wheels until they become too small. 
 
 If a new wheel fails to hold its size when run at a peripheral 
 speed of 5,000 feet per minute, it is a sign that it is too soft. 
 
 199
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 In accepting this statement it is understood, of course, 
 that the operator uses the whole face of the wheel. That 
 is, he has not trued away part of it with the diamond, 
 which practice, for some unknown reason, is followed in 
 some shops. 
 
 If the full face of the wheel is used and the grade seems 
 too soft, the remedy is to substitute a wheel one half or 
 one grade harder or to use a wheel in combination grit. 
 These combination grit wheels have remarkable sizing 
 power and are preferred by many who have made a careful 
 study of the underlying principles of grinding. The wheel 
 used on the machine shown in Fig. 84 is in combination 
 grit with 24 grit as a basis. 
 
 If, however, too hard a grade is used, the wheel will 
 soon fill up and may burn the work. If the work appears 
 unduly hot, so hot the hand cannot be held upon it, it is 
 generally a sign that the wheel is overheating. In some 
 instances, minute black spots are seen on the work, which 
 is a sure sign of burning. 
 
 Some operators are under the impression that a fine-grain 
 wheel is necessary for producing a smooth finish. This 
 supposition, however, is erroneous. For the ordinary run 
 of tool-room surface grinding, 46 grit is fine enough although 
 wheels as fine as 60 grit are sometimes used on very small 
 work. Fine grit wheels cut slow and for this reason are 
 not econoiitical in the long run. A wheel in coarser grit, 
 with its full face utilized, will be found to give a satisfactory 
 finish if it is trued properly. 
 
 When a wheel chatters, the cause can be traced to two 
 sources. Either the wheel is too hard or the spindle bear- 
 ings are loose. Chattering causes a wavy, speckled ap- 
 pearance on the work, readily detected by any mechanic. 
 The remedy is, first to take up any slack in the spindle 
 bearings and if chattering is still in evidence, attention 
 should be paid to the grade of the wheel. 
 
 The machine shown in Fig. 85 represents another type 
 of surface grinder. It is a product of the HeaJd Machine
 
 SURFACE GRINDING 
 
 Co. and is called a ring and surface grinder. In shop lan- 
 guage, however, these machines are generally referred to 
 as piston-ring grinders, owing to the fact that .they are 
 widely used for grinding the sides of piston rings. 
 
 Fig. 85. Grinding piston rings on a Heald ring and surface grinder. 
 
 Briefly described, the main frame of the machine carries 
 a vertical spindle upon which a magnetic chuck is mounted. 
 The spindle is adjustable up and down to accommodate 
 and size different thicknesses of work and is provided 
 with micrometer adjustment for close setting. The upper 
 part of the main frame supports a cross head which carries 
 the wheel spindle. A novel feature of this machine is that 
 an adjustment is provided to enable the wheel to grind 
 tapered as well as flat surfaces. This adjustment is of
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 great value in grinding such work as milling saws which 
 should be thinner at the center than at the periphery to 
 give the proper working clearance. 
 
 A larger machine built on the same principle is shown in 
 Fig. 86. As the illustration shows, this machine is equipped 
 for wet grinding. These machines will grind any kind of 
 
 Fig. 86. Heald rotary surface grinder arranged for wet grinding. 
 
 flat work within the capacity of the chucks, but are especially 
 adapted for finishing round work such as piston rings, 
 thrust collars, milling cutters, etc. 
 
 In comparing rotary surface grinders with surface grind- 
 ers of the reciprocating type, it is seen that in the former, 
 the wheel covers the entire surface of the work being ground 
 in much less time than it does in the latter. For this reason, 
 the sizing power of the wheel is materially increased.
 
 SURFACE GRINDING 
 
 A widely used type of grinding machine is illustrated in 
 Fig. 87, the Pratt & Whitney surface grinder. In the 
 language of the practical man, however, this machine is 
 generally spoken of as a vertical surfacer. It furnishes a 
 
 Fig. 87. Pratt & Whitney surface grinder or vertical surfacer. 
 
 ready means for removing stock accurately and rapidly, 
 not only on the regular work of surface grinding, but on 
 roughing operations where very little metal has to be re- 
 moved. In this work, it replaces the milling machine and 
 planer to some extent. 
 
 Briefly described, this machine consists of a rigid base, 
 upon which the platen travels, and a substantial upright 
 which carries the wheel spindle. The platen has a longi- 
 tudinal movement only. A traverse movement is unnec- 
 
 203
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 essary owing to the fact that the diameter of the wheel used 
 is sufficient to cover the whole width of the platen. 
 
 The machine carries a wheel 14 inches in diameter with 
 a 4-inch face. The rim is 1-1/4 inches which gives a 11-1/2 
 inch hole. The wheel is mounted in a special holder, 
 bedded in hot shellac and held securely by means of clamps. 
 The wheel speed is 1,155 revolutions a minute. 
 
 The problem of locating the work is reduced to a minimum 
 owing to the fact that the machine is equipped with a 
 magnetic chuck. By means of rotary chucks, this machine 
 is able to handle both plain and circular grinding. These 
 chucks are made both magnetic and non-magnetic. Non- 
 magnetic chucks are used for locating work that is not 
 
 n 
 
 IB 
 
 Fig. 88. Plain rotary chuck for use on Pratt & Whitney vertical surfacer. 
 
 attracted by magnetism, such as bronze, aluminum, etc., 
 while magnetic chucks are used for holding pieces made of 
 ferrous metals. A plain rotary chuck with its driving mech- 
 anism is shown in Fig. 88. The base upon which the 
 chuck revolves is clamped to the platen of the machine 
 while the driving mechanism is located outside the water 
 guard. An adjustment is provided for tilting the chuck, 
 which makes possible the grinding of concave or convex 
 
 204
 
 SURFACE GRINDING 
 
 surfaces. The duplex and quadruple chucks shown in Figs. 
 89 and 90 are used on production work where they increase 
 the output materially. The duplex chuck is adjustable 
 
 Fig. 89. Duplex rotary chuck for use on Pratt & Whitney vertical surfacer,. 
 
 for grinding either concave or convex, but the quadruple 
 chuck does not possess this feature. 
 
 Designed for a production machine, the grinder in ques- 
 tion is thoroughly automatic. The table is provided with 
 
 Fig. 90. Quadruple rotary chuck for use on Pratt & Whitney vertical 
 surfacer. 
 
 two feed speeds of 34 and 142 inches per minute. The feed, 
 of the table per revolution of the wheel is 0.029 and 0.123^ 
 inches. 
 
 205
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 An endless variety of flat work, both rectangular and 
 circular, can be finished on this machine as shown in Fig. 91. 
 The pieces shown illustrate blanking dies, thread-cutting 
 dies, ring gauges, chuck bodies, collars, gears, small-arms 
 parts, etc. In fact, any piece, whether hard or soft, can be 
 
 Fig. 91. Samples of work finished on Pratt & Whitney vertical surfacer. 
 
 finished in this manner if its surface is of such a nature as to 
 permit gripping on the magnetic chuck. 
 
 Successful grinding on the vertical surfacer depends more 
 on the selection of wheels than it does on any one other 
 factor. Carbide of silicon wheels should be used for grind- 
 ing cast iron while alumina abrasives are better adapted 
 for steel both in its hard and soft state. A factor peculiar 
 to this machine is that the width of surface to be finished 
 determines the grade of wheel to use. Thus, when finishing 
 comparatively wide surfaces softer wheels are necessary 
 than those used for grinding narrow work. The following 
 grits and grades have been found through practical experi- 
 ment to give good results. On cast-iron and aluminum 
 
 206
 
 SURFACE GRINDING 
 
 grinding; 1 6 to 24 grit, i to 4 grade. For soft steel; 16 to 
 24 grit, 3 to 7 grade. These wheels are also adapted for 
 malleable-iron castings. For grinding hardened-steel parts 
 1 6 to 24 grit, i to 4 grade are used. These gradings are 
 taken from the writer's grade scale. 
 
 To grind work successfully on a vertical surfacer, it 
 must be borne in mind that one wheel cannot be expected 
 to show efficient results on all classes of work; and for 
 this reason several wheels for various purposes should in- 
 variably be kept in stock. 
 
 In grinding, the work should be held securely on the chuck, 
 otherwise the action of the wheel will dislodge it. This 
 sometimes results in a broken wheel, but accidents are 
 readily avoided by placing backing strips around the work. 
 The face of the chuck should be cleaned carefully before 
 placing the work in position, if accurate results are required, 
 because a small amount of dirt can cause an error of several 
 thousandths of an inch. 
 
 While the wheels used with this machine are very free 
 cutting, owing to their soft grade, they should not be 
 crowded. That is, the spindle should not be fed down too 
 great a distance at each reversal of the platen. To ignore 
 this factor is to invite disaster for one of three results is 
 bound to happen. The work will be burned, forced off 
 the chuck or the wheel will be broken. 
 
 The wheel must be kept sharp and free cutting. It is 
 readily trued by the device described for this purpose in 
 Chapter X. An expert grinder can readily detect a wheel 
 that needs dressing even if he cannot see its face. A wheel 
 that needs dressing overheats the work, does not throw 
 sparks freely and leaves a polished surface on the work. 
 
 Work should never be ground dry on machines of this 
 type. A liberal supply of water is necessary for two rea- 
 sons: It keeps down the heat caused by the cutting action 
 of the wheel and it also carries away the metal particles 
 removed from the work. Soda water supplied by the cir- 
 culating pump should be used as plain water rusts both the 
 
 207
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 machine and the work. If the machine is used intermit- 
 tently, it should be cleaned thoroughly after using and oiled 
 each time before starting up, while a machine that is used 
 constantly should be oiled every day and cleaned thoroughly 
 at least once a week. 
 
 Another type of surface-grinding machine is illustrated 
 in Fig. 92. This machine is made by the Blanchard Machine 
 Co., Cambridge, Mass.. and is called a high-power vertical 
 
 Fig. 92. Blanchard high-power vertical surface grinder. 
 
 surface grinder. The initial machine of this type was 
 built by the Blanchard Company, some eight years ago, 
 for their own use. The machine is built very rigidly to 
 eliminate vibration and consists principally of a base carry- 
 ing an upright on which the wheel head is mounted and a 
 revolving platen on which the work is held. 
 
 The wheel spindle on the machine shown is driven directly 
 208
 
 SURFACE GRINDING 
 
 by means of a 2o-horsepower motor although these machines 
 can be arranged for belt drive. In the majority of cases, 
 however, the direct drive is to be preferred. 
 
 The wheel used is a plain ring without flanges, thus 
 clamps are not necessary in holding it in place. It is set 
 in a cast-iron ring either with sulphur or Portland cement. 
 The ring that carries the wheel is fastened to the face plate 
 at the bottom of the driving spindle by means of six screws. 
 To reinforce the wheel in guarding it against possible break- 
 age, a wire banding consisting of two windings 1/2 inch wide 
 of brass wire is applied to the outside. 
 
 A novel and valuable feature peculiar to this machine is 
 the three-point column support. In turning out flat work 
 of uniform thickness it is essential that the wheel spindle 
 be exactly square with the chuck. While this alignment 
 may be correct when the machine is new, it does not follow 
 that any wear that may develop will be uniform. To cor- 
 rect errors due to wear, the three-point support is adjustable,- 
 which feature makes possible correct alignment at all times. 
 This adjustment also furnishes a convenient means for 
 setting the machine to grind concave or convex surfaces. 
 
 The work to be ground is held either magnetically or 
 by clamps or by its own weight on the rotary chuck. The 
 table body on which the chuck is mounted slides on the 
 base and carries the chuck under the wheel where it is 
 rotated by power and the wheel fed down gradually until 
 the desired amount of metal is removed. Both hand and 
 power feeds are provided, the latter having a wide range 
 of feeds with automatic stops that can be set at any point. 
 
 The feed mechanism comprises a hand crank, a graduated 
 rachet wheel and a pawl driven from the chuck motion 
 and arranged to feed once at each revolution of the work. 
 The feed is very sensitive as each tooth of the rachet wheel 
 represents 0.0002 inch. The graduations on the wheel in- 
 dicating thousandths of an inch are 1/2 inch apart. 
 
 Work on this machine is invariably ground wet and means 
 are provided for insuring an ample supply of water which is 
 
 209
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 supplied inside the wheel while guards are provided to pre- 
 vent the escape of spray as it is thrown out by the centrif- 
 ugal action of the wheel. 
 
 An idea of the wide range of work that can be handled 
 on the machine in question is illustrated in Fig. 93. Here 
 are included over one hundred different machine parts 
 
 Fig- 93- Samples of work ground on Blanchard high-power vertical 
 surface grinder. 
 
 comprising units of fire-arms, rings, thrust collars, gears, 
 connecting rods, flatirons, etc. 
 
 The machine is simple in operation, but it should be re- 
 membered that it is a precision machine in every sense of 
 the word. All the bearings should be oiled once a day and 
 the grease cups turned daily while the oil gauges should be 
 kept filled to the center of the glass at all times. 
 
 The solution for cooling the work should consist of a 
 mixture of 50 gallons of water, one to two quarts of cutting 
 oil and three to five pounds of sulphate of soda.
 
 SURFACE GRINDING 
 
 In chucking work, the center of the chuck should be 
 left open whenever possible. A practical method is to 
 place the work in a circle around the chuck leaving an eleven- 
 inch hole in the center. The work should be backed up 
 against slipping by means of a loose steel ring placed around 
 the outside of the work. This point is important and 
 should never be overlooked. It must be remembered that 
 each piece of work, to insure proper holding, must span 
 one or more of the brass rings on the chuck face. Large 
 pieces, the shape of which prevents the use of rings, should 
 be securely blocked to prevent sliding. In grinding non- 
 magnetic work, care must be exercised to block or clamp 
 the same according to shape. As the pressure exerted by 
 the wheel is always downward, danger of tilting the work 
 is reduced to a minimum. 
 
 Soft wheels that wear away readily, thus constantly ex- 
 posing new cutting grains, are to be preferred to harder 
 ones that require constant truing. If the wheel refuses to 
 cut freely and glazes or burns, the remedy can be found 
 in one or more of the following factors : A softer and coarser 
 wheel should be used, more feed with the object of keeping 
 the wheel in cutting condition should be used, the width 
 of the work surface of the wheel should be reduced, the 
 face of the wheel should be roughened with a star-wheel 
 dresser, and, if grinding broad surfaces, the amount of oil 
 in the cooling solution should be reduced or left out 
 altogether. The wheel speed must remain at 1,000 revolu- 
 tions a minute for a 1 6-inch wheel, and 860 revolutions a 
 minute for an 1 8-inch wheel. 
 
 The power feed should be used in preference to hand 
 feeding. An average feed is o.ooi inch for each revolution 
 of the work, but under some conditions, feeds as heavy as 
 0.002 and even 0.003 have been successfully used. The 
 makers of the machine state that ic is better to use too 
 much rather than too little feed as fine feeds glaze the wheel 
 readily. 
 
 The speed of the chuck should be from 13 to 17-1/2
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 revolutions a minute for the average run of work. This can 
 be increased if a comparatively small piece chucked near 
 the center is being ground. On the other hand, the speed 
 should be reduced somewhat when grinding work that 
 practically covers the chuck. To impart a very smooth 
 finish, the chuck speed should be reduced to five revolutions 
 a minute for the last few turns. 
 
 The proper method of operating the machine is first 
 to locate the work, then close the switch and try the work 
 to make sure that it holds. Next, with the wheel high 
 enough to clear the work, the chuck is removed to its grind- 
 ing position, as far as it will go under the wheel. The 
 chuck is next started and the wheel fed down by hand until 
 it starts to grind the work, when the power feed should be 
 thrown in. The wheel should be raised before stopping the 
 chuck or changing the chuck speed and the chuck should be 
 stopped before it is moved from under the wheel. 
 
 The selection of correct wheels for vertical grinding 
 machines should not be done haphazard if the best results 
 are desired. Owing to the comparatively broad contact 
 between the wheel and the work, a slight change in the grade 
 of wheel often causes unsatisfactory work. In this respect, 
 vertical surface-grinding machines are far more sensitive 
 than other types of precision-grinding machines. The 
 width of the surface to be ground often affects the wheel 
 grading. Thus, narrow surfaces require harder wheels than 
 do pieces with comparatively wide surfaces. After much 
 experimentation, the Bl an chard Machine Co. standardized 
 the following wheel list, which gives the kind of wheel to- 
 gether with the proper grit and grade to use for various 
 classes of work. 
 
 To provide means for readily measuring the work without 
 taking it off the chuck, the Blanchard Company developed 
 the continuous reading caliper gauge illustrated in Fig. 94. 
 The attachment eliminates much of the time consumed 
 under ordinary conditions when the work is stopped for 
 the purpose of removing a piece for measurement with
 
 SURFACE GRINDING 
 
 Material 
 
 Width 
 of 
 Surface 
 
 Finer 
 Finish 
 and 
 Narrower 
 Surfaces 
 
 Best 
 Wheel 
 for 
 Average 
 Work 
 
 Faster 
 Cutting 
 and 
 Broader 
 Surfaces 
 
 Fi.-.er 
 Finisii 
 and 
 Narrower 
 Surfaces 
 
 "^est 
 Vv aeel 
 for 
 Aveiage 
 Work 
 
 Faster 
 Cutting 
 and 
 Broader 
 Surfaces 
 
 
 
 Norton Crystolon 
 
 American Carbolite 
 
 Cast 
 Iron 
 
 Narrow 
 
 30 H 
 
 24! 
 
 
 30 H 
 
 20 I 
 
 
 Medium 
 
 30 G 
 
 24 H 
 
 14 H 
 
 
 20 H 
 
 14 I 
 
 Broad 
 
 
 24 G 
 
 14 H 
 
 30 G 
 
 20 G 
 
 14 H 
 
 Chilled 
 Iron 
 
 Narrow 
 
 
 24 I 
 
 
 
 20 I 
 
 
 Medium 
 
 
 24 H 
 
 
 
 20 H 
 
 
 Broad 
 
 
 24 G 
 
 
 30 G 
 
 20 G 
 
 
 
 
 Narrow 
 
 
 24! 
 
 14 I 
 
 
 20 I 
 
 14! 
 
 Medium 
 
 
 24 H 
 
 14 H 
 
 
 20 H 
 
 14 H 
 
 Bioad 
 
 30 G 
 
 24 G 
 
 
 30 G 
 
 20 G 
 
 
 Aluminum 
 
 Narrow 
 
 
 
 
 
 20 I 
 
 
 Medium 
 
 
 
 
 
 20 H 
 
 
 Broad 
 
 
 
 
 
 14 H 
 
 
 
 
 
 Norton Silicate No. 38 Alundum 
 
 American Silicate Corundum 
 
 Malleable 
 Iron 
 
 Narrow 
 
 
 3824! 
 
 
 
 24-iX 
 
 
 Medium 
 
 
 3824 H 
 
 
 24-1 
 
 
 Broad 
 
 3830 G 
 
 3824 G 
 
 
 
 24-K 
 
 
 Soft 
 Steel 
 
 Narrow 
 
 3830 I 
 
 3824! 
 
 
 30-1 
 
 24- 1 X 
 
 
 Medium 
 
 3830 H 
 
 3824 H 
 
 3814! 
 
 30-1 
 
 24-1 
 
 14-1 
 
 Broad 
 
 3824 H 
 
 3814! 
 
 
 30-K 
 
 24-K 
 
 
 Steel 
 Castings 
 
 Narrow 
 
 
 3824! 
 
 
 30-1 
 
 24-iX 
 
 
 Medium 
 
 
 3824 H 
 
 3814! 
 
 30-1 
 
 24-1 
 
 
 Broad 
 
 38 3 oG 
 
 
 
 30-K 
 
 24-K 
 
 
 Hardened 
 Carbon. 
 Steel 
 
 Narrow 
 
 3846 H 
 
 3830 H 
 
 
 46-K 
 
 30-1 
 
 24-1 
 
 Medium 
 
 
 3830 G 
 
 3824 H 
 
 46-K 
 
 30-J< 
 
 24-K 
 
 Broad 
 
 
 3830 G 
 
 3824 G 
 
 
 30-K 
 
 24-*A 
 
 Hardened 
 High-speed 
 Steel 
 
 Narrow 
 
 
 3830 H 
 
 
 
 30-1 
 
 24-1 
 
 Medium 
 
 
 3830 G 
 
 
 
 30-K 
 
 24-K 
 
 Broad 
 
 
 3830 G 
 
 38240 
 
 
 30-K 
 
 24-i 
 
 
 
 
 
 
 ! ' - * 
 
 
 
 WHEELS FOR BLANCHARD SURFACE GRINDER 
 
 Rnisfd to July 10, 1918. 
 
 2I 3
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 the micrometer. The device increases the operator's con- 
 fidence in grinding work accurately and rapidly as he does 
 not have to feel his way toward the final finish. Thus, 
 he can use a heavy feed until the last thousandth is to be 
 removed. 
 
 As the illustration shows, the device consists of an upright 
 and bracket for carrying a dial indicator. A hardened-steel 
 
 Fig. 94. Continuous reading caliper gauge for use on Blanchard high-power 
 vertical surface grinder. 
 
 contact point rests lightly on the work and is connected by 
 means of a rod to the gauge head. The lower face of the 
 contact point is of a flattened cone shape and as its vertical 
 movement is slight, it readily passes over openings in the 
 surface of the work or from piece to piece. 
 
 In setting the gauge, the contact point is brought down 
 on a size block or a finished piece of the desired size which 
 
 214
 
 SURFACE GRINDING 
 
 is placed on the chuck and the dial of the gauge is revolved 
 to bring the zero line to coincide with the pointer. The 
 caliper is aligned to swing the contact point parallel to the 
 surface of the chuck so that accurate readings can be taken 
 at any convenient place on the work. It can be swung out 
 of the way for placing or removing the work without de- 
 stroying its setting. 
 
 In gauging the work, the caliper is swung to bring the 
 contact point over the work while it is being ground. Each 
 piece of work, as it is carried under the contact point, in- 
 dicates on the dial the exact amount of oversize in thou- 
 sandths of an inch.
 
 CHAPTER SEVENTEEN 
 
 CYLINDRICAL GRINDING 
 
 Cylindrical grinders Operation of grinders Driving devices for work 
 Proper wheel speeds for various metals and work Traverse feed Depth 
 of cut Roughing and finishing cuts Spark ng Backrest and steady- 
 rests Lubrication of work Lubricating compounds and mixtures 
 Dressing and truing wjieels while on the grinder Chatter marks and 
 their remedy Selection of proper wheels for use on' cylindrical grinders 
 Universal grinders Grinding tapers Various operations on universal 
 grinder. 
 
 'T'HE modern cylindrical grinder is one of the greatest 
 ^ aids to rapid production as it furnishes a convenient 
 and accurate means for finishing a large variety of machine 
 and other parts, both hard and soft. Cylindrical grinding 
 is a trade in itself involving many factors that are intelli- 
 gently understood only after many years of actual practice 
 and patient experimentation. To be sure, any man who 
 is mechanically inclined, or any woman, too, for that mat- 
 ter, can be taught to operate a cylindrical grinder in a 
 few weeks' time, but to understand thoroughly the many 
 perplexing problems of the grinding department of the 
 average plant calls for knowledge that is acquired only 
 through long practice. 
 
 In the foregoing chapter, it was seen that there are many 
 types of surface grinders, but with cylindrical grinding the 
 types of machines used do not differ materially except in 
 one major point. That is the traverse movement of the 
 machine which carries the work past the wheel. The oldest 
 and most commonly used type consists of a stationary 
 wheel with a movable platen while in a later type of ma- 
 
 216
 
 CYLINDRICAL GRINDING 
 
 chine, the platen does not move while the wheel carriage 
 does. 
 
 As to the most efficient type there is a question. This 
 has never been settled, even among abrasive engineers. 
 However, both types give excellent results in actual prac- 
 tice. For the ordinary run of work, it is the writer's opinion 
 that one type is as efficient as the other. It cannot be 
 denied, however, that in grinding very heavy work (pieces 
 weighing several hundred pounds) the traveling wheel offers 
 a decided advantage, as the frequent reversal of motion of 
 a unit weighing several hundred pounds is eliminated. 
 
 Grinding machines of the types before mentioned, that 
 is those having traveling wheel heads and those having 
 
 Fig- 95- Landis iox36-inch plain grinding machine. 
 
 traveling platens, are again divided into two classes, plain 
 grinders and universal grinders. A plain grinder is a ma- 
 chine designed to take the place of the engine lathe in 
 finishing all kinds of turned work both straight and tapered, 
 provided that the taper is not too abrupt. A universal 
 
 217
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 grinder, as its name indicates, can be used for a wide range 
 of work which includes besides plain grinding, internal 
 grinding, face grinding, taper grinding, cutter grinding and 
 in some cases, surface grinding. In the strictest sense of the 
 word, the universal grinder is not a production machine 
 and its usefulness is mostly confined to the tool-room. 
 
 Figs. 95, 96, 97 and 98 represent modern plain grinding 
 machines as used on production work. The machine shown 
 
 Fig. 96. Landis I2x96-inch plain grinding machine. 
 
 in Fig. 95 is a 10 x 3 6 -inch plain grinder built by the Landis 
 Tool Co., Waynesboro, Pa. It is thoroughly automatic 
 in operation as regards traverse and cross feeds. The wheel 
 carriage on this machine traverses while the platen is 
 stationary. The reversal can be set at any desired place 
 to suit different lengths of work and the cross feed can 
 be set to feed either light or heavy at each reversal of the 
 wheel carriage and also to cease feeding when a desired 
 size has been reached. This feature is of great value in 
 grinding routine work as the " cut-and-try " method is 
 almost wholly eliminated. The work is driven on two dead 
 centers. The machine illustrated in Fig. 96 is also a product 
 of the Landis Company. It takes work up to 12 inches in 
 diameter and 96 inches long. Its essential features are the 
 same as those of the machine shown in Fig. 95, but it has 
 an additional feature that is a decided novelty, the double 
 
 218
 
 CYLINDRICAL GRINDING 
 
 control seen at the front. This is especially valuable in 
 grinding long work as the machine can be fully controlled 
 from either station. Both of the Landis grinders shown 
 are arranged for individual electric drive. 
 
 The machine illustrated in Fig. 97 is a 10 x 36-inch plain 
 grinder, arranged for belt drive. It is built by the Norton 
 
 Fig- 97- Norton iox36-inch plain grinding machine. 
 
 Grinding Co., Worcester, Mass. In this type of grinder, 
 the wheel is stationary while the platen, which carries the 
 head and tail stock, traverses. This is also a production 
 machine and it is entirely automatic in operation. Fig. 
 98 shows another plain grinder built by the Norton Grinding 
 Co. It is a much larger machine than the one shown in 
 Fig. 97, but it operates on the same principles. It takes 
 work 14 inches in diameter and 72 inches long. There are, 
 of course, many other makes of plain grinding machines 
 on the market, but they all work on the same basic princip^s. 
 That is, they provide means for holding and revolving 
 the work to be ground on dead centers, means for auto- 
 
 219
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 matically traversing the work past the wheel, or vice versa, 
 and means for actuating and controlling the cross feed 
 automatically. 
 
 So much for plain grinding machines. Let us now con- 
 sider the subject of cylindrical grinding itself. To permit 
 the grinding machine to produce its maximum output, it 
 is necessary to pay attention to the manner in which the 
 work is prepared for the grinder. In many cases, especially 
 on comparatively small work, no preparation aside from 
 
 Fig. 98. Norton i4X72-inch plain grinding machine. 
 
 centering and squaring up the ends is necessary. This 
 is especially true in cases where pieces are of a given size 
 for their whole length, in which case the material is often 
 cold-rolled steel o.oio oversize. 
 
 With the majority of work, however, experience has 
 proven that one roughing cut in the lathe is generally 
 necessary. The rough feed marks made by coarse-feed, 
 high-speed turning aid materially in the grinding operation 
 as they help to keep the wheel in good cutting condition. 
 When a rough feed is used for turning, 1/32 inch is a fair 
 allowance to leave for grinding. This is a general rule and, 
 of course, is subject to modifications. The Landis Tool Co. 
 has compiled a table of grinding allowances for work run- 
 ning in diameter from 1/2 to 12 inches and from 3 to 48
 
 CYLINDRICAL GRINDING 
 
 inches long. The data were obtained from lengthy experi- 
 mentation and the table follows : 
 
 DIAMETER LENGTH IN INCHES 
 
 INCHES 3 6 9 12 15 18 24 30 36 42 48 
 
 1/2 OIO .OIO .OIO .OIO .015 .015 .OI5 .O2O .O2O .O2O .O2O 
 
 3/4 oio .010 .010 .010 .015 .015 .015 .020 .020 .020 .020 
 
 i oio .010 .010 .015 .015 .015 .015 .020 .020 .020 .020 
 
 I-I/4 OIO .010 .015 .015 .015 .015 .015 .020 .020 .020 .O2O 
 
 I-I/2 OIO .015 .015 .015 .015 .015 .020 .020 .020 .O2O . O2O 
 
 2 015 .015 .015 .015 .015 .020 .020 .020 .O2O .O2O .025 
 
 21/4 OI 5 - OI S -015 -i5 .020 .020 .020 .020 .020 .025 .025 
 
 2-1/2 015 .015 .015 .020 .020 .020 . 02O .O2O .025 .025 .025 
 
 3 015 .015 .020 .020 .020 .020 .C2O .025 .025 .02$ .025 
 
 3-1/2 015 .020 .020 .020 .020 .O2O .025 .02$ .025 .025 .02$ 
 
 4 020 .020 .020 .020 .020 .025 .025 .025 .025 .025 .030 
 
 41/2 02O .O2O .O2O .O2O .025 .025 .025 .025 .025 .030 .030 
 
 5 020 .020 .020 .025 .025 .025 .025 .025 .030 .030 .030 
 
 6 020 .020 .025 .025 .025 .025 .025 .030 .030 .030 .030 
 
 7 020 .025 .025 .025 .025 .025 .030 .030 .030 .030 .030 
 
 8 025 .025 .025 .025 .025 .030 .030 .030 .030 .030 .030 
 
 9 025 .025 .025 .025 .030 .030 .030 .030 .030 .030 .030 
 
 10 025 .025 .025 .030 .030 .030 .030 .030 .030 .030 .030 
 
 II 025 .025 .030 .030 .030 .030 .030 .030 .030 .030 .030 
 
 12 030 .030 .030 .030 .030 .030 .030 .030 .030 .030 .030 
 
 The majority of pieces that are to be finished by grinding 
 are driven by means of a dog placed on one end. The dog 
 engages a pin that projects from the face plate of the head 
 stock. In cases where it is advantageous to traverse the 
 entire length of the work at one setting (in grinding a piece 
 of uniform diameter for its entire length for an illustration) 
 the driving device illustrated in Fig. 99 is used in connection 
 with Brown & Sharpe grinding machines. This consists 
 of a special center (B), over which the driver (A) revolves. 
 The driver is fastened to the dead-center pulley by the 
 stud 68. The work is driven by the two pins (C). The holes 
 in the work should be slightly larger than the pins and 
 they should be drilled by means of a simple drilling jig 
 to insure their slipping over the pins without interference. 
 
 Another device sometimes used is a square-shaped center. 
 In this case, one end of the work is broached to fit the
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 center. For taking comparatively light cuts, this method 
 is satisfactory, but it possesses one disadvantage in that 
 the center has to revolve, getting its motion from the head- 
 stock spindle. However, on special grinding machines such 
 as used by twist-drill manufacturers, this type of center is 
 
 Fig- 99- End driving-dog for use on Brown & Sharpe grinding machines. 
 
 often used as an inspection of the centers seen in some makes 
 of twist drills shows. 
 
 After adjusting the tail stock to suit the length of the 
 work, the machine must be set to grind straight by adjust- 
 ing the swivel on the platen. In theory, this should not 
 be necessary. In actual practice, however, it is found that 
 the machine has to be "straightened up" every time the 
 tail stock is moved. This is generally caused by small 
 particles of dirt that work under the tail stock. It is a 
 simple matter to straighten up the machine as all that is 
 necessary is to take a few cuts over the work, caliper to 
 find the taper, and adjust the swivel platen to offset this. 
 
 As a rule, when many pieces of the same kind are to 
 be ground, it is the best practice to make two grinding 
 operations, one for roughing and one for finishing. In the
 
 CYLINDRICAL GRINDING 
 
 roughing operation, the wheel should be kept sharp and 
 free cutting. This is done by passing the diamond past it 
 with a quick motion. From o.ooi to 0.005 should be left 
 for the finish grinding, the amount depending on the size 
 of the work. In the finishing operation, the wheel should 
 be carefully trued by passing the diamond over it with a 
 comparatively slow feed. 
 
 Economical and efficient cylindrical grinding depends in 
 a great measure on the speed at which the wheel is run. 
 No hard and fast rule can be given- for the correct wheel 
 speed as it can range anywhere from 5,000 to 7,000 feet 
 per minute surface speed. The rule is to slow down a 
 wheel that shows a tendency to glaze and to speed up a 
 wheel that wears away too readily. A little attention to 
 this rule will save much trouble that is often laid to the 
 wheel. 
 
 The speed at which the work is rotated has much to do 
 with successful cylindrical grinding. If a wheel seems to be 
 wearing away too rapidly, the fault can be overcome in 
 many cases by reducing the work speed. On the other hand, 
 if the wheel glazes readily, the fault is often overcome by 
 increasing the work speed. The writer does not hesitate 
 to state that it is impossible to lay down hard and fast 
 rules for either wheel or work speeds. The skilful operator 
 gets the result desired by a combination of both. The 
 following approximate speeds, however, have been found 
 to be satisfactory under general conditions in cases where 
 the grinding wheel was run at a peripheral speed of 5,000 
 feet per minute. 
 
 Cast-iron roughing ". 40 feet per minute. 
 
 Cast-iron finishing 50 feet per minute. 
 
 Steel roughing 20 to 30 feet per minute. 
 
 Steel finishing 30 to 40 feet per minute. 
 
 On the subject of work speeds, the Landis Tool Co. says: 
 "Our experience is that a surface speed of 30 to 60 feet per 
 minute for steel and cast iron gives good results. However, 
 
 223
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 the grade of the material, the quality of finish and the hard- 
 ness of the wheel must be considered in determining the 
 correct speed. Often when failure to produce good results 
 is attributed to the wheel, it may be remedied by changing 
 the speed of the work." 
 
 The traverse speed is another factor that must be con- 
 sidered in economical grinding. By traverse feed is meant 
 the distance the platen travels for each revolution of the 
 work. In roughing out work, this traverse should be very 
 nearly the width of the grinding wheel for each revolution 
 of the work. Thus, if a wheel with a 2 -inch face is used, a 
 traverse feed of 1-7/8 inches will be satisfactory. This 
 practice causes the wheel to wear uniformly inasmuch as 
 the work passes the wheel with a decided shearing action 
 which helps to keep the wheel true. When a fine finish is 
 required, however, the traverse feed should be reduced and 
 the work speed increased. The above rules apply to the 
 general grinding of steel. In grinding cast iron, the pro- 
 cedure is slightly different. For the rough grinding of 
 this material a narrow traverse feed and a deep cut give 
 better results than a wide traverse feed with a slight cut. 
 In finishing cast iron, it is good practice to make as few 
 passes over the work as possible as this has a tendency to 
 prevent wheel glazing. It is seen that this is in direct 
 opposition to the generally accepted rule for finishing steel, 
 in which case an excellent finish is obtained by letting the 
 work traverse back and forth past the wheel without cross- 
 feeding until sparks are hardly visible. In shop language 
 this operation is spoken of as "grinding out" and it is pro- 
 ductive of excellent results, even when a comparatively 
 coarse wheel is used. 
 
 To find the speed in feet per minute of the wheel or the 
 work, multiply the diameter in inches by 3.14 and the result 
 by the number of revolutions per minute; then divide the 
 product by 12. 
 
 The depth of cut is understood as the amount the work 
 is fed toward the wheel at each traverse. In cases where the 
 
 224
 
 CYLINDRICAL GRINDING 
 
 work to be ground is of a substantial nature, that is, com- 
 paratively large in diameter for its length, a heavy cut 
 can be taken; in fact the wheel can be forced into the 
 work until the driving belt or motor, whichever the case 
 may be, is working to its maximum capacity. This rule, 
 however, applies to a hand feeding. When the auto- 
 matic feed is used, a sufficient advance at each reversal 
 of the platen should be made to keep the wheel cutting 
 at its maximum capacity. Heavy cuts in roughing opera- 
 tions have a tendency to keep the wheel true and in 
 cutting condition. 
 
 Sometimes in taking roughing cuts, it is noticed that the 
 wheel sparks heavier on one side of the work than it does 
 on the other. This is not the fault of the machine, but is 
 caused by the internal strains and forces in the work ad- 
 justing themselves or, sometimes, by dirt working in the 
 centers. It is needless to state that both the centers on 
 the machine and in the work should be cleaned before placing 
 the work in position which eliminates this cause of uneven 
 sparking. When the uneven sparking is caused by the work 
 adjusting itself to overcome internal strains, the evil cor- 
 rects itself. The machine detects and corrects the error. 
 When the work sparks uneven, the wheel should be kept 
 sharp and slight feeds used until the work sparks evenly. 
 A slight difference in sparking often leads the inexperienced 
 operator to believe that the work is badly out of true. This, 
 however, is seldom true, for in many cases an error of o.oooi 
 inch will cause uneven sparking. 
 
 To secure maximum production in the grinding depart- 
 ment, the majority of pieces that are ground should be sup- 
 ported in the grinding machine by means of backrests or 
 steady-rests as they are also termed. A visit to many 
 grinding departments reveals the fact that this rule is often 
 neglected. It takes a little time, to be sure, to set back- 
 rests, but the results obtained by their use amply pay for 
 the small amount of time consumed in setting up. There is 
 no hard and fast rule for the number of backrests to use 
 
 225
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 on a given piece of work. One rest to a foot is sufficient, 
 in most cases. 
 
 Backrests are of three kinds: solid, spring and universal. 
 A difference of opinion exists among grinding-machine 
 manufacturers as to what is the most efficient type of back- 
 rest, but all three types possess certain advantages. A solid 
 backrest, as supplied with Norton grinding machines, is 
 illustrated in Fig. 100. In this rest, the shoe forms a cradle 
 for the work to rest in with a saddle or bearing point dia- 
 
 Fig. 100. Plain or solid backrest for Norton grinding machines. 
 
 metrically opposite the grinding, wheel and another on the 
 opposite side of the vertical center line close up to the point 
 where the wheel comes in contact with the work being 
 ground. This is plainly seen in the illustration. Howard 
 W. Dunbar, in Grits and Grinds, a Norton Co. publication, 
 has the following to say in regard to solid backrests: 
 
 "The shoe should be exactly the same diameter as the 
 finished ground work, and should be allowed to come in 
 contact with the surface being ground immediately upon 
 starting the grinding operation. The practice of attempting 
 to true up the seat for the steady-rest shoe before bringing 
 the shoe in contact with the work is wrong, as it allows 
 the face of the wheel to break down, due to vibration of 
 the work being ground. The support should be supplied 
 immediately upon starting the grinding operation. It is a 
 
 226
 
 CYLINDRICAL GRINDING 
 
 fact that work can be, and has been ground round and true 
 with no support other than the steady-rests." 
 A spring backrest made by the Brown & Sharpe Mfg. Co. 
 is shown in Fig. 101, and the following description of this 
 rest and its use is from Commercial Grinding by the Use of 
 
 Fig. 101. Spring backrest for Brown & Sharpe grinding machines. 
 
 Plain Grinding Machines, a shop handbook published by 
 the Brown & Sharpe Mfg. Co. : 
 
 "The shoe is of wood, brass or other soft metal, the end 
 being made approximately to fit the work being ground. 
 The spring keeps the shoe in close contact with the work 
 and also allows the rest to conform to variations in the size 
 of the work. The work, when revolving, tends to climb 
 on the shoe, thus keeping the pressure on the lower roller 
 and supporting the work on the under side. The shoes 
 should be made of brass, soft metal, or wood, thus allowing 
 the revolving work to wear the surface away sufficiently 
 for it to fit the constantly varying size of the work. Brass 
 or soft metal is best, but wood is also used. The shoe should 
 have sufficient surface to last well but not enough to retard 
 the wear mentioned. The shoe should move freely in the 
 slide and be of sufficient mass to absorb slight vibrations. 
 As the illustration shows, the spring holds the shoe in con- 
 tact with the work and the pressure is regulated by the 
 
 227
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 thumb screw. In fitting a shoe of this kind, it should first 
 bear well on the under side of the work. The wear will 
 quickly fit it to the work and the shoe will always have a 
 firm bearing underneath. The shoes should never be made 
 of hard metal or of a V shape. It is not always necessary 
 for the shoe of a spring rest to bear entirely around one- 
 half of the circumference of the work. A shoe of sufficient 
 
 Fig. 102. Universal backrest for Brown & Sharpe grinding machines. 
 
 mass will prevent vibration, and, as it is of soft material, 
 will soon wear to fit the varying circumference." 
 
 A universal backrest is illustrated in Fig. 102. This 
 device is a product of the Brown & Sharpe Mfg. Co. and 
 is suitable for all kinds of work. It possesses the advantages 
 of a solid rest combined with those of the spring rest. A 
 
 228
 
 CYLINDRICAL GRINDING 
 
 Brown & Sharpe grinding machine equipped with universal 
 rests is illustrated in Fig. 103. The Brown & Sharpe Com- 
 pany give the following directions for the use of the universal 
 backrest : 
 
 "One rest is required for each six to ten diameters of 
 work in length. Thus, a piece of work i inch in diameter 
 and 36 inches long would require six rests. Shorter work 
 
 Fig. 103. Brown & Sharpe grinding machine equipped with universal 
 backrests. 
 
 having different diameters, such as lathe spindles, require 
 two or three rests. To place the shoe in proper position 
 proceed as follows : First, select shoes the size of the finished 
 work and hook the trunnions 25 into the Vees 26. Second, 
 turn back the screw 27 far enough to allow the shoe to 
 clear the work and loosen nut 28 entirely to relieve the 
 pressure on spring 29. Then turn back screw 30. Third, 
 turn forward the screw 3 1 until a light pressure is given to 
 the spring 32. Turn forward the screw 27 and, if the spring 
 29 is wholly relieved and the screw 30 is far enough back, 
 the shoe will come in contact with the work at both points 
 A and B. Fourth, press lightly with the thumb, on 36, 
 
 229
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 holding the shoe in gentle contact with the work, and turn 
 the screw 30 carefully, noting the slightest touch of the end 
 against the stop C in order that none of the parts be moved, 
 and, with this screw in contact with the stop, the shoe 
 should bear equally at both points A and B. Turn nut 28 
 to give some pressure to the spring 29. The combined 
 pressure of the springs 29 and 32 should be only sufficient 
 to resist the pressure of the wheel when taking the last cut, 
 and also to prevent vibration of the work when any cut is 
 taken. Constant use of the shoes will wear the surfaces 
 A and B, allowing the work to bear on that part of the shoe 
 between the surfaces. When shoes are worn in this man- 
 ner, clearance should be filed between the surfaces A and B. 
 Fifth, grind the trial piece of work, moving the screw 27 
 to maintain the contact of the shoe with the work and the 
 screw 30 to preserve the relative diameters at the various 
 points. As the work approaches the finished size, measure 
 at the different rests after each cut. After the trial piece 
 is finished, with the diameter alike at all points, the shoe 
 should bear equally at A and B and the sliding nut 33 should 
 rest against the shoulder. Leave the parts in this relation 
 and grind the other piece of work, adjusting screw 27 only 
 as the shoe wears, and screw 30 for the delicate adjustment 
 for diameter. Note the effect of the adjustment upon the 
 sparks to determine the approximate position. When the 
 work is to size, the nut 33 and the screw 30 are intended to 
 rest against the shoulder and stop to prevent further pres- 
 sure of the shoe upon the work. The shoe and wheel will 
 be left in the proper position for sizing duplicate pieces. 
 When unground work is placed between the centers and 
 in the show bearings, the nut 33 and the screw 30 will be 
 forced away from the shoulder and stop, thus compressing 
 the springs 29 and 32. Should the shoe bear unequally 
 at A and B, the screw 28 should be tightened to increase 
 pressure at A and screw 31 to increase pressure at B. Do 
 not make the combined pressure of these springs greater 
 than necessary as long and slender work, although of uni- 
 
 230
 
 CYLINDRICAL GRINDING 
 
 form diameter, may not be straight when released from the 
 shoe unless some allowance is made for elasticity." 
 
 Some twenty-five years ago, when grinding machines 
 were few and far between, cylindrical grinding was often 
 done dry. This practice is now considered unsatisfactory, 
 except perhaps for light intermittent work as sometimes 
 done in the tool-room on very small machines. To secure 
 maximum production on routine work, it is of the utmost 
 importance to cool and lubricate the work at the same time. 
 To the layman, it may sound out of place to speak of lubri- 
 cating the work on a. plain grinding machine. We are apt 
 to recall the all-round machinist of a quarter of a century 
 ago who would, no doubt, hold up his hands in horror at the 
 thought of bringing oil in contact with a grinding wheel. 
 
 Various compounds are now used in lubricating work 
 while grinding. These consist of mixtures of water, soap, 
 oil and sulphite of soda, commonly termed sal soda. Plain 
 water is sometimes used and while this keeps down fric- 
 tional heat, its use rusts both the machine and the work. 
 Soda water is better than plain water as the soda prevents 
 the water from rusting. The various compounds put up 
 especially for the purpose, however, are efficient as they 
 have been worked out by grinding engineers after much 
 practical experimentation. The lubricant should be sup- 
 plied by the circulating pump and should flood the work 
 at the point of grinding contact. 
 
 To produce satisfactory work, it is necessary that the 
 grinding wheel be in condition to perform its work rapidly 
 when taking roughing cuts and smoothly when taking finish- 
 ing cuts. A satisfactory cutting surface is produced on 
 the wheel in two ways: by dressing and truing. These ex- 
 pressions are sometimes confusing, but the generally ac- 
 cepted meaning is that dressing consists of sharpening a 
 wheel to make it cut fast, while truing consists of imparting 
 a surface that will leave a smooth finish. 
 
 As explained in Chapter X, wheels on cylindrical grinding 
 machines can be dressed to advantage with ordinary star- 
 
 231
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 wheel cutters held in a suitable holder. For many years, 
 the man who brought an emery-wheel dresser, as this tool 
 is called, near a precision grinding machine was ridiculed, 
 but latter-day experimentation has proven that grinding- 
 wheel dressers of the Huntington type have their part to 
 play in cylindrical grinding as well as for dressing wheels 
 lor rough grinding work. 
 
 There are several good reasons for using dressers of the 
 kind under consideration, not the least of them being the 
 present high cost of the bort diamonds generally used here- 
 tofore. It must be remembered, however, that the grinding- 
 wheel dresser has its limitations. On the cylindrical grinder, 
 its usefulness ends in preparing wheels for roughing oper- 
 ations. To true the face of the wheel for taking finishing 
 cuts, the diamond should be used. 
 
 In dressing the wheel, the dresser should be held in a 
 special holder, such as the one shown in Fig. 104, which 
 shows a special Huntington dresser in use on a Norton 
 grinding machine, and fed past the wheel with a rapid, 
 even motion. 
 
 In truing a wheel to take smooth finishing cuts, the 
 diamond tool should be held securely in the holder provided 
 ior it and fed past the wheel with an even motion, taking 
 .a very light cut. An expert operator knows how to use a 
 diamond advantageously to bring about the desired results 
 and this knowledge is gained by practice alone. In both 
 truing and dressing operations, the wheel should be flooded 
 with a liberal stream of lubricant. 
 
 Chatter marks on finished work are sometimes present 
 and they can be attributed to a number of causes. Those 
 not thoroughly conversant with the art of cylindrical grind- 
 ing, often lay chatter marks to the gearing in the headstock. 
 It is true, of course, that incorrectly fitted gears cause 
 chatter marks. This cause, however, is not of common 
 occurrence. The unskilled operator who desires to "wish" 
 chatter marks on the headstock gearing generally cites the 
 fact that an incorrectly fitted rack and bull gear on a metal 
 
 232
 
 CYLINDRICAL GRINDING 
 
 planer leaves marks in the finished work and thus tries to 
 establish a parallel case with the grinder. This comparison 
 is not logical. The planer leaves marks in the finished work 
 because the gearing is allowed to bottom either through 
 wear in the ways or from chips and dirt that become im- 
 bedded in the bottom of the bull gear and rack teeth. With 
 the grinder, there are no chips or dirt to work into the 
 
 Fig. 104. Dressing the wheel on a Norton grinding machine with a 
 Huntington star-wheel dresser. 
 
 gearing and, furthermore, wear in the gears in question 
 does not cause them to bottom. 
 
 Chattering in connection with the plain grinder can be 
 laid to many causes, among them being the following: 
 Centers poorly fitted, wheel slide or spindle loose, head or 
 tailstock loose, incorrect relation between wheel and work 
 speed, lack of sufficient steady-rests, improperly trued wheel, 
 wheel out of balance and end play caused by the work not 
 being sufficiently supported by the centers. When chat- 
 
 233
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 tering occurs, the first thing to do is to go over the machine 
 carefully, inspecting all adjustments, and if this does not 
 correct the evil, some of the other above-named causes 
 should be investigated. 
 
 For the economical and efficient operation of any cylin- 
 drical grinding machine, it is very necessary that the wheel 
 be in as perfect running balance as possible. Wheels that 
 are out of balance cause vibration and chatter marks; 
 they wear out spindle boxes rapidly and if badly out of 
 balance, they are liable to burst, which means possible 
 injury to the workman, the loss of a comparatively ex- 
 pensive wheel and curtailment of production until a new 
 wheel is mounted. 
 
 Wheels, as they come from the grinding-wheel manu- 
 facturer, are in balance within very close limits. It is im- 
 possible for the wheel manufacturer to make a wheel that 
 
 Fig. 105. Balancing a grinding wheel by chipping the heavy side. 
 
 is in perfect running balance without some special treat- 
 ment owing to the fact that the wheel texture is apt to 
 vary slightly. Thus, one side of the wheel may be a little 
 heavier than the opposite side. 
 
 One method of balancing a grinding wheel is shown in 
 Fig. 105. In this case, the light side of the wheel is at A and 
 
 234
 
 CYLINDRICAL GRINDING 
 
 the opposite, or heavy side, is chipped away enough to 
 counterbalance the unequal weight. This work is done with 
 an ordinary cold chisel, but care must be used, otherwise 
 the wheel will be broken. The Landis Tool Co. make use 
 of the device illustrated in Fig. 106. This consists of two 
 balancing blocks which have radial movement in a*i annular 
 groove turned in the wheel holder. The blocks can be se- 
 
 Fig. 1 06. Landis wheel- holder equipped with balancing blocks. 
 
 curely clamped in the desired position by means of screws. 
 It is a comparatively easy matter to balance a wheel that 
 is mounted on a holder of this type as all that is necessary 
 is a simple adjustment of the balancing blocks. 
 
 In selecting wheels for use on the plain cylindrical grinder, 
 it must be borne in mind that rapid production depends on 
 the wheel used more than it does on any one other factor. 
 It is impossible to give hard and fast rules governing the 
 selection of wheels for various kinds of work owing to the fact 
 that local conditions often have to be taken into consider- 
 ation. The following grits and grades, however, have been 
 found to give satisfaction for the various classes of work 
 
 235
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 The grades are given in the writer's proposed grade 
 
 listed, 
 scale. 
 
 MATERIAL 
 
 Hard Steel 
 
 Soft Steel 
 
 Cast Iron . ; 
 
 Brass 
 
 Chilled Iron 
 
 Pistons, Cast Iron 
 
 Pistons, Steel 
 
 Pistons, Lyanite 
 
 Piston Rings, Cast Iron 
 
 As before stated, the universal grinder is adapted to a 
 wide range of work. A typical universal grinder is shown 
 in Fig. 107. This machine is made by the Brown & Sharpe 
 
 ABRASIVE 
 
 GRIT 
 
 GRADE 
 
 Alumina 
 
 30 to 40 
 
 5 to 7 
 
 Alumina 
 
 30 to 40 
 
 5 to 6 
 
 Silicon Carbide 
 
 30 to 36 
 
 4 to 7 
 
 Silicon Carbide 
 
 30 to 40 
 
 8 
 
 Silicon Carbide 
 
 36 
 
 8 
 
 Silicon Carbide 
 
 24 to 36 
 
 4 to 6 
 
 Alumina 
 
 24 to 36 ' 
 
 4 to 6 
 
 Silicon Carbide 
 
 30 to 40 
 
 5 to 7 
 
 Silicon Carbide 
 
 36 to 40 
 
 4 to 6 
 
 Fig. 107. Brown & Sharpe i2x3O-inch universal grinding machine. 
 
 Mfg. Co., Providence, R. I. The average universal grinder 
 is somewhat smaller than the plain grinder ordinarily seen. 
 The machine illustrated takes work 30 inches long and will 
 swing 12 inches over the platen while the wheel used is 12 
 inches in diameter and from 3/8 to i inch thick. 
 
 236
 
 CYLINDRICAL GRINDING 
 
 The headstock of any universal grinder is supplied with 
 a live spindle which can be locked when it is desired to 
 grind on dead centers. The live spindle adapts itself to 
 a variety of work, principally internal grinding, in which 
 
 Fig.-ioS. Grinding the -side of a disc on a Brown & Sharpe universal 
 grinding machine. 
 
 case a chuck for holding the work is screwed on the nose 
 of the spindle. The base of the headstock on the machine 
 shown swivels and this permits the machine to handle a 
 variety of angular work. The wheel slide also swivels, 
 
 237
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 which feature is often taken advantage of in grinding 
 abrupt tapers on work that is held between centers. 
 
 The following examples, which graphically illustrate the 
 adaptability of the universal grinder, are furnished by the 
 Brown & Sharpe Mfg. Co. Fig. 108 illustrates the grind- 
 ing of the end of a disk that is fastened to a shaft, the work 
 
 Fig. 109. Grinding an abrupt taper on a Brown & Sharpe universal grinding 
 machine. 
 
 being held between centers. The grinding wheel is placed 
 on the end of the spindle. 
 
 In Fig. 109 is shown the operation of grinding an abrupt 
 238
 
 CYLINDRICAL GRINDING 
 
 taper. In this operation, the swivel platen remains parallel 
 with the ways of the machine as in plain grinding, but the 
 wheel bed is set to the required angle which brings the line 
 of motion of the wheel slide, when operated by the cross 
 feed, parallel with the taper to be ground. The wheel 
 
 Fig. 1 10. Grinding two tapers at one setting on a Brown & Sharpe 
 universal grinding machine. 
 
 platen is set at right angles with the line of movement of 
 the wheel slide, indicated by the arrow, and the face of the 
 wheel is thus brought parallel with the line of the desired 
 taper. The work is revolved by the dead-center pulley as 
 the illustration shows, and the wheel is traversed over the 
 work by means of the cross feed. 
 
 239
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 It is often advantageous to grind two tapers with one 
 setting of the machine as shown in Fig. no. The Five- 
 degree taper is obtained by setting over the swivel plate 
 while the forty-five-degree taper is obtained by setting the 
 wheel bed to the desired angle. In obtaining the angle at 
 which the wheel bed is to be set, after the swivel platen 
 has been set, it must be borne in mind that the angle must 
 equal the sum of the two tapers. The abrupt taper is 
 ground by feeding the wheel across the work by hand, 
 while the slight taper is ground by feeding the platen back 
 and forth automatically. 
 
 Fig. in shows how the centers are ground on the uni- 
 versal grinder. The live spindle is used to drive the center, 
 the headstock being swiveled 30 degrees. 
 
 Fig. ill. Grinding a center on a Brown & Sharpe universal grinding 
 machine. 
 
 An interesting operation is shown in Fig. 112 which con- 
 sists of grinding the sides of such work as hardened collars, 
 washers, etc. The work is held in the chuck which is 
 screwed to the nose of the spindle, while the headstock is 
 set at 90 degrees with the travel of the platen. The wheel 
 
 240
 
 CYLINDRICAL GRINDING 
 
 Fig. 1 12. Grinding the side of a disc which is held in a four- 
 jaw chuck on a Brown & Sharpe universal grinding machine. 
 
 Fig. 113. Appliance for grinding the sides of milling cutters, 
 discs, etc., on a Brown & Sharpe universal grinding machine. 
 
 241
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 is brought against the work by hand feeding and the auto- 
 matic feed is used to traverse the work past the wheel. 
 
 For grinding such work as washers, milling cutters, thrust 
 collars, etc., the appliance illustrated in Fig. 113 is conven- 
 ient. The face plate screws on the end of the spindle and 
 holds the work by means of a split bushing which is ex- 
 panded in the hole in the work. The work is held by the 
 expansion bushing C which is expanded by the screw B 
 and drawn tightly against the face plate by turning the 
 knob A. Different sizes of bushings are readily inserted 
 to take care of a wide range of work. 
 
 From the foregoing, it is readily seen that the universal 
 grinder is adapted for a wide range of work that cannot 
 be done on the plain grinder. For this reason, it is a good 
 plan to install a universal grinder in cases where one machine 
 is depended upon to take care of all the shop needs. Aside 
 from the examples shown, the universal grinder is used for 
 internal grinding and cutter sharpening. These subjects 
 will be treated later.
 
 CHAPTER EIGHTEEN 
 
 INTERNAL GRINDING 
 
 Internal grinding machines Internal grinding on universal grinder Setting 
 up universal grinder for internal work Grinding double tapers Auto- 
 matic grinders Grinding holes in spur and bevel gears Chucks Wet 
 and dry grinding Proper speeds Selection of wheels Operating of 
 cylinder grinders Cylinder grinding. 
 
 DEFORE the advent of the automobile industry, in- 
 ' ternal grinding was confined chiefly to the tool-room 
 and consisted of accurately finishing gauges, bushings, etc., 
 the work being done on the universal grinder. With the 
 growth of the automobile industry, however, came the de- 
 mand for finishing countless numbers of parts by internal 
 grinding and thus special machines have been gradually 
 developed for this purpose. 
 
 Special internal grinding machines are production tools 
 just as the plain cylindrical grinder is a production machine 
 while the universal grinder is still used for the internal 
 grinding of general tool-room work. 
 
 Fig. 114 shows a Brown & Sharpe universal grinder ar- 
 ranged for internal grinding. Here it is seen that the regu- 
 lar wheel spindle has been removed and in its place sub- 
 stituted a jack shaft that drives the internal grinding 
 fixture which is bolted to the wheel platen. It is also seen 
 that the wheel spindle bracket is reversed. As the arrows 
 show, the grinding-wheel spindle rotates away from the 
 operator while the work to be ground, which is held in a 
 chuck screwed to the nose of the headstock spindle, rotates 
 toward the operator. 
 
 Setting up a universal grinder for internal work is a 
 simple operation, but care must be exercised in setting the 
 
 243
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 headstock to bring its spindle in line with the travel of 
 the platen if parallel work is desired. It is almost impossible 
 to accomplish this by relying on the graduations of the 
 headstock swivel and on the platen swivel and as the cut- 
 
 Fig. 114. Brown & Sharpe universal grinding machine arranged for 
 internal grinding. 
 
 and-try method is both slow and uncertain, other means 
 to the desired end are generally used by the mechanic 
 who desires to turn out accurate work. 
 
 The simplest and most practical method for accomplish- 
 ing the desired result that has come to the writer's notice, 
 is described below : First the chuck is screwed on the head- 
 
 244
 
 INTERNAL GRINDING 
 
 stock spindle which is unlocked to allow it to rotate. Next 
 a piece of round stock somewhat longer than the depth of 
 the hole to be ground is clamped in the chuck jaws, allowing 
 several inches to project. Then a relief is ground close 
 to the chuck jaws. This is for the grinding wheel to dwell 
 in during reversal in the subsequent operation. Then the 
 outside of the piece is ground true and calipered carefully 
 and the headstock reset until the wheel grinds the test 
 piece parallel. When parallelism results, it is evident that 
 the headstock spindle is parallel with the travel of the 
 platen, which is the situation necessary for accurate in- 
 ternal grinding. The test piece is now removed and the 
 machine set up for internal grinding. The operator need 
 not pay attention to parallelism after this as it is assured. 
 He is then free to concentrate his efforts to getting his work 
 to the desired size. 
 
 In grinding tapers, the headstock is set over to the desired 
 angle and the work, after being ground, is tested with a 
 taper gauge on which a little Prussian blue is smeared. 
 This furnishes a ready means of detecting any errors that 
 exist. It is readily seen that it is a more simple matter to 
 set up the internal grinding attachment to grind tapers 
 than it is to grind absolutely parallel, that is by the cutting- 
 and- trying method. 
 
 The machine shown in Fig. 115 is arranged to grind a 
 double taper. The swivel platen is set over to give the 
 five-degree taper while the wheel platen is set to impart the 
 forty-five-degree taper. From these illustrations, it is seen 
 that the universal grinder can be adapted to a variety of 
 tool-room work. In fact, it can handle some varieties of 
 work that are beyond the range of the production internal 
 grinder. For this reason, internal grinding on the universal 
 grinder will always be a part of tool-room work. 
 
 Special internal grinding machines are designed as pro- 
 duction tools for rapidly and accurately finishing more 
 work in a given time than it is possible to turn out on the 
 universal grinder. Broadly speaking, these machines can 
 
 245
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 be divided into two groups, those having hand feed and 
 those equipped with automatic feed. This feature applies 
 to the platen. 
 
 Machines equipped with hand feeds are adapted for 
 grinding such work as transmission gears, bevel gears, 
 
 Fig. 1 1 5. Grinding a double internal taper on a Brown & Sharpe universal 
 grinding machine set up for internal work. 
 
 pinions, bushings, or, in fact, any kind of short work. Ex- 
 perience has proven that on work not over three inches long, 
 the average operator will turn out more work with a hand- 
 fed machine than he will with a machine equipped with 
 automatic feed. 
 
 The machine illustrated in Fig. 116 is a product of The 
 Heald Machine Co., Worcester, Mass., and is thoroughly 
 automatic in all its operations. It swings work 15 inches 
 in diameter and will grind holes n inches deep. The head- 
 
 246
 
 INTERNAL GRINDING 
 
 stock is swiveled to permit grinding taper work and different 
 speed changes are provided for roughing and finishing 
 operations. The cross feed is automatic in operation and 
 can be set to release when a given size has been reached. 
 A novel feature of this machine is the protection guard over 
 the wheel. This comes to the position shown in the illus- 
 
 Fig. 116. Heald automatic internal grinding machine. 
 
 tration when the platen is moved away from the work and 
 its object is to prevent the operator's hand from coming 
 in contact with the swiftly revolving wheel should his hand 
 slip while gauging his work. 
 
 By again referring to Fig. 116, it is seen that the work 
 is held in a three-jaw chuck. This procedure is satisfactory 
 in cases where the wall of the bushing, or other work being 
 operated upon, is comparatively thick. With thin-walled 
 bushings, the pressure brought to bear by the chuck jaws 
 is apt to cause distortion if the work is gripped tight enough 
 to hold it securely. To overcome this difficulty, many 
 novel devices have been originated. One of these is shown 
 
 247
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 in Fig. 117. This is a Heald universal bushing chuck. 
 It consists of a body (i) which screws on the spindle, a 
 movable cap (2), and adjustable threaded collar (8), and 
 another collar (3) which centralizes the locating plug (4). 
 The bushing to be ground is shown at 5. As the illustra- 
 
 Fig. 117. rHeald universal bushing grinding chuck. 
 
 tion shows, the part of the plug that engages the bushing 
 is triangular in shape (6), while the end that engages the 
 threaded collar is round as seen at 7. As this chuck grips 
 the work at its ends, it holds it securely without danger of 
 distortion. 
 
 One of the most difficult grinding problems with which 
 the production engineer has to contend, is grinding the 
 holes in spur and bevel gears as used in automobile trans- 
 missions and differentials. These gears are hardened and 
 heat-treated, thus they come to the grinding department 
 in a slightly distorted condition. For smooth running, it 
 is obvious that the pitch line of the gears must run as true 
 as possible after assembling. To this end, special chucks 
 have been developed for holding these gears in which the 
 location is taken from the teeth at the pitch-line circle. 
 
 Fig. 118 illustrates three common methods for locating 
 gears as described by the Heald Company. In A, the gear 
 is held wholly by the outside diameter. In B, jaws of special 
 shape are employed, which grip the gear at the bottom of 
 the tooth space, while in C rolls are used which make con- 
 
 248
 
 INTERNAL GRINDING 
 
 -3 
 
 -C I 
 
 Fig. 1 1 8. Three types of chucks used in grinding the holes in gears on a 
 Heald internal grinding machine. 
 
 249
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 tact at the pitch line. The first and third methods are the 
 ones most commonly used. 
 
 In considering the first method, it is obvious that the 
 outside diameter of the gear is not always concentric with 
 the bore. In cases where the outside diameter is concentric 
 with the bore, the teeth are often eccentric with the hole, 
 owing to the fact that the gear is sometimes* a loose fit on 
 the gear-cutting arbor. Again, the gear-cutting arbor is 
 often slightly out of true, which brings about the same 
 result. 
 
 In the second method, shown at B, the jaws of the chuck 
 make contact at the bottom of the tooth space. This is 
 a better method than the one above described inasmuch as 
 the bottom of the teeth are theoretically all the same dis- 
 tance from the pitch circle. The disadvantages of this 
 method of locating gears is that the bottom of the teeth 
 is often rough and sometimes curved owing to the shape 
 of the tooth at this point and for these reasons the method 
 is not as satisfactory as it might appear. 
 
 The third method, shown at C, called pitch-line control, 
 wherein the gear is clamped in place through the medium 
 of three rolls evenly spaced around the gear as the illustra- 
 tion shows. If the teeth are evenly spaced and the gear 
 unhardened, this method is generally satisfactory. It must 
 be borne in mind, however, that distortion is bound to take 
 place when gears are hardened and this has an effect on 
 the spacing of the gear as well as on its other dimensions. 
 
 It is readily understood that any variation in the tooth 
 spacing is bound to alter the even spacing of the rolls. For 
 example, let it be assumed that one roll is located in a 
 narrow tooth while the next roll happens to fall into a wider 
 tooth. The location of the gear is bound to be eccentric. 
 
 The chucks shown in Fig. 118 are all alike with the ex- 
 ception of the locating points shown at 4. Briefly described, 
 the chuck consists of a body (2) which screws to the nose 
 of the spindle and a collet (3) which is split in three places 
 and drawn into the chuck by means of a drawing rod 
 
 250
 
 INTERNAL GRINDING 
 
 which works through the hole in the grinding-machine head 
 spindle. The gear is shown at 5, while 6 is the grinding 
 wheel and 7 the grinding-wheel spindle. The body of the 
 chuck is generally made of cast iron, while the collet is steel 
 and insured against reasonable wear by case hardening. 
 
 For various work, aside from the grinding of gears, these 
 collet chucks are to be preferred to ordinary three-jaw 
 chucks because the latter soon fill up with particles of 
 metal ground from the work which calls for frequent cleaning. 
 
 For grinding gears where accuracy and quiet running are 
 paramount factors, the Heald Company have developed 
 the chuck shown in Fig. 119. This chuck works on the 
 
 Finish for Indicator 
 
 .-Harafenecf Spiff King 
 
 /Retainer King 
 
 Loose 
 on Rolls. 
 
 Fig. 119. Heald multiple-roll chuck for holding gears for internal grinding. 
 
 multiple-roll system and has a single split ring which- col- 
 lapses as it is forced into the chuck. In this method of 
 locating gears, a number of rolls are used. The number 
 depends on the number of teeth in the gear. In the gear 
 shown in the chuck in Fig. 119, nine rolls are used. The 
 minimum number of rolls to use, however, should not be 
 less than five. The rolls are hardened and are carried 
 loosely in a retainer ring which keeps them in the proper 
 position and in shape to be readily handled by the operator. 
 In Fig. 119, the gear (7) and the rolls (6) are inserted in a 
 
 251
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 split ring (4) made straight inside and tapering on the out- 
 side with a short thread to enable it to be screwed in and 
 out of the body of the chuck. The body (3) is mounted 
 on a face plate (2) which is screwed on the chuck spindle (i). 
 
 The object of making the chuck body in two pieces, 2 
 and 3, is to afford ready means for keeping the chuck 
 running absolutely true. By referring to Fig. 119, it is 
 seen that part of the outside of the piece (3) is ground 
 cylindrical to make a path for the indicator to register on 
 while truing up the chuck. This feature allows the operator 
 to check up the running of the chuck as frequently as de- 
 sired. The split ring (4) is hardened to insure it against 
 wear. Otherwise the pressure of the rolls would soon im- 
 pair its accuracy as they would imbed themselves slightly 
 at the points of contact every time the chuck was tightened. 
 
 In Pig. 120, is shown a Heald chuck for locating large bevel 
 gears as used in automobile rear axles. An unhardened 
 
 Fig. 1 20. Heald chuck for locating large bevel gears for internal grinding. 
 
 gear (2) is mounted on the face plate, which is recessed 
 slightly to center the locating gear so that it will run true, 
 at all times. The gear to be ground (3) is located with its 
 face to the locating gear and is held in place by three clamps 
 
 252
 
 INTERNAL GRINDING 
 
 shown at 4. As the illustration shows, a portion of the teeth 
 of the locating gear are cut back as at 5 leaving full-length 
 teeth (6) at three points of the circumference. This three- 
 point contact insures the gear against rocking on its seat. 
 
 Another novel gear chuck is shown in Fig. 121. This 
 chuck was originated by the Heald Company and is used 
 for grinding bevel pinions. In reality it is a modification 
 
 Fig. 121. Heald chuck for locating bevel pinions for internal grinding. 
 
 of the principle used in the chuck shown in Fig. 119. Taper 
 rolls are used which are spaced around the circumference 
 to locate the gear in proper position according to the pitch 
 line. The taper rolls should be three, five or seven in -num- 
 ber, according to the number of teeth in the gear. 
 
 The method of holding the rolls allows for a certain 
 amount of play for the purpose of taking care of slight 
 variations in the gears, due to hardening. 
 
 Referring to Fig. 121,1 is the spindle, 2 the chuck body, 3 
 the clamp arms that hold the gear in position, 4 the locating 
 rolls and 5 the retaining ring in which the rolls are mounted. 
 
 While the present-day internal grinder is a production 
 machine ia every sense of the word, it is not a tool for 
 "hogging" off stock. It is a machine especially designed 
 for finishing operations. For this reason, attention should 
 be paid to the amount of stock left for grinding, especially 
 in hardened work. 
 
 253
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 The amount to be left for grinding depends on the di- 
 ameter of the hole and its length. In considering hardened 
 work, it is very evident that comparatively long pieces will 
 warp more than shorter ones. On short pieces with holes 
 1-1/2 inches in diameter and down to i inch, 0.008 to o.oio 
 inches is sufficient. On smaller holes, the allowance can 
 be decreased. Larger holes require a more liberal allow- 
 ance. A good plan to determine the amount to leave for 
 finishing on regular production is to start with liberal 
 allowances and note how much the operator has left to 
 grind out after the work has been ground round, that is 
 when the wheel is cutting a complete circle through the 
 entire length of the piece. If several thousandths of an 
 inch are invariably left to remove after the work has assumed 
 a round and true shape, the grinding allowance can be 
 reduced. 
 
 In grinding soft work, the general rule is to leave a little 
 more than is absolutely necessary to true up the work and 
 grind out the tool marks. A little experimentation will 
 determine the correct amounts in all cases. 
 
 Internal grinding is done both wet and dry. The general 
 accepted rule is to grind cast iron and bronze dry and to 
 grind steel wet. However, this rule does not have to be 
 adhered to without exceptions as steel is often ground dry 
 with satisfactory results. In wet grinding, the hood over 
 the chuck keeps the spray from flying. In dry grinding, an 
 exhaust pipe draws away the dust through the hollow-head 
 spindle. This protects the operator and keeps the machine 
 clean at the same time. 
 
 Wheels on internal grinders are run at peripheral speeds 
 ranging from 4,000 to 6,000 feet per minute while the work 
 speed can vary from 25 to 100 feet per minute. There is 
 no hard and fast rule to refer to, but the experienced oper- 
 ator judges the correct combination of wheel and work 
 speed by the quality and quantity of the output and the 
 performance of the wheel. 
 
 In selecting wheels for internal grinding, carbide of silicon 
 254
 
 INTERNAL GRINDING 
 
 is used for cast iron and bronze while alumina abrasives 
 should be used on steel, both hard and soft. For the aver- 
 age run of work, grits from 36 to 50 are used in grades 4 to 6 
 on the writer's grade scale. For grinding cast iron, the 
 grades are somewhat softer, from 2 to 5. As a general rule, 
 soft wheels give the best results. The reason for this lies 
 in the fact that there are comparatively few cutting points 
 on these small wheels, and if they do not wear away readily, 
 bringing new cutting points into action, the wheel glazes 
 quickly. 
 
 Careful attention should be given to keeping wheels on 
 internal grinding machines true. They should never, under 
 any circumstances, be dressed with a star-wheel dresser 
 although a carbide of silicon brick is a good medium to use, 
 provided it is held securely in a holder that is fastened to 
 the platen on the machine. The operator should never 
 attempt to true the wheel by holding the brick in his hand 
 as this gives poor results. The diamond is an ideal tool 
 for truing these wheels, but the present cost of bort stones 
 makes their use prohibitive in cases where another medium 
 will serve the purpose equally well. 
 
 Because of their high rotative speed, internal grinding 
 machine wheel spindles should be properly lubricated with 
 a grade of oil that is especially adapted for the purpose. 
 There is a great difference between ordinary slow-running 
 bearings and those of a high-speed grinding spindle. The 
 former takes a heavy oil which forms a thick film on which 
 the journal rests. With the latter, the bearings are adjusted 
 very closely and for this reason a light-bodied, high-grade 
 oil should be used. 
 
 A special internal grinding machine that is widely used 
 in the automobile and airplane engine industry is shown in 
 Fig. 122. This is a cylinder grinder made by the Heald 
 Machine Co. With the development of the automobile 
 industry, considerable difficulty was experienced in finish- 
 ing cylinders by ordinary methods, that is, boring or ream- 
 ing. This was due to several factors, chief among them 
 
 255
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 being the fact that cylinder walls are comparatively thin, 
 thus they sprang away from the finishing tools which left 
 the cylinder considerably out of true. Again, internal- 
 combustion engine cylinders should be made of a compara- 
 tively hard, close-grained iron which is always difficult to 
 
 Fig. 122. Heald cylinder grinding machine. 
 
 machine accurately. With these factors in mind, engineers 
 turned to the grinding machine for a solution of the difficulty. 
 The ordinary single cylinder of other days was a difficult 
 piece to grind inasmuch .as it could not be rotated readily 
 a special grinding fixture was necessary which had pro- 
 vision for running and balancing each individual cylinder. 
 Again, it would be impossible to rotate a cylinder of the 
 type illustrated, in Fig. 123, which is cast en bloc. There- 
 fore the machine shown in Fig. 122 was developed. The 
 base and upright of this machine are cast in one piece. The 
 wheel spindle is mounted at the top of the upright and is 
 of the planetary type. The main spindle revolves to carry 
 
 256
 
 INTERNAL GRINDING 
 
 the wheel around the wall of the cylinder to be ground 
 while the supplementary spindle rotates rapidly to impart 
 motion to the grinding wheel. A special adjustment, 
 graduated in thousandths of an inch, determines the eccen- 
 tric setting of the wheel spindle. 
 
 The platen can be adjusted at right angles to the wheel 
 spindle by means of a screw feed equipped with a microm- 
 
 Fig. 123. Multiple cylinder for an automobile engine as finished by 
 grinding. 
 
 eter dial, which feature is made use of in grinding cylinders 
 of the type shown in Fig. 123. The platen is fed longi- 
 tudinally by means of an automatic feed, the movement 
 being controlled by adjustable dogs that actuate the re- 
 versal at each end of the stroke. 
 
 The operation of grinding the cylinder shown in Fig. 
 123 is shown in Fig. 124. The cylinder is mounted on a 
 special angle-iron fixture that is clamped to the platen of 
 the machine. One bore of the cylinder is ground at a time 
 and completely finished before moving the platen to grind 
 the next hole. The amount to leave for grinding depends 
 upon the size of the cylinder and the condition in which the 
 holes are left by the rough boring operation. Usually 
 cylinders are rough bored with a coarse feed which leaves 
 deep tool marks. This is advantageous as the tool marks 
 
 257
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 exert a shearing motion of the wheel which helps to keep 
 it true. If the holes are accurately spaced in the boring 
 operation from o.io to 0.15 inches below the bottom of -the 
 boring tool marks are sufficient for finishing. This is not a 
 hard and fast rule by any means as local conditions must 
 be taken into consideration, thus experimentation is the 
 
 Fig. 124. Grinding a four-cylinder unit for an automobile engine on a 
 Heald cylinder grinding machine. 
 
 only accurate guide. If the operator finds that he has a 
 large amount of stock to remove after the holes show up 
 true, the amount left for finishing should be reduced and, 
 on the other hand, if the holes fail to "grind out " the allow- 
 ance must be increased. It is best when first installing a 
 grinder for this work to start with a liberal allowance which 
 can be reduced if too much stock has been left. 
 
 Cylinder grinding is a precision operation in every sense 
 of the word, especially when finishing cylinders for aircraft 
 engines. For this reason, the wheel must be kept true and 
 in cutting condition at all times. By again referring to 
 Fig. 124, it is seen that there is a bracket set at an angle 
 under each cylinder location. These are for holding a dia- 
 
 258
 
 INTERNAL GRINDING 
 
 mond tool used for truing the wheel. In this illustration, 
 the diamond tool is fastened in the bracket at the right of 
 the cylinder being ground. 
 
 For grinding cast-iron cylinders, carbide of silicon wheels 
 should be used. The grits commonly furnished run from 
 30 to 36 and the grades from 2 to 4 on the writer's proposed 
 grade scale. For grinding steel cylinders, alumina abrasives 
 
 Fig. 125. Grinding Hall-Scott airplane engine cylinders on a Heald 
 cylinder grinding machine. 
 
 should be used. The grits in this case run from 30 to 40 
 and the grades from i to 4. 
 
 Two important factors involved in cylinder grinding are: 
 keeping the work cool and carrying away the dust. It is 
 needless to say that the work must be kept cool if accurate 
 sizes are to be maintained while the dust must be disposed 
 of to conform with the laws relative to grinding-room prac- 
 tice in force in the majority of states. 
 
 Excellent means to attain both these ends are illustrated 
 259
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 in Fig. 125 which shows the operation of grinding cylinders 
 for the well-known Hall-Scott airplane engines. The cylinder 
 to be ground is held on a special angle-iron fixture which is 
 clamped to the platen of the machine. Water supplied 
 from the city mains is circulated through the water jacket 
 
 Fig. 126. Grinding a special internal combustion engine cylinder on a 
 Heald cylinder grinding machine. 
 
 by means of the connections seen at the top near the upright 
 of the angle iron and at the end of the cylinder. The dust 
 is exhausted by means of an air suction connected to the 
 exhaust opening of the cylinder. 
 
 Cylinders are often ground, however, with no provision 
 made fqr water cooling, and, if the depth of cut taken is 
 not too heavy, good results are obtained. Such a grinding 
 operation is shown in Fig. 126. The work consists of 
 grinding a special cylinder of the air-cooled type. The dust 
 can be readily disposed of by placing a hood connected to 
 the exhaust system over the end of the hole being ground. 
 
 The cylinder grinder has, without a doubt, gone a long 
 way toward perfecting the present-day automobile and air- 
 plane engine. Ground holes are more accurate than it is pos- 
 
 260
 
 INTERNAL GRINDING 
 
 sible to produce by boring and reaming and every hole can 
 be made exactly the same size with very little trouble. 
 Far less accuracy is required in boring, in fact, the boring 
 
 Fig. 127. Grinding the hole in a coil spring on a Heald cylinder 
 grinding machine. 
 
 operation is for roughing out only and the time spent in 
 reaming is eliminated. Multiple cylinders are handled as 
 easily as are single ones and interchangeability of cylinders, 
 pistons and rings is assured. No time has to be spent in 
 
 Fig. 128. Grinding a hole in a piece of tile pipe on a Heald cylinder 
 grinding machine. 
 
 lapping a ground cylinder and a maximum amount of com- 
 pression is always possible. 
 
 Aside from cylinder grinding, the cylinder grinder lends 
 261
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 itself readily to a number of operations that would be diffi- 
 cult to handle by ordinary methods. A novel grinding 
 operation of this kind is shown in Fig. 127. This shows a 
 flat, coiled spring 14 inches in diameter and 10 inches in 
 length. It was ground to a plus-and-minus dimension of 
 o.ooi inches. Another unusual job is shown in Fig. 128. 
 
 Fig. 129. Grinding a hole in a large worm gear on a Heald cylinder 
 grinding machine. 
 
 This is a piece of tile pipe 16 inches long and 8 inches inside 
 diameter and was ground to within a limit of o.ooi inches, 
 plus-or-minus. Fig. 129 shows a large worm gear mounted 
 for internal grinding. The manner in which the work is 
 held in eacli case is easily understood by referring to the 
 illustrations and it is seen that these pieces did not require 
 elaborate special fixtures for holding them in position.
 
 CHAPTER NINETEEN 
 
 SPECIAL GRINDING OPERATIONS 
 
 Grinding calender rolls Special grinding machines Roll grinders and roll 
 grinding Corrugating flour-mill rolls Grinding crankshafts Grinding 
 cam shafts Locomotive valve gears. 
 
 IN this category can be included a number of grinding 
 operations that are interesting because of the ingenuity 
 shown in adapting the grinding wheel to unusual problems. 
 They are also very important operations. One unusual 
 grinding operation consists of finishing the calender rolls 
 of Fourdrinier paper-making machines. The machine takes 
 its name from Henry Fourdrinier who introduced- the first 
 paper-making machine into England. After the paper has 
 been formed and partially dried, it passes through a series 
 of calender rolls which impart a smooth finish. If paper were 
 not calendered, it would have the appearance of a sheet of 
 newspaper that had been wet and afterward dried. The 
 largest stack of calender rolls in use at the present time 
 in the United States or Canada is shown in Fig. 130. The 
 relative size of the stack can be judged by the man standing 
 at the left. When it is taken into consideration that these 
 rolls are made of hard chilled iron and that they must have a 
 mirror-like finish, to say nothing of fitting together so per- 
 fectly that light will not show between them, it is seen that 
 roll grinding is indeed an exacting operation. 
 
 These rolls are in use at the Ontario Paper Co., Thorold, 
 Canada, and are designated as follows: Bottom, next to 
 bottom, intermediates and top. All these rolls are 196 
 inches long: The bottom roll is 30 inches in diameter and 
 weighs 44,000 pounds. The next to bottom roll is 20 inches 
 
 263
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 in diameter and weighs 18,000 pounds. The intermediate 
 rolls are seven in number, 14 inches in diameter and weigh 
 9,000 pounds each, while the top roll is the same diameter 
 and weight as the next to bottom roll. 
 
 As the work of calender rolls is nothing more or less than 
 to press paper, it would appear that they should stay in 
 
 Fig. 130. The largest stack of calender rolls on the American continent. 
 
 shape indefinitely, but this is not the case. The constant 
 rolling action gradually affects the mirror-like finish and, 
 again, the "doctors," which are thin plates of specially 
 tempered steel used for scraping them, sometimes leave 
 scratches. What is termed a "plug" in paper-mill parlance 
 often occurs. As the paper maker says: "A plug plays the 
 mischief with the rolls." It occurs usually when the web 
 of paper breaks and banks up and a large wad'is pulled be- 
 tween the rolls. When this happens, one roll may stop 
 
 264
 
 SPECIAL GRINDING OPERATIONS 
 
 revolving while the next roll to it continues to revolve. 
 Under these conditions, a flat spot is sometimes worn on the 
 roll. 
 
 It will be seen that a special grinding machine is necessary 
 to keep the calenders in condition. The majority of paper 
 mills keep a few spare rolls in stock which are substituted 
 for worn ones. Most paper mills also have a completely 
 equipped grinding department which saves the time and 
 expense involved in cases w r here rolls are sent to a distant 
 point for grinding. 
 
 As stated in the introduction, roll finishing was one of the 
 first attempts at cylindrical grinding. The rolls in use at 
 that time, some 50 years ago, were, of course, much smaller 
 than the ones shown in Fig. 130. A typical old-time stack, 
 some 50 years old, is still running near Ansonia, Conn., 
 and consists of the following: A top roll 10x50 inches 
 weighing about 1,225 pounds, a bottom roll of the same 
 dimensions and weight, and four five-inch intermediate 
 rolls weighing a little over 300 pounds each. 
 
 Since the original paper machine, the prototype of the 
 present-day Fourdrinier machine, was invented in 1798 by 
 Louis Robert in France, it follows that the early calender 
 rolls were not finished by grinding. The question naturally 
 arises: "How were these hard rolls finished with the proper 
 degree of smoothness to calender paper?" It is the writer's 
 opinion that these old-time rolls were not chilled rolls but 
 simply hard, charcoal-iron, sand-cast rolls. Thus, they 
 could be finished with turning tools, just as roll turners in 
 steel mills finish the passes on rolling-mill rolls at the present 
 time. 
 
 It is definitely known that hard, chilled-iron rolls were 
 made fifty years ago and that they were finished by grind- 
 ing, probab'y with hand-made grinding wheels consisting 
 of emery bonded together with glue~or shellac. Who made 
 the first grinding machine for this purpose, however, is a 
 matter of conjecture. The writer has made diligent search, 
 but is unable to throw any light on the subject. 
 
 265
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 A modern roll-grinding machine is shown in Fig. 131. 
 This machine is a product of the Farrel Foundry & Machine 
 Co., Ansonia, Conn., who are the makers of the rolls illus- 
 trated in Fig. 130. As the illustration shows, this machine 
 differs radically from machines for cylindrical grinding as 
 
 Fig. 131. Parrel self-contained calender-roll grinding machine. 
 
 described in a previous chapter. Roll grinding is a trade 
 in itself and its successful prosecution is possible only with 
 machines built especially for the purpose. 
 
 Briefly described, the roll-grinding machine illustrated 
 consists of a massive bed upon which the carriage, carrying 
 two wheel heads, traverses, deriving its motion by means 
 of an automatic screw feed. The motor for driving the wheels 
 is mounted on a superstructure over the carriage while the 
 carriage-driving mechanism is actuated by means of the 
 motor seen at the right. This motor also imparts the rotary 
 motion to the roll. 
 
 Two grinding wheels, one on either side, work on the roll 
 simultaneously. This is for the object of expediting pro- 
 duction and insuring a straight, true roll at the same time. 
 
 266
 
 SPECIAL GRINDING OPERATIONS 
 
 The latter feature is assured by the swing-rest principle 
 employed in mounting the grinding wheels. This principle 
 has been in use for a number of years. On this plan, the 
 grinding wheels, instead of being mounted rigidly like a 
 lathe tool in a tool post, and each wheel independent of the 
 other, are hung or suspended from "A" frames on the wheel 
 carriage and the wheel heads are connected by a cross bar. 
 One moves with the other. The "A" frames and the links 
 on which the wheel carriages are suspended are plainly 
 shown in the illustrat'on. The swing-rest mechanism is: 
 supported on knife edges of tool steel bearing in links 
 which, in turn, are supported on knife edges on a connecting 
 cross bar. This allows free lateral movement and it insures 
 a straight roll because the straight path in which the wheels 
 are bound to travel is not influenced by any slight irregu- 
 larities in the machine bed. To use a simple illustration, 
 the wheels pass along the rolls just as a mechanic passes a 
 pair of calipers along a piece of shafting or other cylindrical 
 piece of work. 
 
 When a grinding wheel is in a fixed position, as the tool 
 in a lathe, it follows that any slight error in the alignment 
 of the ways will be duplicated on the face of the roll. On 
 the other hand, the grinding wheels on the swing-rest prin- 
 ciple hang like a plummet and maintain their relative posi- 
 tion to each other on account of the cross bar that con- 
 nects them. Thus, they traverse in a straight line, and,, 
 consequently produce straight work. 
 
 Another important factor peculiar to roll grinding is that 
 comparatively long rolls are bound to sag of their own weight.. 
 
 Fig. 132. Calender roll sagged through its own weight. This illustration is 
 exaggerated to illustrate the principle. 
 
 This is shown in Fig. 132 which is exaggerated to illustrate 
 the principle. It is necessary to overcome this on bottom 
 
 267
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 rolls, otherwise the next to bottom roll would not make 
 contact without sagging and so on up the stack. The 
 difficulty is successfully overcome by crowning the bottom 
 .roll so that in its deflected state its upper surface presents 
 
 pig. 133. Crowned calender roll. The crowning compensates the error due 
 
 to the roll's deflection. This illustration is exaggerated to illustrate 
 
 the principle. 
 
 a straight line. This is illustrated in Fig. 133. This illus- 
 tration is also somewhat exaggerated to illustrate the 
 principle. 
 
 The mechanism for crowning is simple and easily under- 
 stood. On one side of the roll grinder bed, extending nearly 
 its whole length, is an arched plate called a master crown 
 plate. This is not shown in Fig. 131 as it is on the other 
 side of the machine. A toe piece on the wheel carriage 
 travels over this master plate and, through the medium of 
 levers, the wheel heads are moved away from the roll as 
 the center is approached and toward the rol' as the other 
 end is approached. This imparts the desired crown. The 
 mechanism is adjustable to impart the amount of crown 
 necessary for different lengths and weights of rolls. It is 
 obvious that a long, comparatively thin roll will deflect 
 , more than a roll of the same length, but of greater diameter, 
 thus this adjustment is necessary. The amount of crown 
 to give a roll to offset the error caused by sagging is de- 
 termined by experiment alone. To the best of the writer's 
 knowledge, no tables giving the amount of crown for differ- 
 ent lengths and diameters of rolls have been published. 
 
 Some years ago, when the roll grinder had to depend on 
 natural abrasives, roll grinding was a long and tedious 
 operation. As a matter of fact, weeks were sometimes 
 consumed in grinding a single roll in cases where it was 
 badly out of shape. The discovery of Carborundum in 
 1891 proved a decided boon to roll grinding as this abrasive 
 
 268
 
 SPECIAL GRINDING OPERATIONS 
 
 made it possible to accomplish in days what theretofore 
 required weeks. At the present day, Carborundum and 
 other carbide of silicon abrasives are used almost exclusively 
 for grinding calender rolls. 
 
 Shellac-bonded wheels are generally used for this oper- 
 ation for two reasons: A shellac-bonded wheel imparts 
 an * exceedingly fine finish which is very desirable and, 
 again, these wheels are quite durable. The grits used run 
 from 24 to 80 in a medium soft to soft grade. For roughing 
 operations, wheels in vitrified bond are sometimes used. 
 
 Roll grinding in itself is a comparatively simple oper- 
 ation. The roll is supported by its journals or necks and 
 revolved by' means of a flexible connection. The grinding 
 should be worked wet under all conditions. The wheels 
 are fed in until they spark heavily and enough passes taken 
 over the roll to grind it true. It is then finished by means of 
 light cuts, the wheels being allowed to traverse until no 
 sparks are visible. 
 
 It is evident that a calender roll with imperfections on 
 its surface will not finish paper satisfactorily and, for this 
 reason, great care must be exercised in grinding and the 
 least tendency to chattering promptly overcome. Chatter- 
 ing, in this case, is caused by one of three things or a com- 
 bination of all three: Loose wheel spindle boxes, excessive 
 work speed or hard wheels. When chattering occurs, the 
 first thing to do is to see that the work speed is normal and 
 then the wheel spindle boxes should be adjusted. If these 
 adjustments do not overcome the difficulty, the wheel speed 
 should be reduced slightly, and if the wheels are too hard 
 the reduction of speed will tend to make them function as 
 softer wheels. 
 
 The correct wheel-surface speed for roll grinding is 5,000 
 feet per minute. Regarding the work speed, however, there 
 is no hard and fast rule. In visiting paper mills in all parts 
 of the country, the writer has observed work speeds ranging 
 all the way from 15 to 60 feet a minute and sometimes more, 
 and in -each case the operator was getting satisfactory re- 
 
 269
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 suits. Local conditions such as the grade and make of 
 wheel used, the hardness of the roll, etc., have to be taken 
 into consideration in determining the work speed. Roll 
 grinding, in the strictest sense of the word, is not a produc- 
 tion operation, thus the operator sets the work speed to 
 suit himself and as long as he is getting a satisfactory finish 
 he is riot concerned whether the time taken to finish a 
 certain roll is three days or a week. 
 
 Another important branch of chilled-iron grinding con- 
 sists of finishing the massive rolls used in steel mills for 
 rolling sheets and plates. This is exacting work as the faces 
 of the rolls should be parallel in order that stock of uniform 
 thickness can be rolled. Until a few years ago, these rolls 
 were finished by the slower process of turning on a regular 
 roll-turning lathe. The manufacturers of cylindrical grind- 
 ing machinery, however, realizing that the steel mills offered 
 a new field for the sale of grinding machinery, began a 
 series of exhaustive experiments which ultimately resulted 
 in the production of extra-heavy, specially designed ma- 
 chines for finishing these rolls. 
 
 The rolls in question are of various sizes ranging all the 
 way from those used for rolling ribbon stock, which are 
 from 8 to 12 inches long and from 6 to 10 inches in diameter, 
 up to the massive rolls used for rolling heavy plates which 
 are often 54 inches in diameter and 15 feet long. The small 
 rolls can be readily ground in a regular cylindrical grinding 
 machine and the process does not differ materially from any 
 other cylindrical grinding job except, perhaps, that the wheel 
 used is a trifle softer inasmuch as the amount of contact 
 between the roll and the wheel prohibits the use of a hard 
 or even of a medium grade wheel. 
 
 A massive grinding machine constructed especially for 
 finishing steel-mill rolls is illustrated in Fig. 134. This 
 machine is a product of the Landis Tool Co. and in general 
 design it does not differ materially from a regular Landis 
 plain grinder. As the illustration shows, the roll is located 
 by its necks or journals and is driven from the face plate 
 
 270
 
 SPECIAL GRINDING OPERATIONS 
 
 by a pin that engages the wobbler. The operator stands 
 on the three-step platform plainly seen at the front of the 
 machine, from which vantage point he has full control of 
 
 Fig. 134. Landis grinding machine for finishing large steel- mill rolls. 
 
 the work at all times. He can look over the roll to observe 
 the cutting action of the wheel without inconvenience. 
 This machine is self-contained and electrically driven. 
 
 Another heavy roll grinding machine is illustrated in Fig. 
 135. This machine is made by the Norton Grinding Co. 
 and is somewhat' more complicated than the first machine 
 shown. In designing this machine, the principle of having 
 the wheel traverse past the work is employed, which is a 
 
 Fig. 135. Norton grinding machine for finishing large steel-mill rolls. 
 
 distinct departure from the Norton Company's practice. 
 
 However, in grinding these massive rolls, it is readily seen 
 
 that it is not practicable to mount the roll on a traversing 
 
 platen. If this were done, the momentum of the massive 
 
 moving body would present serious difficulties in reversing. 
 
 The wheel is mounted on a carriage on which the operator 
 
 271
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 stands. This position allows him to view the grinding oper- 
 ation at all times. The roll is mounted on its journals and 
 revolved from the headstock. The wheel is fed toward the 
 work by means of the upper handwheel shown in the illus- 
 tration. The machine is motor-driven throughout. The 
 equipment consists of five motors as follows: A 40-horse- 
 power unit mounted on the wheel carriage for rotating the 
 grinding wheel and traversing the wheel carriage ; a 1 5 -horse 
 power motor mounted on the headstock for revolving the 
 work and three 2 -horsepower motors. These small motors 
 are placed on the head and tail stocks and on the wheel 
 carriage. The first two are for traversing the parts upon 
 which they are mounted along the ways of the base, while 
 the last drives the pump and traverses the grinding wheel 
 at right angles to the work. This machine is said to be the 
 heaviest grinding machine ever constructed. It weighs 
 100,000 pounds. After the first machine of this type was 
 finished and installed in a steel mill for demonstration, it 
 was found, after exhaustive trials, that it reduced the time 
 required in dressing rolls from 50 to 75 per cent. 
 
 There always has, and probably always will be, con- 
 troversy regarding the manner in which rolls should be 
 located for grinding; that is, by their centers or by their 
 necks. No matter which method is used, the locating points 
 must be true. If the roll is to be located on centers, these 
 must be true 6o-degree centers; perfectly round at all 
 points, and free from scores or imperfections. If the roll 
 is to be located by its necks, it follows that these must be 
 straight, true as regards circumference and in line with 
 each other. If the necks are out of round, as they often 
 are from wear, it follows that the imperfections will be 
 duplicated on the face of the roll. It is a fact that the 
 necks of these massive rolls are often out of true as they 
 wear readily due to the excessive pressure to which they 
 are subjected in actual use. 
 
 A good method, followed by many roll grinders, is first 
 to true out the centers carefully; then mount the roll and 
 
 272
 
 SPECIAL GRINDING OPERATIONS 
 
 grind the necks until they are round and straight. Then the 
 roll is located by the necks and its body ground. On the 
 other hand, many expert roll grinders have achieved excel- 
 lent results by grinding rolls as large as 30 inches in diameter 
 and 1 20 inches long by locating them on centers. 
 
 The surface speed of the wheels used for roll grinding is 
 from 5,000 to 6,000 feet per minute. The surface speed of 
 the work is comparatively high when compared to work 
 speeds used in ordinary cylindrical grinding. In fact, it 
 ranges from 100 to 200 feet per minute. The traverse 
 feed is very nearly the width of the wheel for each revolu- 
 tion of the work. The depth of cut for roughing is all the 
 wheel will stand, while for finishing the cut is comparatively 
 light. It is obvious that rolls for rolling hot steel do not 
 require the mirror-like finish called for on calender rolls. 
 Steel-mill rolls, however, require a comparatively smooth 
 finish as any imperfections would show up on the material 
 rolled. 
 
 Steel-mill rolls are made 'of two materials chilled iron 
 and steel. For grinding the iron rolls, carbide of silicon 
 is used and for steel rolls alumina abrasives. The same 
 grits and grades apply to this work, in a general way, as 
 given for grinding calender rolls. 
 
 Another important branch of roll grinding is the finishing 
 of chilled-iron rolls used in flour mills. This applies to the 
 smooth rolls as well as the corrugated breaking-down rolls. 
 The corrugations of the latter wear down after a few years' 
 service and before re-corrugating them, the worn corruga- 
 tions .are ground away. This work is done on the same type 
 of machine illustrated in Fig. 131. As flour-mill rolls are 
 comparatively small, ranging from 6 inches in diameter and 
 12 inches long to 12 inches in diameter and 60 inches long, 
 a much smaller machine is used. These machines are gen- 
 erally provided with a swing rest for assuring straight rolls, 
 but they are seldom equipped with a crowning attachment 
 as the rolls are not long enough for their diameter to deflect 
 from their own weight. 
 
 273
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Large flour mills have their own grinding and corrugating 
 departments in charge of an experienced operator, but many 
 of the smaller mills send their rolls to repair shops that make 
 a specialty of this work. There seems to be no good reason 
 why this grinding could not be done on a regular cylindrical 
 grinder after the method employed in grinding small stee"- 
 mill rolls, but the type of grinder shown in Fig. 131 seems to 
 have the preference. 
 
 In grinding the worn corrugations from flour-mill rolls, 
 carbide of silicon whee s in 30 to 60 grit and medium grade 
 are used. Shellac-bonded wheels are always used for finish- 
 ing operations, but for roughing some operators prefer 
 vitrified whee's. The work does not differ materially rom 
 any other roll-grinding operation and the process followed 
 is the same. 
 
 After the automobile had passed the' experimental stage 
 and began to be an industry in tself, one of the complex 
 problems it brought about was the finishing of crankshafts. 
 It goes without saying that tne bear ngs and pins of this 
 important member of the modern automobile must be ac- 
 curately and smoothly finished if an easy-running motor 
 is to result and, as may be imagined, abrasive engineers 
 lost no time in adapting the cylindrical grinder for finishing 
 crankshafts. In the early days of the automobile industry, 
 the grinding of crankshafts presented many difficulties. 
 
 Fig. 136^ Typical crankshaft as finished by grinding. 
 
 The shaft was usually held between centers on offset blocks. 
 This method when applied to a four or six throw crankshaft 
 
 2/4
 
 SPECIAL GRINDING OPERATIONS 
 
 is not satisfactory as the shaft is quite liable to spring in 
 the grinding operation, owing to the insecure support. 
 Again, in the early days of four- throw crankshafts, there 
 were no grinding wheels suitable for the work, that is, as 
 we judge such wheels today. 
 
 A typical crankshaft, one that is easily finished by grind- 
 ing, is shown in Fig. 136. This is an easy shaft to grind 
 as it has but one intermediate bearing and four pin bearings. 
 
 Fig. 137. Landis crankshaft grinding machine. 
 
 A modern Landis crankshaft grinder is illustrated in Fig. 
 137. This machine does not differ materially from an 
 ordinary cylindrical grinder with the exception that the 
 crankshaft is rotated and driven from both ends while it 
 is securely held in special indexing devices which are counter- 
 weighted to assure a satisfactory running balance to the 
 shaft during the grinding operation. The double drive is 
 derived from the shaft seen at the front of the machine. 
 
 The work-carrying fixture is shown in Fig. 138. These 
 are attached to the face plates of the machine and carry 
 the work while grinding the pins. The fixtures are equipped 
 with two independent rotary adjustments, one an eccentric 
 for obtaining different throws, the settings for which are 
 
 275
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Fig. 138. Work-carrying fixture for grinding crankshafts on Landis 
 - crankshaft grinding machine. 
 
 Fig. 139. Special wheel-truing device for Landis crankshaft grinding machine. 
 
 276
 
 SPECIAL GRINDING OPERATIONS 
 
 indicated in English and Metric scales, and the other for 
 locating the pins in their relative grinding positions. The 
 setting for this is controlled by a division index which is 
 of the tapered type to insure it against reasonable wear. 
 The counterbalance weights are seen at the bottom of the 
 face plate. 
 
 Another attachment peculiar to crank-grinding machines 
 is the special radius truing device which is absolutely nec- 
 essary in keeping the corners of the wheel at the correct 
 radius to impart the desired fillets on the work. A Landis 
 special wheel-truing device of this type is illustrated in 
 Fig. 139. This is attached to the top of one of the work- 
 rests used in supporting the crank while grinding. The 
 diamond tool is oscillated by the lever at the top. This 
 fixture is also used for truing the face of the wheel and, 
 as the illustration shows, the work need not be removed 
 when the device is in use. As shown, the diamond-setting 
 gauge is turned over and pushed back on its holder where it 
 does not interfere with the truing operation. 
 
 Crankshafts are finished in two ways, grinding from the 
 rough forging and finish grinding after a roughing cut in 
 the lathe. There is some controversy as to which is the 
 best method, but in actual practice both methods give ex- 
 cellent results. In grinding a crankshaft from the rough, 
 it is first centered and the main bearings roughed out. Then 
 it is held in the offset fixtures and the pins roughed out. 
 Next the pins are finished carefully and last of all the main 
 bearings. 
 
 In the other process, the roughing is done in the lathe 
 and the grinding machine used for the finishing operation 
 only. In this case, the main bearings are first rough ground 
 to within a few thousandths of the finished size, then the 
 pins are roughed. Next the pins are finished and last of all 
 a finishing cut is taken over the main bearings. 
 
 Grinding from the rough wears out wheels rapidly, but 
 as the turning operation in the lathe is eliminated, there 
 may be truth in the claim that this method is the most' 
 
 277
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 rapid. However, many leading manufacturers prefer to 
 take the roughing cuts in the lathe. Thus, it is seen that 
 there must be factors in favor of both methods, otherwise 
 one or the other would be adopted universally. 
 
 Crank grinding is an exacting operation and the speed 
 with which the work is turned out is attained only by long 
 practice on the part of the operator. It differs from ordinary 
 grinding in several ways. In the first place, in working on 
 the pins, the traverse feed is eliminated entirely and the 
 work fed directly to the wheel by means of the cross feed. 
 The face of the wheel must be kept true and straight in the 
 finishing operation. Again, the operator has to exercise 
 care in watching the fillets, for a true radius on the wheel 
 corner is necessary in imparting the desired fillet on the 
 finished work. Another point that requires close attention 
 on the part of the operator is the spacing of the pins. Crank- 
 shaft grinding is a special trade in itself and in common 
 with other exacting operations, skill is developed only 
 through long practice. 
 
 As crankshafts are always made of steel, alumina abrasives 
 are used for grinding them. Grinding-wheel manufacturers 
 who cater to this class of trade have developed special 
 wheels for the work. These wheels are generally in com- 
 bination grits and great care has been paid to developing 
 bonds that will insure the corners holding up well with- 
 out danger of burning the work. The wheels used for 
 grinding crankshafts from the rough are coarse and com- 
 paratively hard from 16 to 24 grit in the writer's grades 
 ii to 14. For finishing, finer and softer whee's are used. 
 The grits in this case run from 36 to AO and the grades 
 from 7 to 9. 
 
 Perhaps the greatest difficulty experienced in crankshaft 
 grinding is keeping the work true. It is imperative that 
 free-cutting wheels are used, but they must not be too soft, 
 otherwise more wheel is wasted in keeping the fillets at the 
 proper radii than is used in actual grinding. If the wheels 
 are too hard, in the finishing operation, they heat the metal 
 
 278
 
 SPECIAL GRINDING OPERATIONS 
 
 unduly wfyich causes sprung work and burned spots in the 
 fillets. Especial care must be exercised in taking the finish- 
 ing cuts on the main bearings as these must test true, or 
 at least within close limits, in the finished shaft. An expert 
 can, of course, bend a sprung shaft until it runs true, but 
 it is much better to have the work true as it comes from 
 the grinder. 
 
 The finish left on the journals and pins is another im- 
 portant factor and the high degree of finish required by 
 the government on crankshafts for airplane motors has 
 caused more than one manufacturer much anxiety. There 
 was a time when manufacturers of crankshafts used a final 
 lapping with emery cloth and oil to impart a high degree of 
 finish, but the government frowns on this practice. 
 
 The amount to be left for finishing should be determined 
 by experimentation as it is impossible to set any definite 
 rule. The accuracy with which the shafts are roughed 
 out, both as regards dimensions and the spacing of the off- 
 sets are important factors bearing on this point. Again, 
 the size of the shaft, whether long or short must be con- 
 sidered. On an average, however, 0.020 inch should suffice 
 in the majority of cases where the operator who roughs 
 out the work uses reasonable care. 
 
 Never under any conditions should it be attempted to 
 grind a crankshaft without backresting it. Crank grinding 
 machines are equipped with a special form of back rest that 
 bears directly on the surface being ground and there is no 
 excuse for not using these. 
 
 Another special grinding operation that has been de- 
 veloped by the automobile industry is that of grinding 
 cam shafts. In the early development of the internal- 
 combustion motor, in the days of single cylinder and two 
 cylinder double-opposed type engines, individual cams w r ere 
 used. These were cut by methods used in cutting ordinary 
 face cams after which they were hardened to eliminate wear. 
 These early cams were not ground; for at that time rule-of- 
 thumb methods were the general ones employed, thus after 
 
 279
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 the cams were hardened, a polishing with abrasive cloth 
 was thought sufficient. 
 
 As the automobile engine was gradually improved, the 
 valve-actuating mechanism was given more attention and 
 more accurately finished cams were demanded. Grinding- 
 machine manufacturers turned their attention to the de- 
 velopment of special attachments for cam grinding. 
 
 Present-day internal-combustion engine cams are of two 
 kinds: Integral cams, in which several cams are made in- 
 tegral with their shaft, and individual cams. The former 
 type is the one most extensively used. The latter type is 
 sometimes used on multiple cylinder engines, in which case 
 the cams are pinned or otherwise fastened permanently 
 to the shaft. The majority of individual cams, however, 
 are used on single cylinder engines of various types. 
 
 There are two types of cam-grinding attachments to take 
 care of the two kinds of cams above referred to. An attach- 
 ment made by the Norton Grinding Co. for finishing in- 
 dividual cams is shown in Fig. 140. Briefly described, it 
 consists of a spindle which carries the cam to be ground 
 and the master cam which, running over a roller, produces 
 the desired contour of the cam face. It is driven from the 
 headstock of the . machine and a strong spring keeps the 
 master cam in contact with its roller while the cam is brought 
 to the Wheel by means of the cross feed. 
 
 An attachment designed for grinding integral cams is shown 
 in Fig. 141, while Fig. 142 is a close-up view of the attach- 
 ment taken from the back of the machine. The gear guards 
 are removed in this view to show the operating mechanism. 
 A is the driving arm, B the master cams on their spindle, 
 C the roll which is set in position before the desired leader 
 by slipping along the shaft D. This is equipped with a 
 locking device to hold it in place as occasion requires. 
 E is the case that covers a stiff spring which holds the master 
 cam in contact with the roll. F is the driving dog, G the 
 steady-rests and H the tailstock. As the master cams are 
 revolved their bearing against the roll causes the attach- 
 
 280
 
 SPECIAL GRINDING OPERATIONS 
 
 Fig. 140. Norton grinding attachment for finishing individual cams. 
 
 Fig. 141. Norton grinding attachment for finishing cams made integral with 
 their shafts. 
 
 281
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 ment to oscillate which, of course, produces a duplicate 
 motion of the cams in position before the grinding wheel. 
 
 In cam grinding, no traverse feed is used. The wheel is 
 fed directly into the work by means of the cross feed until 
 the required depth is reached. The handle J is for the pur- 
 
 Fig. 142. Rear view of Norton cam-grinding attachment. 
 
 pose of lifting the work" away from the wheel for inspection 
 and removal and to move the guide roll from one position to 
 another. 
 
 In cam-grinding, it is very necessary to use steady-rests 
 to support the work. These should be located reasonably 
 close to the cam being ground and should bear on the round 
 part of the shaft which is finished by grinding for this pur- 
 pose. The Norton Grinding Co. provide two types of 
 steady-rests, as illustrated in Figs. 143 and 144. Fig. 143 
 is an open type rest and Fig. 144 a closed type rest. It is 
 obvious that the open type has the advantage of being 
 readily handled in locating and removing the work. The 
 closed rest is used in cases where great accuracy is demanded, 
 for instance, on cams for high-class automobile engines and 
 on aircraft engine work. 
 
 282
 
 SPECIAL GRINDING OPERATIONS 
 
 As the cams in question are made of steel, alumina abra- 
 sives are used in grinding them. The degree of accuracy 
 demanded and the finish sought are important factors 
 governing the selection of wheels for cam grinding. For 
 
 Fig. 1 43 . Open - type Norton 
 steady-rest for camshaft grinding. 
 
 Fig. 144. Closed -type Norton 
 steady-rest for camshaft grinding. 
 
 roughing out the cams before they are hardened, which is 
 common practice, wheels in 16 to 24 grit and 12 to 17 grades 
 will be found satisfactory. It is seen here that the wheels 
 used for this purpose are comparatively hard. For roughing 
 out hardened cams 24 to 40 grit in grades 4 to 7 will give 
 good results. For finishing hardened cams, grits 36 to 50 
 in grades 3 to 5 will be found satisfactory. The grades are 
 according to the writer's grade scale. 
 
 One of the most interesting factors pertaining to cam 
 grinding is the method followed in producing the leaders 
 or master cams. It is necessary that these be accurate as 
 regards contour if accurate results in the ground cams are 
 sought. In grinding a cam, we use a leader of the desired 
 form to produce the outline on the cam that oscillates be- 
 fore the grinding wheel. In making these leaders, we re- 
 verse the practice. This will be clearly understood by the 
 following description. The operation is shown in Fig. 145. 
 This is the same attachment used for cam grinding but set 
 up differently. In place of the grinding wheel the disk (2) 
 is used. This is made of cast iron and occupies the position 
 
 283
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 taken by the grinding wheel in grinding operations. The 
 model cam (4) bears against the disk and from it is produced 
 the leader, several of which are shown at 5. This is ground 
 by the grinding wheel (i). The spindle (6) carries the master 
 
 Fig. 145. Grinding the leaders for a Norton cam-grinding attachment. 
 
 cams. The master cams, which are hardened, were roughed 
 approximately to the desired shape before hardening. The 
 bearings of the master-cam spindle and the centers of the 
 attachment must be exactly in line. As the grinding wheel 
 and the master cam revolve, the model runs over the disk 
 which produced the desired contour on the master. It 
 looks simple, which in truth it is, but to assure satisfactory 
 results two .important factors must be borne in mind. The 
 disk (2) must be the size of the grinding wheel that is to be 
 used in grinding the cam on regular production work and 
 the grinding wheel (i) must be exactly the same size as 
 the roll that is to follow over the master cams when they 
 are in use as producers for the finished cams. 
 
 As previously stated the master cams are roughe'd out 
 before they are hardened and a few words concerning a 
 
 284
 
 SPECIAL GRINDING OPERATIONS 
 
 simple method to follow in marking the outline will not 
 be out of place here. The blanks, while soft, are mounted 
 on the roughing master-cam spindle, it being understood 
 that in cam grinding two sets of masters are necessary, one 
 for roughing and the other for finishing master cams. The 
 machine is started up and the model produces the desired 
 motion to the master cam shaft. The wheel (i) is brought 
 to bear slightly against the side of the master where it 
 marks the outline from which the toolmaker roughs out 
 the cam. 
 
 As stated previously, the disk over which the model cam 
 runs in making a master cam must be the same size as the 
 
 -Roll4"Diam. 
 
 Pivcrt^ 
 
 Trammel -9 "Rod. representing 
 Grinding Wheel 
 
 Generated with Generated with Generated with 
 
 Under Sue Wheel Correct Size Wheel Over Size Whel 
 
 (18 Diam.) 
 
 Fig. 146. Effect of varying wheel diameters in cam grinding. 
 
 grinding wheel to be used in grinding the cams later in pro- 
 duction work. As all grinding wheels wear in use, it is 
 evident that after the wheel is worn away somewhat it will 
 not grind the same shape as it did when it was up to size. 
 This is graphically illustrated in Fig. 146 which was pre- 
 pared for explanatory purposes by Howard W. Dunbar, 
 and illustrates clearly just what takes place in cam grinding. 
 The model cam is in position bearing against the guide roll. 
 
 285
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 A piece of cardboard is glued to the master, this taking the 
 place of the cam to be ground under working conditions. 
 The pencil represents the periphery of the grinding wheel. 
 A mark is made on the cardboard with the pencil, the master 
 moved a little and another mark made and so on until the 
 master has made a complete revolution. This gives the 
 cam outline seen in the illustration. If the radius on which 
 the pencil swings is changed to represent the periphery of 
 a smaller wheel, a different shaped cam will be formed. 
 As the three diagrams at the bottom of the illustration 
 show, incorrect wheel sizes make a vast difference in the out- 
 line produced even though the same master is used. From 
 this it is seen that after a wheel is worn down a little, two 
 courses are before the man who wants to produce cams true 
 to a predetermined contour. Either discard the wheel 
 after it has worn away a little and substitute a new one 
 that is up to size or produce a multitude of leaders from 
 different -sized disks to be substituted as the wheel wears 
 away. These masters, it is needless to say, should be 
 stamped to show what size wheel they were made to be 
 used with. 
 
 Another interesting grinding operation consists of finish- 
 ing the radii on links used in valve gears as seen on loco- 
 motives. Three types of links are shown in Fig. 147. A 
 is a built-up link in which the members i and 2, that con- 
 fine the block D, are held together with bolts, the intervening 
 spaces being filled with the filler pieces 3. Links of this 
 type are generally made of wrought iron and protected 
 against excessive wear by case hardening. A solid link 
 is shown at B. Links of this type are generally made from 
 steel castings. Sometimes they are case hardened, but in 
 other instances they are left in their soft state. The link 
 shown at C is the type used in the Walschaert valve gear. 
 
 Considering the link shown at A, it is evident that case 
 hardening will distort it to a certain extent. If satisfactory 
 working surfaces are desired, the errors must be corrected 
 by grinding. Some years ago, links of this type were ground 
 
 286
 
 SPECIAL GRINDING OPERATIONS 
 
 by hand on the face of a wide wheel. This practice, of course, 
 called for the services of an expert workman and even 
 under these conditions the results were not always satis- 
 factory. 
 
 The machine shown in Fig. 148 was designed especially 
 for grinding links and link blocks and is called a radial 
 
 Fig. 147. Three types of locomotive valve-gear links. 
 
 grinder. However, as these machines are used principally 
 in railroad shops they are generally called link grinders. 
 The machine is designed and built by H. G. Hammett, 
 Troy, N. Y. 
 
 The fulcrum of the bar seen in the foreground is adjust- 
 able to accommodate links of different radii and causes 
 the upper section of the platen to describe a curve as it 
 traverses back and forth. The grinding wheel is carried on 
 a vertical spindle and is fed downward as the grinding pro- 
 gresses. The link is lined up to the desired radius and 
 securely strapped to the platen of the machine, although in 
 some cases special fixtures are provided for locating the work. 
 
 287
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 In fitting up links of any kind, the first step is generally 
 to grind the block which is then used as a gauge in grinding 
 the link to the correct width. This is a much easier pro- 
 cedure than to attempt to grind the link first and then 
 
 Fig. 148. Hammett link-grinding machine. 
 
 fit the block. In fitting up new links of the type shown at A, 
 the built-up link, excellent results can be obtained by grind- 
 ing the block and fillers at one operation and the other 
 members next. In assembling, the clearance to allow the 
 block to slide is obtained by means of paper shims or liners 
 placed between the fillers and the members i and 2. 
 
 Links wear quite rapidly, especially those used in con- 
 nection with Stephenson link motions. This is due prin- 
 cipally to the slip of the block caused, among other things, 
 by offsetting the saddle pin to secure the desired cut-off 
 motion. Built-up links can be readily re-ground and new 
 blocks fitted, but with solid links the only thing to do is to 
 grind them until the radii are trued up and then fit new 
 blocks. 
 
 The operation of link grinding is simple after the link 
 288
 
 SPECIAL GRINDING OPERATIONS 
 
 has been correctly located on the platen of the machine. 
 The depth of cut should be comparatively light as this 
 work is done dry and the wheel should be fed down by means 
 of the automatic feed. The wheels generally used are from 
 30 to 40 grits in the writer's 12 grade. As the work is 
 steel, an alumina abrasive should be used.
 
 CHAPTER TWENTY 
 
 CUTTER SHARPENING 
 
 Machines employed for cutter grinding Adjustments and attachments on 
 cutter grinders Grinding spiral cutters General operation of cutter 
 grinders Selection of wheels Speeds Depth of cut. 
 
 'T'O insure maximum production on the milling machine, 
 A it is necessary to use properly sharpened cutters. Dull 
 cutters throw an extra load on the machine, produce un- 
 satisfactory surfaces and leave heavy burrs. Cutter sharpen- 
 ing is a comparatively simple operation that can be done 
 by any mechanic of ordinary ability, provided reasonable 
 care is exercised to see that the depth of cut is not deep 
 enough to cause the wheel to burn the teeth. There are 
 two kinds of machines used for cutter grinding, small 
 universal grinders arranged for dry grinding and special 
 cutter sharpening machines. A machine of the former type 
 is illustrated in Fig. 149. This is a product of the Cin- 
 cinnati Milling Machine Co. and is the result of many 
 years' study and experimentation to produce an economical 
 machine that could be adapted to cutter grinding and small 
 tool-room cylindrical grinding. 
 
 On this machine the base, platen and head are all equipped 
 with swivel adjustments while a vertical adjustment is also 
 provided to enable the machine to take care of such work 
 as grinding formed cutters without having to resort to the 
 use of drop centers. Owing to its wide range of adjust- 
 ments, this machine can be readily adapted to any kind of 
 cutter grinding. 
 
 The machine shown in Fig. 150 is a Brown & Sharpe 
 290
 
 CUTTER SHARPENING 
 
 cutter grinder. It embodies a number of adjustments and, 
 with the necessary attachments, can be set up to do any 
 kind of cutter grinding. The operation shown in Fig. 150 
 
 Fig. 149. Cincinnati universal grinding machine adapted for tool-room 
 and cutter grinding. 
 
 is that of grinding the peripheral teeth on an ordinary 
 milling cutter, For grinding end mills, the work is located 
 
 291
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 in a sleeve that fits the swivel head seen under the oper- 
 ator's hand. The attachment shown in Fig. 155, is for 
 grinding the end teeth of cutters and similar pieces while 
 the attachment illustrated in Fig. 163 is for grinding formed 
 cutters. 
 
 While the primary object in sharpening a milling cutter 
 is to put its teeth in cutting condition, care must be exer- 
 
 Fig. 150. Grinding the peripheral teeth of a milling cutter on a Brown & 
 Sharpe cutter grinding machine. 
 
 cised to see that the cutter is kept round and that the teeth 
 are ground straight with the axis of the cutter. If the cutter 
 is not round, comparatively few of its teeth cut and if it is 
 tapered accurate work cannot be obtained. 
 
 One of the most rapid and simple methods of sharpening 
 a cutter properly, with the above factors in mind, is shown 
 
 292
 
 CUTTER SHARPENING 
 
 in Fig. 1 50. The cutter is mounted on a hollow work arbor 
 as shown in Fig. 151 where it is held between two collars, 
 A and B. These collars have several steps on them to ac- 
 commodate cutters with different -sized arbor holes. This 
 hollow arbor carrying the cutter is slid back and forth by 
 
 Fig. 151. Hollow work arbor for locating milling cutters for grinding. 
 
 hand along the bar C, which is also seen in Fig. 150. This 
 bar is clamped in the swivel head. If the bar is straight, it 
 naturally follows that the teeth of the cutter will be ground 
 parallel, regardless of the setting of the swivel head, and 
 if the work arbor is true, a round cutter will result. This 
 method of cutter grinding is not new by any means, but it 
 produces accurate results. 
 
 The first step in setting up the cutter grinder is to clamp 
 the cutter on the work arbor, set the bar in place and then 
 set the guiding finger under the cutter tooth nearest the 
 wheel to impart the correct angle for clearance. This is 
 generally from five to seven degrees. Too little clearance 
 will cause the cutter to cut slowly, while too great a clear- 
 ance makes the teeth dull quickly. In setting the guide 
 finger to impart the desired clearance, the expert operator 
 is generally guided by experience alone. 
 
 In grinding, the cutter should be fed past the wheel with 
 a fairly quick motion and the depth of cut should be com- 
 paratively light as this work is generally done dry and 
 thus it is obvious that a deep cut will burn the tooth. It 
 is a good plan to mark the first tooth with chalk and grind 
 the teeth evenly and carefully until all have been sharpened. 
 It is generally found that the wheel wears a little in going 
 around the cutter once and for this reason a very light 
 finishing cut should be taken to insure the cutter not being 
 
 293
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 out of round from excessive wheel wear. In connection 
 with this point it may be well to mention the fact that com- 
 paratively wide-faced wheels give better results in cases 
 where they can be used than do narrow ones, owing to the 
 fact that the wide-faced wheel wears longer. 
 
 A spiral cutter is ground in the same manner as a straight 
 one with the exception that the guide finger is set to con- 
 form to the pitch of the spiral. It is a more difficult matter 
 
 Fig. 152. Grinding a milling cutter with the guide-finger over the tooth. 
 
 to grind spiral cutters than straight ones as an inexperienced 
 operator sometimes has difficulty in setting the guide finger 
 properly and in keeping the cutter in correct contact. 
 
 There are two ways to locate the guide finger in grinding 
 milling cutters and both have their good and bad features. 
 By again referring to Fig. 150, it is seen that the guide 
 finger is under the tooth being ground. The wheel is run- 
 ning toward the operator. Thus the action of the wheel 
 
 294
 
 CUTTER SHARPENING 
 
 keeps the cutter tooth in contact with the guide finger. 
 This is the safest way to grind a milling cutter, but it is 
 more liable to burn the teeth than the method illustrated 
 in Fig. 152 In the latter method, it is seen that the guide 
 finger is placed just opposite to what it is in the former case 
 and also that the cutter has been reversed. The operator 
 must exercise great care to keep the cutter in contact with 
 the wheel, the action of which has a tendency to pull the 
 work away from the guide finger. Should the operator 
 relax his diligence, the wheel might force the tooth away 
 from the guide finger which would result in an injured tooth 
 or perhaps a broken wheel. In grinding cutters by this 
 method, the wheel is not as liable to burn the work, thus a 
 deeper cut can be taken. For this reason, this method is used 
 by many mechanics. In considering the best method to use, it 
 is best for a green operator to use the first-described one while 
 the latter should be left for more experienced operators. 
 
 In grinding the teeth of a straight or spiral milling cutter, 
 the clearance is obtained by raising or lowering the guide 
 finger. In grinding angular cutters, however, another 
 
 Fig. 153. Correct and incorrect methods of locating angular cutters for 
 grinding, j 
 
 method must be used. Correct and incorrect set-up posi- 
 tions for angular cutters are shown in Fig. 153. A illus- 
 trates the correct position in which the tooth makes a 
 straight line toward the center. This is necessary in pre- 
 serving the correct angle as given by the swivel head when 
 
 295
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 the machine is set up for the grinding operation. If the 
 guide fingers were dropped to give the clearance angle, 
 the result as shown in B would be had. Here it is seen that 
 the tooth does not bear evenly on the guide finger. 
 
 In setting up the cutter grinder for grinding teeth on 
 angular cutters, the clearance is obtained by raising the 
 
 Fig. 154. Grinding an angular milling cutter on a Cincinnati grinder. 
 
 wheel center above that of the cutter in the machine shown 
 in Fig. 154, which is a Cincinnati grinder set up for grind- 
 ing the peripheral teeth of an angular cutter. The cutter 
 is held on the end of the swivel head spindle and the angle 
 for clearance obtained by raising the wheel head, while the 
 swivel head is set over to the desired angle. 
 
 As a general thing, the side teeth of milling cutters require 
 grinding but seldom, owing to the fact that most of the cut- 
 
 296
 
 CUTTER SHARPENING 
 
 ting is done by the peripheral teeth. In some cases, however, 
 the side teeth require sharpening, it being obvious that this is 
 imperative with new cutters that have never been backed off. 
 Side teeth are sharpened in two ways, that is to say, 
 with the face or the periphery of the wheel. For some milling 
 operations, the periphery of the wheel is to be preferred 
 as it gives a better cutting clearance. Grinding under these 
 conditions is illustrated in Fig. 155 which shows an attach- 
 
 Fig. 155. Grinding the side teeth of a milling cutter on the periphery of the 
 wheel on a Brown & Sharpe cutter grinding attachment. 
 
 ment for this purpose on the Brown & Sharpe cutter grinder 
 depicted in Figs. 150 and 152. The cutter is held on the 
 end of an arbor that fits in 'the head and is fed back and 
 forth by the lever seen in the lower part of the illustration. 
 The guide finger at the right locates the teeth. 
 
 297
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 The operation of sharpening side teeth with the side of 
 the wheel is illustrated in Fig., 156. The work is held on 
 the end of an arbor which fits the swivel head and fed back 
 and forth past the face of the wheel. The machine is a 
 Cincinnati grinder and its makers give the following direc- 
 tions for setting up for this operation. 
 
 "After the cutter is placed in position as above described, 
 the head should be set to zero and the cutter set central 
 by means of the centering gauge. The tooth-rest is next 
 
 Fig. 156. Grinding the side teeth of a milling cutter using the side of the 
 wheel on a Cincinnati grinder. 
 
 adjusted and the head depressed to give the proper angle 
 of clearance. The knee of the machine is next set to 90-1/2 
 degrees so that the grinding is done with the down side of 
 the wheel, the upper side clearing. Should the tooth next 
 
 298
 
 CUTTER SHARPENING 
 
 to the one being ground strike the wheel, the table should 
 be raised to make the clearance desired. The above applies 
 to the grinding of right side teeth. In grinding the left side 
 teeth, the operation is reversed and the knee set to 89-1/2 
 degrees so that the grinding is done with the up side of the 
 wheel instead of the down side." 
 
 Another device often made use of in grinding the side 
 teeth of milling cutters is shown in Fig. 157 and is called a 
 universal head. These heads are very handy for a diversity 
 
 Fig. 157. Universal head for grinding milling cutters, etc. 
 
 of grinding operations. The machine shown is a Walker 
 grinder and the operator is grinding -the end teeth of a 
 butt mill. This is held on a short arbor which is located 
 in the vee block of the universal head. The head is tilted 
 to impart the desired angle and the teeth are located by 
 means of the guide finger which is strapped to the platen 
 of the machine. 
 
 On first thought, it might seem that a large machine 
 would be necessary to sharpen large inserted-tooth milling 
 
 299
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 cutters. This is not the case, however, as they are readily 
 sharpened on ordinary cutter grinding machines. Fig. 158 
 illustrates the operation of sharpening the face teeth of a 
 large mill on a Cincinnati grinder. The cutter is mounted 
 on a shank held in the swivel head spindle and the swivel 
 
 Fig. 158. Grinding a large inserted-tooth milling cutter on a 
 Cincinnati grinder. 
 
 head is depressed to impart the desired clearance. The 
 face of the tooth should be brought to a horizontal position 
 and the tooth-rest adjusted to bear on it. 
 
 It is a well-known fact that the corners of the teeth of 
 any face mill wear readily and experience has proven that 
 excellent results are obtained by rounding these corners. 
 A corner relieved in this manner is illustrated in Fig. 159 
 and the operation of grinding it on a Cincinnati grinder is 
 
 300
 
 CUTTER SHARPENING 
 
 illustrated in Fig. 160. The cut is obtained by swiveling 
 the head 45 degrees, 22-1/2 degrees and 67-1/2 degrees. 
 While grinding large cutters, it is often necessary to swivel 
 
 Fig. 159. Relieved corners on face-mill tooth 
 
 both the table and the head to allow for clearance. In 
 this method the angle is obtained by a combination of both 
 dials. 
 
 Fig. 1 60. Cincinnati grinder set up to relieve corners of cutter teeth. 
 301
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 The operation of sharpening the peripheral teeth of 
 large end mills is shown in Fig. 161. By referring to the 
 illustration, it is seen that the tooth-rest is fastened to 
 the top of the swivel head which avoids interference with 
 
 Fig. 161. Grinding the peripheral teeth of a large milling cutter on a 
 Cincinnati grinder. 
 
 the grinding-wheel head. The angle for clearance is ob- 
 tained from the graduations on the swivel head. 
 
 As the illustrations show, cup wheels are used in grinding 
 these large cutters. As the grinding is done with the face 
 of the wheel, it is obvious that a straight surface is obtained. 
 This is considered a decided advantage in these large cut- 
 ters as it insures the maximum amount of wear. 
 
 An important branch of cutter grinding consists of sharp- 
 ening the so-called formed cutters as used for milling irregu- 
 lar outlines. While an ordinary milling cutter is ground by 
 
 302
 
 CUTTER SHARPENING 
 
 cutting away its periphery, a different method must be 
 followed with formed cutters as the outline is often of such 
 a complicated shape that it would be impossible to grind 
 it. The relief of these cutters is in the form of regular 
 curves, and they can readily be sharpened by grinding 
 away the dulled part of the tooth face. The principle is 
 illustrated in Fig. 162, wherein A is the. cutter and B the 
 grinding wheel. In grinding formed cutters the dotted 
 
 Fig. 162. Principle involved in grinding formed cutters. 
 
 line C, which is a continuation of the wheel face, must pass 
 through the center of the cutter. Otherwise the cutter 
 will not mill exactly the form for which it was designed. 
 
 303
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 This is an important point in the grinding of formed cutters 
 that is sometimes overlooked. 
 
 The operation of grinding a formed cutter is shown in 
 Fig. 163. The work is done on a Brown & Sharpe formed 
 
 Fig. 163. Grinding a formed cutter on a Brown & Sharpe formed-cutter 
 grinding attachment. 
 
 cutter-grinding attachment that is fitted to the company's 
 regular cutter grinder as shown in Fig. 150. The work is 
 held on an arbor between two centers and the cutter is 
 
 304
 
 CUTTER SHARPENING 
 
 indexed around by means of the worm wheel seen in the 
 illustration. 
 
 The first step in setting up the machine for grinding 
 cutters of this type is to see that the face of the wheel is 
 perfectly true. As a matter of fact, it is a good plan to 
 true the face of the wheel every time it is placed on the 
 spindle. Next, the center must be brought in line with the 
 face of the wheel. After the cutter is in position on its 
 arbor, the wheel is adjusted to the correct depth and one 
 tooth fed around radially until it strikes the wheel. Then 
 the index pin is located. The cut taken should be com- 
 paratively light as it is an easy matter to burn the teeth 
 of the cutters in question, even with the best wheels ob- 
 tainable. One tooth should be ground at a time with a 
 fairly rapid reciprocating motion until the wheel ceases to 
 spark heavily. After all the teeth have been ground enough 
 to insure their being sharp, the cutter should be gone 
 around once or twice with a slight cut to make sure that the 
 grinding has left the teeth evenly spaced. Otherwise, only a 
 few of the teeth will cut after the cutter is put in operation. 
 
 While the operation of sharpening milling cutters of any 
 kind is comparatively simple, care should be exercised in 
 the selection of the wheels used which should be free cutting 
 and made of an alumina abrasive, since the work is steel 
 grinding. It should also be borne in mind that wheels for 
 sharpening high-speed-steel cutters should be somewhat 
 coarser than those used for sharpening carbon-steel cutters. 
 Again, the cup-and-saucer wheels used for sharpening both 
 plain and formed cutters should be somewhat softer than 
 the disk wheels so commonly used for sharpening peripheral 
 teeth. The following wheels have been found to give good 
 results in cutter grinding. The gradings are according to 
 the writer's grade scale. For high-speed-steel cutters, 36 
 to 46 grit, 4 to 7 grade. For carbon-steel cutters, 50 to 
 60 grit, 4 to 7 grade. 
 
 After the peripheral teeth of an ordinary milling cutter 
 have been sharpened several times, the tooth land becomes 
 
 3S
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 so wide that the clearance for chips is practically ground 
 away, in which case the cutter is consigned to the scrap 
 heap or annealed and re-cut on the milling machine. This 
 process generally destroys the size of the hole, and, again, 
 many cutters are lost in this manner through fire cracking. 
 Milling cutters can be successfully re-cut, without an- 
 nealing them, on the attachment illustrated in Fig. 163 or 
 on the surface grinder, in which case it is understood that 
 
 ^-Grinding Wheel 
 
 Fig. 164. Method followed in re-cutting milling cutters without 
 annealing them. 
 
 they are held on an arbor between centers. The method 
 followed in re-cutting cutters without annealing them is 
 illustrated in Fig. 164. After the cutter is placed on an 
 arbor and the arbor located between centers, the first step 
 is to grind grooves as shown at A. The illustration is self- 
 explanatory. The wheel used for this work should be of 
 medium grade in shellac bond about 40 to 50 grit. After 
 the cutter has been gone around and all the teeth cut out, 
 
 306
 
 CUTTER SHARPENING 
 
 the next operation is to grind away the superfluous stock 
 as shown at B. This work is done with a wheel in 46 grit 
 on the writer's 6 grade. The face of the wheel is trued to 
 produce the desired angle to the teeth. 
 
 The operation is simple and after a little practice, the 
 average operator can secure excellent results through the 
 exercise of a little care. In gashing out the teeth, one tooth 
 should be operated on at a time and several cuts taken to 
 bring the gash to the required depth. In the re-cutting 
 operation with the beveled wheel, the depth of cut should 
 
 Fig. 165. Steps taken in re-cutting a milling cutter without annealing. 
 
 not be deep enough to cause the wheel to burn the work. 
 In the latter operation also, one tooth should be worked 
 on at a time until it is ground to the required depth as this 
 practice will give better results than can be obtained by 
 taking a small cut from each tooth, one after another. 
 
 Upon first trial, the operator will, no doubt, burn and 
 ruin a few cutters, but a little practice will make him pro- 
 ficient. In Fig. 165, two cutters are shown. Cutter A 
 has been gashed only while B shows the finished cutter ready 
 to be put to use again. The side teeth can be cut if neces- 
 sity demands, but since these teeth are seldom ground, 
 they are rarely worn to the extent of needing re-cutting. 
 
 307
 
 CHAPTER TWENTY-ONE 
 
 SAW SHARPENING 
 
 Band saws and circular saws Operation of band-saw sharpening machine 
 Sharpening band saws Grinding in new teeth Care of machine 
 Selection of wheels for saw gumming Machines for sharpening cold saws 
 Sharpening hack-saw blades. 
 
 WHEN we stop a moment to consider the vast amount 
 of timber that is annually cut and converted into 
 lumber for various purposes, it is easy to see why saw sharp- 
 ening, or saw' gumming as it is termed in lumber mills end 
 other wood-working establishments, is an extensive trade 
 in itself. A man who sharpens wood-working saws is in- 
 variably called a filer, although he seldom uses a file in his 
 work, and the room where the saws are repaired is called 
 the filing room. The name, of course, dates from the time 
 when the file was the only tool to be had for saw sharpening 
 .and, in common with many other misplaced trade terms, 
 it probably will endure for years to come. 
 
 Saws are of two kinds, that is to say, band saws and 
 circular saws, and there are various types of each kind. 
 For cutting up logs, circular saws are not as economical 
 as band saws owing to the fact that the former have to be 
 of a comparatively thicker gauge to insure the necessary 
 stiffness and strength. The added thickness, of course, 
 makes extra sawdust which is an economic waste. Nowa- 
 days, circular saws are used in comparatively few mills. 
 Still, there are a few circular mills left which carry saws 
 as large as 6 feet in diameter. Many circular saws are used 
 as cut-off saws for various purposes such as cutting long 
 
 308
 
 SAW SHARPENING 
 
 logs into the desired lengths before they are sawed into 
 boards and for edging and trimming lumber, etc. 
 
 The majority of mills" today are band mills and the saws 
 used are often 50 feet long, being driven by two large pulleys, 
 in width, they run from 10 to 14 inches. A smaller type of 
 band saw, called a re-saw, is generally about 25 feet long 
 and from 6 to 10 inches wide. Many filers make their re- 
 saws from old hand saws. 
 
 Two machines used for saw gumming are shown in Figs. 
 1 66 and 167. The machine shown in Fig. 166 is for sharp- 
 ening band saws, while the one shown in Fig. 167 is for 
 
 Fig. 1 66. Type of machine used for gumming band saws. 
 
 circular saws, the saw shown being a cut-off saw which is 
 readily seen from the shape of the teeth. 
 
 Both types of machines operate on practically the same 
 principle, that is to say, means are provided for feeding 
 the saw under the wheel, tooth by tooth, and for lowering 
 
 309
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 and raising the wheel to form the desired shape of the teeth. 
 In the machine illustrated in Fig. 166, the head is set over 
 at an angle and is fed up and down by an adjustable cam 
 arrangement which can be set to form different kinds of 
 teeth. The saw is fed forward by means of an adjustable 
 dog that pulls the saw along tooth by tooth the desired 
 distance, the feeding taking place while the saw is out of 
 the gullet of the tooth. 
 
 The machine shown in Fig. 167 has practically the same 
 arrangement for feeding the saw along, but the head travels 
 straight up and down. It also swivels alternately to form 
 the desired angle on the teeth. Both machines shown are 
 fully automatic. 
 
 The grinding of band saws is divided into two distinct 
 operations called by the filer, "roughing out" and "pointing 
 up." The latter operation is comparatively simple and re- 
 quires only a few cuts around the saw. This operation 
 takes place after the dull saw is taken from the mill. After 
 a saw has been in use a few days, it has to be re-swaged and 
 after this operation it has to be ground again before it is 
 fit for use. 
 
 The operation of roughing out is where the real work of 
 the filer comes, for logs, as they come to the mill, are not 
 composed wholly of wood by any means. Sometimes, in 
 felling, a small stone becomes imbedded in the wood. 
 Again perhaps, the log grew on a farm, and some thrifty 
 farmer might have hung a horseshoe, a piece of broken chain 
 or other bit of discarded metal in the crotch of one of the 
 limbs, which in time grew over and covered up the metal. 
 Logs are often bound together in rafts for floating down 
 the river by wooden cross-pieces, held together by tree- 
 nails. The holes for the treenails are bored with ship 
 augers and sometimes an auger is broken off and left in 
 the log. The rafts are often chained together and the chains 
 are spiked to the logs. From this it is seen that many 
 factors are present to keep the filer continually on the 
 job for when a saw, traveling at a high speed, strikes one 
 
 310
 
 SAW SHARPENING 
 
 of these obstructions it sometimes happens that every tooth 
 is literally stripped off nearly down to the bottom of the 
 gullets. 
 
 When accidents of this kind happen, the operation of 
 roughing out the saw is in order. This requires much grind- 
 
 Fig. 167. Type of machine used for gumming circular saws. 
 
 ing as every tooth has to be ground in again, to the desired 
 depth, which takes many hours of heavy grinding. When 
 the filer makes a new saw from a blank, which is common 
 practice in some parts of the country, the roughing out
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 operation also takes place. It is first necessary to stamp the 
 teeth in the saw and then grind them to the correct shape. 
 The stamping operation is essential, otherwise the feed . 
 dog would have no depressions to grip to carry the saw 
 along. 
 
 From the above, it is seen that the filer in a large band 
 mill works under difficulties and aside from the above 
 hindrances he has other troubles to contend with. It is, 
 of course, necessary that the filing room be in close prox- 
 imity to the mills on which the saws are used. The ideal 
 location for the filing room is in a detached room on the 
 level with the mill floor. The object of the detached build- 
 ing is to eliminate, as much as possible, the vibration which 
 is always a detriment to good grinding of any kind what- 
 soever. 
 
 Another factor that is the cause of much trouble in the 
 filing room is that the engine that runs the mill also runs 
 the line shaft in the filing room. Thus, when the saw goes 
 through a large log the speed of the engine is lowered a 
 few revolutions per minute before the governor can feed 
 more steam to compensate for the extra load. While the 
 engine lowers its speed a few revolutions a minute, it is 
 readily seen that the grinding wheel on the saw-gumming 
 machine is lowered in speed in a greater ratio as it runs 
 correspondingly faster than the engine. This factor of 
 uneven wheel speed interferes with good results and for 
 this reason the mills, where careful planning is in evidence, 
 are equipped with small independent engines for supplying 
 power to the filing room. 
 
 Saw-grinding machines are very seldom equipped with 
 means for carrying away the dust caused by grinding, and 
 for this reason they should receive careful attention. The 
 wheel spindle boxes should be examined frequently and the 
 wear taken up when necessary, for a loose wheel spindle 
 cannot be depended upon for the best results. The cams 
 and their rolls should be examined and oiled frequently. 
 The cams wear out of shape in time: thus they fail to pro- 
 
 312
 
 SAW SHARPENING 
 
 duce the proper kind of tooth. A worn cam lets the wheel 
 down into the gullet of the tooth too abruptly, which not 
 only spoils the shape of the tooth, but wears away the 
 wheel too rapidly. 
 
 Great care should be used in the selection of wheels 
 for saw gumming because inferior abrasives often burn and 
 case harden the saws, causing them to crack. If a crack 
 shows up at the bottom of a tooth, the only thing to do is 
 to cut the tooth out and braze in a new one which is an 
 expensive operation. These wheels should be of an alumina 
 abrasive and soft enough to cut freely, but not soft enough 
 to wear out too fast. The grade depends principally on the 
 condition the machine is in and other local factors such as 
 undue vibration. Too much vibration wears out the wheels 
 
 V ' . '-./' ' , '; 
 
 c 
 
 Fig. 1 68. Three types of wheels used for saw gumming. 
 
 readily and a harder wheel must be used than could be 
 employed under more favorable conditions. The wheels 
 used for this work run from 30 to 46 grit and 7 to 10 grade 
 according to the writer's grade scale. Combination grit 
 wheels with a base of 30 or 36 are excellent for this purpose. 
 There are three shapes of wheels used for saw gumming, 
 as illustrated in Fig. 168. A is a plain straight wheel, B 
 is tapered on both sides while C is a shape called a Covel 
 saw gummer. There is a difference of opinion among filers 
 as to which shape is the best to use. Some filers get ex- 
 cellent results with plain straight wheels, while others in- 
 
 313
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 sist that the tapered cutting side gives a better wheel clear- 
 ance and there is, no doubt, some truth in the claim. 
 
 Re-saws are ground in exactly the same manner as are 
 large band saws with the exception that the machine used 
 is comparat vely smaller. A re-saw grinding operation in 
 a planing mill is shown in Fig. 169. The filer in the planing 
 mill has comparatively few troubles compared to his brother 
 
 Fig. 169. Grinding a small band re-saw. 
 
 in the big band mill, for the saws in planing mills, aside from 
 cutting through an occasional nail, are seldom put to severe 
 use. 
 
 A different type of machine than the one heretofore shown 
 for sharpening circular saws is shown in Fig. 170. This 
 machine is used for sharpening small circular saws as used 
 in planing mills and furniture factories. The saw is located 
 in a horizontal position. This machine is not automatic 
 as far as the feed is concerned as the operator has to space 
 the teeth around by means of the lever operated by his 
 left hand. For small saws, these semi-automatic machines 
 give excellent results. The same wheels are used for re-saws 
 
 314
 
 SAW SHARPENING 
 
 and small circular saws as are used for larger saws, the only 
 exception being that the grits are somewhat finer. 
 
 Another important branch of saw sharpening consists 
 of grinding metal cutting saws as shown in Fig. 171. These 
 are often termed "cold saws" and are used for cutting 
 
 t t 
 
 Fig.' 170. Metal cutting or cold saw used for cutting large steel sections. 
 
 bar stock, structural-steel sections, rails, etc. They are 
 also frequently used in steel foundries for cutting away the 
 sprues from large castings. As may be imagined, they are 
 often put to severe usage and for this reason they require 
 frequent grinding. 
 
 The operation of sharpening the saw shown in Fig. 171 
 is il'ustrated in Fig. 172. This machine is a product of the 
 Matteson Mfg. Co., Chicago, and is designed on the prin- 
 ciple involved in the saw-sharpening machines previously
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 described in this chapter. That is to say, it has means 
 for feeding the wheel with an up-and-down motion while the 
 saw is fed onward, tooth by tooth, by a feed dog. These 
 motions are automatic. 
 
 The operation of sharpening cold saws is somewhat simi- 
 lar to re-cutting milling cutters as previously described, 
 because two cuts are generally taken; one to grind out the 
 gullets and a following cut to sharpen the teeth, giving 
 
 Fig. 171. Type of semi-automatic machine used for sharpening small 
 circular saws. 
 
 them the proper relief at the same time. For grinding out 
 the gullets, the wheel is beveled to the correct angle, the 
 wheel being dropped directly into the tooth. For sharpening 
 the periphery of the saw, the wheel is beveled slightly; 
 only just enough to insure the proper cutting clearance. 
 
 Another machine extensively used for sharpening cold 
 saws is shown in Fig. 173. This is made by the Newton 
 Machine Tool Works, Philadelphia. The machine is self- 
 contained and electrically driven by means of a motor placed 
 
 316
 
 SAW SHARPENING 
 
 on a supplementary base while the rest of the mechanism 
 is supported by a cast-iron column. 
 
 This machine is fully automatic in operation beyond 
 locating the saw and setting the hand adjustment for depth 
 of cut. To insure each tooth being of the correct contour, 
 
 Fig. 172. Sharpening a cold saw on a Matteson saw-sharpening machine. 
 
 the feeding pawl is set so that the wheel grinds both the 
 back and the front of the tooth in the roughing-out opera- 
 tion. In grinding saws in which a tooth or two has been 
 broken out (which is not infrequent) an auxiliary feed pawl is 
 provided. This pawl engages the next tooth back of the 
 break.
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 Fig. 173. Newton self-contained automatic cold-saw sharpening machine.
 
 SAW SHARPENING 
 
 Broadly speaking, the operation of sharpening cold saws 
 is simp'e and it is easily carried out if a few simple pre- 
 cautions are taken. In the first place, these saws should be 
 sharpened frequently. It should be borne in mind that they 
 are really no more or less than huge milling cutters and as 
 such they should be given careful attention. When slightly 
 dull, they cannot work to maximum efficiency, but if they 
 are kept sharp they will yield excellent results. Several 
 saws for each machine should be kept on hand and dull 
 saws should be replaced with sharp ones at frequent intervals. 
 
 The wheels used for sharpening cold saws should be of 
 a free-cutting nature and at the same time they should 
 hold their shape well. This applies to the wheels used for 
 grinding the periphery of the teeth as well as those used for 
 forming out the gullets. As the grinding in question is 
 steel, the wheels should be made of an alumina abrasive. 
 Grits from 40 to 60 in the writer's grades ranging from 10 
 to 1 2 generally give good results. 
 
 The machine shown in Fig. 174 was designed especially 
 for sharpening hack-saw blades and the slow-running band 
 saws as used at the present day for cutting metals of various 
 kinds. Some years ago, when hack-saw blades were made 
 of carbon steel they were thrown away as soon as the teeth 
 became too dull for practical use. At the present time, 
 however, when the majority of hack-saw blades are made 
 of high-speed steel, it is evident that the average manufac- 
 turing plant's expenditure for blades under such conditions 
 is comparatively high and attention has been directed to 
 reclaiming the worn blades. 
 
 The machine in question is designed and made by the 
 Wardwell Mfg. Co., Cleveland, Ohio, and its operation is 
 comparatively simple. As the illustration shows, it is not 
 unlike the machines previously described for sharpening 
 wood- working saws. The machine is provided with a main 
 drive which extends across the back of the frame and power 
 is transmitted by means of a belt to the shaft seen in the 
 foreground, upon which the grinding wheel is mounted. 
 
 3-IQ
 
 ABRASIVES AND ABRASIVE WHEELS 
 
 This wheel is comparatively thin, is made in elastic bond, 
 and is of medium grit and grade. 
 
 The grinding-wheel shaft, or spindle, is suspended at 
 the end of an arm, the opposite end of which swings in 
 pivoted bearings, placed well part to reduce side motion to 
 a minimum. This feature is necessary to insure correct 
 spacing of the saw teeth. The arm is supported in a seg- 
 
 Fig. 174. Wardwell automatic saw-sharpening machine. 
 
 ment which allows the wheel to be set at an angle. This 
 permits one edge, or corner, only of the wheel to come in 
 contact with the face of the tooth being ground while the 
 opposite edge, or corner, bears on the back of the tooth. 
 This action serves to keep the wheel dressed constantly 
 so that it always presents the proper shape for forming the 
 gullets of the teeth. 
 
 Two adjustments control the movements of the grinding- 
 wheel head. One governs the depth the grinding wheel is 
 allowed to sink into the tooth gullet, while the other regu- 
 lates the amount of cut to be taken from the back of the 
 tooth. The last adjustment is made by an adjusting screw 
 
 320
 
 SAW SHARPENING 
 
 which comes in contact at the proper time with a roll which 
 bears on the face of the cam. This cam is adjustable for 
 forming all the different shaped backs of teeth. 
 
 Power from the feed mechanism is derived from the main 
 drive shaft through a worm gear to a shaft at the left- 
 hand side of the machine. On the end of this shaft is a 
 slotted eccentric equipped with a screw feed. This eccentric 
 governs the feed of the blade to the machine. 
 
 The operation of the machine is simple and exact and 
 it is said that as little as one-half thousandth of an inch 
 can be removed from either the face or the back of the 
 tooth. The machine is automatic in operation, and, after 
 being started, it requires no more attention until the saw 
 has been sharpened, that is, when grinding a band saw. 
 With hack saws, a group is placed in position and the feed 
 pawls take these one at a time and feed them through the 
 machine. A group of hack-saw blades are placed in the 
 machine, being held by spring tension. The feed pawl bears 
 on the inner blade only, thus as soon as this is fed out of 
 the way, the spring action forces another in a position to 
 be fed forward. 
 
 The blades are fed along by a double-pawl arrangement. 
 Two pawls work at the same time, one on each side of the 
 grinding wheel. The one on the right draws the blade in 
 and starts the grinding of the first tooth, while the other on 
 the left draws the blade clear of the grinding wheel and dis- 
 charges it.
 
 INDEX 
 
 Abrasive action, 133. 
 
 Abrasive discs, manufacture of, 169. 
 
 Abrasive discs, materials used, 173. 
 
 Abrasive discs, selection of, 173. 
 
 Abrasive discs, testing, 174. 
 
 Abrasive paper and cloth, coating- 
 machine for making, 167. 
 
 Abrasive paper and cloth, early manu- 
 facture of, 167. 
 
 Abrasive paper and cloth, grits of, 89. 
 
 Abrasive paper and cloth, sizes and 
 numbers of, 168. 
 
 Abrasive paper and cloth, uses of, 166. 
 
 Abrasive temper, 52. 
 
 Abrasives, artificial, 37. 
 
 Abrasives, natural, 13. 
 
 Abrasives used for die grinding, 192. 
 
 Accidents, blame for, 164. 
 
 Accidents caused by tight wheel 
 bushings, 153. 
 
 Accidents caused by work rest, 155. 
 
 Acheson, Edward G., 38. 
 
 Action, abrasive, 133. 
 
 Action, grindstone, 124. 
 
 Adamite, 63. 
 
 Adaptability of cylinder grinder, 261. 
 
 Adapting wheel for surface grinding. 
 199. 
 
 Advantage of coarse feed marks in 
 grinding, 181. 
 
 Advantages of combination grits, 89. 
 
 Advantages of re-bushing grinding 
 wheels, 139. 
 
 Advantages of using large grinding 
 wheels, 130. 
 
 Allowance for finish chip, 223. 
 
 Allowance for internal grinding, 253. 
 
 Allowances for grinding, 220. 
 
 Aloxite, 58. 
 
 Aloxite, characteristics of, 60. 
 
 Aloxite, color of, 60. 
 
 Aloxite, furnace, 58. 
 
 Aloxite, furnace, power required to 
 operate, 58. 
 
 Aloxite grain, preparation of, 59. 
 
 Aloxite, how crushed, 59. 
 
 Aloxite ingot, 59. 
 
 Aloxite ingots, how broken, 59. 
 
 Aloxite, process of making, 58. 
 
 Aloxite, purity of, 59. 
 
 Aloxite, uses of, 60. 
 
 Aloxite, where made, 58. 
 
 Alumina, artificial, Dollner's, 51. 
 
 Alumina, percentage of in emery, 17. 
 
 Alundum, 57. 
 
 Alundum furnace, horsepower re- 
 quired to operate, 57. 
 
 Alundum, how crushed, 57. 
 
 Alundum pigs, 57. 
 
 Alundum, process of making, 57. 
 
 Alundum, uses of, 58. 
 
 Alundum, varieties of, 58. 
 
 Alundum varieties, how designated, 
 58. 
 
 American corundum, 25. 
 
 American emery, discovery of, 16. 
 
 Amount ^for finishing in crankshaft 
 grinding, 279. 
 
 Amperage of Carborundum furnace, 
 40. 
 
 Analysis of .Corubin, 51. 
 
 Analysis of corundum, 23. 
 
 Angular cutters, grinding, 295. 
 
 Angular grit, 64. 
 
 Angular grit, composition of, 64. 
 
 Angular grit, sizes of, 64. 
 
 Angular grit, uses of, 64. 
 
 Arkansas sharpening stones, 35. 
 
 Arkansas sharpening stones, com- 
 position of, 35. 
 
 Arkansas sharpening stones, uses of, 
 35- 
 
 Arkansas sharpening stones, varieties 
 of, 35- 
 
 Arkansas sharpening stones, where 
 found, 35. 
 
 323
 
 INDEX 
 
 Artificial abrasive, Werlein's, 61. 
 
 Artificial abrasives, 37. 
 
 Artificial alumina, Dr. G. Dollner's, 
 
 Si- 
 
 Artificial corundum, 47. 
 
 Artificial corundum, development of, 
 
 48. 
 Artificial corundum, first successful 
 
 production of, 48. 
 Artificial corundum, Jacobs' process 
 
 for making, 56. 
 
 Artificial corundum, temper of, 56. 
 Artificial corundum, when first made, 
 
 47, 48. 
 
 Artificial sharpening stones, 83. 
 Automobile engine cams, types of, 280. 
 Axe grinding, 125. 
 Axe grinding, advantages of grinding 
 
 wheels in, 126. 
 Axe grinding, future of grinding wheel 
 
 for, 127. 
 Axe grinding, time consumed, 126. 
 
 B 
 
 Backrest, setting, Norton, 226. 
 Backrest, solid, Norton, 226. 
 Backrest, spring, Brown & Sharpe, 
 
 227. 
 Backrest, universal, Brown & Sharpe, 
 
 228. 
 
 Backrests, kinds of, 226. 
 Balance wheel, 234. 
 Balancing device, Landis, 235. 
 Balancing grinding wheels, 76. 
 Balas ruby, 47. 
 Band re-saws, 309. 
 Band re-saws, grinding, 314. 
 Band saws, 308. 
 Barrel corundum, 22. 
 Bauxite, 53, 57. 
 Bauxite, color of, 53. 
 Bauxite, discovery of, 53. 
 Bauxite, origin of name, 53. 
 Bauxite, where found, 53, 54. 
 Belgian razor hone, 35. 
 Belts, garnet paper, testing, 172. 
 Berthier, P., 53. 
 Blame for accidents, 164. 
 Blanchard continuous reading caliper 
 
 gauge, 212. 
 Blanchard grinder, chuck speed for, 
 
 211. 
 
 Blanchard grinder, locating work on, 
 
 211. 
 
 Blanchard grinder, operation of, 212. 
 
 Blanchard grinder, wheels for, 212. 
 
 Blanchard grinder, wheel speed, 211. 
 
 Blanchard surface grinding machine, 
 208. 
 
 Blanchard surface grinder, samples of 
 work done on, 210. 
 
 Bond of grinding wheels, 66. 
 
 Bonding materials, 66. 
 
 Bonding materials, how tested, 67. 
 
 Bonds, grinding wheel, how standard- 
 ized, 67. 
 
 Boro-Carbone, 62. 
 
 Boro-Carbone, characteristics of, 62. 
 
 Boro-Carbone, color of, 62. 
 
 Boro-Carbone, uses of, 62. 
 
 Boro-Carbone, where made, 62. 
 
 Bort diamonds, 31. 
 
 Branch pipes, size of for dust-col- 
 lecting system, 146. 
 
 Breakage, grinding wheels, causes of, 
 151 
 
 Breaking Aloxite ingots, 59. 
 
 Brown & Sharpe cutter grinder, 290. 
 
 Brown & Sharpe cutter grinding at- 
 tachment, 297. 
 
 Brown & Sharpe formed-cutter grind- 
 ing attachment, 304. 
 
 Brown & Sharpe spring backrest, 227. 
 
 Brown & Sharpe surface grinder, 188. 
 
 Brown & Sharpe universal backrest, 
 228. 
 
 Brown & Sharpe universal grinder, 
 236. 
 
 Burning a Carborundum furnace, 40. 
 
 Bushing grinding wheels, 75. 
 
 By-product of Carborundum furnace, 
 40* 
 
 Calender rolls, causes of wear of, 264. 
 Calender rolls, early, how finished, 
 
 265. 
 
 Calender rolls, how ground, 269. 
 Calender rolls, largest stack of, 263. 
 Calender rolls, old installation, 265. 
 Caliper gauge, continuous-reading, 
 
 Blanchard, 212. 
 Cam grinder, leaders for, 283. 
 Cam-grinding attachment, Norton, 
 
 280. 
 
 324
 
 INDEX 
 
 Cam-grinding, effect of wheel wear 
 
 in, 285. 
 
 Cam-grinding leaders, how made, 284. 
 Cam-grinding, steady-rests for, 282. 
 Cam-grinding, wheels for, 283. 
 Cams, types of in automobile engines, 
 
 280. 
 
 Canadian corundum, 21. 
 Canadian corundum deposits, 21. 
 Carbide of silicon, 38. 
 Carbide of silicon, German, 46. 
 Carbonado, fracture of, 32. 
 Carbonado, specific gravity of, 29. 
 Carbonado, uses of, 32. 
 Carbonado, where found, 32. 
 Carborundum, cleavage, 41. 
 Carborundum cloth, 168. 
 Carborundum, color of, 41. 
 Corborundum, composition of, 38. 
 Carborundum crystals, shape of, 41. 
 Carborundum for steel grinding, 45. 
 Carborundum, fracture of, 41. 
 Carborundum furnace, 38. 
 Carborundum furnace, amperage, 40. 
 Carborundum furnace, burning, 40. 
 Carborundum furnace, by-product of, 
 
 40. 
 
 Carborundum furnace, charge of, 39. 
 Carborundum furnace, contents of, 40. 
 Carborundum furnace, heat of, 40. 
 Carborundum furnace, how charged, 
 
 39- 
 
 Carborundum furnace, voltage, 40. 
 Carborundum grain, numbers of, 44. 
 Carborundum, hardness of, 41. 
 Carborundum, how crushed, 42. 
 Carborundum, how graded, 43. 
 Carborundum, how purified, 42. 
 Carborundum, impurities of, 42. 
 Carborundum paper, 168. 
 Carborundum powder, how graded, 
 
 44- 
 
 Carborundum, process of making, 39. 
 Carborundum, raw materials, 38. 
 Carborundum razor hones, 85. 
 Carborundum rubs, 86. 
 Carborundum sharpening stones, 83. 
 Carborundum sharpening stones, 
 
 combination, 86. 
 Carborundum sharpening stones, grits 
 
 of, 85. 
 Carborundum sharpening stones, how 
 
 finished, 86. 
 
 Carborundum sharpening stones, how 
 
 molded, 84. 
 
 Carborundum, specific gravity of, 41. 
 Carborundum, uses of, 45. 
 Carborundum, when discovered, 38. 
 Carborundum, why not found in 
 
 nature, 41. 
 Carbosolite, 46. 
 Carbosolite, color of, 47. 
 Care of saw grinding machines, 312. 
 Car-wheel grinding, testing wheels 
 
 for, 1 06. 
 
 Case hardening of saws, cause of, 313. 
 Cause of chatter marks, 232. 
 Causes of chattering in roll grinding, 
 
 269. 
 
 Causes of hard and soft spots, 72. 
 Center, square, 221. 
 Centers, grinding, 240. 
 Chain link grinding, 112. 
 Change in grade, effect of, 105. 
 Characteristics of Aloxite, 60. 
 Characteristics of Boro-Carbone, 62. 
 Characteristics of emery, 1 7. 
 Characteristics of grindstones, 127. 
 Characteristics of pressed wheels, 68. 
 Charge of Carborundum furnace, 39. 
 Charging a Carborundum furnace, 39. 
 Chatter marks, cause of, 232. 
 Chattering, causes of, in roll grinding, 
 
 269. 
 
 Chattering, wheel, 200. 
 Chilled iron roll grinding test, 1 08. 
 Chuck, bushing, Heald, 248. 
 Chuck for ring wheel, 180. 
 Chuck, magnetic, Heald, 194. 
 Chuck, magnetic, swivel, 194. 
 Chuck, magnetic, taper, 194. 
 Chuck speed for Blanchard grinder, 
 
 211. 
 
 Chucking work for internal grinder, 
 
 247. 
 
 Chucks, gear, 248, 251, 252, 253. 
 Chucks, magnetic, current for, 197. 
 Chucks, rotary, for surface grinder, 
 
 204. 
 
 Cincinnati cutter grinder, 290. 
 Circular saws, 308. 
 Circular saws, machine for grinding, 
 
 3H- 
 
 Classes of diamonds, 29. 
 Cleanouts for dust collecting system, 
 149. 
 
 325
 
 INDEX 
 
 Clearance, cutter, how obtained, 295. 
 
 Cleavage of Carborundum, 41. 
 
 Cloth, Carborundum, 168. 
 
 Cloth, emery, 168. 
 
 Coarse feed, advantages of in grind- 
 ing, 181. 
 
 Coating-machine for making abrasive 
 paper and cloth, 167. 
 
 Collars for dust collecting system, de- 
 sign of, 147. 
 
 Collecting systems, dust, advantages 
 of, 145. 
 
 Collector, location of, for dust col- 
 lecting system, 150. 
 
 Color of Aloxite, 60. 
 
 Color of bauxite, 53. 
 
 Color of Boro-Carbone, 62. 
 
 Color of Carborundum, 41. 
 
 Color of Carbosolite, 47. 
 
 Color of diamonds, 31. 
 
 Color of emery, 15. 
 
 Colors of sandstone, 14. 
 
 Combination Carbprundum sharpen- 
 ing stones, 85. 
 
 Combination grits, 89. 
 
 Combination grits, advantages of, 89. 
 
 Comparative grade lists, inaccuracy 
 of, 91. 
 
 Comparative values of grinding 
 wheels, 129. 
 
 Comparison of surface grinders, 202. 
 
 Component parts of corundum, 22. 
 
 Component parts of spinel emery, 16. 
 
 Composition of angular grit, 64. 
 
 Composition of Arkansas sharpening 
 stones, 35. 
 
 Composition of Carborundum, 38. 
 
 Composition of flint, 34. 
 
 Composition of grinding wheels, 65. 
 
 Composition of Oxalumina, 63. 
 
 Composition of quartz, 34. 
 
 Composition of ruby, 48. 
 
 Cones, pyrometric, 72. 
 
 Contents of Carborundum furnace,4O. 
 
 Continuous reading caliper gauge, 
 Blanchard, 212. 
 
 Correct method of testing trial wheels, 
 
 100. 
 
 Corubin, analysis of, 51. 
 Corubin, uses of, 52. 
 Corundum, American, 25. 
 Corundum, analysis of 23. 
 Corundum, artificial, 47. 
 
 Corundum, artificial, first successful 
 production of, 48. 
 
 Corundum, barrel, 22. 
 
 Corundum, Canadian, 21. 
 
 Corundum, component parts of, 22. 
 
 Corundum, Craigmont, 23. 
 
 Corundum, Craigmont, when dis- 
 covered, 24. 
 
 Corundum, hardness of, 22. 
 
 Corundum, how crystallized, 21. 
 
 Corundum, how prepared, 24. 
 
 Corundum, how tested, 25. 
 
 Corundum, ideal, 22. 
 
 Corundum, origin of name, 20. 
 
 Corundum, uses of, 29. 
 
 Corundum, varieties of, 21. 
 
 Corundum, where found, 21, 25, 26. 
 
 Corundum, why not used more ex- 
 tensively, 26. 
 
 Cost comparisons, grinding wheels and 
 grindstones, 126. 
 
 Craigmont corundum, 23. 
 
 Craigmont corundum, when discov- 
 ered, 24. 
 
 Crank cases, finishing, 185. 
 
 Crankshaft grinder, Landis, 275. 
 
 Crankshaft grinder, radius truing de- 
 vice, 277. 
 
 Crankshaft grinding, 277. 
 
 Crankshaft grinding, amount for fin 
 ishing, 279. 
 
 Crankshaft grinding, wheels for, 278. 
 
 Crankshaft grinding, work carrying 
 fixtures for, 275. 
 
 Crocus, 63. 
 
 Cross feed for die grinding, 192. 
 
 Crowning mechanism, roll, Parrel, 
 268. 
 
 Crowning rolls, reason for, 267. 
 
 Crushed steel, 63. 
 
 Crushed steel, how made, 63. 
 
 Crushed steel, sizes of, 64. 
 
 Crushed steel, uses of, 64. 
 
 Crushing Aloxite, 59. 
 
 Crushing alundum, 57. 
 
 Crushing Carborundum, 42. 
 
 Crystallization of corundum, 21. 
 
 Crystallization of garnet, 32. 
 
 Crystallization of quartz, 34. 
 
 Crystals, Carborundum, shape of, 41. 
 
 Crystolon, 47. 
 
 Crystolon, how made, 47. 
 
 Cup wheels for cutter grinding, 302. 
 
 326
 
 INDEX 
 
 Current for magnetic chucks, 197. 
 Cut, depth of, 224. 
 Cut, depth of for die grinding, 192. 
 Cutter clearance, how obtained, 295. 
 Cutter grinder, Brown & Sharpe, 
 
 290. 
 
 Cutter grinder, Cincinnati, 290. 
 Cutter grinder, Walker, 299. 
 Cutter grinding attachment, Brown 
 
 & Sharpe, 297. 
 
 Cutter grinding, cup wheels for, 302. 
 Cutter grinding, locating work, 291. 
 Cutter grinding, machines used for, 
 
 290. 
 
 Cutter grinding sleeve, 293. 
 Cutter grinding wheels, fixture for 
 
 truing, 136. 
 
 Cutter grinding, wheels for, 305. 
 Cutter grinding, wide faced wheels 
 
 for, 294. 
 
 Cutter teeth corners, rounding, 300. 
 Cutters, angular, grinding, 295. 
 Cutters, formed, grinding, 302, 305. 
 Cylinder grinder, adaptability of, 261. 
 Cylinder grinder, Heald, 255. 
 Cylinder grinding, 257. 
 Cylinder grinding, wheels for, 259. 
 Cylindrical grinding, applications of, 
 
 238. 
 Cylindrical grinding, how to order 
 
 wheels for, 144. 
 
 Cylindrical grinding, machine for test- 
 ing wheels for, 119. 
 Cylindrical grinding machines, 216. 
 Cylindrical grinding, speed for wheel, 
 
 223. 
 Cylindrical grinding, testing wheels 
 
 for, 121. 
 
 Cylindrical grinding, wheels for, 235. 
 Cylindrical grinding wheels, star 
 
 wheel dresser for truing, 137. 
 
 Data for wheel test, 101. 
 
 De Beers diamond mines, 30. 
 
 De-grades, 91. 
 
 Demagnetizer, Heald, 197. 
 
 Demagnetizing switch, 196. 
 
 Deposits of Canadian corundum, 21. 
 
 Deposits of garnet, 33. 
 
 Depth of cut, 224. 
 
 Depth of cut for die grinding, 192. 
 
 Depth of finishing cut for surface 
 grinding, 199. 
 
 Design of collars for dust collecting 
 system, 147. 
 
 D.esign of elbows for dust collecting 
 system, 147. 
 
 Designation of alundum varieties, 58. 
 
 Designation of wheel grades, 91. 
 
 Determining grit and grade, 143. 
 
 Development of artificial corundum, 
 48. 
 
 Deville, E. H., Sainte-Claire, 53. 
 
 Diamond, 13, 29. 
 
 Diamond, bort, 31. 
 
 Diamond, classes of, 29. 
 
 Diamond, color of, 31. 
 
 Diamond cutting, introduction of, 31. 
 
 Diamond, fracture of, 29. 
 
 Diamond, hardness of, 29. 
 
 Diamond, how found, 30. 
 
 Diamond, how mined, 30. 
 
 Diamond, how to use for truing grind- 
 ing wheel, 135. 
 
 Diamond mines, De Beers, 30. 
 
 Diamond powder, how prepared, 31. 
 
 Diamond powder, uses of, 31. 
 
 Diamond, preparing for market, 30. 
 
 Diamond, resetting of, 135, 
 
 Diamond, specific gravity of, 29. 
 
 Diamond steel emery, 64. 
 
 Diamond, wheel truing, setting of, 
 
 134- 
 
 Diamond, where found, 29. 
 Diamonds, sorting, 31. 
 Diamonds, wheel truing, kinds of, 
 
 133- 
 
 Die grinding, 187. 
 Die grinding, abrasives used, 192. 
 Die grinding, cross feed for, 192. 
 Die, grinding, depth of cut, 192. 
 Die grinding fixture, 190. 
 Die grinding, wheels for, 188, 192, 
 
 199. 
 
 Die grinding wheels, truing, 19*3. 
 Die, sheared, 190. 
 Dies, locating for grinding, 188.. 
 Dioscorides, 14. 
 
 Discovery of American emery, 16. 
 Discovery of bauxite, 52. 
 Discovery of Carborundum, 38. 
 Discovery of Craigmont corundum, 
 
 24. 
 Discs, abrasive, manufacture of, 169. 
 
 327
 
 INDEX 
 
 Discs, abrasive, selection of, 173. 
 
 Discs, abrasive, testing, 1 74. 
 
 Dog, grinding, 221. 
 
 Dollner's artificial alumina, 51. 
 
 Double tapers, internal grinding, 245. 
 
 Dust collecting system, branch pipes, 
 size of, 146. 
 
 Dust collecting system, cleanouts for, 
 149. 
 
 Dust collecting system, design of col- 
 lars for, 147. 
 
 Dust collecting system, design of el- 
 bows for, 147. 
 
 Dust collecting system, location of 
 fan, 150. 
 
 Dust collecting system, main pipes, 
 148. 
 
 Dresses, emery wheel practicability 
 of, 138. 
 
 Dressing grinding wheel, 232. 
 
 Dressing grinding wheels, tools used 
 for, 133. 
 
 Dull milling cutters, results of using, 
 290. 
 
 Dunbar, Howard W., 285. 
 
 Dust collecting hood, 145. 
 
 Dust collecting system, location of 
 collector, 150. 
 
 Dust collecting systems, advantages 
 of, 145. 
 
 E 
 
 Early calender rolls, how finished, 
 265. 
 
 Early manufacture of abrasive paper 
 and cloth, 167. 
 
 Early production of artificial corun- 
 dum, 47, 48. 
 
 Early uses of emery, 14. 
 
 Earning power of grinding wheels, 
 
 102. 
 
 Ebelmen, J. J., 48. 
 Economical use of wheels, 153. 
 Economical value of soft wheels, 104. 
 Effect of change in grade, 105. 
 Effect of fine grit wheels on surface 
 
 grinding, 200. 
 Effect of vibration, 131. 
 Effect of wheel speed on grade, 95. 
 Efficiency of grindstones, 125. 
 Efficiency of large grinding wheels, 
 
 131- 
 Efficiency test, ideal casting for, 101. 
 
 Elastic process, 80. 
 
 Elastic wheels, purposes used for, 80. 
 
 Elbows for dust collecting system, de- 
 sign of, 147. 
 
 Electric furnace, Hasslacher's, 49. 
 
 Electric furnace, Jacobs', 54. 
 
 Electrolon, 47. 
 
 Electrolon, how made, 47. 
 
 Emery, 14. 
 
 Emery characteristics of, 17. 
 
 Emery cloth, 168. 
 
 Emery, color of, 15. 
 
 Emery, diamond steel, 64. 
 
 Emery, early uses of, 14. 
 
 Emery, how found, 15. 
 
 Emery, how mined, 15. 
 
 Emery, impurities of, 17. 
 
 Emery, Naxos, 16. 
 
 Emery paper, 168. 
 
 Emery, percentage of alumina, 17. 
 
 Emery, specific gravity of, 17. 
 
 Emery, spinel, 16. 
 
 Emery, spinel, component parts of, 
 16. 
 
 Emery, spinel, hardness of, 16. 
 
 Emery stones, 19. 
 
 Emery, Turkish, 15. 
 
 Emery, uses of, 19. 
 
 Emery wheel dressers, practicability 
 of, 138. 
 
 Emery, where found, 14. ' 
 
 End mills, grinding, 302. 
 
 Face grinding, 240. 
 
 Face grinding machine, 180. 
 
 Face of wheel, grinding with, 238. 
 
 Facing and edging grinding wheels,74. 
 
 Facing gear case covers, 184, 185. 
 
 Facing grinding wheels, tools used, 74. 
 
 Factors for laboratory tests, 116. 
 
 Factors to consider in selecting grind- 
 ing wheels, 129. 
 
 Fallacy of medium grade, 92. 
 
 Fan, location of in dust collecting 
 system, 150. 
 
 Farrel roll crowning mechanism, 268. 
 
 Farrel roll grinder, 266. 
 
 Feed, cross, for die grinding, 192. 
 
 Feed traverse, 224. 
 
 Feed, traverse, for roll grinding, 273. 
 
 Feil, C, 48. 
 
 328
 
 INDEX 
 
 Ferro silicon, 59. 
 Filing room, 312. 
 Fine grit wheels, effect of on surface 
 
 grinding, 200. 
 Finish allowance in cylinder grinding, 
 
 257- 
 Finishing Carborundum sharpening 
 
 stones, 86. 
 
 Finishing chip, allowance for, 223. 
 Finishing crank cases, 185. 
 Finishing cut, depth of for surface 
 
 grinding, 199. 
 
 Firing a grinding wheel kiln, 71. 
 Fixture for holding punches, 192. 
 Fixture for truing cutter grinding 
 
 wheels, 136. 
 
 Fixture for die grinding, 190. 
 Fixture for truing surface grinding 
 
 wheels, 136. 
 
 Fixture, grinding, rotary, 183. 
 Flanges, safety, 154. 
 Flanges, wheel, plain, danger of, 153. 
 Flanges, wheel, proportion of, 153. 
 Flint, composition of, 34. 
 Flint, fracture of, 34. 
 Flint quartz, uses of, 35. 
 Flint quartz, where found, 35. 
 Flint, specific gravity of, 34. 
 Formation of Tripoli, 36. 
 Formed cutter grinding attachment, 
 
 Brown & Sharpe, 304. 
 Formed cutters, grinding, 302, 305. 
 Fourgrinder, Henry, 263. 
 Fracture of carbonado, 32. 
 Fracture of Carborundum, 41. 
 Fracture of diamond, 29. 
 Fracture of flint, 34. 
 Fracture of quartz, 34. 
 Fremy, E., 48. 
 Full heat of kiln, 73. 
 Furnace, Aloxite, 58. 
 Furnace, Carborundum, 38. 
 Furnace, Carborundum, by-product 
 
 of, 40. 
 Furnace, Carborundum, contents of, 
 
 40. 
 Furnace, Carborundum, heat of, 40. 
 
 Garnet, 32. 
 
 Garnet, hardness of, 33. 
 
 Garnet, how crystallized, 32. 
 
 Garnet, how found, 33. 
 Garnet, how prepared, 33. 
 Garnet, impurities of, 171. 
 Garnet, kinds of, 32. 
 Garnet paper belts, testing, 172. 
 Garnet paper, kinds of, 168. 
 Garnet paper, testing, 170. 
 Garnet, specific gravity of, 33. 
 Garnet, testing, 171. 
 Garnet, uses of, 33. 
 Garnet, where found, 33. 
 Gaudin, M. A. A., 48. 
 Gear case covers, facing, 184, 185. 
 Gear chucks, 248, 251, 252, 253. 
 Gears, grinding holes in, 248. 
 German artificial corundum, how 
 
 made, 49. 
 
 German carbide of silicon, 46. 
 Grade blocks, master, 91. 
 Grade, change in, effect of, 105. 
 Grade list, reliable, how compiled, 92. 
 Grade lists, comparative, inaccuracy 
 
 of, 91. 
 
 Grade, running, 96. 
 Grade scale, reliability of, 94. 
 Grade scale, universal, 93, 94. 
 Grades of grinding wheels, 91. 
 Grades, wheel, how designated, 91. 
 Grading Carborundum, 43. 
 Grading Carborundum powder, 44. 
 Grinder, cylindrical, preparing work 
 
 for, 220. 
 
 Grinder, plain cylindrical, 217. 
 Grinder, roll, Parrel, 266. 
 Grinder, setting straight, 222. 
 Grinder, surface, Brown & Sharpe, 
 
 1 88. 
 Grinder, surface, Pratt & Whitney, 
 
 203. 
 
 Grinder, universal, 217. 
 Grinding allowance for cylinders, 257. 
 Grinding allowances, 220. 
 Grinding a taper, 238, 240. 
 Grinding axes, 125. 
 Grinding calender rolls, 269. 
 Grinding centers, 240. 
 Grinding chain links, 1 1 2. 
 Grinding chilled car wheels, 106. 
 Grinding crankshafts, 277. 
 Grinding cylinders, 257. 
 Grinding, cylindrical, applications of, 
 
 238. 
 Grinding, cylindrical, wheels for, 235. 
 
 329
 
 INDEX 
 
 Grinding dies, 187. 
 
 Grinding dog, 221. 
 
 Grinding, face, 240. 
 
 Grinding fixture, rotary, 183. 
 
 Grinding holes in gears, 248. 
 
 Grinding, internal, 243. 
 
 Grinding internal tapers, 245. 
 
 Grinding links, 288. 
 
 Grinding locomotive guide bars, 
 
 marks, 181. 
 
 Grinding lubricant, 210, 231. 
 Grinding machine, face, 180. 
 Grinding machine, surface, wet, 193. 
 Grinding machines, cylindrical, 216. 
 Grinding machines, internal, types of, 
 
 245- 
 
 Grinding machines, modern, 218. 
 Grinding machines, saw, 309. 
 Grinding metal cutting saws, 315, 319. 
 Grinding milling cutters, 292. 
 Grinding pearl buttons, 114. 
 Grinding plow points, 105. 
 Grinding punches, 191. 
 Grinding saws, 310. 
 Grinding sides of milling cutters, 243. 
 Grinding size blocks, 176. 
 Grinding, spot, 176. 
 Grinding steel with Carborundum, 
 
 45- 
 
 Grinding wheel bond, 66. 
 
 Grinding wheel bonds, how standard- 
 ized, 67. 
 
 Grinding wheel bonds, varieties of, 67. 
 
 Grinding wheel, dressing, 232. 
 
 Grinding wheel, early development of, 
 123. 
 
 Grinding wheel, efficiency value of, 
 1 06. 
 
 Grinding wheel, future of, in axe in- 
 dustry, 127. 
 
 Grinding wheel grades, 91. 
 
 Grinding wheel grits, 88. 
 
 Grinding wheel, how to true with dia- 
 mond, 135. 
 
 Grinding wheel kiln, firing, 71. 
 
 Grinding wheel materials, methods 
 
 - used in mixing, 68. 
 
 Grinding wheel press, 68. 
 
 Grinding wheel, rebushing, 141. 
 
 Grinding wheel sagers, 71. 
 
 Grinding wheel speeds, 96. 
 
 Grinding wheel, surface, guards for, 
 159- 
 
 Grinding wheel, surface, sizing power 
 
 of, 199. 
 
 Grinding wheel, truing, 232. 
 Grinding wheel volume, how to find, 
 
 io 7 . 
 Grinding wheels, advantages of, in 
 
 axe grinding, 126. 
 Grinding wheels, balancing, 76. 
 Grinding wheels, causes of breakage, 
 
 151. 
 
 Grinding wheels, comparative val- 
 ues of, 129. 
 
 Grinding wheels, composition of, 65. 
 Grinding wheels, cutter, fixture for 
 
 truing, 136. 
 
 Grinding wheels, earning power, 102. 
 Grinding wheels, economical use of, 
 
 153- 
 Grinding wheels, facing* and edging, 
 
 74- 
 
 Grinding wheels, factors to consider 
 in selecting, 129. 
 
 Grinding wheels and grindstones, 
 comparative costs of, 126. 
 
 Grinding wheels, hardness, how con- 
 trolled, 67. 
 
 Grinding wheels, how bushed, 75. 
 
 Grinding wheels, inspecting for grade, 
 
 74- 
 Grinding wheels, large, advantages 
 
 of using, 130. 
 Grinding wheels, large, efficiency of, 
 
 131-- 
 
 Grinding wheels, mounting, 153. 
 
 Grinding wheels, operating speed, 
 how designated, 152. 
 
 Grinding wheels, ordering, informa- 
 tion to give, 142. 
 
 Grinding wheels, reasons for over- 
 speeding, 152. 
 
 Grinding wheels, re-bushing, advan- 
 tages of, 139. 
 
 Grinding wheels, re-bushing tools 
 used for, 139. 
 
 Grinding wheels, selection of, 97. 
 
 Grinding wheels, shaving, 69. 
 
 Grinding wheels, small, why used, 132. 
 
 Grinding wheels, sorting, 73. 
 
 Grinding wheels, special how to order, 
 144. 
 
 Grinding wheels, speed testing, 76. 
 
 Grinding wheels, surface, fixture for 
 truing, 136. . 
 
 330
 
 INDEX 
 
 Grinding wheels, tamping, 79. 
 Grinding wheels, testing for sound- 
 ness, 74. 
 Grinding wheels, tests, laboratory. 
 
 US- 
 
 Grinding wheels, three methods of 
 testing, 114. 
 
 Grinding wheels, tools used for dress- 
 ing. * 33- 
 
 Grinding wheels, wire web, 124. 
 
 Grinding wheels, wire web, 80. 
 
 Grinding with face of wheel, 238. 
 
 Grindstone action, 124. 
 
 Grindstone, efficiency of, 125. 
 
 Grindstone, life of, 125. 
 
 Grindstone, uses of, 125. 
 
 Grindstones and grinding wheels, cost 
 comparisons, 126. 
 
 Grindstones, characteristics of, 127. 
 
 Grindstones, uses of, 14. 
 
 Grit and grade, how determined, 143. 
 
 Grit and grade of wheels for spot 
 grinding, 178. 
 
 Grit, angular, 64. 
 
 Grits, combination, 89. , 
 
 Grits of abrasive paper and cloth, 89. 
 
 Grits of Carborundum sharpening 
 stones, 85. 
 
 Grits, grinding wheel, 88. 
 
 Grits, mixed, 88. 
 
 Grits, straight, 88. 
 
 Guard, pulley, 162. 
 
 Guard, spindle, 161. 
 
 Guard, wheel, 247. 
 
 Guarded surface grinding wheels, 159. 
 
 Guards, wheel, 156. 
 
 Guards, wheel, unsafe, 164. 
 
 Guide bar, locomotive, grinding, 181. 
 
 Guide bars, locomotive, lapping, 170. 
 
 Guide bars, locomotive, wear on, 181. 
 
 Guide finger, locating, 294. 
 
 H 
 
 Hack saw blade grinder, Ward well, 
 
 3I9- 
 
 Hack saw blades, grinding, 321. 
 Hammett link grinder, 287. 
 Hard and soft spots, how caused, 72. 
 Hard or soft wheels, how to rectify, 95. 
 Hard or soft wheels, how to remedy, 
 
 144. 
 Hardness of Carborundum, 41. 
 
 Hardness of corundum, 22. 
 Hardness of diamonds, 29. 
 Hardness of garnet, 33. 
 Hardness of grinding wheels, how 
 
 controlled, 7. 
 Hardness of quartz, 34. 
 Hardness of spinel emery, 16. 
 Hasslacher's electric furnace, 49. 
 Hasslacher, Franz, 49. 
 Haultain, H. E. T., 21, 24. 
 Head, universal, 299. 
 Heald bushing chuck, 248. 
 Heald cylinder grinder, 255. 
 Heald demagnetizer, 197. 
 Heald internal grinder, 246. 
 Heald magnetic chuck, 194. 
 Heald ring grinder, 200. 
 Heald rotary surface grinder, 202. 
 Heat of Carborundum furnace, 40. 
 Holes in gears, grinding, 248. 
 Hollinger, J. H., 108. 
 Hone, razor, Belgian, 35. 
 Hood, dust collecting, 145. 
 Horsepower required to operate Alun- 
 
 dum furnace, 57. 
 
 Ideal casting for efficiency test, 101. 
 
 Ideal corundum, 22. 
 
 Impurities of Carborundum, 42. 
 
 Impurities of emery, 17. 
 
 Impurities of garnet, 171. 
 
 Impurities of pumice, 36. 
 
 Impurities of sandstone, 14. 
 
 Inaccuracy, causes of, in roll winding, 
 272. 
 
 Inaccuracy of comparative grade lists, 
 91. 
 
 Information to give in ordering grind- 
 ing wheels, 142. 
 
 Ingot, Aloxite, 59. 
 
 Inspecting grinding wheels for grade, 
 
 74- 
 
 Internal grinder, Heald, 246. 
 Internal grinding, 243. 
 Internal grinding, allowance for, 253. 
 Internal grinding, chucking work for, 
 
 247. 
 Internal grinding machines, types of, 
 
 245- 
 
 Internal grinding, setting up univer- 
 sal grinder for, 243. 
 
 331
 
 INDEX 
 
 Internal grinding, wheel speeds for, 
 
 254- 
 
 Internal grinding wheels, truing, 255. 
 Internal tapers, grinding, 245. 
 Introduction of diamond cutting, 31. 
 
 Jacobs, Charles B., 53. 
 Jacobs' electric furnace, 54. 
 Jacobs process for making artificial 
 corundum, 56. 
 
 K 
 
 Kiln, full heat of, 73. 
 
 Kiln grinding wheel firing, 71. 
 
 Kiln, low melting point of, 72. 
 
 Kiln, red heat of, 72. 
 
 Kiln, testing heat of, 72. 
 
 Kiln, vitrifying, 70. 
 
 Kinds of backrests, 226. 
 
 Kinds of garnet, 32. 
 
 Kinds of wheel truing diamonds, 133. 
 
 Laboratory grinding wheel tests, 115. 
 Laboratory test on wheels for rough 
 
 grinding operations, how carried 
 
 out, 1 1 8. 
 
 Laboratory tests, factors for, 115. 
 Landis balancing device, 235. 
 Landis crankshaft grinder, 275. 
 Landis mill roll grinder, 270. 
 Landis plain grinder, 217. 
 Lapping locomotive guide bars, 170. 
 Large cutters, sharpening, 299. 
 Large grinding wheels, advantages of 
 
 using, 130. 
 Large grinding wheels, efficiency of, 
 
 131- 
 
 Leaders for cam grinder, 283. 
 Leaders for cam grinding, how made, 
 
 284. 
 
 Life of grindstone, 125. 
 Limits in using soft wheels, 104. 
 Link grinder, Hammett, 287. 
 Link grinding, 288. 
 Link grinding, wheels for, 289. 
 Links, valve gear, types of, 286. 
 Loading grinding wheel sagers, 71. 
 Locating cutters for grinding, 291. 
 
 Locating dies for grinding, 188. 
 Locating guide finger, 294. 
 Locating mill rolls for grinding, 272. 
 Locating work on Blanchard grinder, 
 
 211. 
 
 Location of Arkansas sharpening 
 stone deposits, 35. 
 
 Location of bauxite deposits, 53, 54. 
 
 Location of carbonado deposits, 32. 
 
 Location of corundum deposits, 21, 
 25,26. 
 
 Location of diamond deposits, 29. 
 
 Location of emery deposits, 15. 
 
 Location of flint quartz deposits, 
 35- 
 
 Location of Tripoli deposits, 36. 
 
 Locomotive guide bar grinding, 181. 
 
 Locomotive guide bar grinding, test- 
 ing wheels for, no. 
 
 Locomotive guide bars, lapping, 171. 
 
 Locomotive guide bars, wear on, 181. 
 
 Loose spindles, 156. 
 
 Low melting point of kiln, 72. 
 
 Lubricant, grinding, 210, 231. 
 
 Lubrication of spindle, 255, 258. 
 
 Lucas, Dr. H. S., 16. 
 
 M 
 
 Machine, coating, for making abra- 
 sive paper and cloth, 167. 
 
 Machine for testing wheels used on 
 cylindrical grinding, 119. 
 
 Machine for testing wheels used for 
 rough operations, 116. 
 
 Machine, shaving, 69. 
 
 Machines used for cutter grinding, 
 290. 
 
 Magnetic chuck, Heald, 194. 
 
 Magnetic chuck, taper, 194. 
 
 Magnetic chuck, swivel, 194. 
 
 Magnetic chucks, current for, 197. 
 
 Manufacture of abrasive discs, 169. 
 
 Manufacture of Alundum, 57. 
 
 Manufacture of Crystolon, 47. 
 
 Manufacture of Electrolon, 47. 
 
 Manufacture of German artificial cor- 
 undum, 49. 
 
 Marks, chatter, cause of, 232. 
 
 Master grade blocks, 91. 
 'Materials, bonding, 66. 
 
 Materials, raw, Carborundum, 38. 
 
 Materials used on abrasive discs, 173. 
 
 332
 
 INDEX 
 
 Matteson saw grinder, 315. 
 Medium grade, fallacy of, 92. 
 Metal cutting saws, 315. 
 Metal cutting saws, grinding, 315, 
 
 319. 
 
 Methods of mixing grinding wheel 
 
 materials, 68. 
 
 Mill roll grinder, Landis, 270. 
 Mill roll grinder, Norton, 271. 
 Mill rolls, locating fcr grinding, 272. 
 Milling cutters, dull, results of using, 
 
 290. 
 
 Milling cutters, grinding, 292. 
 Milling cutters, grinding sides of, 242. 
 Milling cutters, re-cutting, 306. 
 Mills, end, grinding, 302. 
 Mineral, Spanish, 33. 
 Mining of diamonds, 30. 
 Mining of emery, 15. 
 Mixed grits, 88. 
 Mixing grinding wheel materials, 
 
 methods used, 68. 
 Modern grinding machines, 218. 
 Molding Carborundum sharpening 
 
 stones, 84. 
 Mounting grinding wheels, 153. 
 
 X 
 
 Natural abrasives, 13. 
 Natural sharpening stones, 35. 
 Naxos emery, 16. 
 Newton saw grinder, 316. 
 Norton backrest, setting, 226. 
 Norton cam grinding attachment, 280. 
 Norton mill roll grinder, 271. 
 Norton plain grinder, 219. 
 Norton solid backrest, 226. 
 Numbers of Carborundum grain, 44. 
 
 Operating speed of grinding wheels, 
 how designated, 152. 
 
 Operation of Blanchard grinder, 212. 
 
 Ordering grinding wheels, informa- 
 tion to give, 142. 
 
 Ordering special grinding wheels, 144. 
 
 Ordering wheels for cylindrical grind- 
 ing, 144. 
 
 Oriental ruby, 47. 
 
 Origin of name of bauxite, 53. 
 
 Origin of pumice, 36. 
 
 Overspeeding of grinding wheels, rea- 
 sons for, 152. 
 Oxalumina, 63. 
 
 Oxalumina, composition of, 63. 
 Oxalumina, how made, 63. 
 Oxalumina, uses of, 63. 
 
 Paper and cloth, abrasive, early man- 
 ufacture of, 167. 
 Paper and cloth, abrasive, uses of, 
 
 1 66. 
 
 Paper, Carborundum, 168. 
 Paper, emery, 168. 
 Paper, garnet, kinds of, 168. 
 Paper, garnet, testing, 170. 
 Paper, sand, 169. 
 Pearl button grinding, 114. 
 Peripheral speed, effect on surface 
 
 grinding, 199. 
 Pigs, Alundum, 57. 
 Plain cylindrical grinder, 217. 
 Plain grinder, Landis, 217. 
 Plain grinder, Norton, 219. 
 Plain grinding wheel flanges, danger 
 
 of, 153- 
 Pliny, 14. 
 
 Plow points, grinding, 105. 
 Pointing up saws, 310. 
 Power required to operate Aloxite 
 
 furnace, 58. 
 
 Pratt & Whitney surface grinder, 203. 
 Pratt & Whitney surface grinder, 
 
 samples of work done on, 206. 
 Pratt, Prof. J. H., 20, 21. 
 Preparation of Aloxite grain, 59. 
 Preparation of corundum, 24. 
 Preparation of diamond powder, 31. 
 Preparation of garnet, 33. 
 Preparation of work for cylindrical 
 
 grinder, 220. 
 
 Preparing diamonds for market, 30. 
 Press, grinding wheel, 68. 
 Pressed process, 68. 
 Pressed wheels, characteristics of, 68. 
 Process for making Jacobs' artificial 
 
 corundum, 56. 
 
 Process of making Aloxite, 58. 
 Process of making Alundum, 57. 
 Process of making Carborundum, 39. 
 Process of making crushed steel, 63. 
 Process of making Oxalumina, 63. 
 
 333
 
 INDEX 
 
 Process, elastic, 80. 
 
 Process, pressed, 68. 
 
 Process, puddled, 69. 
 
 Process, rubber, 81. 
 
 Process, silicate, 79. 
 
 Process, vitrified, 67. 
 
 Proportion of wheel flanges, 153. 
 
 Puddled process, 69. 
 
 Pulley guard, 162. 
 
 Pulp stones, 125. 
 
 Pumice, impurities of, 36. 
 
 Pumice, origin of, 36. 
 
 Pumice stone, 36. 
 
 Pumice, uses of, 36. 
 
 Punches, fixture for holding, 192. 
 
 Punches, grinding, 191. 
 
 Purifying Carborundum, 42. 
 
 Purity of Aloxite, 59. 
 
 Pyrometric cones, 72. 
 
 Quartz, 34. 
 
 Quartz, composition .of , 34. 
 Quartz, flint, where found, 35. 
 Quartz, fracture of, 34. 
 Quartz, hardness of, 34. 
 Quartz, how crystallized, 34. 
 Quartz, specific gravity of, 34. 
 Quartz, uses of, 34'. 
 
 Radius truing device for crankshaft 
 grinder, 277. 
 
 Rapid wheel wear, 104. 
 
 Raw materials, Carborundum, 38. 
 
 Razor hone, Belgian, 35. 
 
 Razor hones, Carborundum, 85. 
 
 Re-bushing grinding wheels, 141. 
 
 Re-bushing grinding wheels, advan- 
 tages of, 139. 
 
 Re-bushing grinding wheels, tools 
 used for, 139. 
 
 Records of tests, how to keep, 119. 
 
 Rectifying hard or soft wheels, 95. 
 
 Re-cutting milling cutters, 306. 
 
 Red heat of kiln, 72. 
 
 Reliability of grade scale, 94. 
 
 Reliable grade list, how compiled, 92. 
 
 Remedying hard or soft wheels, 144. 
 
 Re-saws, band, 309. 
 
 Re-saws, band, grinding, 314. 
 
 Resetting diamonds, 135. 
 
 Rest, work, 154. 
 
 Rest, work, cause of accidents, 155. 
 
 Ring grinder, Heald, 200. 
 
 Ring wheel chuck, 1 80. 
 
 Robert, Louis, 265. 
 
 Roll crowning mechanism, Parrel, 
 
 268. 
 
 Roll crowning, reason for, 267. 
 Roll grinder, Parrel, 266. 
 Roll grinding, causes of inaccuracy, 
 
 272. 
 
 Roll grinding, testing wheels, on, 108. 
 Roll grinding, traverse feed for, 273. 
 Roll grinding, wheel speed, 273. 
 Roll grinding, wheel speed for, 269. 
 Roll grinding, wheels for, 268. 
 Roll grinding, work speed for, 273. 
 Rolls, calender, causes of wear of, 264. 
 Rolls, calender, early, how finished, 
 
 265. 
 
 Rolls, calender, grinding, 269. 
 Rolls, calender, largest stack of, 263. 
 Rolls, calender, old installation, 26. 
 Rolls for steel mills, 270. 
 Rolls, flour mill, grinding, 273. 
 Rolls, flour mill, wheels for grinding, 
 
 274. 
 
 Rolls, mill, locating for grinding, 272. 
 Rolls, steel mill, grinding, 272. 
 Room, filing, 312. 
 Rotary chucks for surface grinder, 
 
 204. 
 
 Rotary grinding fixture, 183. 
 Rotary surface grinder, Heald, 202. 
 Rotten stone, 36. 
 Rouge, 63. . 
 Rough grinding operations, machine 
 
 used for testing wheels for, 116. 
 Rough grinding operations, testing 
 
 wheels for, 118. 
 Roughing out saws, 310. 
 Rounding cutter teeth corners, 300. 
 Rubber process, 81. 
 Rubs, Carborundum, 86. 
 Ruby, balas, 47. 
 Ruby, composition of, 48. 
 Ruby, Oriental, 47. 
 Ruby, spinel, 47. 
 Ruby, value of, 47. 
 Running grade, 96. 
 Rule for finding wheel speed, 224. 
 Rushing chuck, Heald, 248. 
 
 334
 
 INDEX 
 
 S 
 
 Safety flanges, 154. 
 
 Sagers, grinding wheel, 71. 
 
 Sagers, how loaded, 71. 
 
 Samples of work done on Blanchard 
 
 surface grinder, 210. 
 Samples of work done on Pratt & 
 
 Whitney surface grinder, 206. 
 Sand-paper, 169. 
 Sandstone, 13. 
 Sandstone, colors of, 14. 
 Sandstone, impurities of, 14. 
 Sandstone, where found, 14. 
 Saw grinder, Matteson, 315. 
 Saw grinder, Newton, 316. 
 Saw grinding, effect of speed in,~3I2. 
 Saw grinding machines, 309. 
 Saw grinding machines, care of, 312. 
 Saw grinding wheels, shapes of, 313. 
 Saw grinding, wheels used for, 313. 
 Saws, band, 308. 
 
 Saws, case hardening, causes of, 313. 
 Saws, circular, 308. 
 Saws, grinding, 310. 
 Saws, hack, grinding, 321. 
 Saws, metal cutting, 315. 
 Saws, metal cutting, grinding, 315, 
 
 319. 
 
 Saws, pointing up, 310. 
 Saws, roughing out, 310. 
 Saws, wood-working, types of, 308. 
 Scythe stones, 36. 
 Selecting grinding wheels, factors to 
 
 consider, 129. 
 
 Selection of abrasive discs, 173. 
 Selection of grinding wheels, 97. 
 Selection of wheels for surfacing, 187. 
 Semi-automatic grinding operations, 
 
 testing wheels for, in. 
 Setting grinders straight, 222. 
 Setting wheel truing diamond, 134. 
 Shafting, testing wheels for grinding, 
 
 109. 
 
 Shape of Carborundum crystals, 41. 
 Shapes of saw grinding wheels, 313. 
 Sharpening large cutters, 299. 
 Sharpening stories, Arkansas, 35. 
 Sharpening stones, artificial, 83. 
 Sharpening stones, Carborundum, 83. 
 Sharpening stones, Carborundum, 
 
 how finished, 86. 
 Sharpening stones, natural, 35. 
 
 Sharpening stones, Turkey, 35. 
 
 Shaving machine, 69. 
 
 Sheared die, 190. 
 
 Side surfacer, 180. 
 
 Side surfacer, varieties of work 
 ground on, 182. 
 
 Side teeth, grinding, 297, 298. 
 
 Silicate bonded wheels, purposes used 
 for, 79. 
 
 Silicate process," 79. 
 
 Silicon carbide, 38. 
 
 Silicon, ferro, 59. 
 
 Size blocks, grinding, 176. 
 
 Size of branch pipes for dust collect- 
 ing system, 146. , / 
 
 Sizes and numbers of abrasive paper 
 and cloth, 168. 
 
 Sizes of angular grit, 64. 
 
 Sizes of crushed steel, 64. 
 
 Sizing power of surface grinding 
 wheel, 199. 
 
 Sleeve for cutter grinding, 293. 
 
 Small grinding wheels, why used, 132. 
 
 Smith, Dr. J. Lawrence, 15. 
 
 Soft wheels, economical value of, 104. 
 
 Soft wheels, limits in using, 104. 
 
 Solid backrest, Norton, 226. 
 
 Sorting diamonds, 31. 
 
 Sorting grinding wheels, 73. 
 
 Spanish mineral, 33. 
 
 Sparking, uneven, 225. 
 
 Special wheels, how to order, 144. 
 
 Specific gravity of carbonado, 29 
 
 Specific gravity of Carborundum, 41. 
 
 Specific gravity of diamond, 29. 
 
 Specific gravity of emery, 17. 
 
 Specific gravity of flint, 34. 
 
 Specific gravity of garnet, 33. 
 
 Specific gravity of quartz, 34. 
 
 Speed, effect of, in saw grinding, 312. 
 
 Speed of wheel for cylindrical grind- 
 ing, 223. 
 
 Speed of wheel, rule for finding, 224. 
 
 Speed, table for surfacing, 187. 
 
 Speed testing grinding wheels, 76. 
 
 Speed, work, 223. 
 
 Speed, work, for roll grinding, 269. 
 
 Speeds for surface grinding, 185. 
 
 Speeds of grinding wheels, 96. 
 
 Spindle guard, 161. 
 
 Spindles, loose, 156. 
 
 Spinel, emery, 16. 
 
 Spinel, emery, component parts of, 16. 
 
 335
 
 INDEX 
 
 Spinel, emery, hardness of, 16. 
 
 Spinel, ruby, 47. 
 
 Spot grinding, 176. 
 
 Spot grinding wheels, grit and grade 
 
 of, 178. 
 
 Square center, 221. 
 Standardization of grinding wheel 
 
 bonds, 67. 
 
 Standardized wheel grades, 94. 
 Star wheel dresser for truing cylin- 
 drical grinding wheels, 137. 
 Steady-rests for cam grinding, 282. 
 Steel grinding with Carborundum, 45. 
 Steel mill rolls, 270. 
 Steel mill rolls, grinding, 272. 
 Stone, pumice, 36. 
 Stone, rotten, 36. 
 Stones, emery, 19. 
 Stones, pulp, 125. 
 Stones, scythe, 36. 
 Stones, sharpening, natural, 35. 
 Stones, sharpening, Turkey, 35. 
 Straight grits, 88. 
 
 Surface grinder, Brown & Sharpe, 188. 
 Surface grinder, Pratt & Whitney, 
 
 203. 
 Surface grinder, Pratt & Whitney, 
 
 selection of wheels for, 206. 
 Surface grinder, rotary, Heald, 202. 
 Surface grinders, comparison of, 202. 
 Surface grinding, adapting wheel for, 
 
 199. 
 
 Surface grinding chucks, rotary, 204. 
 Surface grinding, depth of finishing 
 
 cut, 199. 
 Surface grinding, effect of fine grit 
 
 wheels, 200. 
 Surface grinding, effect of peripheral 
 
 speed on, 199. 
 Surface grinding machine, Blanchard, 
 
 208. 
 
 Surface grinding machine, wet, 193. 
 Surface grinding, speeds for, 185. 
 Surface grinding wheel guards, 159. 
 Surface grinding wheel, sizing power 
 
 of, 199. 
 Surface grinding wheels, fixture for 
 
 truing, 136. 
 Surfacer, side, 180. 
 Surfacer, side, varieties of work, 
 
 ground on, 182. 
 
 Surfacing, selection of wheels for, 187. 
 Surfacing, table speed for, 187. 
 
 Switch, demagnetizing, 196. 
 Swivel magnetic chuck, 194. 
 System, dust collecting, main pipes 
 
 for, 148. 
 Systems, dust collecting, advantages 
 
 of, 145. 
 
 Table speed for surfacing, 187. 
 
 Tamping grinding wheels, 79. 
 
 Taper grinding, 238, 240. 
 
 Taper magnetic chuck, 194. 
 
 Tapers, grinding double internal, 245. 
 
 Teeth, side grinding, 297, 298. 
 
 Temper, abrasive, 52. 
 
 Temper of artificial corundum, 56. 
 
 Test records, how to keep, 119. 
 
 Test wheel data, 101. 
 
 Testing abrasive discs, 174. 
 
 Testing bonding materials, 67. 
 
 Testing corundum, 25. 
 
 Testing garnet, 171. 
 
 Testing garnet paper, 170. 
 
 Testing garnet paper belts, 172. 
 
 Testing grinding wheels for sound- 
 ness, 74. 
 
 Testing grinding wheels in the lab- 
 oratory, 115. 
 
 Testing heat of kiln, 72. 
 
 Testing operation, truing wheel in, 
 118. 
 
 Testing trial wheels, wrong method, 
 98. 
 
 Testing wheels for car wheel grinding, 
 106. 
 
 Testing wheels for cylindrical grind- 
 ing, 121. 
 
 Testing wheels for grinding shafting, 
 109. 
 
 Testing wheels for locomotive guide 
 bar grinding, no. 
 
 Testing wheels for semi-automatic 
 grinding operations, in. 
 
 Testing wheels on chilled iron roll 
 grinding, 108. 
 
 Three methods of testing grinding 
 wheels, 114. 
 
 Tight wheel bushings as cause of 
 accidents, 153. 
 
 Time consumed in axe grinding, 126. 
 
 Time necessary to vitrify wheels, 73. 
 
 Tools used for dressing grinding 
 wheels, 133. 
 
 336
 
 INDEX 
 
 Tools used for facing grinding wheels, 
 
 74- 
 Tools used for re-bushing grinding 
 
 wheels, 139. 
 Traverse feed, 224. 
 
 Traverse feed for roll grinding, 273. 
 Trial wheels, correct method of test- 
 ing, IOO. 
 Trial wheels, wrong method of testing, 
 
 98. 
 
 Tripoli, 36. 
 
 Tripoli, how formed, 36. 
 Tripoli, uses of, 36. 
 Tripoli, where found, 36. 
 Truing cylindrical grinding wheels 
 
 with star wheel dresser, 137. 
 Truing die grinding wheels, 192. 
 Truing grinding wheel, 232. 
 Truing internal grinding wheels, 255, 
 
 258. 
 Truing wheel in testing operation, 
 
 118. 
 Truing wheels on vertical spindle 
 
 grinder, 138. 
 
 Turkey sharpening stones, 35. 
 Turkish emery, 15. 
 
 U 
 
 Uneven sparking, 225. 
 
 Unguarded wheels, 157. 
 
 Universal Brown & Sharpe backrest, 
 228. 
 
 Universal grade scale, 93, 94. 
 
 Universal grinder, 217. 
 
 Universal grinder, Brown & Sharpe, 
 236. 
 
 Universal grinder, setting up for inter- 
 nal grinding, 243. 
 
 Universal head, 299. 
 
 Unsafe wheel guards, 164. 
 
 Uses of abrasive paper and cloth, 166. 
 
 Uses' of Aloxite, 60. 
 
 Uses of Alundum, 58. 
 
 Uses of angular grit, 64. 
 
 Uses of Arkansas sharpening stones, 
 35- 
 
 Uses of Boro-Carbone, 62. 
 
 Uses of carbonado, 32. 
 
 Uses of Carborundum, 45. 
 
 Uses of Corubin, 52. 
 
 Uses of corundum, 29. 
 
 Uses of crushed steel, 64. 
 
 Uses of diamond powder, 3l c 
 
 Uses of emery, 19. 
 
 Uses of flint quartz, 35. 
 
 Uses of garnet, 33. 
 
 Uses of grindstones, 14, 125. 
 
 Uses of Oxalumina, 63. 
 
 Uses of pumice, 36. 
 
 Uses of quartz, 34. 
 
 Uses of Tripoli, 36. 
 
 Value of grinding wheel efficiency, 1 
 
 106. 
 
 Value of ruby, 47. 
 Valve gear links, types of, 286. 
 Varieties of Alundum, 58. 
 Varieties of Arkansas sharpening 
 
 stones, 35. 
 
 Varieties of corundum, 21. 
 Varieties of grinding wheel bonds, 67. 
 Varieties of work finished on side sur- 
 
 facer, 182. 
 Vertical spindle grinder, truing 
 
 wheels on, 138. 
 Vertical surface grinder, Pratt & 
 
 Whitney, selection of wheels for, 
 
 206. 
 
 Vibration, effect of, 131. 
 Vitrified process, 67. 
 Vitrifying kiln, 70. 
 Vitrifying process, time consumed to 
 
 carry out, 73. 
 
 Voltage of Carborundum furnace, 40. 
 Volume of grinding wheel, how to 
 
 find, 107. 
 von Berquen, L., 31. 
 
 W 
 
 Walker cutter grinder, 299. 
 
 Ward well hack sawblade grinder, 319. 
 
 Wear on locomotive guide bars, 181. 
 
 Werlein's artificial abrasive, 61. 
 
 Wet surface grinding machine, 193. 
 
 Wheel balance, 234. 
 
 Wheel chattering, 200. 
 
 Wheel flanges, proportion of, 153. 
 
 Wheel grades, how designated, 91. 
 
 Wheel grades, standardization of, 94. 
 
 Wheel guard, 247. 
 
 Wheel guards, 156. 
 
 Wheel guards, unsafe, 164. 
 
 337
 
 INDEX 
 
 Wheel speed, effect on grade, 95. 
 Wheel speed for Blanchard grinder, 
 
 211. 
 
 Wheel speed for cylindrical grinding, 
 
 223. 
 Wheel speed for roll grinding, 269, 
 
 273- 
 
 Wheel speed, rule for finding, 224. 
 Wheel speeds for internal grinding, 
 
 254- . 
 
 Wheel test data, 101. 
 Wheel truing diamond, setting of, 134. 
 Wheel truing diamonds, kinds of, 133. 
 Wheel wear, effect of, in cam grinding, 
 
 285. 
 
 Wheel wear, rapid, 104. 
 Wheels, elastic, purposes used for, 80. 
 Wheels for Blanchard grinder, 212. 
 Wheels for cam grinding, 283. 
 Wheels for crankshaft grinding, 278. 
 Wheels for cutter grinding, 305. 
 Wheels for cylinder grinding, 259. 
 Wheels for cylindrical grinding, 235. 
 Wheels for die grinding, 188, 192, 199. 
 Wheels for flour mill roll grinding, 274. 
 Wheels for link grinding, 289. 
 
 Wheels for roll grinding, 268. 
 
 Wheels, pressed, characteristics of, 68. 
 
 Wheels, selection of, for surfacing, 
 187. 
 
 Wheels, silicate, purposes used for, 
 79- 
 
 Wheels, soft, limits in using, 104. 
 
 Wheels, unguarded, 157. 
 
 Wheels used for rough operations, ma- 
 chine for testing, 116. 
 
 Wheels used for saw grinding, 313. 
 
 Wheels, wide faced for cutter grind- 
 ing, 294. 
 
 Why Carborundum is not found in 
 nature, 41. 
 
 Why corundum is not used more ex- 
 tensively, 26. 
 
 Williams, Richard G., 57. 
 
 Wire web grinding wheels, 80, 124. 
 
 Wood working saws, types of, 308. 
 
 Work carrying fixtures for crankshaft 
 grinding, 275. 
 
 Work rest, 154. 
 
 Work rests as cause of accidents, 155. 
 
 Work speed, 223. 
 
 Work speed for roll grinding, 269, 273. 
 
 THE END
 
 1919 
 
 CATALOGUE 
 
 of the Latest and Best 
 
 Practical and Mechanical Books 
 
 Including Automobile and Aviation Books 
 
 PRACTICAL BOOKS FOR PRACTICAL MEN 
 
 Each Book in this Catalogue is written by an 
 Expert and is written so you can understand it 
 
 PUBLISHED BY 
 
 THE NORMAN W. HENLEY PUBLISHING Co. 
 
 2 West 45th Street, New York, U. S. A. 
 
 Established 1890 
 Any Book in this Catalogue sent prepaid on receipt of price
 
 INDEX 
 
 PAGE 
 
 Air Brakes ....................... 23, 26 
 
 Arithmetic ................... 14, 27, 35 
 
 Automobile Books ................ 3, 4, 5 
 
 Automobile Carburetors ........... 5 
 
 Automobile Charts ............... 6 
 
 Automobile Ignition Systems ....... 4 
 
 Automobile Lighting .............. 4 
 
 Automobile Questions and Answers . 4 
 Automobile Repairing ............. 3 
 
 Automobile Starting Systems ...... 4 
 
 Automobile Trouble Chart ........ 6 
 
 Automobile Welding .............. 5 
 
 Aviation ......................... 7 
 
 Aviation Chart ................... 6 
 
 Bevel Gear ...................... 21 
 
 Boiler Room Chart ............... 9 
 
 Brazing ......................... 8 
 
 Cams ........................... 21 
 
 Carburetion Trouble Chart ........ 6 
 
 Carburetors ...................... 5 
 
 Change Gear ...................... 21 
 
 Charts .......................... 6, 7 
 
 Coal ............................ 24, 30 
 
 Coke ............................ 10 
 
 Combustion .......... ............ 24 
 
 Compressed Air .................. 10 
 
 Concrete ............... ...... 10, 11, 12 
 
 Concrete for Farm Use ............ 12 
 
 Concrete for Shop Use ............ 12 
 
 Cosmetics ....................... 31 
 
 Cyclecars .................... ____ 5 
 
 Dictionary ....................... 12, 13 
 
 Dies 
 
 Drawing 
 
 Drawing for Plumbers 
 
 DropFo ' 
 
 Dynamo 
 
 Electric Bells 
 
 Electric Switchboards ............. 15, 17 
 
 Electric Toy Making .............. 15 
 
 Electric Wiring ............... 15, 16, 17 
 
 Electricity ................. 15, 16, 17,18 
 
 26 
 
 E-T Air Brake 
 
 " Everyday Engineering " 
 
 Factory Management 
 
 Ford Automobile 
 
 Ford Trouble Chart 
 
 Formulas and Recipes 
 
 Fuel 
 
 8 as Engine Construction 
 as Engines 19, 20, 21 
 
 Gas Tractor 37 
 
 Gearing and Cams 
 
 Heating 
 
 High Frequency Apparatus 
 
 Horse Power Chart 
 
 Hot Water Heating 
 
 House Wiring 
 
 Hydraulics 
 
 Ice 
 
 Ignition Systems , 
 
 Ignition Trouble Chart 
 
 India Rubber 
 
 Interchangeable Manufacturing ... 
 
 Inventions , 
 
 Knots 
 
 Lathe Work 
 
 Link Motions 
 
 21 
 
 PAGE 
 
 Liquid Air. . , 23 
 
 Locomotive Boilers 24 
 
 Locomotive Breakdowns 24 
 
 Locomotive Engineering. . . .23, 24, 25, 26 
 
 Machinist Books 26, 27, 28, 29 
 
 Manual Training 
 
 Marine Engineering 
 
 Marine Gasoline Engines 
 
 Mechanical Drawing 
 
 Mechanical Movements 
 
 Metal Work . . 
 
 Mining 
 odel 
 
 29 
 20 
 14 
 28 
 13 
 30 
 29 
 5 
 
 22 
 31 
 31 
 14 
 
 32, 33 
 21 
 13 
 
 Model Making 
 
 Motorcycles 
 
 Patents 
 
 Pattern Making 
 
 Perfumery 
 
 Perspective 
 
 Plumbing 
 
 Producer Gas 
 
 Punches 
 
 Questions and Answers on Auto- 
 mobile 4 
 
 Questions on Heating 36 
 
 Radio 17 
 
 Railroad Accidents 25 
 
 Railroad Charts 9 
 
 Recipe Book 33 
 
 Refrigeration 22 
 
 Repairing Automobiles 3 
 
 Rope Work 22 
 
 Rubber 34 
 
 Rubber Stamps 34 
 
 Saw Filing 34 
 
 Saws, Management of 34 
 
 Sheet Metal Works 13 
 
 Shop Construction 19 
 
 Shop Management 19 
 
 Shop Practice 19 
 
 Shop Tools 28 
 
 Sketching Paper 14 
 
 Soldering 8 
 
 Splices and Rope Work 22 
 
 Steam Engineering 34, 35, 36 
 
 Steam Heating 36 
 
 Steel 37 
 
 Storage Batteries 18 
 
 Submarine Chart 30 
 
 Switch Boards 15, 17 , 
 
 Tapers 
 
 Telegraphy, Wireless 
 
 Telephone 
 
 Thread Cutting ' 
 
 Tool Making 
 
 Toy Making 
 
 Tractive Power Chart 
 
 Tractor, Gas 
 
 Tram Rules 
 
 Turbines 
 
 Vacuum Heating 
 
 Valve Setting 
 
 Ventilation 
 
 Walschaert Valve Gear 
 
 Waterproofing 
 
 Welding .-. 
 
 Wireless Telegraphy K 
 
 Wiring 
 
 Wiring Diagrams 
 
 25 
 
 :<7 
 M 
 _>4 
 :<i> 
 _'G 
 l_' 
 
 
 , 18 
 
 . .15, 16, 17 
 15 
 
 Any of these books promptly sent prepaid to any address 
 in the world on receipt of price. 
 
 How to remit. By Postal Money Order, Express Money Order, 
 Bank Draft or Registered Letter.
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 AUTOMOBILES AND MOTORCYCLES 
 
 THE MODERN GASOLINE AUTOMOBILE ITS DESIGN, CONSTRUC- 
 TION, MAINTENANCE AND REPAIR. By VICTOR W. PAGE, M.E. 
 The latest and most complete treatise on the Gasoline Automobile ever issued. Written 
 in simple language by a recognized authority, familiar with every branch of the auto- 
 
 mobile industry. Free from technical terms. Everything is explained so simply 
 that anyone of average intelligence may gain a comprehensive knowledge of the 
 gasoline automobile. The information is up-toKlate and includes, in addition to an 
 exposition of principles of construction and description of all types of automobiles and 
 their components, valuable money-saving hints on the care and operation of motor- 
 cars propelled by internal combustion engines. Among some of the subjects treated 
 might be mentioned: Torpedo and other symmetrical body forms designed to reduce 
 air resistance: sleeve valve, rotary valve and other types of silent motors; increasing 
 tendency to favor worm-gear power -transmission; universal application of magneto 
 ignition; development of automobile electric-lighting systems; block motors; under- 
 slung chassis; application of practical self-starters; long stroke and offset cylinder 
 motors; latest automatic lubrication systems; silent chains for valve operation and 
 change-speed gearing; the use of front wheel brakes and many other detail refinements. 
 By a careful study of the pages of this book one can gain practical knowledge of auto- 
 mobile construction that will save time, money and worry. The book tells you just 
 what to do, how and when to do it. Nothing has been omitted, no detail has been 
 slighted. Every part of the automobile, its equipment, accessories, tools, supplies, 
 spare parts necessary, etc., have been discussed comprehensively. If you are or 
 intend to become a motorist, or are in any way interested in the modern Gasoline 
 Automobile, this is a book you cannot afford to be without. Over 1,000 pages 
 and more than 1,000 new and specially made detail illustrations, as well as many full- 
 page and double-page plates, showing all parts of the automobile. Including 12 large 
 folding plates. Price $3.50 
 
 WHAT IS SAID OF THIS BOOK: 
 
 " It is the best book on the Automobile seen up to date." J. H. Pile, Associate Editor 
 Automobile Trade Journal. 
 
 "Every Automobile Owner has use for a book of this character." The Tradesman. 
 "This 'book is superior to any treatise heretofore published on the subject." The 
 Inventive Age. 
 
 "We know of no other volume that is so complete in all its departments, and in which 
 the wide field of automobile construction with its mechanical intricacies is so plainly 
 handled, both in the text and in the matter of illustrations." The Motorist. 
 "The book is very thorough, a careful examination failing to disclose any point in 
 connection with the automobile, its care and repair, to have been overlooked." 
 Iron Age. 
 
 "Mr. Page has done a great work, and benefit to the Automobile Field." W. O. 
 Hasford, Mgr. Y. M. C. A. Automobile School, Boston, Mass. 
 
 "It is just the kind of a book a motorist needs if he wants to understand his car." 
 American Thresherman. 
 
 THE MODEL T FORD CAR, ITS CONSTRUCTION, OPERATION AND 
 REPAIR, INCLUDING THE FORD FARM TRACTOR. By VICTOR W. 
 PAGE, M.E. 
 
 This is a complete instruction book. All parts of the Ford Model T Car are described 
 and illustrated; the construction is fully described and operating principles made 
 clear to everyone. Every Ford owner needs this practical book. You don't have to 
 guess about the construction or where the trouble is, as it shows how to take all parts 
 apart and how to locate and fix all faults. The writer, Mr. Page', has operated a Ford 
 car for four years and writes from actual knowledge. Among the contents are: 
 1. The Ford Car. Its Parts and Their Functions. 2. The Engine and Auxiliary 
 Groups. How the Engine Works The Fuel Supply System The Carburetor 
 Making the Ignition Spark Cooling and Lubrication. 3. Details of Chassis. 
 Change Speed Gear Power Transmission Differential Gear Action Steering Gear 
 Front Axle Frame and Springs Brakes. 4. How to Drive and Care for the Ford. 
 The Control System Explained Starting the Motor Driving the Car Locating 
 Roadside Troubles Tire Repairs Oiling the Chassis Winter Care of Car. 5. Sys- 
 tematic Location of Troubles and Remedies. Faults in Engine Faults in Carburetor 
 Ignition Troubles Cooling and Lubrication System Defects Adjustment of 
 Transmission Gear General Chassis Repairs. The Ford Tractor and Tractor con- 
 version sets and Genuine Ford Tractor. 106 illustrations. 310 pages. Two large 
 folding plates. Price . . $1.00 
 
 AUTOMOBILE REPAIRING MADE EASY. By VICTOR W. PAG, M.E. 
 A comprehensive, practical exposition of every phase of modern automobile repairing 
 practice. Outlines every process incidental to motor car restoration. Gives plans for
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 workshop construction, suggestions for equipment, power needed, machinery and tools 
 necessary to carry on the business successfully. Tells how to overhaul and repair all 
 parts of all automobiles. Everything is explained so simply that motorists and students 
 can acquire a full working knowledge of automobile repairing. This work starts with 
 the engine, then considers carburetion, ignition, cooling and lubrication systems. The 
 clutch, change speed gearing and transmission system are considered in detail. Contains 
 instructions for repairing all types of axles, steering gears and other chassis parts. 
 Many tables, short cuts in figuring and rules of practice are given for the mechanic. 
 Explains fully valve and magneto timing, "tuning" engines, systematic location of 
 trouble, repair of ball and roller bearings, shop kinks, first aid to injured and a multi- 
 tude of subjects of interest to all in the garage and repair business. 
 This book contains special instructions on electric starling, lighting and ignition systems, 
 tire repairing and rebuilding, autogenous welding, brazing and soldering, heat treatment of 
 steel, latest timing practice, eight and twelve-cylinder motors, etc. 5^x8. Cloth. 1056 
 pages, 1,000 illustrations, 11 folding plates. Price $3.50 
 
 WHAT IS SAID OF THIS BOOK: 
 
 " 'Automobile Repairing Made Easy ' is the best book on the subject I have ever seen 
 and the only book I ever saw that is of any value in a garage." Fred Jeffrey, Martins- 
 burg, Neb. 
 
 "I wish to thank you for sending me a copy of 'Automobile Repairing Made Easy.* I 
 do not think it could be excelled." S. W. Gisriel, Director of Instruction, Y. M. C. A.. 
 Philadelphia, Pa. 
 
 QUESTIONS AND ANSWERS RELATING TO MODERN AUTOMOBILE 
 CONSTRUCTION, DRIVING AND REPAIR. By VICTOR W. PAGE, M.E. 
 
 A practical self-instructor for students, mechanics and motorists, consisting of thirty- 
 seven lessons in the form of questions and answers, written with special reference to the 
 requirements of the non-technical reader desiring easily understood, explanatory 
 matter relating to all branches of automobiling. The subject-matter is absolutely 
 correct and explained in simple language. If you can't answer all of the following 
 questions, you need this work. The answers to these and nearly 2000 more are to 
 be found in its pages. Give the name of all important parts of an automobile and 
 describe their functions? Describe action of latest types of kerosene carburetors? 
 What is the difference between a "double" ignition system and a "dual" ignition 
 system? Name parts of an induction coil? How are valves timed? What is an 
 electric motor starter and how does it work? What are advantages of worm drive 
 gearing? Name all important types of ball and roller bearings? What is a "three- 
 quarter" floating axle? What is a two-speed axle? What is the Vulcan electric gear 
 shift? Name the causes of lost power hi automobiles? Describe all noises due to 
 deranged mechanism and give causes? How can you adjust a carburetor by the 
 color of the exhaust gases? What causes "popping" in the carburetor? What tools 
 and supplies are needed to equip a car? How do you drive various makes of cars? 
 What is a differential lock and where is it used? Name different systems of wire 
 wheel construction, etc., etc. A popular work at a popular price. 5M x7 Y 2 . Cloth. 
 650 pages, 350 illustrations, 3 folding plates. Price $2.00 
 
 WHAT IS SAID OF THIS BOOK: 
 "If you own a car get this book." The Glassworker. 
 
 "Mr. Page has the faculty of making difficult subjects plain and understandable." 
 Bristol Press. 
 
 "We can name no writer better qualified to prepare a book of instruction on auto- 
 mobiles than Mr. Victor W. Page." Scientific American. 
 "The best automobile catechism that has appeared." Automobile Topics. 
 " There are few men, even with long experience, who will not find this book useful. 
 Great pains have been taken to make it accurate. Special recommendation must be 
 given to the illustrations, which have been made specially for the work. Such ex- 
 cellent books as this greatly assist in fully understanding your automobile." En- 
 gineering News. 
 
 MODERN STARTING, LIGHTING AND IGNITION SYSTEMS. By VICTOR 
 W. PAGE, M.E. 
 
 This practical volume has been written with special reference to the requirements of the 
 non-technical reader desiring easily understood, explanatory matter, relating to all 
 types of automobile ignition, starting and lighting systems. It can be understood by 
 anyone, even without electrical knowledge, because elementary electrical principles are 
 considered before any attempt is made to discuss features of the various systems. 
 These basic principles are clearly stated and illustrated with simple diagrams. All the 
 leading systems of starling, lighting and ignition have been described and illustrated with 
 the co-operation of the experts employed by the manufacturers. Wiring diagrams ar
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 shown in both technical and non- technical forms. All symbols are fully explained. It 
 is a comprehensive review of modern starting and ignition system practice, and includes 
 a complete exposition of storage battery construction, care and repair. All types of 
 starting motors, generators, magnetos, and all ignition or lighting system units are 
 fully explained. The systems of cars already in use as well as those that are to come 
 in 1919 are considered. Every person in the automobile business needs this volume. 
 . Cloth. 530 pages, 297 illustrations, 3 folding plates. Price . . $2.0O 
 
 GASOLINE AND KEROSENE CARBURETORS, CONSTRUCTION, IN- 
 STALLATION AND ADJUSTMENT. By MAJOR VICTOR W. PAGE. A 
 New Up-to-date Book on Modern Carburetion Practice. 
 
 This is a simple, comprehensive, and authoritative treatise for practical men ex- 
 plaining all basic principles pertaining to carburetion, showing how liquid fuels are 
 vaporized and turned into gas for operating all types of internal combustion engines in- 
 tended to operate on vapors of gasoline, kerosene, benzol, and alcohol. All leading types 
 of carburetors are described in detail, special attention being given to the forms devised 
 to use the cheaper fuels such as kerosene. Carburetion troubles, fuel system troubles, 
 carburetor repairs and installation, electric primers and economizers, hot spot mani- 
 folds and all modern carburetor developments are considered in a thorough manner. 
 Methods of adjusting all types of carburetors are fully discussed as well as sugges- 
 tions for securing maximum fuel economy and obtaining highest engine power. 
 This book is invaluable to repairmen, students, and motorists, as it includes the 
 most complete exposition on kerosene carburetors ever published. The drawings 
 showing carburetor construction are made from accurate engineering designs and 
 show all parts of late types of carburetors. 250 pages. 89 illustrations. . $1.50 
 
 HOW TO RUN AN AUTOMOBILE. By VICTOR W. PAGE. 
 
 This treatise gives concise instructions for starting and running all makes of gasoline 
 automobiles, how to care for them, and gives distinctive features of control. De- 
 scribes every step for shifting gears, controlling engine, etc. Among the chapters 
 contained are: I. Automobile Parts and Their Functions. II. General Starting 
 and Driving Instructions. III. Typical 1919 Control Systems Care of Auto- 
 mobiles. Thoroughly illustrated. 178 pages. 72 illustrations. Price . . $1.00 
 
 THE AUTOMOBILIST'S POCKET COMPANION AND EXPENSE RECORD. 
 By VICTOR W. PAGE. 
 
 This book is not only valuable as a convenient cost record, but contains much in- 
 formation of value to motorists. Includes a condensed digest of auto laws of all 
 States, a lubrication schedule, hints for care of storage battery, and care of tires, 
 location of road troubles, anti-freezing solutions, horse-power table, driving hints 
 and many useful tables and recipes of interest to ah 1 motorists. Not a technical 
 book in any sense of the word, just a collection of practical facts in simple language 
 for the every-day motorist. Convenient pocket size. Price .'.... $1.00 
 
 AUTOMOBILE WELDING WITH THE OXY-ACETYLENE FLAME.J By 
 M. KEITH DUNHAM. 
 
 Explains in a simple manner apparatus to be used, its care, and how to construct 
 necessary shop equipment. Proceeds then to the actual welding of .all automobile 
 parts, in a manner understandable by every one. Gives principles never to be for- 
 gotten. This book is of utmost value, since the perplexing problems arising when 
 metal is heated to a melting point are fully explained and the proper methods to 
 overcome them shown. 167 pages. Fully illustrated. Price ..... $1.25 
 
 MOTORCYCLES, SIDE CARS AND CYCLECARS, THEIR CONSTRUCTION, 
 MANAGEMENT AND REPAIR. By VICTOR W. PAGE, M.E. 
 
 The only complete work published for the motorcyclist and cyclecarist. Describes 
 fully all leading types of machines, their design, construction, maintenance, operation 
 and repair. This treatise outlines fully the operation of two- and four-cycle power 
 plants and all ignition, carburetion and lubrication systems in detail. Describes all 
 representative types of free engine clutches, variable speed gears and power trans- 
 mission systems. Gives complete instructions for operating and repairing all types. 
 Considers fully electric self-starting and lighting systems, all types of spring frames 
 and springs forks and shows leading control methods. For those desiring technical 
 information a complete series of tables and many formulae to assist in designing are 
 included. The work tells how to figure power needed to climb grades, overcome air 
 resistance and attain high speeds. It shows how to select gear ratios for various 
 weights and powers, how to figure braking efficiency required, gives sizes of belts and 
 chains to transmit power safely, and shows how to design sprockets, belt pulleys, etc. 
 This work also includes complete formulae for figuring horse-power, shows how dyna-
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 mometer tests are made, defines relative efficiency of air- and water-cooled engines, plain 
 and anti-friction bearings and many other data of a practical, helpful, engineering 
 nature. Remember that you get this information in addition to the practical de- 
 scription and instructions which alone arc worth several times the price of the book. 
 550 pages. 350 specially made illustrations, 5 folding plates. Cloth. Price . $2.00 
 
 WHAT IS SAID OP THIS BOOK: 
 
 " Here Is a book that should be in the cycle repairer's kit." American Blacksmith. 
 " The best way for any rider to thoroughly understand his machine, is to get a copy 
 of this book; it is worth many times its price." Pacific Motorcyclist. 
 
 AUTOMOBILE, AVIATION AND MOTORCYCLE CHARTS 
 
 AVIATION CHART LOCATION OF AIRPLANE POWER PLANT TROUBLES 
 MADE EASY. By MAJOR VICTOR W. PAGE, A.S., S.C.U.S.R. 
 A large chart outlining all parts of a typical airplane power plant, .showing the points 
 where trouble is apt to occur and suggesting remedies for the common defects. In- 
 tended especially for aviators and aviation mechanics on school and field duty. 
 Price 50 cents 
 
 CHART. GASOLINE ENGINE TROUBLES MADE EASY A CHART SHOW- 
 ING SECTIONAL VIEW OF GASOLINE ENGINE. Compiled by VICTOR 
 W. PAGE, M.E. ^ 
 
 It shows clearly all parts of a typical four-cylinder gasoline engine of the four-cycle 
 type. It outlines distinctly all parts liable to give trouble and also details the de- 
 rangements apt to interfere with smooth engine operation. 
 
 Valuable to students, motorists, mechanics, repairmen, garagemen, automobile sales- 
 men, chauffeurs, motorboat owners, motor-truck and tractor drivers, aviators, motor- 
 cyclists, and all others who have to do with gasoline power plants. 
 It simplifies location of all engine troubles, and while it will prove invaluable to the 
 novice, it can be used to advantage by. the more expert. It should be on the walls of 
 every public and private garage, automobile repair shop, clubhouse or school. It can 
 be carried in the automobile or pocket with ease, and will insure against loss of time 
 when engine trouble manifests itself. 
 
 This sectional view of engine is a complete review of all motor troubles. It is prepared 
 by a practical motorist for all who motor. More information for the money than ever 
 before offered. No details omitted. Size 25x38 inches. Securely mailed on receipt 
 of 25 cents 
 
 CHART. LOCATION OF FORD ENGINE TROUBLES MADE EASY. Com- 
 piled by VICTOR W. PAGE, M.E. 
 
 This shows clear sectional views depicting all portions of the Ford power plant and 
 auxiliary groups. It outlines clearly all parts of the engine, fuel supply system, igni- 
 tion group and cooling system, that are apt to give trouble, detailing all derangements 
 that are liable to make an engine lose power, start hard or work irregularly. This 
 chart is valuable to students, owners, and drivers, as it simplifies location of all engine 
 faults. Of great advantage as an instructor for the novice, it can be used equally well 
 by the more expert as a work of reference and review. It can be carried in the tool- 
 box or pocket with ease and will save its cost in labor eliminated the first time engine 
 trouble manifests itself. Prepared with special reference to the average man's needs 
 and is a practical review of all motor troubles because it is based on the actuaj ex- 
 perience of an automobile engineer-mechanic with the mechanism the chart describes. 
 It enables the non-technical owner or operator of a Ford car to locate engine de- 
 rangements by systematic search, guided by easily recognized symptoms instead of by 
 guesswork. It makes the average owner independent of the roadside repair shop 
 when touring. Must be seen to be appreciated. Size 25x38 inches., Printed on 
 heavy bond paper. Price 25 cents 
 
 CHART. LUBRICATION OF THE MOTOR CAR CHASSIS. Compiled by 
 VICTOR W. PAGE, M.E. 
 
 This chart presents the plan view of a typical six-cylinder chassis of standard design 
 and all parts are clearly indicated that demand oil, also the frequency with which they 
 must be lubricated and the kind of oil to use. A practical chart for all interested in 
 motor-car maintenance. Size 24x38 inches. Price 25 cents 
 
 CHART. LOCATION OF CARBURETION TROUBLES MADE EASY. Com- 
 piled by VICTOR W. PAGE, M.E. 
 
 This chart shows all parts of a typical pressure feed fuel supply system and gives 
 causes of trouble, how to locate defects and means of remedying them. Size 24x38 
 inches. Price 25 cents
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 CHART. LOCATION OF IGNITION SYSTEM TROUBLES MADE EASY. 
 Compiled by VICTOR W. PAGE, M.E. 
 
 In this diagram all parts of a typical double ignition system using battery and magneto 
 current are shown, and suggestions are given for readily finding ignition troubles and 
 eliminating them when found. Size 24x38 inches. Price 25 cents 
 
 CHART. LOCATION OF COOLING AND LUBRICATION SYSTEM FAULTS. 
 Compiled by VICTOR W. PAGE, M.E. 
 
 This composite diagram shows a typical automobile power plant using pump circulated 
 water-cooling system and the most popular lubrication method. Gives suggestions 
 for curing all overheating and loss of power faults due to faulty action of the oiling 
 or cooling group. Size 24x38 inches. Price 25 cents 
 
 CHART. MOTORCYCLE TROUBLES MADE EASY. Compiled by VICTOR 
 W. PAGE, M.E. 
 
 A chart showing sectional view of a single-cylinder gasoline engine. This chart 
 simplifies location of all power-plant troubles. A single-cylinder motor is shown for 
 simplicity. It outlines distinctly all parts liable to give trouble and also details the 
 
 derangements apt to interfere with smooth engine operation. This chart will prove 
 of value to all who have to do with the operation, repair or sale of motorcycles. No 
 details omitted. Size 30x20 inches. Price 25 cents 
 
 AVIATION 
 
 A B C OF AVIATION By MAJOR VICTOR W. PAGE. 
 
 This book describes the basic principles of aviation, tells how a balloon or dirigible 
 is made and why it floats in the air. Describes how an airplane flies. It shows in 
 detail the different parts of an airplane, what they are and what they do. Describes 
 all types of airplanes and how they differ in construction; as well as detailing the 
 advantages and disadvantages of different types of aircraft. It includes a complete 
 dictionary of aviation terms and clear drawings of leading airplanes. The reader 
 will find simple instructions for unpacking, setting up, and rigging airplanes. A 
 full description of airplane control principles is given and methods of flying are dis- 
 cussed at length. 
 
 This book answers every question one can ask about modern aircraft, their con- 
 struction and operation. A self-educator on aviation without an equal. 275 pages. 
 130 specially made illustrations with 7 plates. Price $2.50 
 
 AVIATION ENGINES DESIGN; CONSTRUCTION; REPAIR. By MAJOR 
 VICTOR W. PAGE, A.S., S.C.U.S.R. 
 
 This treatise, written by a recognized authority on all of the practical aspects of 
 internal combustion engine construction, maintenance, and repair, fills the need as 
 no other book does. The matter is logically arranged; all descriptive matter is 
 simply expressed and copiously illustrated, so that anyone can understand airplane 
 engine operation and repair even if without previous mechanical training. This 
 work is invaluable for anyone desiring to become an aviator or aviation mechanic. 
 The latest rotary types, such as the Gnome Monosoupape, and LeRhone, are fully 
 explained, as well as the recently developed Vee and radial types. The subjects 
 of carburetion, ignition, cooling, and lubrication also are covered in a thorough manner. 
 The chapters on repair and maintenance are distinctive and found in no other book 
 on this subject. Not a technical book, but a practical, easily understood work of 
 reference for all interested in aeronautical science. 576 pages. 253 illustrations. 
 Price, net $3.00 
 
 GLOSSARY OF AVIATION TERMS ENGLISH-FRENCH; FRENCH- 
 ENGLISH. By MAJOR VICTOR W. PAGE, A.S., S.C.U.S.R., and LIEUT. 
 PAUL MONTARIOL, of the French Flying Corps. 
 
 A complete glossary of practically all terms used in aviation, having lists in both 
 French and English with equivalents in either language. Price, net . . $1.00 
 
 AVIATION CHART LOCATION OF AIRPLANE POWER PLANT TROUBLES 
 MADE EASY. By MAJOR VICTOR W. PAGE, A.S., S.C.U.S.R. 
 
 A large chart outlining all parts of a typical airplane power plant, showing the points 
 where trouble is apt to occur and suggesting remedies for the common defects. In- 
 tended especially for aviators and aviation mechanics on school and field duty. 
 Price 50 cents
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 BRAZING AND SOLDERING 
 
 BRAZING AND SOLDERING. By JAMES F. HOBART. 
 
 The only book that shows you just how to handle any job of brazing or soldering that 
 comes along: it tells you what mixture to use, how to make a furnace if you need one. 
 Full of valuable kinks. The fifth edition of this book has just been published, and to 
 it much new matter and a large number of tested formulae for all kinds of solders and 
 fluxes have been added. Illustrated 35 cents 
 
 CHARTS 
 
 AVIATION CHART LOCATION OF AIRPLANE POWER PLANT TROUBLES 
 MADE EASY. By MAJOR VICTOR W. PAGE, A.S., S.C.U.S.R. 
 
 A large chart outlining all parts of a typical airplane power plant, showing the points 
 where trouble is apt to occur and suggesting remedies for the common defects. 
 Intended especially for aviators and aviation mechanics on school and field duty. 
 Price 50 cents 
 
 GASOLINE ENGINE TROUBLES MADE EASY A CHART SHOWING SEC- 
 TIONAL VIEW OF GASOLINE ENGINE. Compiled by VICTOR W. PAGE. 
 It shows clearly all parts of a typical four-cylinder gasoline engine of the four-cycle 
 type. It outlines distinctly all parts liable to give trouble and also details the de- 
 rangements apt to interfere with smooth engine operation. 
 
 Valuable to students, motorists, mechanics, repairmen, garagemen, automobile sales- 
 men, chauffeurs, motor-boat owners, motor-truck and tractor drivers, aviators, motor- 
 cyclists, and all others who have to do with gasoline power plants. 
 It simplifies location of all engine troubles, and while it will prove invaluable to the 
 novice, it can be used to advantage by the more expert. It should be on the walls of 
 every public and private garage, automobile repair shop, club house or school. It can 
 be carried in the automobile or pocket with ease and will insure against loss of time 
 when engine trouble manifests itself. 
 
 This sectional view of engine is a complete review of all motor troubles. It is pre- 
 pared by a practical motorist for all who motor. No details omitted. Size 25x38 
 inches 25 cents 
 
 LUBRICATION OF THE MOTOR CAR CHASSIS. 
 
 This chart presents the plan view of a typical six-cylinder chassis of standard design 
 and all parts are clearly indicated that demand oil, also the frequency with which they 
 must be lubricated and the kind of oil to use. A practical chart for all interested in 
 motor-car maintenance. Size 24x38 inches. Price 25 cents 
 
 LOCATION OF CARBURETION TROUBLES MADE EASY. 
 
 This chart shows all parts of a typical pressure feed fuel supply system and gives 
 causes of trouble, how to locate defects and means of remedying them. Size 24x38 
 inches. Price 25 cents 
 
 LOCATION OF IGNITION SYSTEM TROUBLES MADE EASY. 
 
 In this chart all parts of a typical double ignition system using battery and magneto 
 current are shown and suggestions are given for readily finding ignition troubles and 
 eliminating them when found. Size 24x38 inches. Price 25 cents 
 
 LOCATION OF COOLING AND LUBRICATION SYSTEM FAULTS. 
 
 This composite chart shows a typical automobile power plant using pump circulated 
 water-cooling system and the most popular lubrication method. Gives suggestions 
 for curing all overheating and loss of bower faults due to faulty action of the oiling or 
 cooling group. Size 24x38 inches. Price 25 cents 
 
 MOTORCYCLE TROUBLES MADE EASY A CHART SHOWING SEC- 
 TIONAL VIEW OF SINGLE-CYLINDER GASOLINE ENGINE. Compiled 
 by VICTOR W. PAGE. 
 
 This chart simplifies location of all power-plant troubles, and will prove invaluable to 
 all who have to do with the operation, repair or sale of motorcycles. No details 
 Size 25x38 inches. Price 25 cents 
 
 8
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 LOCATION OF FORD ENGINE TROUBLES MADE EASY. Compiled by 
 VICTOR W. PAGE, M.E. 
 
 This shows clear sectional views depicting all portions of the Ford power plant and 
 auxiliary groups. It outlines clearly all parts of the engine, fuel supply system, 
 ignition group and cooling system, that are apt to give trouble, detailing all derange- 
 ments that are liable to make an engine lose power, start hard or work irregularly. This 
 chart is valuable to students, owners, and drivers, as it simplifies location of all engine 
 faults. Of great advantage as an instructor for the novice, it can be used equally well 
 by the more expert as a work of reference and review. It can be carried in the tool- 
 box or pocket with ease and will save its cost in labor eliminated the first time engine 
 trouble manifests itself. Prepared with special reference to the average man's needs 
 and is a practical review of all motor troubles because it is based on the actual ex- 
 perience of an automobile engineer-mechanic with the mechanism the chart describes. 
 It enables the non-technical owner or operator of a Ford car to locate engine de- 
 rangements by systematic search, guided by easily recognized symptoms instead of by 
 guesswork. It makes the average owner independent of the roadside repair shop 
 when touring. Must be seen to be appreciated. Size 25x38 inches. Printed on heavy 
 bond paper. Price 25 cents 
 
 MODERN SUBMARINE CHART WITH 200 PARTS NUMBERED AND 
 NAMED. 
 
 A cross-section view, showing clearly and distinctly all the interior of a Submarine of 
 the latest type. You get more information from this chart, about the construction and 
 operation of a Submarine, than in any other way. No details omitted everything 
 is accurate and to scale. It is absolutely correct in every detail, having been approved 
 by Naval Engineers. All the machinery and devices fitted in a modern Submarine 
 Boat are shown, and to make the engraving more readily understood, all the features 
 are shown in operative form, with Officers and Men in the act of performing the duties 
 assigned to them in service conditions. This CHART IS REALLY AN ENCYCLO- 
 PEDIA OF A SUBMARINE 25 cents 
 
 BOX CAR CHART. 
 
 A chart showing the anatomy of a box'car. having every part of the car numbered and 
 its proper name given in a reference list 25 cents 
 
 GONDOLA CAR CHART. 
 
 A chart showing the anatomy of a gondola car, having every part of the car numbered 
 and its proper reference name given in a reference list 25 cents 
 
 PASSENGER-CAR CHART. 
 
 A chart showing the anatomy of a passenger-car, having every part of the car numbered 
 and its proper name given in a reference list 25 cents 
 
 STEEL HOPPER BOTTOM COAL CAR. 
 
 A chart showing the anatomy of a steel Hopper Bottom Coal Car, having every part 
 of the car numbered and its proper name given in a reference list 25 cents 
 
 TRACTIVE POWER CHART. 
 
 A chart whereby you can find the tractive power or drawbar pull of any locomotive 
 without making a figure. Shows what cylinders are equal, how driving wheels and 
 steam pressure affect the power. What sized engine you need to exert a given drawbar 
 pull or anything you desire in this line 50 cents 
 
 HORSE-POWER CHART 
 
 Shows the horse-power of any stationary engine without calculation. No matter what 
 the cyh'nder diameter of stroke, the steam pressure of cut-off, the revolutions, or 
 whether condensing or non-condensing, it's all there. Easy to use, accurate, and 
 saves time and calculations. Especially useful to engineers and designers. 50 cents 
 
 BOILER ROOM CHART. By GEO. L. FOWLER. 
 
 A charts-size 14x28 inches showing in isometric perspective the mechanisms be- 
 longing in a modern boiler room. The various parts are shown broken or removed, 
 so that the. internal construction is fully illustrated. Each part is given a reference 
 number, and these, with the corresponding name, are given in a glossary printed at 
 the sides. This chart is really a dictionary of the boiler room the names of more than 
 200 parts being given 25 cents
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 COKE 
 
 COKE MODERN COKING PRACTICE, INCLUDING ANALYSIS OF 
 MATERIALS AND PRODUCTS. By J. E. CHRISTOPHER and T. H. BYROM. 
 
 This, the standard work on the subject, has just been revised and is now issued in 
 two volumes. It is a practical work for those engaged in Coke manufacture and 
 the recovery [of By-products. Fully illustrated with folding plates. It has been 
 the aim of the authors, in preparing this book, to produce one which shall be of use 
 and benefit to those who are associated with, or interested in, the modern develop- 
 ments of the industry. Among the chapters contained in Volume I are: Introduc- 
 tion. Classification of Fuels. Impurities of Coals. Coal Washing. Sampling 
 and Valuation of Coals, etc. Chlorific Power of Fuels. History of Coke Manu- 
 facture. Developments in Coke Oven Design; Recent Types of Coke Ovens. 
 Mechanical Appliances at Coke. Ovens. Chemical and Physical Examination of 
 Coke. Volume II covers By-p'roducts. Each volume is fully illustrated, with 
 folding plates. Price, per volume $3.00 
 
 COMPRESSED AIR 
 
 COMPRESSED AIR IN ALL ITS APPLICATIONS. By GARDNER D. Hiscox. 
 
 This is the most complete book on the subject of Air that has ever been issued, and its 
 thirty-five chapters include about every phase of the subject one can think of. It may 
 be called an encyclopedia of compressed air. It is written by an expert, who, in its 
 665 pages, has dealt with the subject in a comprehensive manner, no phase of it being 
 omitted. Includes the physical properties of air from a vacuum to its highest pressure, 
 its thermodynamics, compression, transmission and uses as a motive power, in the 
 Operation of Stationary' and Portable Machinery, in Mining, Air Tools, Air Lifts, 
 Pumping of Water, Acids, and Oils; the Air Blast for Cleaning and Painting, the 
 Sand Blast and its Work, and the Numerous Appliances in which Compressed Air is 
 a Most Convenient and Economical Transmitter of Power for Mechanical Work, 
 Railway Propulsion, Refrigeration, and the Various Uses to which Compressed Air 
 has been applied. Includes forty-four tables of the physical properties of air, its 
 compression, expansion, and volumes required for various kinds of work, and a list 
 of patents on compressed air from 1875 to date. Over 500 illustrations, 5th Edition, 
 revised and enlarged. Cloth bound, $6.00. Half Morocco, price .... $7.50 
 
 CONCRETE 
 
 JUST PUBLISHED CONCRETE WORKERS' REFERENCE BOOKS. A 
 SERIES OF POPULAR HANDBOOKS FOR CONCRETE USERS. 
 Prepared by A. A. HOUGHTON Each 60 cents 
 
 The author, in preparing this Series, has not only treated on the usual types of construction, 
 but explains and illustrates molds and systems that are not patented, but which are equal 
 in value and often superior to those restricted by patents. These molds are rery easily and 
 cheaply constructed and embody simplicity, rapidity of operation, and the most successful 
 results in the molded concrete. Each of these Twelve books is fully illustrated, and the 
 subjects are exhaustively treated in plain English. 
 
 CONCRETE WALL FORMS. By A. A. HOUGHTON. 
 
 A new automatic wall clamp is illustrated- with working drawings. Other types of 
 
 wall forms, clamps, separators, etc., are also illustrated and explained. 
 
 (No. 1 of Series) 60 cents 
 
 CONCRETE FLOORS AND SIDEWALKS. By A. A. HOUGHTON. 
 
 The molds for molding squares, hexagonal and many other styles of mosaic floor and 
 sidewalk blocks are fully illustrated and explained. (No. 2 of Series) . . 60 cents 
 
 PRACTICAL CONCRETE SILO CONSTRUCTION. By A. A. HOUGHTON. 
 
 Complete working drawings and specifications are given for several styles of concrete 
 silos, with illustrations of molds for monolithic and block silos. The tables, data, and 
 information presented in this book are of the utmost value'in planning and constructing 
 all forms of concrete silos. (No. 3 of Series) 60 cents 
 
 10
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 MOLDING CONCRETE CHIMNEYS, SLATE AND ROOF TILES. By A. A. 
 
 HOUGHTON. 
 
 The manufacture of all types of concrete slate and roof tile Is fully treated. Valuable 
 data on all forms of reinforced concrete roofs are contained within its pages. The 
 construction of concrete chimneys by block and monolithic systems is fully illustrated 
 and described. A number of ornamental designs of chimney construction with molds 
 are shown in this valuable treatise. (No. 4 of Series.) 60 cents 
 
 MOLDING AND CURING ORNAMENTAL CONCRETE. By A. A. HOUGHTON. 
 
 The proper proportions of cement and aggregates for various finishes, also the method 
 of thoroughly mixing and placing in the molds, are fully treated. An exhaustive 
 treatise on this subject that every concrete worker will find of daily use and value. 
 (No. 5 of Series.) 60 cents 
 
 CONCRETE MONUMENTS, MAUSOLEUMS AND BURIAL VAULTS. By 
 A. A. HOUGHTON. 
 
 The molding of concrete monuments to imitate the most expensive cut stone is ex- 
 plained in this treatise, with working drawings of easily built molds. Cutting in- 
 scriptions and designs are also fully treated. (No. 6 of Series.) ... 60 cents 
 
 MOLDING CONCRETE BATHTUBS, AQUARIUMS AND NATATORIUMS. 
 By A. A. HOUGHTON. 
 
 Simple molds and instruction are given for molding many styles of concrete bathtubs, 
 swimming-pools, etc. These molds are easily built and permit rapid and successful 
 work. (No. 7 of Series.) 60 cents 
 
 CONCRETE BRIDGES, CULVERTS AND SEWERS. By A. A. HOUGHTON. 
 A number of ornamental concrete bridges with illustrations of molds are given. A 
 collapsible center or core for bridges, culverts and sewers is fully illustrated with de- 
 tailed instructions for building. (No. 8 of Series.) 60 cents 
 
 CONSTRUCTING CONCRETE PORCHES. By A. A. HOUGHTON. 
 
 A number of designs with working drawings of molds are fully explained so any one 
 can easily construct different styles of ornamental concrete porches without the pur- 
 chase of expensive molds. (No. 9 of Series.) 60 cents 
 
 MOLDING CONCRETE FLOWER-POTS, BOXES, JARDINIERES, ETC. 
 By A. A. HOUGHTON. 
 
 The molds for producing many original designs of flower-pots, urns, flower-boxes, 
 jardinieres, etc., are fully illustrated and explained, so the worker can easily construct 
 and operate same. (No. 10 of Series.) 60 cents 
 
 MOLDING CONCRETE FOUNTAINS AND LAWN ORNAMENTS. By A. 
 A. HOUGHTON. 
 
 The molding of a number of designs of lawn seats, curbing, hitching posts, pergolas, sun 
 dials and other forms of ornamental concrete for the ornamentation of lawns and gar- 
 dens, is fully illustrated and described. (No. 11 of Series) 60 cents 
 
 CONCRETE FROM SAND MOLDS. By A. A. HOUGHTON. 
 
 A Practical Work treating on a process which has heretofore been held as a trade secret 
 by the few who possessed it, and which will successfully mold every and any class of 
 ornamental concrete work. The process of molding concrete with sand molds is of 
 the utmost practical value, possessing the manifold advantages of a low cost of molds, 
 the ease and rapidity of operation, perfect details to all ornamental designs, density 
 and increased strength of the concrete, perfect curing of the work without attention 
 and the easy removal of the molds regardless of any undercutting the design may have. 
 192 pages. Fully illustrated. Price $2.00 
 
 ORNAMENTAL CONCRETE WITHOUT MOLDS. By A. A. HOUGHTON. 
 The process for making ornamental concrete without molds has lone been held as a 
 secret, and now, for the first time, this process is given to the public. The book 
 reveals the secret and is the only book published which explains a simple, practical 
 method whereby the concrete worker is enabled, by employing wood and metal tem- 
 plates of different designs, to mold or model in concrete any Cornice, Archivolt, 
 Column, Pedestal, Base Cap, Urn or Pier in a monolithic form right upon the job. 
 These may be molded in units or blocks, and then built up to suit the specifications 
 demanded. This work is fully illustrated, with detailed engravings. Price . $2.0O 
 
 II
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 CONCRETE FOR THE FARM AND IN THE SHOP. BY H. COLIN 
 CAMPBELL, C.E., E.M. 
 
 "Concrete for the Farm and In the Shop" is a new book from cover to cover, illustrat- 
 ing and describing in plain, simple language many of the numerous applications of 
 concrete within the range of the home worker. Among the subjects treated are: 
 Principles of reinforcing; methods of protecting concrete so as to insure proper harden- 
 ing; home-made mixers; mixing by hand and machine; form construction, described 
 and illustrated by drawings and photographs; construction of concrete walls and 
 fences; concrete fence posts; concrete gate posts; corner posts; clothes line posts; 
 grape arbor posts; tanks; troughs; cisterns; hog wallows; feeding floors and barn- 
 yard pavements ; foundations ; well curbs and platforms ; indoor floors ; sidewalks ; steps ; 
 concrete hotbeds and cold frames; concrete slab roofs; walls far buildings; repairing 
 leaks in tanks and cisterns; and all topics associated with th^s 1 subjects as bearing 
 upon securing the best results from concrete are dwelt upon atsuffici >nt 1 ngth in plain 
 every-day English so that the inexperienced person desiring to und rtaka a piece of 
 concrete construction can, by following the directions set forth in this book, secute 10O 
 per cent success every time. A number of convenient and practical tubl -s for estimating 
 quantities, and some practical examples, are also given. (5x7). 149 pages, 51 il- 
 lustrations. Price $1.OO 
 
 POPULAR HANDBOOK FOR CEMENT AND CONCRETE USERS. By 
 
 MYRON H. LEWIS. 
 
 This is a concise treatise of the principles and methods employed in the manufacture 
 and use of cement in all classes of modern works. The author has brought together 
 in this work all the salient matter of interest to the user of concrete and its many 
 diversified products. The matter is presented in logical and systematic order, clearly 
 written, fully illustrated and free from involved mathematics. Everything of value to 
 the concrete user is given, including kinds of cement employed in construction, concrete 
 architecture, inspection and testing, waterproofing, coloring and painting, rules, tables, 
 working and cost data. The book comprises thirty-three chapters, as follows: 
 Introductory. Kinds of Cements and How They are Made. Properties. Testing 
 and Requirements of Hydraulic Cement. Concrete and its Properties. Sand, Broken 
 Stone and Gravel for Concrete. How to Proportion the Materials. How to Mix 
 and Place Concrete. Forms of Concrete Construction. The Architectural and Artistic 
 Possibilities of Concrete. Concrete Residences. Mortars, Plasters and Stucco, and 
 How to Use them. The Artistic Treatment of Concrete Surfaces. Concrete Building 
 Blocks. The Making of Ornamental Concrete. Concrete Pipes, Fences, Posts, etc. 
 Essential Features and Advantages of Reenforced Concrete. How to Design Reen- 
 forced Concrete Beams, Slabs and Columns. Explanations of the Methods and 
 Principles in Designing Reenforced Concrete Beams and Slabs. Systems of Reen- 
 forcement Employed. Reenforced Concrete in Factory and General Building Con- 
 struction. Concrete in Foundation Work. Concrete Retaining Walls, Abutments 
 and Bulkheads. Concrete Arches and Arch Bridges. Concrete Beam and Girder 
 Bridges. Concrete in Sewerage and Drainage Works. Concrete Tanks, Dams and 
 Reservoirs. Concrete Sidewalks, Curbs and Pavements. Concrete in Railroad Con- 
 structions. The Utility of Concrete on the Farm. The Waterproofing of Concrete 
 Structure. Grout of Liquid Concrete and Its Use. Inspection of Concrete Work. Cost 
 of Concrete Work. Some of the special features of the book are: 1. The Attention 
 Paid to the Artistic and Architectural Side of Concrete Work. 2. The Authoritative 
 Treatment of the Problem of Waterproofing Concrete. 3. An Excellent Summary of 
 the Rules to be Followed in Concrete Construction. 4. The Valuable Cost Data and 
 Useful Tables given. A valuable Addition to the Library of Every Cement and 
 Concrete User. Price $3.00 
 
 WHAT IS SAID OF THIS BOOK: 
 
 "The field of Concrete Construction is well covered and the matter contained is well 
 within the understanding of any person." Engineering-Contracting. 
 " Should be on the bookshelves of every contractor, engineer, and architect in the 
 land." National Builder. 
 
 WATERPROOFING CONCRETE. By MYRON H. LEWIS. 
 
 Modern Methods of Waterproofing Concrete and Other Structures. A condensed 
 statement of the Principles, Rules, and Precautions to be Observed in Waterproofing 
 and Dampproofing Structures and Structural Materials. Paper binding. Illustrated. 
 Price 60 cents 
 
 DICTIONARIES 
 
 STANDARD ELECTRICAL DICTIONARY. By T. O'CoNOR SLOANE. 
 
 An indispensable work to all interested in electrical science. Suitable alike for the 
 student and professional. A practical handbook of reference containing definitions of 
 about 5000 distinct words, terms and phrases. The definitions are terse and concise 
 
 12
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 and include every term used in electrical science. Recently issued. An entirely new 
 edition. Should be in the possession of all who desire to keep abreast with the progress 
 of this branch of science. Complete, concise and convenient. 682 pages. 393 illustra- 
 tions. Price $3.00 
 
 AVIATION TERMS ENGLISH-FRENCH; FRENCH-ENGLISH. By MAJOR 
 VICTOR W. PAGE, A.S., S.C.U.S.R., and LIEUT. PAUL MONTARIOL of the 
 French Flying Corps. 
 
 A- complete glossary of practically all terms used in aviation, having lists in both 
 French and English with equivalents in either language. Include all words in 
 common use. A complete, well illustrated volume intended to facilitate conversa- 
 tion between English-speaking and French aviators. The lists are confined to essen- 
 tials, and special folding plates are included to show all important airplane parts. 
 The lists are divided into four sections: 1. Flying Field Terms. 2. The Airplane. 
 3. The Engine. 4. Tools and Shop Terms. Should be in every aviator's and 
 mechanic's kit. Price Sl.OO 
 
 DIES METAL WORK 
 
 DIES: THEIR CONSTRUCTION AND USE FOR THE MODERN WORKING 
 OF SHEET METALS. By J. V. WOODWORTH. 
 
 A most useful book, and one which should be in the hands of all engaged in the presa 
 working of metals; treating on the Designing, Constructing, and Use of Tools, Fixtures 
 and Devices, together with the manner in which they should be used in the Powr 
 Press, for the cheap and rapid production of the great variety of sheet-metal articles 
 now in use. It is designed as a guide to the production of sheet-metal parts at the 
 minimum of cost with the maximum of output. The hardening and tempering of 
 Press tools and the classes of work which may be produced to the best advantage by 
 the use of dies in the power press are fully treated. Its 505 illustrations show dies, 
 press fixtures and sheet-metal working devices, the descriptions of which are so clear and 
 practical that all metal-working mechanics will be able to understand how to design, 
 construct and use them. Many of the dies and press fixtures treated were either 
 constructed by the author or under his supervision. Others were built by skilful 
 ' mechanics and are in use in large sheet-metal establishments and machine shops. 
 5th Edition. Price $3.50 
 
 PUNCHES, DIES AND TOOLS FOR MANUFACTURING IN PRESSES. By 
 J. V. WOODWORTH. 
 
 This work is a companion volume to the author's elementary work entitled "Dies, Their 
 Construction and Use." It does not go into the details of die-making to the extent of 
 the author's previous book, but gives a comprehensive review of the field of operations 
 carried on by presses. A large part of the information given has been drawn from the 
 author's personal experience. It might well be termed an Encyclopedia of Die-Making, 
 Punch-Making, Die-Sinking, Sheet-Metal Working, and Making of Special Tools, Sub- 
 presses, Devices and Mechanical Combinations for Punching, Cutting, Bending, Form- 
 ing, Piercing, Drawing, Compressing and Assembling Sheet-Metal Parts, and also Arti- 
 cles of other Materials in Machine Tools. 2d Edition. Price $4.50 
 
 DROP FORGING, DIE-SINKING AND MACHINE-FORMING OF STEEL. 
 By J. V. WOODWORTH. 
 
 This is a practical treatise on Modern Shop Practice, Processes, Methods, Machine 
 Tools, and Details treating on the Hot and Cold Machine-Forming of Steel and Iron 
 into Finished Shapes; together with Tools, Dies, and Machinery involved in the 
 manufacture of Duplicate Forgings and Interchangeable Hot and Cold Pressed Parts 
 from Bar and Sheet Metal. This book fills a demand of long standing for information 
 regarding drop-forgings, die-sinking and machine-forming of steel and the shop 
 practice involved, as it actually exists in the modern drop-forging shop. The processes 
 of die-sinking and force-making, which are thoroughly described and illustrated in this 
 admirable work, are rarely to be found explained in such a clear and concise manner 
 as is here set forth. The process of die-sinking relates to the engraving or sinking of 
 the female or lower dies, such as are used for drop-forgings, hot and cold machine 
 forging, swedging and the press working of metals. The process of force-making 
 relates to the engraving or raising of the male or upper dies used in producing the 
 lower dies for the press-forming and machine-forging of duplicate parts of metal. 
 In addition to the arts above mentioned the book contains explicit information re- 
 garding the drop-forging and hardening plants, designs, conditions, equipment, drop 
 hammers, forging machines, etc., machine forging, hydraulic forging, autogenous 
 welding and shop practice. The book contains eleven chapters, and the information
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 contained in these chapters is just what will prove most valuable to the forged-metal 
 worker. All operations described in the work are thoroughly illustrated by means of 
 perspective half-tones and outline sketches of the machinery employed. 300 detailed 
 Illustrations. L Price $3.0O 
 
 DRAWING SKETCHING PAPER 
 
 PRACTICAL PERSPECTIVE. By RICHARDS and COLVIN. 
 
 Shows just how to make all kinds of mechanical drawings in the only practical per- 
 spective isometric. Makes everything plain so that any mechanic can understand 
 a sketch or drawing in this way. Saves time in the drawing room, and mistakes in the 
 shops. Contains practical examples of various classes of work. 4th Edition. 60 cents 
 
 LINEAR PERSPECTIVE SELF-TAUGHT. By HERMAN T. C. KRAUS. 
 
 This work gives the theory and practice of linear perspective, as used in architectural, 
 engineering and mechanical drawings. Persons taking up the study of the subject 
 by themselves will be able, by the use of the instruction given, to readily grasp the 
 subject, and by reasonable practice become good perspective draftsmen. The arrange- 
 ment of the book is good; the plate is on the left-hand, while the descriptive text 
 follows on the opposite page, so as to be readily referred to. The drawings are on 
 sufficiently large scale to show the work clearly and are plainly figured. There is 
 included a self-explanatory chart which gives all information necessary for the thorough 
 understanding of perspective. This chart alone is worth many times over the price of 
 the book. 2d Revised and enlarged Edition $2.5O 
 
 SELF-TAUGHT MECHANICAL DRAWING AND ELEMENTARY MACHINE 
 DESIGN. By F. L. SYLVESTER, M.E., Draftsman, with additions by ERIK 
 OBERG, associate editor of "Machinery." 
 
 This is a practical treatise on Mechanical Drawing and Machine Design, comprising 
 the first principles of geometric and mechanical drawing, workshop mathematics, 
 mechanics, strength of materials and the calculations and design of machine details. 
 The author's aim has been to adapt this treatise to the requirements of the practical 
 mechanic and young draftsman and to present the matter in as clear and concise a 
 manner as possible. To meet the demands of this class of students, practically all the 
 important elements of machine design have been dealt with, and in addition algebraic 
 formulas have been explained, and the elements of trigonometry treated in the manner 
 best suited to the needs of the practical man. The book is divided into 20 chapters, 
 and in arranging the material, mechanical drawing, pure and simple, has been taken 
 up first, as a thorough understanding of the principles of representing objects facilitates 
 the further study of mechanical subjects. This is followed by the mathematics neces- 
 sary for the solution of the problems in machine design which are presented later, and 
 a practical introduction to theoretical mechanics and the strength of materials. The 
 various elements entering into machine design, such as cams, gears, sprocket-wheels, 
 cone pulleys, bolts, screws, couplings, clutches, shafting and fly-wheels, have been 
 treated in such a way as to make possible the use of the work as a text-book for a 
 continuous course of study. It is easily comprehended and assimilated even by 
 students of limited previous training. 330 pages, 2 15 engravings. Price . . $2.50 
 
 A NEW SKETCHING PAPER. 
 
 A new specially ruled paper to enable you to make sketches or drawings in isometric 
 perspective without any figuring or fussing. It is being used for shop details as well 
 as for assembly drawings, as it makes one sketch do the work of three, and no workman 
 can help seeing just what is wanted. Pads of 40 sheets, 6x9 inches, 25 cents. Pads 
 of 40 sheets. 9x12 inches, 50 cents; 40 sheets, 12x18, Price $1.00 
 
 ELECTRICITY 
 
 ARITHMETIC OF ELECTRICITY. By Prof. T. O'CoNOR SLOANE. 
 
 A practical treatise on electrical calculations of all kinds reduced to a series of rules, all 
 of the simplest forms, and involving only ordinary arithmetic; each rule illustrated 
 by one or more practical problems, with detailed solution of each one. This book is 
 classed among the most useful works published on the science of electricity, covering 
 as it does the mathematics of electricity in a manner that will attract the attention 
 of those who are not familiar with algebraical formulas. 20th Edition. 160 pages.
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 COMMUTATOR CONSTRUCTION. By WM. BAXTER, JR. 
 
 The business end of any dynamo or motor of the direct current type is the commutator. 
 This book goes into the designing, building, and maintenance of commutators, showa 
 how to locate troubles and how to remedy them; everyone who fusses with dynamos 
 needs this. 4th Edition 35 cents 
 
 DYNAMO BUILDING FOR AMATEURS, OR HOW TO CONSTRUCT A 
 FIFTY- WATT DYNAMO. By ARTHUR J. WEED, Member of N. Y. Electrical 
 Society. 
 
 A practical treatise showing in detail the construction of a small dynamo or motor, the 
 entire machine work of which can be done on a small foot lathe. Dimensioned working 
 drawings are given for each piece of machine work, and each operation is clearly 
 described. This machine, when used as a dynamo, has an output of fifty watts; when 
 used as a motor it will drive a small drill press or lathe. It can be used to drive a 
 sewing machine on any and all ordinary work. The book is illustrated with more 
 than sixty original engravings showing the actual construction of the different parts. 
 Among the contents are chapters on: 1. Fifty-Watt Dynamo. 2. Side Bearing 
 Rods. 3. Field Punching. 4. Bearings. 5. Commutator. 6. Pulley. 7. Brush 
 Holders. 8. Connection Board. 9. Armature Shaft. 10. Armature. 11. Armature 
 Winding. 12. Field Winding. 13. Connecting and Starting. Price, cloth, $1.0O 
 
 ELECTRIC WIRING, DIAGRAMS AND SWITCHBOARDS. By NEWTON 
 HARRISON. 
 
 A thoroughly practical treatise covering the subject of Electric Wiring in all its branches, ' 
 including explanations and diagrams which are thoroughly explicit and greatly simplify 
 the subject. Practical, every-day problems in wiring are presented and the method 
 of obtaining intelligent results clearly shown. Only arithmetic is used. Ohm's law 
 is given a simple explanation with reference to wiring for direct and alternating 
 currents. The fundamental principle of drop of potential in circuits is shown with its 
 various applications. The simple circuit is developed with the position of mains, 
 feeders and branches; their treatment as a part of a wiring plan and their employ- 
 ment in house wiring clearly illustrated. Some simple facts about testing are included 
 in connection with the wiring. Molding and conduit work are given careful considera- 
 tion; and switchboards are systematically treated, built up and illustrated, showing 
 the purpose they serve, for connection with the circuits, and to shunt and compound 
 wound machines. The simple principles of switchboard construction, the develop- 
 ment of the switchboard, the connections of the various instruments, including the 
 lightning arrester, are also plainly set forth. 
 
 Alternating current wiring is treated, with explanations of the power factor, conditions 
 calling for various sizes of wire, and a simple way of obtaining the sizes for single-phase, 
 two-phase and three-phase circuits. This is the only complete work issued showing 
 and telling you what you should know about direct and alternating current wiring. It 
 is a ready reference. The work is free from advanced technicalities and mathematics, 
 arithmetic being used throughout. It is in every respect a handy, well-written, 
 instructive, comprehensive volume on wiring for the wireman, foreman, contractor, 
 or electrician. 272 pages; 105 illustrations. Price $2.0O 
 
 ELECTRIC FURNACES AND THEIR INDUSTRIAL APPLICATIONS. By 
 J. WRIGHT. 
 
 This is a book which will prove of interest to many classes of people: the manufacturer 
 who desires to know what product can be manufactured successfully in the electric 
 furnace, the] chemist who wishes to post himself on electro - chemistry, and the 
 student of science who merely looks into the subject from curiosity. New revised 
 and enlarged edition. 320 pages. Fully illustrated. Cloth. Price . . $3.50 
 
 ELECTRIC TOY MAKING, DYNAMO BUILDING, AND ELECTRIC MOTOR 
 CONSTRUCTION. By Prof. T. O'CoNOR SLOANE. 
 
 This work treats of the making at home of electrical toys, electrical apparatus, motors, 
 dynamos and instruments in general, and is designed to bring within the reach of 
 young and old the manufacture of genuine and useful electrical appliances. The work 
 is especially designed for amateurs and young folks. 
 
 Thousands of our young people are daily experimenting, and busily engaged in making 
 electrical toys and apparatus of various kinds. The present work is just what is want- 
 ed to give the much needed information in a plain,practical manner, with illustrations 
 to make easy the carrying out of the work. 20th Edition. Price .... $1.00 
 
 PRACTICAL ELECTRICITY. By Prof. T. O'CONOR SLOANE. 
 
 This work of 768 pages was previously known as Sloane's Electricians' Hand Book, and 
 is intended for the practical electrician who has to make things go. The entire 
 
 15
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 field of electricity is covered within its pages. Among some of the subjects treated 
 are: The Theory of the Electric Current and Circuit, Electro-Chemistry, Primary 
 Batteries, Storage Batteries, Generation and Utilization of Electric Powers, Alter- 
 nating Current, Armature Winding, Dynamos and Motors, Motor Generators. 
 Operation of the Central Station Switchboards, Safety Appliances, Distribution 
 of Electric Light and Power, Street Mains, Transformers, Arc and Incandescent 
 Lighting, Electric Measurements, Photometry, Electric Rtulways, Telephony, Bell- 
 Wiring, Electric-Plating, Electric Heating, Wireless Telegraphy, etc. It contains no 
 useless theory; everything is to the point. It teaches you just what you want to 
 know about electricity. It is the standard work published on the subject. Forty- 
 one chapters, 556 engravings. Price $3.50 
 
 ELECTRICITY SIMPLIFIED. By Prof. T. O'CoNOR SLOANE. 
 
 The object of "Electricity Simplified" is to make the subject as plain as possible and 
 to show what the modern conception of electricity is; to show how two plates of 
 different metal, immersed in acid, can send a message around the globe; to explain 
 how a bundle of copper wire rotated by a steam engine can be the agent in lighting 
 our streets, to tell what the volt, ohm and ampere are, and what high and low tension 
 mean; and to answer the questions that perpetually arise in the mind in this age of 
 electricity. 13th Edition. 172 pages. Illustrated. Price $1.00 
 
 HOUSE WIRING. By THOMAS W. POPPE. 
 
 This work describes and illustrates the actual installation of Electric Light Wiring, 
 the manner in which the work should be done, and the method of doing it. The book 
 can be conveniently carried in the pocket. It is intended for the Electrician, Helper 
 and Apprentice. It solves all Wiring Problems and contains nothing that conflicts 
 with the rulings of the National Board of Fire Underwriters. It gives just the informa- 
 tion essential to the Successful Wiring of a Building. Among the subjects treated are: 
 Locating the Meter. Panel Boards. Switches. Plug Receptacles. Brackets. Ceiling 
 Fixtures. The Meter Connections. The Feed Wires. The Steel Armored Cable 
 System. The Flexible Steel Conduit System. The Ridig Conduit System. A digest 
 of the National Board of Fire Underwriters' rules relating to metallic wiring systems. 
 Various switching arrangements explained and diagrammed. The easiest method of 
 testing the Three- and Four-way circuits explained. The grounding of all metallic 
 wiring systems and the reason for doing so shown and explained. The insulation of 
 the metal parts of lamp fixtures and the reason for the same described and illustrated. 
 125 pages. 2nd Edition, revised and enlarged. Fully illustrated. Flexible cloth. 
 Price 60 cents 
 
 WHAT IS SAID OF THIS BOOK: 
 
 " The information given is exact and exhaustive without being too technical or over- 
 laden with details." Druggists' Circular. 
 
 HOW TO BECOME A SUCCESSFUL ELECTRICIAN. By Prof. T. O'CoNOH 
 SLOANE. 
 
 Every young man who wishes to become a successful electrician should read this book. 
 It tells in simple language the surest and easiest way to become a successful electrician. 
 The studies to be followed, methods of work, field of operation and the requirements 
 of the successful electrician are pointed out and fully explained. Every young en- 
 gineer will find this an excellent stepping stone to more advanced works on electricity 
 which he must master before success can be attained. Many young men become dis- 
 couraged at the very outstart by attempting to read and study books that are far 
 beyond their comprehension. This book serves as the connecting link between the 
 rudiments taught hi the public schools and the real study of electricity. It is inter- 
 esting from cover to cover. Eighteenth Revised Edition, just issued. 205 pages. 
 Illustrated. Price $1.00 
 
 STANDARD ELECTRICAL DICTIONARY. By T. O'CONOR SLOANE. 
 
 An indispensable work to all interested in electrical science. Suitable alike for the 
 student and professional. A practical handbook of reference containing definitions 
 of about 5,000 distinct words, terms and phrases. The definitions are terse and 
 concise and include every term used in electrical science. Recently issued. An en- 
 tirely new edition. Should be in the possession of all who desire to keep abreast with 
 the progress of this branch of science. In its arrangement and typography the book 
 is very convenient. The word or term defined is printed in black-faced type which 
 readily catches the eye, while the body of the page is in smaller but distinct type. The 
 definitions are well worded, and so as to be understood by the non-technical reader. 
 The general plan seems to be to give an exact, concise definition, and then amplify 
 and explain in a more popular way. Synonyms are also given, and references to other 
 words and phrases are made. A very complete and accurate index of fifty pages is 
 at the end of the volume; and as this index contains all synonyms, and as all phrases 
 
 j6
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 are indexed in every reasonable combination of words, reference to the proper place 
 in the body of the book is readily made. It is dimcult to decide how far a book of 
 this character is to keep the dictionary form, and to what extent it may assume the 
 encyclopedia form. For some purposes, concise, exactly worded definitions are needed ; 
 for other purposes, more extended descriptions are required. This book seeks to satisfy 
 both demands, and does it with considerable success. Complete, concise and con- 
 venient. 682 pages. 393 illustrations. Twelfth Edition. Price .... $3.00 
 
 SWITCHBOARDS. By WILLIAM BAXTER, JR. 
 
 This book appeals to every engineer and electrician who wants to knew the practical 
 side of things. It takes up all sorts and conditions of dynamos, connections and 
 circuits, and shows by diagram and illustration just how the switchboard should be 
 connected. Includes direct and alternating current boards, also those for arc lighting, 
 incandescent and power circuits. Special treatment on high voltage boards for power 
 transmission. 2d Edition. 19O pages. Illustrated. Price $2.00 
 
 TELEPHONE CONSTRUCTION, INSTALLATION, WIRING, OPERATION 
 AND MAINTENANCE. By W. H. RADCLIFFE and H. C. GUSHING. 
 
 This book is intended for the amateur, the wireman, or the engineer who desires to 
 establish a means of telephonic communication between the rooms of his home, office, 
 or shop. It deals only with such things as may be of use to him rather than with 
 theories. 
 
 Gives the principles of construction and operation of both the Bell and Independent 
 instruments : approved methods of installing and wiring them ; the means of protecting 
 them from lightning and abnormal currents; their connection together for operation 
 as series or bridging stations ; and rules for their inspection and maintenance. Line 
 wiring and the wiring and operation of special telephone systems are also treated. 
 Intricate mathematics are avoided, and all apparatus, circuits and systems are thor- 
 oughly described. The appendix contains definitions of units and terms used in the 
 text. Selected wiring tables, which are very helpful, are also included. Among the 
 subjects treated are Construction, Operation, and Installation of Telephone Instru- 
 ments; Inspection and Maintenance of Telephone Instruments; Telephone Line 
 Wiring; Testing Telephone Line Wires and Cables ; Wiring and Operation of Special 
 Telephone Systems, etc. 2nd Edition, revised and enlarged. 223 pages. 154 
 illustrations $1.25 
 
 WIRELESS TELEGRAPHY AND TELEPHONY SIMPLY EXPLAINED. By 
 ALFRED P. MORGAN. 
 
 This is undoubtedly one of the most complete and comprehensible treatises on the 
 subject ever published, and a close study of its pages will enable one to master all the 
 details of the wireless transmission of messages. The author has filled a long-felt 
 want and has succeeded in furnishing a lucid, comprehensible explanation in simple 
 language of the theory and practice of wireless telegraphy and telephony. 
 Among the contents are: Introductory; Wireless Transmission and Reception The 
 Aerial System, Earth Connections The Transmitting Apparatus, Spark Coils and 
 Transformers; Condensers, Helixes, Spark Gaps, Anchor Gaps, Aerial Switches The 
 Receiving Apparatus, Detectors, etc. Tuning and Coupling, Tuning Coils, Loose 
 Couplers, Variable Condensers, Directive Wave Systems Miscellaneous Apparatus, 
 Telephone Receivers, Range of Stations, Static Interference Wireless Telephones, 
 Sound and Sound Waves, The Vocal Cords and Ear Wireless Telephone, How Sounds 
 Are Changed into Electric Waves Wireless Telephones, The Apparatus Summary. 
 154 pages. 156 engravings. Price $1.25 
 
 WHAT IS SAID OF THIS BOOK: 
 "This book should be in both the home and school library." The Youths' Instructor. 
 
 WIRING A HOUSE. By HERBERT PRATT. 
 
 Shows a house already built; tells just how to start about wiring it; where to begin; 
 what wire to use; how to run it according to Insurance Rules; in fact, just the informa- 
 tion you need. Directions apply equally to a shop. Fourth edition . . 35 cents 
 
 RADIO TIME SIGNAL RECEIVER. By AUSTIN C. LESCARBOURA. 
 
 This new book, "A Radio Time Signal Receiver," tells you how to build a simple 
 outfit designed expressly for the beginner. You can build the outfits ii> your own 
 workshop and install them for jewelers either on a one-payment or a rental basis. 
 The apparatus is of such simple design that it may be made by the average amateur 
 mechanic possessing a few ordinary tools. 42 pages. Paper. Price . . 35 cents 
 
 17
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 CONSTRUCTION OF A TRANSATLANTIC WIRELESS RECEIVING SET. 
 By L. G. PACENT and T. S. CURTIS. 
 
 A work for the Radio student who desires to construct and operate apparatus that 
 will permit of the reception of messages from the large stations in Europe with an 
 aerial .of amateur proportions. 36 pages. 23 illustrations, cloth. Price . 35 cents 
 
 ELECTRIC BELLS. By M. B. SLEEPER. 
 
 A complete treatise for the practical worker in installing, operating, and testing 
 bell circuits, burglar alarms, thermostats, and other apparatus used with electric 
 bells. Both the electrician and the experimenter will find in this book new material 
 which is essential in their work. Tools, bells, batteries, unusual circuits, burglar 
 alarms, annunciators, systems, thermostats, circuit breakers, time alarms, and other 
 apparatus used in bell circuits are described from the standpoints of their applica- 
 tion, construction, and repair. The detailed instructions for building the apparatus 
 will appeal to the experimenter particularly. The practical worker will find the 
 chapters on Wiring Calculation of Wire Sizes and Magnet Windings, Upkeep of 
 Systems and the Location of Faults of the greatest value in their work. 124 pages. 
 Fully illustrated. Price 60 cents 
 
 EXPERIMENTAL HIGH FREQUENCY APPARATUS HOW TO MAKE 
 AND USE IT. By THOMAS STANLEY CURTIS. 
 
 This book tells you how to build simple high frequency coils for experimental purpose 
 in the home, school laboratory, or on the small lecture platform. The book is really 
 a supplement to the same author's "High Frequency Apparatus." The experimental 
 side only is covered in this volume, which is intended for those who want to build 
 
 small coils giving up to an eighteen-inch spark. The book contains valuable in- 
 formatipn for the physics or the manual training teacher who is on the lookout for 
 interesting projects for his boys to build or experiment with. The apparatus is 
 
 simple, cheap and perfectly safe, and with it some truly startling experiments may be 
 performed. Among the contents are: Induction Coil Outfits Operated on Battery 
 Current. Kicking Coil Apparatus. One-Half Kilowatt Transformer Outfit. Parts 
 and Materials, etc., etc. 69 pages. Illustrated. Price 50 cents 
 
 HIGH FREQUENCY APPARATUS, ITS CONSTRUCTION AND PRACTICAL 
 APPLICATION. By THOMAS STANLEY CURTIS. 
 
 The most comprehensive and thorough work on this interesting subject ever produced. 
 The book is essentially practical in its treatment and it constitutes an accurate record 
 of the researches of its author over a period of several years, during which time dozens 
 of coils were built and experimented with. The work has been divided into six basic 
 parts. The first two chapters tell the uninitiated reader what the high frequency 
 current is, what it is used for, and how it is produced. The second section, comprising 
 four chapters, describes in detail the principles of the transformer, condenser, spark 
 gap, and oscillation transformer, and covers the main points in the design and con- 
 struction of these devices as applied to the work in hand. The third section covers 
 the construction of small high frequency outfits designed for experimental work in the 
 home laboratory or in the classroom. The fourth section is devoted to electro- 
 therapeutic and X-Ray apparatus. The fifth describes apparatus for the cultivation 
 of plants and vegetables. The sixth section is devoted to a comprehensive discussion 
 of apparatus of large size for use upon the stage in spectacular productions. The 
 closing chapter, giving the current prices of the parts and materials required for the 
 construction of the apparatus described, is included with a view to expediting the 
 purchase of the necessary goods. 248 pages. Fully illustrated. Price . $2.50 
 
 STORAGE BATTERIES SIMPLIFIED. BY VICTOR W. PAGE, M.S.A.E. 
 
 *( A complete treatise on storage battery operating principles, repairs and applications. 
 The greatly increasing application of storage batteries in modern engineering and 
 mechanical work has created a demand for a book that will consider this subject 
 completely and exclusively. This is the most thorough and authoritative treatise 
 ever published on this subject. It is written in easily understandable, non-technical 
 language so that any one may grasp the basic principles of storage battery action as 
 well as their practical industrial applications. All electric and gasoline automobiles 
 use storage batteries. Every automobile repairman, dealer or salesman should have a 
 good knowledge of maintenance and repair of these important elements of the motor 
 car mechanism. This book not only tells how to charge, care for and rebuild storage 
 batteries but also outlines all the industrial uses. Learn how they run street cars, 
 locomotives and factory trucks. Get an understanding of the important functions they 
 perform in submarine boats, isolated lighting plants, railway switch and signal systems, 
 marine applications, etc. This book tells how they are used in central station standby 
 service, for starting automobile motors and in ignition systems. Every practical use 
 of the modern storage battery is outlined in this treatise. 
 
 18
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 Chapters contained are: Chapter 1 Storage Battery Development Types of Storage 
 Batteries Lead Plate Types The Edison Cell. Chapter 2 Storage Battery 
 Construction Plates and Grids Plante Plates Faure Plates Non-Lead Plates 
 Commercial Battery Designs. Chapter 3 Charging Methods Rectifiers Con- 
 verters Rheostats Rules for Charging. Chapter 4 Battery Repairs and Main- 
 tenance. Chapter 5 Industrial Application of Storage Batteries Glossary of 
 Storage Battery Terms. 320 pages. Fully illustrated. Price .... $2.00 
 
 FACTORY MANAGEMENT, ETC. 
 
 MODERN MACHINE SHOP CONSTRUCTION, EQUIPMENT AND 
 MANAGEMENT. By O. E. PERRIGO, M.E. 
 
 The only work published that describes the modern machine shop or manufacturing 
 plant from the time the grass is growing on the site intended for it until the finished 
 product is shipped. By a careful study of its thirty-two chapters the practical man 
 may economically build, efficiently equip, and successfully manage the modern machine 
 shop or manufacturing establishment. Just the book needed by those contemplating 
 the erection of modern shop buildings, the rebuilding and reorganization of old ones, 
 or the introduction of modern shop methods, time and cost systems. It is a book 
 written and illustrated by a practical shop man for practical shop men who are too 
 busy to read theories and want facts. It is the most complete all-around book of its 
 kind ever published. It is a practical book for practical men, from the apprentice in 
 the shop to the president in the office. It minutely describes and illustrates the most 
 simple and yet the most efficient time and cost system yet devised. Price . $5.00 
 
 FUEL 
 
 COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By WM. 
 
 M. BARR. 
 
 This book has been prepared with special reference to the generation of heat by the 
 combustion of the common fuels found in the United States, and deals particularly 
 with the conditions necessary to the economic and smokeless combustion of bituminous 
 coals in Stationary and Locomotive Steam Boilers. 
 
 The presentation of this important subject is systematic and progressive. The ar- 
 rangement of the book is in a series of practical questions to which are appended 
 accurate .answers, which describe in language, free from technicalities, the several 
 processes involved in the furnace combustion of American fuels; it clearly states the 
 essential requisites for perfect combustion, and points out the best methods for furnace 
 construction for obtaining the greatest quantity of heat from any given quality of 
 coal. Nearly 350 pages, fully illustrated. Price $1.25 
 
 SMOKE PREVENTION AND FUEL ECONOMY. By BOOTH and KERSHAW. 
 
 As the title indicates, this book of 197 pages and 75 illustrations deals with the prob- 
 lem of complete combustion, which it treats from the chemical and mechanical 
 standpoints, besides pointing out the economical and humanitarian aspects of the 
 question. Price $3.00 
 
 GAS ENGINES AND GAS 
 
 THE GASOLINE ENGINE ON THE FARM: ITS OPERATION, REPAIR 
 AND USES. By XENO W. PUTNAM. 
 
 This is a practical treatise on the Gasoline and Kerosene Engine intended for the man 
 who wants to know just how to manage his engine and how to apply it to all kinds of 
 farm work to the best advantage. 
 
 This book abounds with hints and helps for the farm and suggestions for the home 
 and housewife. There is so much of value in this book that it is impossible to ade- 
 quately describe it in such small space. Suffice to say that it is the kind of a book 
 every farmer will appreciate and every farm home ought to have. Includes selecting 
 the most suitable engine for farm work, its most convenient and efficient installation, 
 with chapters on troubles, their remedies, and how to avoid them. The care and 
 management of the farm tractor in plowing, harrowing, harvesting and road grading 
 are fully covered ; also plain directions are given for handling the tractor on the road. 
 Special attention is given to relieving farm life of its drudgery by applying power to 
 
 19
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS _ 
 
 the disagreeable small tasks which must otherwise be done by hand. Many home- 
 made contrivances for cutting wood, supplying kitchen, garden, and barn with water, 
 loading, hauling and unloading hay, delivering grain to the bins or the feed trough 
 are included; also full directions for making the engine milk the cows, churn, wash, 
 
 are ncue; also u rectons or mang te engine milk the cows, churn, wash, 
 sweep the house and clean the windows, etc. Very fully illustrated with drawings of 
 working parts and cuts showing Stationary, Portable and Tractor Engines doing all 
 kinds of farm w6rk. All money-making farms utilize power. Learn how to utilize 
 power by reading the pages of this book. It is an aid to the result getter, invaluable 
 to the up-to-date fanner, student, blacksmith, implement dealer pjid, in fact, all who 
 can apply practical knowledge of stationary gasoline engines or gas tractors to advan- 
 tage. 530 pages. Nearly 180 engravings. Price. . ........ $2.50 
 
 -making farms utilize powe 
 
 power by reading the pages of this book. It is an aid to the result getter, invaluable 
 to the up-to-date farmer, student, blacksmith, implement dealer rjid, in fact, all who 
 can apply practical knowledge of stationary gasoline engines or gas tractors to advan- 
 tage. 530 pages. Nearly 180 engravings. Price. $2.50 
 
 WHAT IS SAID OF THIS BOOK: 
 
 "Am much pleased with the book and find it to be very complete and up-to-date. 
 I will heartily recommend it to students^and farmers whom I think would stand in 
 need of such a work, as I think it is an exceptionally good one." N. S. Gardiner 
 Prof, in Charge, Clemson Agr. College of S. C.; Dept. of Agri. and Agri. Exp. Station. 
 Clemson College. S. C. 
 
 "I feel that Mr. Putnam's book covers the main points which a farmer should know." 
 R. T. Burdick, Instructor in Agronomy, University of Vermont, Burlington, Vt. 
 "It will be a valuable addition to our library upon Farm Machinery." James A. 
 Farra, Inst. hi Agri. Engineering, State University of Ky., Lexington, Ky. 
 
 GASOLINE ENGINES : THEIR OPERATION, USE AND CARE. By A. HYATT 
 VERRILL. 
 
 The simplest, latest and most comprehensive popular work published on Gasoline 
 Engines, describing what the Gasoline Engine is ; its construction and operation ; how 
 to install it; how to select it; how to use it and how to remedy troubles encountered. 
 Intended for Owners, Operators and Users of Gasoh'ne Motors of all kinds. This 
 work fully describes and illustrates the various types of Gasoline Engines used in 
 Motor Boats, Motor Vehicles and Stationary Work. The parts, accessories and 
 appliances are described, with chapters on ignition, fuel, lubrication, operation and 
 engine troubles. Special attention is given to the care, operation and repair of motors, 
 with useful hints and suggestions on emergency repairs and makeshifts. A complete 
 glossary of technical terms and an alphabetically arranged table of troubles and their 
 symptoms ferm most valuable and unique features of this manual. Nearly every 
 illustration in the book is original, having been made by the author. Every page is 
 full of interest and value. A book which you cannot afford to be without. 275 pages. 
 152 specially made engravings. Price $2.00 
 
 GAS, GASOLINE,i AND OIL ENGINES.^ By GARDNER D. Hiscox. 
 
 Just issued, 22d revised and enlarged edition. Every user of a gas engine needs this 
 book. Simple, instructive, and right up-to-date. The only complete work on the 
 subject. Tells all about the running and management of gas, gasoline and oil engines, 
 as designed and manufactured in the United States. Explosive motors for stationary 
 marine and vehicle power are fully treated, together with illustrations of their parts 
 and tabulated sizes, also their care and running are included. Electric ignition by 
 induction coil and jump spark are fully explained and illustrated, including valuable 
 information on the testing for economy and power and the erection of power plants. 
 The rules and regulations of the Board of Fire Underwriters in regard to the installation 
 and management of gasoline motors are given in full, suggesting the safe installation 
 of explosive motor power. A list of United States Patents issued on gas, gasoline, and 
 oil engines and their adjuncts from 1875 to date is included. 640 pages. 435 engrav- 
 ings. Folding plates. Price $3.00 
 
 GAS ENGINE CONSTRUCTION, OR HOW TO BUILD A HALF-HORSE- 
 POWER GAS ENGINE. By PARSELL and WEED. 
 
 A practical treatise of 300 pages describing the theory and principles of the action of 
 Gas Engines of various types and the design and construction of a half-horse-power 
 Gas Engine, with illustrations of the work in actual progress, together with the dimen- 
 sioned working drawings, givmg clearly the sizes of the various details: for the student. 
 the scientific investigator, and the amateur mechanic. This book treats of the subject 
 more from the standpoint of practice than that of theory. The principles of operation 
 of Gas Engines are clearly and simply described, and then the actual construction of a 
 half-horse-power engine is taken up, step by step, showing in detail the making of the 
 Gas Engine. 3d Edition. 300 pages. Price $3.00 
 
 HOW TO RUN AND INSTALL GASOLINE ENGINES. By C. VON CULIN. 
 Revised and enlarged edition 'just issued. The object of this little book is to furnish 
 a pocket instructor for the beginner, the busy man who uses an engine for pleasure or 
 profit, but who does not have the tune or inclination for a technical book, but simply 
 
 20
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 to thoroughly understand how to properly operate, install and care for his own engine. 
 The index refers to each trouble, remedy, and subject alphabetically. Being a quick 
 reference to find the cause, remedy and prevention for troubles, and to become an 
 expert with his own engine. Pocket size. Paper binding. Price . . 25 cents 
 
 MODERN GAS ENGINES AND PRODUCER GAS PLANTS. By R. E. 
 
 MATHOT. 
 
 A guide for the gas engine designer, user, and engineer in the construction, selection, 
 purchase, installation, operation, and maintenance of gas engines. More than one 
 book on gas engines has been written, but not one has thus far even encroached on the 
 field covered by this book. Above all Mr. Mathot's work is a practical guide. Recog- 
 nizing the need of a volume that would assist the gas engine user in understanding 
 thoroughly the motor upon which he depends for power, the author has discussed his 
 subject without the help of any mathematics and without elaborate theoretical ex- 
 planations. Every part of the gas engine is described in detail, tersely, clearly, with 
 a thorough understanding of the requirements of the mechanic. Helpful suggestions 
 as to the purchase of an engine, its installation, care, and operation, form a most 
 valuable feature of the work. 320 pages. 175 detailed illustrations. Price . $3.00 
 
 THE MODERN GAS TRACTOR. By VICTOR W. PAGE. 
 
 A complete treatise describing all types and sizes of gasoline, kerosene and oil tractors. 
 Considers design and construction exhaustively, gives complete instructions for care, 
 operation and repair, outlines all practical applications on the road and in the field. 
 The best and latest work on farm tractors and tractor power plants. A work needed 
 by farmers, students, blacksmiths, mechanics, salesmen, implement dealers, designers 
 and engineers. 500 pages. Nearly 300 illustrations and folding plates. Price $2.50 
 
 CHEMISTRY OF GAS MANUFACTURE. By H. M. ROYLES. 
 
 This book covers points likely to arise in the ordinary course of the duties of the 
 engineer or manager of a gas works not large enough to necessitate the employment 
 of a separate chemical staff. It treats of the testing of the raw materials employed 
 in the manufacture of illuminating coal gas and of the gas produced. The preparation 
 of standard solutions is given as well as the chemical and physical examination of gas 
 coal. 5% x 8%. Cloth, 328 pages. 82 illustrations, 1 colored plate. Price $5.00 
 
 GEARING AND CAMS 
 
 BEVEL GEAR TABLES. By D. Ao. ENGSTROM. 
 
 A book that will at once commend itself to mechanics and draftsmen. Does away 
 with all the trigonometry and fancy figuring on bevel gears, and makes it easy for any- 
 one to lay them out or make them just right. There are 36 full-page tables that 
 show every necessary dimension for all sizes or combinations you're apt to need. No 
 puzzling, figuring or guessing. Gives placing distance, all the angles (including 
 cutting angles), and the correct cutter to use. A copy of this prepares you for any- 
 thing in the bevel-gear line. 3d Edition. 66 pages $1.25 
 
 CHANGE GEAR DEVICES. By OSCAR E. PERRIGO. 
 
 A practical .book for every designer, draftsman, and mechanic interested in the inven- 
 tion and development of the devices for feed changes on the different machines requir- 
 ing such mechanism. All the necessary information on this subject is taken up, 
 analyzed, classified, sifted, and concentrated for the use of busy men who have not the 
 time to go through the masses of irrelevant matter with which such a subject is usu- 
 ally encumbered and select such information as will be useful to them. 
 It shows just what has been d9ne, how it has been done, when it was done, and who 
 did it. It saves time in hunting up patent records and re-inventing old ideas. 88 
 pages $1.25 
 
 DRAFTING OF CAMS. By Louis ROUILLION. 
 
 The laying out of cams is a serious problem unless you know how to go at it right. 
 This puts you on the right road for practically any kind of cam you are likely to run 
 up against. 3d Edition 35 cents 
 
 HYDRAULICS 
 
 HYDRAULIC ENGINEERING. By GARDNER D. Hiscox. 
 
 A treatise on the properties, power, and resources of water for all purposes. Including 
 the measurement of streams, the flow of water in pipes or conduits ; the horse-power 
 of falling water, turbine and impact water-wheels, wave motors, centrifugal, recipro- 
 
 21
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 eating! and air-lift pumps. With 300 figures and diagrams and 30 practical tables. 
 All who are interested in water-works development will find this book a useful one, 
 because it is an entirely practical treatise upon a subject of present importance, and 
 cannot fail in having a far-reachiag influence, and for this reason should nave a place 
 in the working library of every engineer. Among the subjects treated are: Historical 
 Hydraulics, Properties of Water, Measurement of the Flow of Streams; Flow 
 from Sub-surface Orilices and Nozzles; Flow of Water in Pipes: Siphons of Various 
 Kinds: Dams and Great Storage Reservoirs: City and Town Water Supply; Wells 
 and Their Reinforcement; Air Lift Methods of Raising Water; Artesian Wells; 
 Irrigation of Arid Districts; Water Power; Water Wheels; Pumps and Pumping. 
 Machinery; Reciprocating Pumps; Hydraulic Power Transmission; Hydraulic 
 Mining; Canals; Ditches; Conduits and Pipe Lines; Marine Hydraulics; Tidal and 
 Sea Wave Power, etc. 320 pages. Price 94.5 O 
 
 ICE AND REFRIGERATION 
 
 POCKETBOOK OF REFRIGERATION AND ICE MAKING. By A. J. 
 
 WALLIS-TAYLOR. 
 
 This is one of the latest and most comprehensive reference books published on the 
 subject of refrigeration and cola storage. It explains the properties and refrigerating 
 effect of the different fluids in use, the management of refrigerating machinery and the 
 construction and insulation of cold rooms with their required pipe surface for different 
 degrees of cold: freezing mixtures and non-freezing brines, temperatures of cold rooms 
 for all kinds of provisions, cold storage charges for all classes of goods, ice making 
 and storage of ice, data'and memoranda for constant reference by refrigerating engineers, 
 with nearly one hundred tables containing valuable references to every fact and con- 
 dition required in the installment and operation of a refrigerating plant. New 
 edition just published. Price $2.00 
 
 INVENTIONS PATENTS 
 
 INVENTORS' MANUAL, HOW TO MAKE A PATENT PAY. 
 
 This is a book designed as a guide to inventors in perfecting their inventions, taking 
 out their patents and disposing of them. It is not infany sense a Patent Solicitor's 
 Circular nor a Patent Broker's Advertisement. No advertisements of any description 
 appear in the work. It is a book containing a quarter of a century's experience of a 
 successful inventor, together with notes based upon the experience of many other 
 inventors. 
 
 Among the subjects treated in this work are: How to Invent. How to Secure a 
 Good Patent. Value of Good Invention. How to Exhibit an Invention. How to 
 Interest Capital. How to Estimate the Value of a Patent. Value of Design Patents. 
 Value of Foreign Patents. Value of Small Inventions. Advice on Selling Patents. 
 Advice on the Formation of Stock Companies. Advice on the Formation of Limited 
 Liability Companies. Advice on Disposing of Old Patents. Advice as to Patent 
 Attorneys. Advice as to Selling Agents. Forms of Assignments. License and Con- 
 tracts. State Laws Concerning Patent Rights. 1900 Census of the United States by 
 Counts of Over 10,000 Population. New revised and enlarged edition. 144 pages. 
 Illustrated. Price 91.25 
 
 KNOTS 
 
 KNOTS, SPLICES AND ROPE WORK. By A. HYATT VERRILL. 
 
 This is a practical book giving complete and simple directions for making all the most 
 useful and ornamental knots hi common use, with chapters on Splicing, Pointing. 
 Seizing, Serving, etc. This book is fully illustrated with one hundred and fifty 
 original engravings, which show how each knot, tie or splice is formed, and its appear- 
 ance when finished. The book will be found of the greatest value to Campers, Yachts- 
 men, Travelers, Boy Scouts, in fact, to anyone having occasion to use or handle rope 
 or knots for any purpose. The book is thoroughly reliable and practical, and is not 
 only a guide, but a teacher. It is the standard work on the subject. Among the 
 contents are: 1. Cordage, Kinds of Rope. Construction of Rope, Parts of Rope 
 Cable and Bolt Rope. Strength of Rope, Weight of Rope. 2. Simple Knots and 
 
 and Hitches. 4. 
 
 . and Salvages. 6. 
 
 Lashings, Seizings and Splices. 7. Fancy Knots and Rope Work. 128 pages. 150 
 original engravings. Price 91.00
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 LATHE WORK 
 
 LATHE DESIGN, CONSTRUCTION, AND OPERATION, WITH PRACTICAL 
 EXAMPLES OF LATHE WORK. By OSCAR E. PEBRIGO. 
 A new revised edition, and the only complete American work on the subject, written 
 by a man who knows not only how work ought to be done, but who also knows how 
 to do it, and how to convey this knowledge to others. It is strictly up-to-date in its 
 descriptions and illustrations. Lathe history and the relations of the lathe to manu- 
 facturing are given; also a description of the various devices for feeds and thread 
 cutting mechanisms from early efforts in this direction to the present time. Lathe 
 design is thoroughly discussed, including back gearing, driving cones, thread-cutting 
 gears, and all the essential elements of the modern lathe. The classification of lathes 
 
 is taken up, giving the essential differences of the several types of lathes including, 
 as is usually understood, engine lathes, bench lathes, speed lathes, forge lathes, gap 
 lathes, pulley lathes, forming lathes, multip.e-spindle lathes, rapid-reduction lathes. 
 
 precision lathes, turret lathes, special lathes, electrically-driven lathes, etc. In addi- 
 tion to the complete exposition on construction and design, much practical matter on 
 lathe installation, care and operation has been incorporated in the enlarged 1915 edi- 
 tion. All kinds of lathe attachments for drilling, milling, etc., are described and 
 complete instructions are given to enable the novice machinist to grasp the art of lathe 
 operation as well as the principles involved in design. A number of difficult machining 
 operations are described at length and illustrated. The new edition has nearly 500 
 pages and 350 illustrations. Price . . .......... $3.00 
 
 WHAT IS SAID OF THIS BOOK: 
 
 " This is a lathe book from beginning to end, and is just the kind of a book which one 
 delights to consult, a masterly treatment of the subject in hand." Engineering Neics. 
 " This work will be of exceptional interest to anyone who is interested in lathe practice, 
 as one very seldom sees such a complete treatise on a subject as this is on the lathe." 
 Canadian Machinery. . 
 
 TURNING AND BORING TAPERS. By FRED H. COLVTN. 
 
 There are two ways to turn tapers; the right way and one other. This treatise has 
 to do with the right way; it tells you how to start the work properly, how to set the 
 lathe, what tools to use and how to use them, and forty and one other little things 
 that you should know. Fourth edition. Price ......... 35 cents 
 
 LIQUID AIR 
 
 LIQUID AIR AND THE LIQUEFACTION OF GASES. By T. O'CoxoR SLOANE. 
 
 This book gives the history of 'the theory, discovery, and manufacture of Liquid Air, 
 
 and contains an illustrated description of all the experiments that have excited the 
 
 wonder of audiences all over the country. It shows how liquid air, like water, is 
 
 carried hundreds of miles and is handled in open buckets. It tells what may be ex- 
 
 pected from it in the near future. 
 
 A book that renders simple one of the most perplexing chemical problems of the 
 
 century. Startling developments illustrated by actual experiments. 
 
 It is not only a work of scientific interest and authority, but is intended for the general 
 
 reader, being written in a popular style easily understood by every one. Second 
 
 edition. 365 pages. Price ................. $2.50 
 
 LOCOMOTIVE ENGINEERING 
 
 AIR-BRAKE CATECHISM. By ROBERT H. BLACKALL. 
 
 This book is a standard text book. It covers the "Westinshouse Air-Brake Equipment, 
 including the No. 5 and the No. 6 E. T. Locomotive Brake Equipment; the K (Quick 
 Service) Triple Valve for Freight Service; and the Cross-Compound Pump. The 
 operation of all parts of the apparatus is explained in detail, and a practical way of 
 finding their peculiarities and defects, with a proper remedy, is given. It contains 
 2,000 questions with their answers, which will enable any railroad man to pass any 
 examination on the subject of Air Brakes. Endorsed and used by air-brake instruc- 
 tors and examiners on nearly every railroad in the United States. 27th Edition. 411 
 pages, fully illustrated with colored plates and diagrams. Price ..... $3.50 
 
 23
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 AMERICAN COMPOUND LOCOMOTIVES. By FBED H. COLVIN. 
 
 The only book on compounds for the engineman or shopman that shows in a plain, 
 practical way the various features of compound locomotives in use. Shows how they 
 are made, what to do when they break down or balk. Contains sections as follows: 
 A Bit of History. Theory of Compounding Steam Cylinders. Baldwin Two-Cylinder 
 Compound. Pittsburg Two-Cylinder Compound. Rhode Island Compound. Rich- 
 mond Compound. Rogers Compound. Schenectady Two-Cylinder Compound. 
 Vauclain Compound. Tandem Compounds. Baldwin Tandem. The Colvin-Wight- 
 man Tandem. Schenectady Tandem. Balanced Locomotives. Baldwin Balanced 
 Compound. Plans for Balancing. Locating Blows. Breakdowns. Reducing Valves. 
 Drifting. Valve Motion. Disconnecting. Power of Compound Locomotives. Practi- 
 cal Notes. 
 
 Fully illustrated and containing ten special " Duotone" inserts on heavy Plate Paper, 
 showing different types of Compounds. 142 pages. Price $1.00 
 
 COMBUSTION OF COAL AND THE PREVENTION OF SMOKE. By WM. 
 M. BARR. 
 
 This book has been prepared with special reference to the generation of heat by the 
 combustion of the common fuels found in the United States and deals particularly 
 with the conditions necessary to the economic and smokeless combustion of bituminous 
 coal in Stationary and Locomotive Steam Boilers. 
 
 Presentation of this important subject is systematic and progressive. The ar- 
 rangement of the book is in a series of practical questions to which are appended 
 accurate answers, which describe in language free from technicalities the several 
 processes involved in the furnace combustion of American fuels; it clearly states the 
 essential requisites for perfect combustion, and points out the best methods of furnace 
 construction for obtaining the greatest quantity of heat from any given quality of 
 coal. Nearly 350 pages, fully illustrated. Price $ 1 .25 
 
 DIARY OF A ROUND-HOUSE FOREMAN. By T. S. REILLT. 
 
 This is the greatest book of railroad experienced ever published. Containing a fund of 
 information and suggestions along the line of handling men, organizing, etc.. that one 
 cannot afford to miss. 176 pages. Price _. $1.25 
 
 LINK MOTIONS, VALVES AND VALVE SETTING. By FRED H. COLVIN, 
 Associate Editor of American Machinist. 
 
 A handy book for the engineer or machinist that clears up the mysteries of valve 
 setting. Shows the different valve gears in use. how they work, and why. Piston 
 and slide valves of different types are illustrated and explained. A book that every 
 railroad man in the motive power department ought to have. Contains chapters on 
 Locomotive Link Motion, Valve Movements, Setting Slide Valves, Analysis by 
 Diagrams, Modern Practice, Slip of Block, Slice Valves, Piston Valves, Setting Piston 
 Valves, Joy-Allen Valve Gear, Walschaert Valve Gear, Gooch Valve Gear, Alfree- 
 Hubbell Valve Gear, etc., etc. Fully illustrated. Price SO.cents 
 
 LOCOMOTIVE BOILER CONSTRUCTION. By FRANK A. KLEINHANS. 
 
 The construction of boilers in general is treated, and, following this, the locomotive 
 boiler is taken up hi the order in which its various parts go through the shop. Shows 
 all types of boilers used ; gives details of construction ; practical facts, such as life of 
 riveting, punches and dies; work done per day, allowance for bending and flanging 
 sheets, and other data. Including the recent Locomotive Boiler Inspection Laws 
 and Examination Questions with their answers for Government Inspectors. Contains 
 chapters on Laying Out Work; Flanging and Forging; Punching; Shearing; Plate 
 Planing; General Tables; Finishing Parts; Bending; Machinery Parts; Riveting; 
 Boiler Details; Smoke Box Details; Assembling and Calking; Boiler Shop 
 Machinery, etc., etc. 
 
 There isn't a man who has anything to do with boiler work, either new or repair work, 
 who doesn't need this book. The manufacturer, superintendent, foreman, and boiler 
 worker all need it. No matter what the tyne of boiler, you'll find a mint of informa- 
 tion that you wouldn't be without. Over 400 pages, five large folding plates. 
 Price $3.50 
 
 LOCOMOTIVE BREAKDOWNS AND THEIR REMEDIES. By GEO. L. 
 FOWLER. Revised by WM. W. WOOD, Air-Brake Instructor. Just issued. 
 Revised pocket edition. 
 
 It is out of the question to try and tell you about every subject that is covered in this 
 pocket edition of Locomotive Breakdowns. Just imagine all the common troubles 
 that an engineer may expect to happen some time, and then add all of the unexpected 
 
 2 4
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 ones, troubles that could occur, but that you have never thought about, and you will 
 find that they are all treated with the very best methods of repair. Walschaert 
 Locomotive Valve Gear Troubles, Electric Headlight Troubles, as well as Questions 
 and Answers on the Air Brake are all included. 312 pages. 8th Bevised Edition. 
 Fully illustrated $1.25 
 
 LOCOMOTIVE CATECHISM. By ROBERT GBIMSHAW. 
 
 The revised edition of "Locomotive Catechism," by Robert Grimshaw, is a New Book 
 from Cover to Cover. It contains twice as many pages and double the number of 
 illustrations of previous editions. Includes the greatest amount of practical informa- 
 tion ever pubh'shed on the construction and management of modern locomotives. 
 Specially Prepared Chapters on the Walschaert Locomotive Valve Gear, the Alr- 
 Brake Equipment and the Electric Headlight are given. 
 
 It commends itself at once to every Engineer and Fireman, and to-all who are going in 
 for examination or promotion. In plain language, with full, complete answers, not only 
 all the questions asked by the examining engineer are given, but those which the 
 young and loss experienced would ask the veteran, and which old hands 
 
 is ask as "stick- 
 ers." It is a veritable Encyclopedia of the Locomotive, is entirely free from mathe- 
 
 matics, easily imderstood and thoroughly up-to-date. Contains over 4,000 Examina- 
 tion Questions with their Answers. 825 pages, 437 illustrations and three folding 
 plates. 2Sth Revised Edition. Price $2.50 
 
 and the Two-Cylinder Simple Engine; Compounding and Superheating; Designs of 
 Locomotive Superheaters; Constructive Details of Locomotives Using Hig~~ 
 Superheated Steam. Experimental and Working Results. Illustrated with folc 
 
 APPLICATION OF HIGHLY SUPERHEATED STEAM TO LOCOMOTIVES. 
 
 By ROBERT GARBE. 
 
 A practical book which cannot be recommended too highly to those motive-power 
 men who are anxious to maintain the highest efficiency in their locomotives. . Con- 
 tains special chapters on Generation of Highly Superheated Steam ; Superheated Steam 
 
 - - rheating; Designs of 
 tives Using Highly 
 strated with folding 
 plates and tables. Cloth. Price $3.0O 
 
 PRACTICAL INSTRUCTOR AND REFERENCE BOOK FOR LOCOMOTIVE 
 FIREMEN AND ENGINEERS. By CHAS. F. LOCKHART. 
 An entirely new book on the Locomotive. It appeals to every railroad man, as it 
 tells him how things are done and the right way to do them. Written by a man who 
 has had years of practical experience in locomotive shops and on the road firing and 
 running. The information given in this book cannot be found in any other similar 
 treatise. Eight hundred and fifty-one questions with their answers are included, 
 which will prove specially helpful to those preparing for examination. Practical 
 information on: The Construction and Operation of Locomotives; Breakdowns and 
 their Remedies; Air Brakes and Valve Gears. Rules and Signals are handled in a 
 thorough manner. As a book of reference it cannot be excelled. The book is divided 
 into six parts, as follows: 1. The Fireman's Duties. 2. General Description of the 
 Locomotive. 3. Breakdowns and their Remedies. 4. Air Brakes. 5. Extracts 
 from Standard Rules. 6. Questions for Examination. The 851 questions have been 
 carefulty selected and arranged. These cover the examinations required by the 
 different railroads. 368 pages. 88 illustrations. Price $2.0O 
 
 PREVENTION OF RAILROAD ACCIDENTS, OR SAFETY IN RAILROADING. 
 
 By GEORGE BRADSHAW. 
 
 This book is a heart-to-heart talk with Railroad Employees, dealing with facts, not 
 theories, and showing the men in the ranks, from every-day experience, how accidents 
 occur and how they may be avoided. The book is illustrated with seventy original 
 photographs and drawings showing the safe and unsafe methods of work. No vision- 
 ary schemes, no ideal pictures. Just plain facts and Practical Suggestions are given. 
 Every railroad employee who reads the book is a better and safer man to have in 
 railroad service. It gives just the information which will be the means of preventing 
 many injuries and deaths. All railroad employees should procure a copy; read it, 
 and do your part in preventing accidents. 169 pages. Pocket size. Fully illustrated. 
 Price 60 cents 
 
 TRAIN RULE EXAMINATIONS MADE EASY. By G. E. COLLINGWOOD. 
 This is the only practical work on train rules in print. Every detail is covered, and 
 puzzling points are explained in simple, comprehensive language, making it a practical 
 treatise for the Train Dispatcher, Engineman, Trainman, and all others who have to 
 do with the movements of trains. Contains complete and reliable information of the 
 Standard Code of Train Rules for single track. Shows Signals in Colors, as used on 
 the different roads. Explains fully the practical application of train orders, giving a 
 clear and definite understanding of all orders which may be used. The meaning and 
 necessity for certain rules are explained in such a manner that the student may know 
 beyond a doubt the rights conferred under any orders he may receive or the action 
 
 25
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 required by certain rules. As nearly all roads require trainmen to pass regular exami- 
 nations, a complete set of examination questions, with their answers, arc included. 
 These will enable the student to pass the required examinations with credit to himself 
 and the road for which he works. 256 pages. Fully illustrated with Train Signals 
 in Colors. Price $1.5O 
 
 THE WALSCHAERT AND OTHER MODERN RADIAL VALVE GEARS FOR 
 LOCOMOTIVES. By WM. W. WOOD. 
 
 If you would thoroughly understand the Walschaert Valve Gear you should possess a 
 copy of this book, as the author takes the plainest form of a steam engine.- a stationary 
 engine in the rough, that will only turn its crank in one direction and from it builds 
 up with the reader's help a modern locomotive equipped with the Walschaert 
 Valve Gear, complete. The points discussed are clearly illustrated ; two large folding 
 plates that show the positions of the valves of both inside or outside admission type, as 
 well as the links and other parts of the gear when the crank is at nine different points 
 in its revolution, are especially valuable in making the movement clear. These employ 
 sliding cardboard models which are contained in a pocket in the cover. 
 The book is divided Into five general divisions, as follows: 1. Analysis of the gear. 
 2. Designing and erecting the gear. 3. Advantages of the gear. 4. Questions and 
 answers relating to the Walschaert Valve Gear. 5. Setting valves with the Wal- 
 schaert Valve Gear; the three primary types of locomotive valve motion; modem 
 radial valve gears other than the Walschaert; the Hobart All-free Valve and Valve 
 Gear, with questions and answers on breakdowns; the Baker-Pilliod Valve Gear; the 
 Improved Baker-Pilliod Valve Gear, with questions and answers on breakdowns. 
 The questions with full answers given will be especially valuable to firemen and engi- 
 neers in preparing for an examination for promotion. 245 pages. Third Revised 
 Edition. Price $2.00 
 
 WESTINGHOUSE E-T AIR-BRAKE INSTRUCTION POCKET BOOK. By 
 
 WM. W. WOOD, Air-Brake Instructor. 
 
 Here is a book for the railroad man, and the man who aims to be one. It is without 
 doubt the only complete work published on the Westinghouse E-T Locomotive Brake 
 Equipment. Written by an Air-Brake Instructor who knows just what is needed. It 
 covers the subject thoroughly. Everything about the New Westinghouse Engine and 
 Tender Brake Equipment, including the standard No. 5 and the Perfected No. 6 
 style of brake, is treated in detail. Written in plain English and profusely illustrated 
 with Colored Plates, which enable one to trace the flow of pressures throughout the 
 entire equipment. The best book ever published on the Air Brake. Equally good for 
 the beginner and the advanced engineer. Will pass any one through any examination. 
 It informs and enlightens you on every point. Indispensable to every engineman and 
 trainman. . 
 
 Contains examination questions and answers on the E-T equipment. Covering what 
 the E-T Brake is. How it should be operated. What to do when defective. Not a 
 question can be asked of the engineman up for promotion, on either the No. 5 or the 
 No. 6 E-T equipment, that is not asked and answered in the book. If you want to 
 thoroughly understand the E-T equipment get a copy of this book. It covers every 
 detail. Makes Air-Brake troubles and examinations easy. Price . . . . $2.00 
 
 MACHINE-SHOP PRACTICE 
 
 AMERICAN TOOL MAKING AND INTERCHANGEABLE MANUFACTURE 
 ING. By J. V. WOODWORTH. 
 
 A "shoppy" book, containing no theorizing, no problematical or experimental devices, 
 there are no badly proportioned and impossible diagrams, no catalogue cuts, but a 
 valuable collection of drawings and descriptions of devices, the rich fruits of the author's 
 own experience. In its 500-odd pages the one subject only. Tool Making, and what- 
 ever relates thereto, is dealt with. The work stands without a rival. It is a complete 
 practical treatise on the art of American Tool Making and system of interchangeable 
 manufacturing as carried on to-day in the United States. In it are described and 
 illustrated all of the different types and classes of small tools, fixtures, devices, and 
 special appliances which are in general use in all machine-manufacturing and metal- 
 working establishments where economy, capacity, and interchangeability in the pro- 
 duction of machined metal parts are imperative. The science of jig making is exhaus- 
 tively discussed, and particular attention is paid to drill jigs, boring, profiling and milling 
 fixtures and other devices hi which the parts to be machined are iocated and fastened 
 within the contrivances. All of the tools, fixtures, and devices illustrated and de- 
 scribed have been or are used for the actual production of work, such as parts of drill 
 presses, lathes, patented machinery, typewriters, electrical apparatus, mechanical ap- 
 pliances, brass goods, composition parts, mould products, sheet metal articles, drop- 
 forgings, jewelry, watches, medals, coins, etc. 531 pages. Price .... $4.50 
 
 26
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 MACHINE-SHOP ARITHMETIC. By COLVIN-CHENEY. 
 
 This is an arithmetic of the things you have to do with daily. It tells you plainly 
 about: how to find areas in figures; how to find surface or volume of balls or spheres; 
 handy ways for calculating; about compound gearing; cutting screw threads on any 
 lathe; drilling for taps; speeds of drills; taps, emery wheels, grindstones, milling 
 cutters, etc.; all about the Metric system with conversion tables; properties of metals; 
 strength of bolts and nuts; decimal equivalent of an inch. All sorts of machine-shop 
 figuring and 1,001 other things, any one of which ought to be worth more than 
 the price of this book to you, and it saves you the trouble of bothering the boss. 6th 
 edition. 131 pages. Price 60 cents 
 
 MODERN MACHINE-SHOP CONSTRUCTION, EQUIPMENT AND MAN- 
 AGEMENT. By OSCAR E. PERRIGO. 
 
 The only work published that describes the Modern Shop or Manufacturing Plant 
 from the time the grass is growing on the site intended for it until the finished product 
 is shipped. Just the book needed by those contemplating the erection of modern shop 
 buildings, the rebuilding and reorganization of old ones, or the introduction of Modern 
 Shop Methods, time and cost systems. It is a book written and illustrated by a prac- 
 tical shop man for practical shop men who are too busy to read theories and want facts. 
 It is the most complete all-round book of its kind ever published. 400 large quarto 
 pages. 225 original and specially-made illustrations. 2d Revised and Enlarged 
 Edition. Price $5.00 
 
 " SHOP KINKS." By ROBERT GRIMSHAW. 
 
 A book of 400 pages and 222 illustrations, being entirely different from any other 
 book on machine-shop practice. Departing from conventional style, the author 
 avoids universal or common shop usage and limits his work to showing special ways 
 of doing things better, more cheaply and more rapidly than usual. As a result the 
 advanced methods of representative establishments of the world are placed at the 
 disposal of the reader. This book shows the proprietor where large savings are possible, 
 and how products may be improved. To the employee it holds out suggestions that, 
 properly applied, will hasten his advancement. No shop can afford to be without it. 
 It bristles with valuable wrinkles and helpful suggestions. It will benefit all, from 
 apprentice to proprietor. Every machinist, at any age, should study its pages. Fifth 
 edition. Price $3.00 
 
 THREADS AND THREAD CUTTING. By COLVIN and STABEL. 
 
 This clears up many of the mysteries of thread-cutting, such as double and triple 
 threads, internal threads, catching threads, use of hobs, etc. Contains a lot of useful 
 hints and several tables. Third edition. Price 35 cents 
 
 EVERYDAY ENGINEERING THE BEST MECHANICAL MAGAZINE ON 
 THE MARKET. ONLY ONE DOLLAR AND FIFTY CENTS A YEAR 
 FOR TWELVE NUMBERS. SUBSCRIBE TO-DAY. 
 
 Every practical man needs a magazine which will tell him how to make and do things. 
 A monthly magazine devoted to practical mechanics for every-day men. Its aim is 
 to popularize engineering as a science, teaching the elements of applied mechanics 
 and electricity in a straightforward and understandable manner. The magazine 
 maintains its own experimental laboratory, where the devices described in articles 
 submitted to the Editor are first tried out and tested before they are published. This 
 important innovation places the standard of the published material very high, and 
 it insures accuracy and dependability. 
 
 The magazine is the only one hi this country that specializes in practical model build- 
 ing. Articles in past issues have given comprehensive designs for many model boats, 
 including submarines and chasers, model steam and gasoline engines, electric motors 
 and generators, etc., etc. This feature is a permanent one in the magazine. 
 Aether popular department is that devoted to automobiles and airplanes. Care, 
 maintenance, and operation receive full and authoritative treatment. Every article 
 is written from the practical, every-day man standpoint, rather than from that of the 
 professional. 
 
 The magazine entertains while it instructs. It is a journal of practical, dependable 
 information, given in a style that it may be readily assimilated and applied by the 
 man with little or no technical training. The aimTis to place before the man who 
 leans toward practical mechanics a series of concise, crisp, readable talks on what 
 is going on and how it is done. These articles are profusely illustrated with clear, 
 snappy photographs, specially posed to illustrate the subject in the magazine's own 
 studio by its own staff of technically-trained illustrators and editors. 
 The subscription price of the magazine is $1.50 per year of twelve numbers. 
 Sample copy sent on receipt of fifteen cents. 
 Enter your subscription to this practical magazine with as. 
 
 27
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 THE WHOLE FIELD OF MECHANICAL MOVEMENTS 
 COVERED BY MR. HISCOX'S TWO BOOKS 
 
 We publish two books by Gardner D. Hiscox that will keep you from "inventing" things 
 that haw been done before, and suggest ways of doing things that you have not thought of 
 before. Many a man spends time and money, pondering over some mechanical problem, 
 only to learn, after he has solved the problem, that the same thing has been accomplished 
 and put in practice by others long before. Time and money spent in an effort to accom- 
 plish what has already been accomplished are time and money LOST. The whole field 
 of mechanics, every known mechanical movement, and practically every device is covered 
 by these two books. If the thing you want has been invented, it is illustrated in them. If 
 it hasn't been invented, then you'll find in them the nearest things to what you want, some 
 movements or devices that will apply in your case, perhaps; or which will give you a key 
 from which to work. No book or set of books ever published is of more real value to the 
 Inventor, Draftsman, or practical Mechanic than the two volumes described below. 
 
 MECHANICAL MOVEMENTS, POWERS, AND DEVICES. By GARDNER D. 
 Hiscox. 
 
 This is a collection of 1,890 engravings of different mechanical motions and appliances, 
 accompanied by appropriate text, making it a book of great value to the inventor, 
 the draftsman, and to all readers with mechanical tastes. The book is divided into 
 eighteen sections or chapters, in which the subject-matter is classified under the follow- 
 ing heads: Mechanical Powers; Transmission of Power; Measurement of Power; 
 Steam Power; Air Power Appliances; Electric Power and Construction; Navigation 
 and Roads; Gearing; Motion and Devices; Controlling Motion; Horological; 
 Mining; Mill and Factory Appliances; Construction and Devices; Drafting Devices; 
 Miscellaneous Devices, etc. 15th edition enlarged. 400 octavo pages. Price . $3.00 
 
 MECHANICAL APPLIANCES, MECHANICAL MOVEMENTS AND NOVEL- 
 TIES OF CONSTRUCTION. By GARDNER D. Hiscox. 
 
 This is a supplementary volume to the one upon mechanical movements. Unlike the 
 first volume, which is more elementary in character, this volume contains illustrations 
 and descriptions of many combinations of motions and of mechanical devices and 
 appliances found in different lines of machinery, each device being shown by a line 
 drawing with a description showing its working parts and the method of operation. 
 From the multitude of devices described and illustrated might be mentioned, in 
 passing, such items as conveyors and elevators, Prony brakes, thermometers, various 
 types of boilers, solar engines, oil-fuel burners, condensers, evaporators, Corliss and 
 other valve gears, governors, gas engines, water motors of various descriptions, air- 
 ships, motors and dynamos, automobile and motor bicycles, railway lock signals, 
 car couplers, link and gear motions, ball bearings, breech block mechanism for heavy 
 guns, and a large accumulation of others of equal importance. 1,000 specially made 
 engravings. 396 octavo pages. 4th Edition enlarged. Price $3.00 
 
 MACHINE-SHOP TOOLS AND SHOP PRACTICE. By W. H. VANDERVOORT. 
 
 A work of 555 pages and 673 illustrations, describing in every detail the construction, 
 operation, and manipulation of both hand and machine tools. Includes chapters 
 on filing, fitting, and scraping surfaces; on drills, reamers, taps, and dies; the lathe 
 and its tools; planers, shapers, and their tools; milling machines and cutters; gear 
 cutters and gear cutting; drilling machines and drill work; grinding machines and 
 their work; hardening and tempering; gearing, belting, and transmission machinery; 
 . Pri 
 
 useful data and tables. 6th edition. Price $4.25 
 
 THE MODERN MACHINIST. By JOHN T. USHER. 
 
 This is a book showing, by plain description and by profuse engravings made expressly 
 for the work, all that is best, most advanced, and of the highest efficiency in modern 
 machine-shop practice, tools, and implements, showing the way by which and through 
 which, as Mr. Maxim says, "American machinists have become and are the finest me- 
 chanics in the world." Indicating as it does, in every line, the familiarity of the author 
 with every detail of daily experience in the shop, it cannot fail to be of service to any 
 man practically connected with the shaping or finishing of metals. 
 There is nothing experimental or visionary about the book, all devices being in actual 
 use and giving good results. It might be called a compendium of shop methods, 
 showing a variety of special tools and appliances which will give new ideas to many 
 mechanics, from the superintendent down to the man at the bench. It will be found 
 
 28
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 a valuable edition to any machinist's library, and should be consulted whenever a 
 new or difficult job is to be done, whether it is boring, milling, turning, or planing, 
 as they are all treated in a practical manner. Fifth edition. 320 pages. 250 Illustra- 
 tions. Price $2.50 
 
 HENLEY'S ENCYCLOPEDIA OF PRACTICAL ENGINEERING AND ALLIED 
 TRADES. Edited by JOSEPH G. HORNER, A.M.I.Mech.E. 
 
 This book covers the entire practice of Civil and Mechanical Engineering. The 
 best known experts in all branches of engineering have contributed to these volumes. 
 The Cyclopedia is admirably well adapted to the needs of the beginner and the self- 
 taught practical man, as well as the mechanical engineer, designer, draftsman, shop 
 superintendent, foreman and machinist. 
 
 It is a modern treatise in five volumes. Handsomely hound in half morocco, each 
 volume containing nearly 500 pages, with thousands of illustrations, including dia- 
 grammatic and sectional drawings with full explanatory details. For the complete 
 set of five volumes. Price $30.00 
 
 MODEL MAKING Including Workshop Practice, Design and Construction of 
 Models. Edited by RAYMOND F. YATES. Editor of " Everyday Engineering 
 Magazine." 
 
 This book does not describe the construction of toys. Its pages are devoted to model 
 engineering and the mechanical sciences associated with it. It contains descriptions 
 with illustrations of the complete models made by some of the leading model engineers 
 in this country. It is the only book published on this important subject. 
 The first part of the book is devoted to the mechanical sciences and processes related 
 to model engineering and mechanics hi general. To the inexperienced workman, who 
 wishes to make models but is untrained in the fundamental mechanics, this book will 
 afford all the information necessary. For the experienced mechanic, there are many 
 hints and short cuts that will be found helpful. Few mechanics, no matter how well 
 trained, know how to make their own patterns. Yet a complete treatise on this im-* 
 portant craft is given. The same holds true in regard to the intelligent use of abrasives 
 in the home shop. This, too, is completely covered in a way that will not only help the 
 beginner but teach the trained man a few things that he may not have understood* 
 before. In short, the fore part of the.book will prepare men to more thoroughly under- 
 stand the processes connected with model making no matter what their standing. 
 This book will help you to become a better mechanic. It is full of suggestions for those 
 who like to make things, amateur and professional alike. It has been prepared es- 
 pecially for men with mechanical hobbies. Some may be engineers, machinists, jew- 
 elers, pattern makers, office clerks or bank presidents. Men from various walks of 
 life have a peculiar interest in model engineering. MODEL MAKING will be a help and 
 an inspiration to such men. It tells them " how-to-do" and "how-to-make" things* 
 in simple, understandable terms. Not only this, it is full of good, clear working 
 drawings and photographs of the models and apparatus described. Each model has 
 been constructed and actually works if it is made according to directions. 375 pages. 
 300 illustrations. Price $3.00 
 
 MARINE ENGINEERING 
 
 THE NAVAL ARCHITECT'S AND SHIPBUILDER'S POCKETBOOK. Of 
 
 Formulae, Rules, and Tables and Marine Engineer's and Surveyor's Handy 
 Book of Reference. By CLEMENT MACKROW and LLOYD WOOLLARD. 
 
 The eleventh revised and enlarged edition of this most comprehensive work has just 
 been issued. It is absolutely indispensable to all engaged hi the Shipbuilding Industry, 
 as it condenses into a compact form all data and formulae|that are ordinarily required. 
 The book is completely up to date, including among other subjects a section on 
 Aeronautics. 750 pages, limp leather binding. Price $6.00 
 
 MARINE ENGINES AND BOILERS THEIR DESIGN AND CONSTRUC- 
 TION. THE STANDARD BOOK. By DR. G. BAUER, LESLIE S. ROBERTSON 
 and S. BRYAN DONKIN. 
 
 In the words of Dr. Bauer, the present work owes its origin to an oft felt want of a 
 condensed treatise embodying the theoretical and practical rules used in designing 
 marine engines and boilers. The need of such a work has been felt by most en- 
 gineers engaged hi the construction and working of marine engines, not only by the 
 younger men, but also by those of greater experience. The fact that the original 
 German work was written by the chief engineer of the famous Vulcan Works, Stettin, 
 is in itself a guarantee that this book is in all respects thoroughly up-to-date, and 
 
 29
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 that it embodies all the information which is necessary for the design and construction 
 of the highest types of marine onginc-s and boilers. It may be said that the motive 
 power which Dr. Bauer has placed in the fast German liners that have been turned 
 out of late years from the Stettin Works represent the very best practice in marine 
 engineering of the present day. The work is clearly written, thoroughly systematic, 
 theoretically sound; while the character of the plans, drawings, tables, and statistics 
 is without reproach. The illustrations are careful reproductions from actual working 
 drawings, with some well-executed photographic views of completed engines and 
 boilers. 744 pages. 550 illustrations, and numerous tables. Cloth. Price. $10.00 
 
 MODERN SUBMARINE CHART. 
 
 A cross-section view, showing clearly and distinctly all the interior of a Submarine 
 of the latest type. You get more information from this chart about the construction 
 and operation of a submarine tha"n in any other way. No details omitted every- 
 thing is accurate and to scale. It is absolutely correct in every detail, having been 
 approved by naval engineers. All the machinery and devices fitted in a modern 
 Submarine Boat are shown, and to make the engraving more readily understood 
 all the features are shown in operative form, with Officers and Men in the act of per- 
 forming thr duties assi-ncd to them in service'conditions. THIS CHART IS REALLY 
 AN ENCYCLOPEDIA OF A SUBMARINE. It is educational and worth many 
 times its cost. Mailed in a tube for 25 cents 
 
 MANUAL TRAINING 
 
 ECONOMICS OF MANUAL TRAINING. By Louis ROUILLION. 
 
 The only book published that gives just the information needed by all interested in 
 Manual Training, regarding Buildings, Equipment, and Supplies. Shows exactly 
 what is needed for all grades of the work from the Kindergarten to the High and 
 Normal School. Gives itemized lists of everything used in Manual Training Work 
 and tells just what it ought to cost. Also shows where to buy supplies, etc. Contains 
 174 pages, and is fully illustrated. 2d edition. Price $2.00 
 
 MINING 
 
 ORE DEPOSITS, WITH A CHAPTER ON HINTS TO PROSPECTORS. 
 By J. P. JOHNSON. 
 
 This book gives a condensed account of the ore deposits at present known in South 
 Africa. It is also intended as a guide to the prospector. Only an elementary knowl- 
 edge of grology and some mining experience are necessary in order to understand this 
 work. With these qualifications, it will materially assist one in his search for me- 
 talliferous mineral occurrences and, so far as simple ores are concerned, should enable 
 one to form some idea of the possibilities of any he may find. Illustrated. 
 Cloth. Price $2.00 
 
 PRACTICAL COAL MINING. By T. H. COCKIN. 
 
 An important work, containing 428 pages and 213 illustrations, complete with practical 
 details, which will intuitively impart to the reader not only a general knowledge of the 
 principles of coal mining, but also considerable insight into allied subjects. The 
 treatise is positively up-to-date in every instance, and should be in the hands of every 
 colliery engineer, geologist, mine operator, superintendent, foreman, and all others 
 who are interested in or connected with the industry. Third edition . . $2.50 
 
 PHYSICS AND CHEMISTRY OF MINING. By T. H. BYROM. 
 
 A practical work for the use of all preparing for examinations in mining or qualifying 
 for colliery managers' certificates. The aim of the author in this excellent book is 
 to place clearly before the reader useful and authoritative data which will render him 
 valuable assistance in his studies. The only work of its kind published. The in- 
 formation incorporated in it will prove of the greatest practical utility to students, 
 mining engineers, colliery managers, and all others who are specially interested in the 
 present-day treatment of mining problems. Second edition, revised. 188 pages. 
 Illustrated: Price ...... $2.00 
 
 30
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 PATTERN MAKING 
 
 PRACTICAL PATTERN MAKING. By F. W. BARROWS. 
 
 This book, now in its second edition, is a comprehensive and entirely practical treatise 
 on the subject of pattern making, illustrating pattern work in both wood and metal, 
 and with definite instructions on the use of plaster of paris in the trade. It gives 
 specific and detailed descriptions of the materials used by pattern makers and de- 
 scribes the tools, both those for the bench and the more interesting machine tools; 
 having complete chapters on the Lathe, the Circular Saw, and the Band Saw. It gives 
 many examples of pattern work, each one fully illustrated and explained with much 
 detail. These examples, in their great variety, offer much that will be found of 
 interest to all pattern makers, and especially to the younger ones, who are seeking 
 information on the more advanced branches of their trade. 
 
 In this second edition of the work will be found much that is new, even to those who 
 have long practised this exacting trade. In the description of patterns as adapted 
 to the Moulding Machine many difficulties which have long prevented the rapid and 
 economical production of castings are overcome; and this great, new branch of the 
 trade is given much space. Stripping plate and stool plate work and the less expen- 
 sive vibrator, or rapping plate work, are all explained in detail. 
 
 Plain, everyday rules for lessening the cost of patterns, with a complete system of 
 cost keeping, a detailed method of marking, applicable to all branches of the trade, 
 with complete information showing what the pattern is, its specific title, its cost, 
 date of production, material of which it is made, the number of pieces and core- 
 boxes, and its location in the pattern safe, all condensed into a most complete card 
 record, with cross index. 
 
 The book closes with an original and practical method for the inventory and valua- 
 tion of patterns. Containing nearly 350 pages and 1 70 illustrations. Price. $2.5O 
 
 PERFUMERY 
 
 PERFUMES r AND COSMETICS, THEIR PREPARATION AND MANUFAC- 
 TURE. By G. W. ASKINSON, Perfumer. 
 
 A comprehensive treatise, in which there has been nothing omitted that could be of 
 value to the perfumer or manufacturer of toilet preparations. Complete directions 
 for making handkerchief perfumes, smelling-salts, sachets, fumigating pastilles; 
 preparations for the care of the skin, the mouth, the hair, cosmetics, hair dyes and 
 other toilet articles are given, also a detailed description of aromatic substances ; their 
 nature, tests of purity, and wholesale manufacture, including a chapter on synthetic 
 products, with formulas for their use. A book of general, as well as professional in- 
 terest, meeting the wants not only of the druggist and perfume manufacturer, but 
 also of the general public. Among the contents are: 1. The History of Perfumery. 
 2. About Aromatic Substances in General. 3. Odors from the Vegetable Kingdom. 
 4. The Aromatic Vegetable Substances Employed in Perfumery- 5. The Animal Sub- 
 stances Used in Perfumery. 6. The Chemical Products Used in Perfumery. 7. The Ex- 
 traction of Odors. 8. The Special Characteristics of Aromatic Substances. 9. The Adul- 
 teration of Essential Oils and Their Recognition. 10. Synthetic Products. 11. Table of 
 Physical Properties of Aromatic Chemicals. 12. The Essences or Extracts Employed 
 in Perfumery- 13. Directions for Making the Most Important Essences and Extracts. 
 14. The Division of Perfumery. 15. The Manufacture of Handkerchief Perfumes. 
 16. Formulas for Handkerchief Perfumes. 17. Ammoniacal and Acid Perfumes. 
 18. Dry Perfumes. 19. Formulas for Dry Perfumes. 20. The Perfumes Used for 
 Fumigation. 21. Antiseptic and Therapeutic Value of Perfumes. 22. Classification of 
 Odors. 23. Some Special Perfumery Products. 24. Hygiene and Cosmetic Perfumery. 
 25. Preparations for the Care of the Skin. 26. Manufacture of Casein. 27. Formulas 
 for Emulsions. 28. Formulas for Cream. 29. Formulas for Meals, Pastes and Vege- 
 table Milk. 30. Preparations Used for the Hair. 31. Formulas for Hair Tonics and 
 Restorers. 32. Pomades and Hair Oils. 33. Formulas for the Manufacture of 
 Pomades and Hair Oils. 34. Hair Dyes and Depilatories. 35. Wax Pomades, Bando- 
 lines and Brilliantines. 36. Skin Cosmetics and Face Lotions. 37. Preparations for 
 the Nails. 38. Water Softeners and Bath Salts. 39. Preparations for the Care of the 
 Mouth. 40. The Colors Used in Perfumery. 41. The Utensils Used in the Toilet. 
 Fourth edition much enlarged and brought up-to-date. Nearly 400 pages, illus- 
 trated. Price $5.0O 
 
 WHAT IS SAID OF THIS BOOK: 
 
 " The most satisfactory work on the subject of Perfumery that we have ever seen. 
 " We feel safe in saying that here is a book on Perfumery that will not disappoint you, 
 for it has practical and excellent formulae that are within your ability to prepare 
 readily. 
 
 " We recommend the volume as worthy of confidence, and say that no purchaser will be 
 disappointed in securing from its pages good value for its cost, and a large dividend 
 
 31
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 on the same, even if he should use but one per cent of its working formulae. There 
 is money in it for every user of its information." Pharmaceutical Record. 
 
 HENLEY'S TWENTIETH CENTURY BOOK OF RECIPES, FORMULAS 
 AND PROCESSES. Edited by G. D. Hiscox. 
 
 The most valuable techno-chemical receipt book published. Contains over 10,000 
 practical receipts, many of which will prove of special value to the 
 perfumer. Price .... $3.0O 
 
 PLUMBING 
 
 MECHANICAL DRAWING FOR PLUMBERS. By R. M. STARBUCK. 
 
 comprehensive and practical treatise on the subject of mechanical drawing 
 ous modern applications to the work of all who are in any way connected 
 
 vauons 01 separate parts 01 me piumoing system. ID. juevauons iroin me arcruiect s 
 plans. 17. Drawings of detail plumbing connections. 18. Architect's plans and plumb- 
 ing elevations of residence. 19. Plumbing elevations of residence (continued) ; plumb- 
 ing plans for cottage. 20. Plumbing elevations; roof connections. 21. Plans and 
 
 A concise, 
 in its variot 
 
 with the plumbing trade. Nothing will so help the plumber in estimating and in 
 explaining work to customers and workmen as a knowledge of drawing, and to the 
 workman it is of inestimable value if he is to rise above his position to positions of 
 greater responsibility. Among the chapters contained are: 1. Value to plumber of 
 knowledge of drawing; tools required and their use; common views needed in mechan- 
 ical drawing. 2. Perspective versus mechanical drawing in showing plumbing con- 
 struction. 3. Correct and incorrect methods in plumbing drawing; plan and elevation 
 explained. 4. Floor and cellar plans and elevation; scale drawings; use of triangles. 
 5. Use of triangles ; drawing of fittings, traps, etc. 6. Drawing plumbing elevations 
 and fittings. 7. Instructions in drawing plumbing elevations. 8. The drawing of 
 plumbing fixtures; scale drawings. 9. Drawings of fixtures and fittings. 10. Inking 
 of drawings. 11. Shading of drawings. 12. Shading of drawings. 13. Sectional 
 drawings ; drawing of threads. 14. Plumbing elevations from architect's plan. 15. Ele- 
 vations of separate parts of the plumbing system. 16. Elevations from the architect's 
 plans, 
 ing ele 
 
 ing plans for cottage. 20. Plumbing 
 plumbing elevations for six-flat building. 22. Drawing of various parts of the plumb- 
 ing system; use of scales. 23. Use of architect's scales. 24. Special features in the 
 illustrations of country plumbing. 25. Drawing of wrought-iron piping, valves, radia- 
 tors, coils, etc. 26. Drawing of piping to illustrate heating systems. 150 illustrations. 
 Price . . $2.00 
 
 MODERN PLUMBING ILLUSTRATED. By R. M. STARBUCK. 
 
 This book represents the highest standard of plumbing work. It has been adopted 
 and used as a reference book by the United States Government, in its sanitary work in 
 Cuba, Porto Rico, and the Philippines, and by the principal Boards of Health of the 
 United States and Canada. 
 
 It gives connections, sizes and working data for all fixtures and groups of fixtures. It 
 is helpful to the master plumber in demonstrating to his customers and in figuring 
 work. It gives the mechanic and student quick and easy access to the best modern 
 plumbing practice. Suggestions for estimating plumbing construction are contained 
 in its pages. This book represents, in a word, the latest and best up-to-date practice 
 and should be in the hands of every architect, sanitary engineer and plumber who 
 wishes to keep himself up to the minute on this important feature of construction. 
 Contains following chapters, each illustrated with a full-page plate: Kitchen sink, 
 laundry tubs, vegetable wash sink; lavatories, pantry sinks, contents of marble slabs; 
 bath tub, foot and sitz bath, shower bath ; water closets, venting of water closets ; low- 
 down water closets, water closets operated by flush valves, water closet range ; slop sink, 
 urinals, the bidet; hotel and restaurant sink, grease trap; refrigerators, safe wastes, laun- 
 dry waste, lines of refrigerators, bar sinks, soda fountain sinks; horse stall, frost-proof 
 water closets; connections for S traps, venting; connections for drum traps; soil pipe 
 connections; supporting of soil pipe; main trap and fresh air inlet; floor drains and 
 cellar drains, subsoil drainage; water closets and floor connections; local venting; 
 connections for bath rooms; connections for bath rooms, continued; connections for 
 bath rooms, continued; connections for bath rooms, continued; examples of poor 
 practice; roughing work ready for test?; testing of plumbing system; method of con- 
 tinuous venting; continuous venting for two-floor work; continuous venting for two 
 lines of fixtures on three or more floors; continuous venting of water closets; plumb- 
 ing for cottage house; construction for cellar piping; plumbing for residence, use of 
 special fittings; plumbing for two-flat house; plumbing for apartment building, plumb- 
 ing for double apartment building; plumbing for office building; plumbing for public 
 toilet rooms; plumbing for public toilet rooms, continued; plumbing for bath estab- 
 lishment; plumbing for engine house, factory plumbing; automatic flushing for 
 schools, factories, etc.; use of flushing valves; urinals for public toilet rooms; the 
 Durham system, the destruction of pipes by electrolysis; construction of work without 
 
 32
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 use of lead; automatic sewage lift; automatic sump tank; country plumbing; construc- 
 tion of cesspools ; septic tank and automatic sewage siphon ; country plumbing ; water 
 supply for country house; thawing of water mains and service by electricity; double 
 boilers; hot water supply of large buildings: automatic control of hot water tank; sug- 
 gestion for estimating plumbing construction. 407 octavo pages, fully illustrated by 58 
 full-page engravings. Third, revised and enlarged edition just issued. Price . $.500 
 
 STANDARD PRACTICAL PLUMBING. By R. M. STARBUCK. 
 
 A complete practical treatise of 450 pages covering the subject of Modern Plumbing 
 in all its branches, a large amount of space being devoted to a very complete and 
 practical treatment of the subject of Hot Water Supply and Circulation and Range 
 Boiler Work. Its thirty chapters include about every phase of the subject one can 
 think of, making it an indispensable work to the master plumber, the journeyman 
 plumber, and the apprentice plumber, containing chapters on: the plumber's tools; 
 wiping solder; composition and use; joint wiping; lead work; traps; siphonage of 
 traps; venting; continuous venting; house sewer and sewer connections; house drain; 
 soil piping, roughing; main trap and fresh air inlet; floor, yard, cellar drains, rain 
 leaders, etc.; fixture wastes; water closets; ventilation; improved plumbing connec- 
 tions; residence plumbing; plumbing for hotels, schools, factories, stables, etc.; 
 modern country plumbing; nitration of sewage and water supply; hot and cold 
 supply; range boilers; circulation; circulating pipes; range boiler problems; hot 
 
 water for large buildings; water lift and its use; multiple connections for hot water 
 boilers; heating of radiation by supply system; theory for the plumber; drawing for 
 the plumber. Fully illustrated by 347 engravings. Price S3. 50 
 
 RECIPE BOOK 
 
 HENLEY'S TWENTIETH CENTURY BOOK OF RECIPES, FORMULAS AND 
 PROCESSES. Edited by GARDNER D. Hiscox. 
 
 The most valuable Techno-chemical Formula Book published, including over 10,000 
 selected scientific, chemical, technological, and practical recipes and processes. 
 This is the most complete Book of Formulas ever published, giving thousands of 
 recipes for the manufacture of valuable articles for everyday use. Hints, Helps. 
 Practical Ideas, and Secret Processes are revealed within its pages. It covers every 
 branch of the useful arts and tells thousands of ways of making money, and is just the 
 book everyone should have at his command. 
 
 Modern in its treatment of every subject that properly falls within its scope* the book 
 may truthfully be said to present the very latest formulas to be found in the arts and 
 industries, and to retain those processes which long experience has proven worthy of a 
 permanent record. To present here even a limited number of the subjects which find 
 a place in this valuable work would be difficult. Suffice to say that in its pages will 
 be found matter of intense interest and immeasurably practical value to the scientific 
 amateur and to him who wishes to btain a knowledge of the many processes used in 
 the arts, trades and manufacture, a knowledge which will render his pursuits more 
 instructive and remunerative. Serving as a reference book to the small and large 
 manufacturer and supplying intelligent seekers with the information necessary to 
 conduct a process, the work will be found of inestimable worth to the Metallurgist, the 
 Photographer, the Perfumer, the Painter, the Manufacturer of Glues, Pastes, Cements, 
 and Mucilages, the Compounder of Alloys, the Cook, the Physician, the Druggist, the 
 Electrician, the Brewer, the Engineer, the Foundryman, the Machinist, the Potter, the 
 Tanner, the Confectioner, the Chiropodist, the Manicure, the Manufacturer of Chem- 
 ical Novelties and Toilet Preparations, the Dyer, the Electroplater, the Enameler, the 
 Engraver, the Provisioner, the Glass Worker, the Goldbeater, the Watchmaker, the 
 Jeweler, the Hat Maker, the Ink Manufacturer, the Optician, the Farmer, the Dairy- 
 man, the Paper Maker, the Wood and Metal Worker, the Chandler and Soap Maker, 
 the Veterinary Surgeon, and the Technologist in general. 
 
 A mine of information, and up-to-date hi every respect. A book which will prove of 
 value to EVERYONE, as it covers every branch of the Useful Arts. Every home 
 needs this book; every office, every factors', every store, every public and private en- 
 terprise EVERYWHERE should have a copy. 800 pages. Price. . . $3.00 
 
 WHAT IS SAID OF THIS BOOK: 
 
 "Your Twentieth Century Book of Recipes, Formulas, and Processes duly received. 
 I am glad to have a copy of it. and if I could not replace it, money couldn't buy it. It 
 is the best thing of the sort I ever saw." (Signed) M. E. TRUX, Sparta. Wis. 
 
 " There are few persons who would not be able to find in the book some single formula 
 that would repay several times the cost of the book." Merchants' Record and Show 
 Window, 
 
 33
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 " I purchased your book ' Henley's Twentieth Century Book of Recipes, Formulas and 
 Processes' about a year ago and it is worth its weight in gold." WM. H. MURRAY, 
 Bennington, Vt. 
 
 "THE BOOK WORTH THREE HUNDRED DOLLARS" 
 
 "On close examination of your 'Twentieth Century Receipt Book,' I find it to be a 
 very valuable and useful book with the very best of practical information obtainable. 
 The price of the book, S3.OO, is very small in comparison to the benefits which one can 
 obtain from it. I consider the book worth fully three hundred dollars to anyone." 
 DR. A. C. SPETTS, New York. 
 
 "ONE OF THE WORLD'S MOST USEFUL BOOKS" 
 
 "Some time ago, I got one of your 'Twentieth Century Books of Formulas' and have 
 made my living from it ever since. I am alone since my husband's death with two 
 small children to care for and am trying so hard to support them. I have customers 
 who take from me Toilet Articles I put up, following directions given in the book, 
 and I have found every one of them to be fine." MRS. J. H. MCMAKEX, West Toledo, 
 Ohio. 
 
 RUBBER 
 
 RUBBER HAND STAMPS AND THE MANIPULATION OF INDIA RUBBER. 
 By T. O'CoNOR SLOANE. 
 
 This book gives full details on all points, treating in a concise and simple manner the 
 elements of nearly everything it is necessary to understand for a commencement 'in 
 any branch of the India Rubber Manufacture. The making of all kinds of Rubber 
 Hand Stamps, Small Articles of India Rubber, U. S. Government Composition, Dating 
 Hand Stamps, the Manipulation of Sheet Rubber, Toy Balloons, India Rubber Solu- 
 tions, Cements, Blackings, Renovating Varnish, and Treatment for India Rubber 
 Shoes, etc. ; the Hektograph Stamp Inks, and Miscellaneous Notes, with a Short 
 Account of the Discovery, Collection and Manufacture of India Rubber, are set forth 
 in a manner designed to be readily understood, the explanations being plain and simple. 
 Including a chapter on Rubber Tire Making and Vulcanizing; also a chapter on the 
 uses of rubber in Surgery and Dentistry. Third revised and enlarged edition. 175 
 pages. Illustrated $1.25 
 
 HENLEY'S TWENTIETH CENTURY BOOK OF RECIPES, FORMULAS 
 AND PROCESSES. Edited by GARDNER D. Hiscox. 
 
 Contains upward of 10,000 practical receipts, including among them formulas on 
 artificial rubber. Price $3.0O 
 
 SAWS 
 
 SAW FILINGS AND MANAGEMENT OF* SAWS. By ROBERT GRIMSHAW. 
 A practical hand-book on filing, gumming, swaging, hammering, and the brazing of 
 band saws, the speed, work, .and power to run circular saws, etc. A handy book for 
 those who have charge of saws, or for those mechanics who do their own filing, as it deals 
 with the proper shape and pitches of saw teeth of all kinds and gives many useful hints 
 and rules for gumming, setting, and filing, and is a practical aid to those who use saws 
 for any purpose. Complete tables of proper shape, pitch, and saw teeth as well as 
 sizes and number of teeth of various saws are included. Fourth edition, revised and 
 enlarged. Illustrated. Price $1.25 
 
 STEAM ENGINEERING 
 
 AMERICAN STATIONARY ENGINEERING. By W. E. CRANE. 
 
 This book begins at the boiler room and takes in the whole power plant. A plain 
 talk on every-day work about engines, boilers, and their accessories. It is not intended 
 to be scientific or mathematical. All formulas are in simple form so that any one 
 understanding plain arithmetic can readily understand any of them. The author 
 has made this the most practical book in print; has given the results of his years of 
 experience, and has included about all that has to do with an engine room or a power 
 plant. You are not left to guess at a single point. You are shown clearly what to 
 expect under the various conditions; how to secure the best results; ways of prevent- 
 ing "shut downs" and repairs: in short, all that goes to make up the requirements 
 of a good engineer, capable of taking charge of a plant. It's plain enough for practical 
 men and yet of value to those high in the profession. 
 
 34
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 A partial list of contents is: The boiler room, cleaning boilers, firing, feeding; pumps, 
 inspection and repair; chimneys, sizes and cost; piping; mason work; foundations; 
 testing cement; pile driving; engines, slow and high speed; valves; valve setting; 
 Corliss engines, setting valves, single and double eccentric; air pumps and condensers: 
 different types of condensers; water needed; lining up; pounds; pins not square in 
 crosshead or crank; engineers' tools; pistons and piston rings; bearing metal; 'hard- 
 ened copper; drip pipes from cy Under jackets; belts, how made, care of; oils; greases; 
 testing lubricants; rules and tables, including steam tables; areas of segments; 
 squares and square roots; cubes and cube root; areas and circumferences of circles. 
 Notes on: Brick work; explosions; pumps; pump valves; heaters, economizers; 
 safety valves; lap, lead, and clearance. Has a complete examination for a license, 
 etc., etc. Second edition. 285 pages. Illustrated. Price $2 .50 
 
 ENGINE RUNNER'S CATECHISM. By ROBERT GRIMSHAW. 
 
 A practical treatise for the stationary engineer, telling how to erect, adjust, and run 
 the principal steam engines in use in the United States. Describing the principal 
 features of various special and well-known makes of engines: Temper Cut-off, Shipping 
 and Receiving Foundations, Erecting and Starting, Valve Setting, Care and Use, 
 Emergencies, Erecting and Adjusting Special Engines. 
 
 The questions asked throughout the catechism are plain and to the point, and the 
 answers are given in such simple language as to be readily understood by anyone. All 
 the instructions given are complete and up-to-date; and they are written in a popular 
 style, without any technicalities or mathematical formulae. The work is of a handy 
 size for the pocket, clearly and well printed, nicely bound, and profusely illustrated. 
 To young engineers this catechism will be of great value, especially to those who may 
 be preparing to go forward to be examined for certificates of competency; and <o 
 engineers generally it will be of no little service, as they will find in this volume more 
 really practical and useful information than is to be found anywhere else within a like 
 compass. 387 pages. Seventh edition. Price $2.00 
 
 HORSE-POWER CHART. 
 
 Shows the horse-power of any stationary engine without calculation. No matter what 
 the cylinder diameter of stroke, the steam pressure of cut-off, the revolutions, or 
 whether condensing or non-condensing, it's all there. Easy to use, accurate, and 
 saves time and calculations. Especially useful to engineers and designers. 50 cents 
 
 MODERN STEAM ENGINEERING IN THEORY AND PRACTICE. By 
 GARDNER D. Hiscox. 
 
 This is a complete and practical work issued for Stationary Engineers and Firemen, 
 dealing with the care and management of boilers, engines, pumps, superheated steam, 
 refrigerating machinery, dynamos, motors, elevators, air compressors, and all other 
 branches with which the modern engineer must be familiar. Nearly 200 questions with 
 their answers on steam and electrical engineering, likely to be asked by the Examin- 
 ing Board, are included. 
 
 Among the chapters are: Historical: steam and its properties; appliances for the 
 generation of steam; types of boilers; chimney and its work; heat economy of the 
 feed water; steam pumps and their work; incrustation and its work; steam above 
 atmospheric pressure; flow^of steam from nozzles; superheated steam and its work; 
 adiabatic expansion of steam; indicator and its work; steam engine proportions; slide 
 valve engines and valve motion; Corliss engine and its valve gear; compound engine 
 and its theory; triple and multiple expansion engine; steam turbine; refrigeration; 
 elevators and their management; cost of power; steam engine troubles; electric 
 power and electric plants. 487 pages. 405 engravings. 3d Edition. . . . $3.50 
 
 STEAM ENGINE CATECHISM. By ROBERT GRIMSHAW. 
 
 This unique volume of 413 pages is not only a catechism on the question and answer 
 principle, but it contains formulas and worked-out answers for all the Steam problems 
 that appertain to the operation and management of the Steam Engine. Illustrations 
 of various valves and valve gear with their principles of operation are given. Thirty- 
 four Tables that are indispensable to every engineer and fireman that wishes to be 
 progressive and is ambitious to become master of his calling are within its pages. It is 
 a most valuable instructor in the service of Steam Engineering. Leading engineers 
 have recommended it as a valuable educator for the beginner as well as a reference book 
 for the engineer. It is thoroughly indexed for every detail. Every essential question 
 on the Steam Engine with its answer is contained in this valuable work. Sixteenth 
 edition. Price $2.00 
 
 STEAM ENGINEER'S ARITHMETIC. By COLVIN-CHENET. 
 
 A practical pocket-book for the steam engineer. Shows how to work the problems of 
 the engine room and shows "why." Tells how to figure horsepower of engines ana 
 boilers; area of boilers; has tables of areas and circumferences; steam tables; has a 
 dictionary of engineering terms. Puts you on to all of the little kinks in figuring what- 
 ever there is to figure around a power plant. Tells you about the heat unit ; absolute 
 zero: adiabatic expansion: duty of engines; factor of safety: and a thousand and one 
 other things; and everything is plain and simple not the hardest way to figure, but 
 the easiest. Second Edition 60 centi 
 
 35
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 STEAM ENGINE TROUBLES. By H. HAMKENS. 
 
 It is safe to say that no book has ever been published which gives the practical en- 
 gineer such valuable and coniprehensive information on steam engine design and 
 troubles. There are descriptions of cylinders, valves, pistons, frames, pillow blocks 
 and other bearings, connecting rods, wristplates, dashpots, reachrods, valve gears, 
 governors, piping, throttle, and emergency valves, safety stops, flywheels, oilers, 
 etc. If there is any trouble with these parts, the book gives you the reasons and 
 tells how to remedy them. 350 pages. 276 illustrations. Price .... $2.50 
 
 BOILER ROOM CHART. By GE^. L. FOWLER. 
 
 A chart size 14 x 28 inches showing in isometric perspective the mechanism be- 
 longing in a modern boiler room. The various parts are shown broken or removed, 
 so that the internal construction is fully illustrated. Each part is given a reference 
 number, and these, with the corresponding name, are given in a glossary printed 
 at the sides. Price 25 cents 
 
 STEAM HEATING AND VENTILATION 
 
 PRACTICAL STEAM, HOT- WATER HEATING AND VENTILATION. By 
 A. G. KING. 
 
 This book is the standard and latest work published on the subject and has been pre- 
 pared for the use of all engaged in the business of steam, hot-water heating, and ventila- 
 tion. It is an original and exhaustive work. Tells how to get heating contracts, how 
 to install heating and ventilating apparatus, the best business methods to be used, 
 with "Tricks of the Trade" for shop use. Rules and data for estimating radiation 
 and cost and such tables and information as make it an indispensable work for every- 
 
 one interested in steam, hot- water heating, and ventilation. It describes all the principal 
 systems of steam, hot-water, vacuum, vapor, and vacuum-vapor heating, together 
 with the new accelerated systems of hot-water circulation, including chapters on 
 
 up-to-date methods of ventilation and the fan or blower system of heating and ventila- 
 tion. Containing chapters on: I. Introduction. II. Heat. III. Evolution of 
 artificial heating apparatus. IV. Boiler surface and settings. V. The chimney flue. 
 VI. Pipe and fittings. VII. Valves, various kinds. VIII. Forms of radiating 
 surfaces. IX. Locating of radiating surfaces. X. Estimating radiation. XI. Steam- 
 heating apparatus. XII. Exhaust-steam heating. XIII. Hot-water heating. XIV. 
 Pressure systems of hot-water work. XV. Hot-water appliances. XVI. Greenhouse 
 heating. XVII. Vacuum vapor and vacuum exhaust heating. XVIII. Miscella- 
 neous heating. XIX. Radiator and pipe connections. XX. Ventilation. XXI, 
 Mechanical ventilation and hot-blast heating. XXII. Steam appliances. XXIII. 
 District heating. XXIV. Pipe and boiler covering. XXV. Temperature regulation 
 and heat control. XXVI. Business methods. XXVII. Miscellaneous. XXVIII. 
 Rules, tables, and useful information. 367 pages. 300 detailed engravings. Second 
 Edition Revised. Price $3.5O 
 
 500 PLAIN ANSWERS TO DIRECT QUESTIONS ON STEAM, HOT-WATER, 
 VAPOR AND VACUUM HEATING PRACTICE. By ALFRED G. KING. 
 This work, just off the press, is arranged in question and answer form ; it is intended as 
 a guide and text-book for the younger, inexperienced fitter and as a reference book for 
 all fitters. This book tells "how" and also tells "why." No work of its kind has 
 ever been published. It answers all the questions regarding each method or system 
 that would: be asked by the steam fitter or heating contractor, and may be used as a 
 text or reference book, and for examination questions by Trade Schools or Steam 
 Fitters' Associations. Rules, data, tables and descriptive methods are given, to- 
 gether with much other detailed information of daily practical use to those engaged in 
 
 or interested in the various methods of heating. Valuable to those preparing for 
 examinations. Answers every question asked relating to modern Steam, Hot- Water, 
 Vapor and Vacuum Heating. Among the contents are: The Theory and Laws of 
 Heat. Methods of Heating. Chimneys and Flues. Boilers for Heating. Boiler 
 Trimmings and Settings. Radiation. Steam Heating. Boiler, Radiator and Pipe 
 Connections for Steam Heating. Hot Water Heating. The Two-Pipe Gravity 
 System of Hot Water Heating. The Circuit System of Hot Water Heating. The 
 Overhead System of Hot Water Heating. Boiler, Radiator and Pipe Connections for 
 Gravity Systems of Hot Water Heating. Accelerated Hot Water Heating. Ex- 
 pansion Tank Connections. Domestic Hot Water Heating. Valves and Air Valves. 
 Vacuum Vapor and Vacuo- Vapor Heating. Mechanical Systems of Vacuum Heating. 
 Non-Mechanical Vacuum Systems. Vapor Systems. Atmospheric and Modulating 
 Systems. Heating Greenhouses. Information, Rules and Tables. 200 pages, 127 
 illustrations. Octavo. Cloth. Price . . . . $2.00 
 
 36
 
 CATALOGUE OF GOOD, PRACTICAL BOOKS 
 
 STEEL 
 
 STEEL: ITS SELECTION, ANNEALING, HARDENING, AND TEMPERING. 
 
 By E. R. MARKHAM. 
 This 
 
 This work was formerly known as "The American Steel Worker," but on the pub- 
 lication of the new, revised edition, the publishers deemed it advisable to change its 
 title to a more suitable one. It is the standard work on Hardening, Tempering, 
 and Annealing Steel of all kinds. 
 
 This book tells how to select, and how to work, temper, harden, and anneal steel for 
 everything on earth. It doesn't tell how to temper one class of tools and then leave 
 the treatment of another kind of tool to your imagination and judgment, but it gives 
 careful instructions for every detail of every tool, whether it be a tap, a reamer or just 
 a screw-driver. It tells about the tempering of small watch springs, the hardening of 
 cutlery, and the annealing of dies. In fact, there isn't a thing that a steel worker 
 would want to know that isn't included. It is the standard book on selecting, harden- 
 ing, and tempering all grades of steel. Among the chapter headings might be mentioned 
 the following subjects: Introduction; the workman; steel; methods of heating; 
 heating tool steel; forging; annealing; hardening baths; baths for hardening; harden- 
 ing steel; drawing the temper after hardening; examples of hardening; pack harden- 
 ing; case hardening; spring tempering; making tools of machine steel; special steels; 
 steel for various tools; causes of trouble; high speed steels, etc. 400 pages. Very 
 fully illustrated. Fourth Edition. Price $3.0O 
 
 HARDENING, TEMPERING, ANNEALING, AND FORGING OF STEEL. 
 By J. V. WOODWORTH. 
 
 A new work treating in a clear, concise manner all modern processes for the heating, 
 annealing, forging, welding, hardening, and tempering of steel, making it a book of 
 great practical value to the metal-working mechanic in general, with special directions 
 for the successful hardening and tempering of all steel tools used in the arts, including 
 milling cutters, taps, thread dies, reamers, both solid and shell, hollow mills, punches 
 and dies, and all kinds of sheet metal working tools, shear blades, saws, fine cutlery, and 
 metal cutting tools of all description, as well as for all implements of steel both large 
 and small. In this work the simplest and most satisfactory hardening and temper- 
 ing processes are given. 
 
 The uses to which the leading brands of steel may be adapted are concisely presented, 
 and their treatment for working under different conditions explained, also the special 
 methods for the hardening and tempering of special brands. 
 
 A chapter devoted to the different processes for case-hardening is also included, and 
 special reference made to the adaptation of machinery steel for tools of various kinds. 
 Fourth Edition. 288 pages. 201 illustrations. Price $3.00 
 
 TRACTORS 
 
 THE MODERN GAS TRACTOR. By Major VICTOR W. PAGE. 
 
 A complete treatise describing all types and sizes of gasoline, kerosene, and oil tractors. 
 Considers design and construction exhaustively, gives complete instructions for care, 
 operation and repair, outlines all practical applications on the road and in the field. 
 The best and latest work on farm tractors and tractor power plants. A work needed 
 by farmers, students, blacksmiths, mechanics, salesmen, implement dealers, designers, 
 and engineers. 500 pages. Nearly 300 illustrations and folding plates. Price $2.50 
 
 TURBINES 
 
 MARINE STEAM TURBINES. By DR. G. BAUER and O. LASCHE. Assisted 
 by E. LCDWIG and H. VOGEL. Translated from the German and edited by 
 M. G. S. SWALIX>W. 
 
 The book is essentially practical and discusses turbines in which the full expansion of 
 steam passes through a number of separate turbines arranged for driving two or more 
 shafts, as in the Parsons system, and turbines in which the complete expansion of 
 steam from inlet to exhaust pressure occurs in a turbine on one shaft, as in the case 
 of the Curtis machines. It will enable a designer to carry out all the ordinary calcula- 
 tion necessary for the construction of steam turbines, hence it nils a want which 
 is hardly met by larger and more theoretical works. Numerous tables, curves and 
 diagrams will be found, which explain with remarkable lucidity the reason why 
 turbine blades are designed as they are, the course which steam takes through tur- 
 bines of various types, the thermodynamics of steam turbine calculation, the influence 
 of vacuum on steam consumption of steam turbines, etc. In a word, the very in- 
 formation which a designer and builder of steam turbines most requires. Large 
 octavo, 214 pages. Fully illustrated and containing 18 tables, including an entropy 
 chart. Price.net $4.00 
 
 37
 
 Every Practical Man Needs A Magazine Which 
 
 Will Tell Him How To Make And Do Things 
 
 |l l{ 
 
 Have us enter your subscription to the best mechanical 
 magazine on the market. Only one dollar and fifty 
 cents a year for twelve numbers. Subscribe today to 
 
 Everyday Engineering 
 Magazine 
 
 A MONTHLY magazine devotei whole-heartedly to Model Making, Electricity, 
 Chemistry, Mechanics, Radiotelegraphy, etc. It is a magazine with a peculiar 
 and interesting "mechanical personality" that has made many friends in the 
 past and will make many in the future. Its articles are alive with interest, lucra- 
 tive with facts and bright in appearance with their many clear illustrations and 
 their pleasant arrangement. 
 
 "Everyday's" articles are prepared by many of the best technical journalists 
 'in the United States. Among these are mechanical engineers, electrical engineers, 
 model makers, chemists and radio enthusiasts. These men write with a knowledge 
 of what the readers of Everyday like and need. Many of them are experimental 
 engineers and "hobbyists" who well know what their own class like to read best. 
 
 Do you like to make model steam engines? Do you know how high-frequency 
 alternators work? Would you like to read some understandable literature on the 
 inner nature of steel? Do you know how to manipulate a micrometer? Would 
 you like to make simple experiments in radioactivity? Do you build model power 
 racing boats or airplanes? Do you know how Diesel engines work? Do you 
 understand synthetic chemistry? Can you perform qualitative chemical analysis? 
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 "Everyday" will be your helpmate and advisor during the period of one year for 
 $1.50. 
 
 Sample copy sent on receipt of 15 cents. Send your subscription direct to 
 
 The Norman W. Henley Pub. Co. 
 
 2 West 45th Street, New York
 
 THE MOST VALUABLE TECHNO-CHEM1CAL RECEIPT BOOK PUBLISHED 
 
 Henley's Twentieth Century Book of 
 
 Recipes, Formulas 
 and Processes 
 
 Edited by GARDNER D. HISCOX, M.E. 
 
 Price Cloth . . . $3.OO 
 
 800 large octavo (6x9 J^) pages 
 
 Contains over 10,000 selected scientific, chemical, technological 
 and practical Recipes and Processes, including hundreds of so- 
 called trade secrets for every business. 
 
 TO present here even a limited numl>er of the subjects which find a place in this valuable work 
 would be difficult. Suffice to say that in its pages will be found matter of intense interest 
 and immeasurable practical value to the scientific amateur and to him who wishes to obtain a 
 knowledge of the many processes used in the arts, trades and manufactures, a knowledge which 
 will render his pursuits more instructive and remunerative. Serving as a reference book to the 
 Email and large manufacturer and supplying intelligent seekers with the information necessary to 
 conduct a process, the work will be found of inestimable worth to the Metallurgist, the Photographer, 
 the Perfumer, the Painter, the Manufacturer of Glues, Pastes, Cements, and Mucilages, the Com- 
 pounder of Alloys, the Cook, the Physician, the Druggist, the Electrician, the Brewer, the Engineer, 
 the Foundryman, the Machinist, the Potter, the Tanner, the Confectioner, the Chiropodist, the 
 Manicure, the Manufacturer of Chemical Novelties and Toilet Preparations, the Dyer, the Elec- 
 troplater, the Enaineler, the Engraver, the Provisioner, the Glass Worker, the Goldbeater, the Watch- 
 maker and Jeweler, the Hat Maker, the Ink Manufacturer, the Optician, the Farmer, the Dairyman, 
 the Paper Maker, the Wood and Metal Worker, the Chandler and Soap Maker, the Veterinary 
 Surgeon, and the Technologist in general. 
 
 A mine of information, and up to date in every respect. A book which will prove of value to 
 everyone, as it covers every branch of the useful Arts. 
 
 AMONG THE RECIPES GIVEN ARE: 
 
 Bleaching Recipes; Etching and Engraving Recipes; Recipes for Glass Making; Paper Making 
 Recipes; Recipes for Ointments; Mirror Making Formulas; Paint Making Formulas; Gilding Recipes; 
 Galvanizing Recipes; Bronzing Recipes; Tinning Recipes; Silvering Recipes; Recipes for Adhesives; 
 Recipes for Plating and Enameling; Cleaning Processes; Soap Making; Leather and its Preparation; 
 Recipes for Alloys; Recipes for Solders; Photographic Formulas; Shoe Dressing Recipes; Stove 
 Blacking Recipes; Rust Preventive Recipes; Recipes for Lubricants: Recipes for Oils; Recipes for 
 Dyes, Colors, and Pigments; Recipes for Dryers; Ink Recipes; Recipes for Artificial Gem Making; 
 Jewelers' and Watchmakers' Recipes; Household Formulas; Waterproofing Recipes; Fireprooflng 
 Recipes; Recipes for Cements, Glues, Mucilage; Fireworks Recipes; Recipes for Eradicators; Alco- 
 hol and its Uses; Recipes for Essences and Extracts; Dentifrice Recipes; Cosmetic Recipes; Perfume 
 Recipes; Tanning Recipes; Metallurgical Formulas; Hair Restorers; Depilatories. 
 
 And many thousands more Equally important in the Arts and Manufactures. 
 
 WHAT IS SAID OF THIS BOOK: 
 
 Your Twentieth Century Book of Recipes, Formulas and Processes duly received. I am glad 
 to have a copy of it, and if I could not replace it money couldn't buy it. It is the best thing of 
 the sort I ever saw. M. E. Trux, Sparta, Wis. 
 
 We can most thoroughly recommend that you obtain a copy of this book as you will find it a 
 work of the most useful character, and one that will repay its possessor if kept constantly at I " 
 side. Trade Mark Record. 
 
 Many small fortunes, and not a few large ones, have been made by the aid of a book of thia 
 character, since the receipts have all been successfully used and are known to be correct. Southern 
 Machinery. 
 
 Lack of space prevents the publisher from including other reviews of this book.
 
 JUST OFF THE PRESS NEW REVISED EDITION 
 
 Lathe Design, Construction, 
 and Operation 
 
 with 
 
 Practical Examples of Lathe Work 
 
 By OSCAR E. PERRIGO, M.E. 
 
 500 Pages (6x9) . Cloth Binding 
 
 350 Detailed Engravings made from Special Drawings 
 
 Price $3.OO 
 
 c/4 new revised edition, and the only complete American work on the sub- 
 ject, written by a man who knows not only how work ought to be done, 
 but who also knows how to do it, and how to convey this knowledge to 
 others. It is strictly up-to-date in its descriptions and illustrations. 
 
 ETHE history and the relations of the lathe to manufacturing are given; also a description of 
 the various devices for feeds and thread cutting mechanisms from early efforts in this direction 
 to the present time. Lathe design is thoroughly discussed, including back gearing, driving 
 cones, thread cutting gears, and all the essential elements of the modern lathe. The classifica- 
 tion of lathes is taken up, giving the essential differences of the several types of lathes, including, as 
 is usually understood, engine lathes, bench lathes, speed lathes, forge lathes, gap lathes, pulley lathes, 
 forming lathes, multiple-spindle lathes, rapid-reduction lathes, precision lathes, turret lathes, special 
 lathes, electrically driven lathes, etc. In addition to the complete exposition on construction and 
 design, much practical matter on lathe installation, care and operation has been incorporated in the 
 enlarged 1916 edition. All kinds of lathe attachments for drilling, milling, etc., are described and 
 complete instructions are given to enable the novice machinist to grasp the art of lathe operation as 
 well as the principles involved in design. A number of difficult machining operations are described 
 at length and illustrated. 
 
 CONTAINS SPECIAL CHAPTERS ON: 
 
 I. History of the Lathe up to the Introduction of Screw Threads. II. The Development of the 
 Lathe Since the Introduction of Screw Threads. III. Classification of Lathes. IV. Lathe Design 
 The Bed and Its Supports. V. Lathe Design The Head-Stock Casting, the Spindle and the Spindle 
 Cone. VI. Lathe Design The Spindle Bearings, the Back Gears and the Triple Gear Mechanism. 
 VII. Lathe Design The Tail-Stock, the Carriage, the Apron, etc. VIII. Lathe Design Turning 
 Rests, Supporting Rests, Shaft Straighteners, etc. IX. Lathe Attachments. X. Rapid Change Gear 
 Mechanisms. XI. Lathe Tools, High-Speed Steel, Speeds and Feeds, Power for Cutting Tools, etc. 
 XII. Testing a Lathe. XIII. Lathe Work. XIV. Lathe Work Continued. XV. Engine Lathes. 
 XVI. Engine Lathes Continued. XVII. Heavy Lathes. XVIII. High Speed Lathes. XIX. Special 
 Lathes. XX. Regular Turret Lathes. XXI. Special Turret Lathes. XXII. ElectricaHy Driven 
 Lathes. XXIII. Practical Instructions on Lathe Operation. 
 
 WHAT IS SAID OF THIS BOOK : 
 
 The book is written in a clear and interesting style and evefy page shows how thoroughly the 
 author has mastere* 1 his subject. Locomotive Engineering. 
 
 The book treats the subject in a clear and comprehensive manner. Boiler Maker. 
 
 Just the kind of a book which one delights to consult; a masterly treatment of the subject 
 
 Engineering Newt.
 
 JUST PUBLISHED 
 
 Drop Forging, Die Sinking 
 
 and 
 
 Machine Forming of Steel 
 
 By JOSEPH V. WOODWORTH 
 
 Author of " Dies : Their Construction and Use," " American Tool 
 Making and Interchangeable Manufacturing, etc." 
 
 326 Pages (6x9) 300 Illustrations Cloth Binding 
 
 Price $3.OO 
 
 This is a practical treatise on the hot and cold machine forming of steel 
 and iron into finished shapes; together with tools, dies and machinery 
 involved in the manufacture of duplicate forgings and interchangeable hot 
 and cold pressed parts from bar and sheet metal. 
 
 A COMPREHENSIVE and modern book on Drop Forging, Die Sinking, etc., has long been 
 /\ desired, and the publishers now offer such a volume written by an expert. The text of the 
 A^m. treatise is concise; technical and ambiguous terms have been replaced by practical and 
 familiar shop words; and all the illustrations and descriptions are plain and simple to under- 
 stand. The description of every subject and method involved has been boiled down to the 
 simplest and fewest words possible; so that the "meat" of all may be arrived at and digested in the 
 shortest time by the busy men of metals who will consult its pages, which contain a valuable mine 
 of information on modern shop practice, processes, methods, machines, tools and details. This is a 
 useful book of reference and one worth reading from cover to cover. 
 
 THIS EXCELLENT TREATISE IS FULL OF FACTS ON: 
 
 Die Sinking and Drop Forging Practice and Design for Modern Forging, Pressing and Stamping 
 of Duplicate Parts Die Sinking Methods, Processes, Machines and Tools Drop Forging Dies, 
 Their Design, Construction and Use in Drop Hammer and Forging Machine Press Forming of 
 Heavy Hot and Cold Stock in Dies Drop Forging and Hardening Plants; Their Designs, Funda- 
 mental Conditions and Equipment Involved in Their Attainment Steel and Iron, Their Treatment 
 for Twisting, Reducing, Forging and Working in Drop Dies Hot Pressed Steel and Iron Parts; 
 Their Manufacture and Assembling into Finished Products Drop Hammers, Their Development, 
 Weights, Foundations and Dies Forging Machine, Steam Hammer, Bulldozer and Swaging Machine 
 Methods and Processes Machine Forging wjtfc Examples of Modern Practice and Tools Involved., 
 
 WHAT IS SAID OF THIS BOOK: 
 
 The author is to be commended for this much needed work. Engineering Record. 
 A book worth reading from cover to cover. American Cutler. 
 The author's style is clear and direct. Engineering News. 
 
 This book is written from a thoroughly practical point of view and will prove extremely use- 
 ful. Scientific American. 
 
 This is a practical treatise by a practical man and covers many phases of a subject upon which 
 there has thus far been little literature. American Metal Market.
 
 JUST PUBLISHED SIXTH REVISED EDITION 
 
 Machine Shop Tools and 
 Shop Practice 
 
 Their Construction, Operation and Manipulation, 
 Including both Hand and Machine Tools 
 
 By W. H. VANDERVOORT, M. E. 
 555 Pages (6x9 K) 673 Illustrations Cloth Binding 
 
 Price $4.25 
 
 entirely new and fully illustrated work describing in every detail the 
 construction, operation and manipulation of both hand and machine tools : 
 being a work of practical instruction in all classes of machine shop practice. 
 
 A BOOK that should be found in every machine shop. Suppose it is desired to know how to cut 
 
 /\ bevel gears, to calculate milling machine spirals or to make countershaft calculatfons ; or to get 
 
 /""% information about tap drill sizes, the classification of files; change gear calculations; deep hole 
 
 drilling ; turning tapers ; testing lathes, etc. ; or any one of the numerous questions that a little 
 
 information might be desired upon occasionally these pages will be found to contain the satisfactory 
 
 answer. The book has numerous tables, and in addition to the chapters strictly on tools are several 
 
 on fastenings, gearing, belting, shafting, and the treatment of steel. 
 
 The work is logically arranged; the various hand and machine tools being grouped into classes. 
 and description of each is given in proportion to their relative importance. The illustrations repre- 
 sent the very latest tools and methods, all of which are clearly described. Each tool is considered 
 from the following points: First Its construction with hints as to its manufacture. Second Ita 
 operation, proper manipulation and care. Third Numerous examples of work performed. 
 
 SPECIAL CHAPTERS ON 
 
 /I. The Hammer and Cold Chisel. II. The File and Filing. III. Scrapers and Surface Platea. 
 IV. Standards of Measures. V. Calipers. VI. Gauges and Indicators. VII. Rules, Squares and other 
 Small Tools. VIII. Drills. IX. Reamers. X. Screw Threads, Tap and Dies. XI. Drill and Tap 
 Holders. XII. Mandrels. XIII. The Lathe. XIV. The Lathe in Modified Forms. XV. Lathe 
 Tools. XVI. Chucks and Drivers for Lathe Work. XVII. Lathe Work Between Centers. XVIH. 
 Lathe Work on Face Plate Chuck and Carriage. XIX. Boring and Turning Mills. XX. Planing and 
 Shaping Machines; their Tools and Attachments. XXI. Planer and Shaper Work. XXII. The 
 Slotting Machine and Key Seater. XXIII. Milling Machines. XXIV. Milling Machine Cutters. 
 XXV. Milling Machine Work. XXVI. Gear Cutters and Gear Cutting. XXVII. Drilling Machines 
 and Drilling Work. XXVIII. Grinding Machines. XXIX. Hardening and Tempering. XXX. 
 Fastening. XXXI. Gearing. XXXII. Belting and Transmission Machinery. XXXIII. Miscel- 
 laneous Shop Equipment and Conveniences. XXXIV. Useful Data and Tables. 
 
 WHAT A CUSTOMER SAID OF THIS BOOK: 
 
 *** I am just in receipt of the book "Modern Machine Shop Tools" by Vandervoort. I am very 
 much pleased with it. It is a masterpiece on the machine shop. Comprehensive, thorough and con- 
 cise. It is a decided improvement on the many works on the same subject. 
 
 (Signed) E. H. WILMARTH, 
 Instructor in Shop Work, Stout Manual Training School. 
 
 Menomonie. Wis. 
 
 This book is strictly up to date in all respects and is the most complete, concise and useful work 
 ever published on the subject. No machinist can afford to be without this book. Scientific American.
 
 By OSCAR E. PERRIGO, M.E. 
 
 101 Pages (5^x8) 
 
 Illustrated 
 
 Cloth Binding 
 
 Price $1.25 
 
 cA practical book for every designer, draftsman, and mechanic 
 interested in the invention and development of the devices for 
 feed changes on the different machines requiring such mechanism. 
 All the necessary information on this subject is taken up, 
 analyzed, classified, sifted, and concentrated for the use of 
 busy men who have not the time to go through the masses of 
 irrelevant matter with which such a subject is usually encum- 
 bered and select such information as will be useful to them. 
 
 (HE author shows the beginning of this class of devices, how they were developed by others, 
 the methods of their working, their differences from others designed for like purposes, and in 
 what points they were similar to other devices intended to effect the same results. All their 
 details are clearly brought out, illustrated, and described so as to show the designer and the 
 mechanic just the points they want to know. 
 
 It shows just what has been done, how it has been done, when it was done, and who did it. 
 It saves time in hunting up patent records and re-inventing old devices. 
 
 CONTENTS: 
 
 Introduction Some Lathe History The Change Gear Patents Recent Advances in the 
 Invention of Change Gear Devices Conclusion. 
 
 Bevel Gear Tables 
 
 66 Pages 
 
 By D. Ag. ENGSTROM 
 
 Illustrated 
 
 Price $1.25 
 
 Cloth Binding 
 
 A BOOK that will at once commend itself to mechanics and drafts- 
 men. Does away with all the trigonometry and fancy figuring 
 on bevel gears and makes it easy for anyone to lay them out or 
 make them just right. There are 36 full page tables that show every 
 necessary dimension for all sizes or combinations you're apt to 
 need. No puz/ling figuring or guessing. Gives placing distance, all the 
 angles (including cutting angles) , and the correct cutter to use. A copy 
 of this prepares you for anything in the bevel gear line. 
 
 CONTENTS: 
 
 Tooth Elements Tooth Elements for Diametrical Pitches Tooth Elements for Circular 
 Pitches Table-Value Reduced for Circular Pitches Construction of Bevel Gears Explanation of 
 Terms Calculating Bevel Gears Forms of Teeth in Bevel Gears How Tables are to be Used 
 How to Use Tables When Number of Teeth is Greater than Given in Tables, Etc., Etc. 
 
 WHAT IS SAID OF THIS BOOK: 
 
 For draftsmen and others having much to do with bevel gears this book is of decided value. 
 American Machinist.
 
 SEVENTH EDITION 
 
 Machine Shop 
 Arithmetic 
 
 131 Pages (4x6) 
 
 By COLV1N-CHENEY 
 
 Price 6O Cents 
 
 Cloth Binding 
 
 <HIS is an arithmetic of the things you have to do with daily. It tells you plainly about: How 
 to find areas of figures how to find surface or volume of balls or spheres handy ways for 
 
 T! 
 calculating about compound gearing cutting screw threads on any lathe drilling for taps 
 speeds of drills, taps, emery wheels, grindstones, milling cutters, etc. all about the Metric 
 system with conversion tables properties of metals strength of bolts and nuts decimal equivalent 
 of an inch. All sorts of machine shop figuring and 1001 other things, any one of which ought to be 
 worth more than the price of this book to you, and it saves you the trouble of bothering the boss. 
 
 CHAPTERS CONTAINED ARE: 
 
 Decimals. Conventional Rule for Square Root. Conventional Rule for Cube Root. 
 Mensuration. Rules for Selecting Change Gears for Screw Cutting. Depth of V Threads. 
 for Taps. Bolts and Nuts. Speed of Pulleys and Gears. Calculating Speed of Milling 
 Drills or Work. Speeds of Drills and Taps. Speeds of Grindstones. Principles of Square Root. 
 Principles of Cube Root. Foundation Principles. Principles of Screen Cutting. Handy Ways for 
 Calculating. Allowances for Running and Force Fits. Metric System of Measurements. 
 
 Formulas. 
 . Drilling 
 g Cutters. 
 
 Shop Kinks 
 
 By ROBERT GRIMSHAW 
 400 Pages (5x7 H) 224 Illustrations Cloth Binding 
 
 SHOP 
 KINKS 
 
 Price $3.OO 
 
 A most useful book for the machinist, containing trade 
 secrets and mechanical shop wrinkles. 
 
 A BOOK entirely different from any other book on machine shop practice. Departing from 
 conventional style, the author avoids universal or common shop usage and limits his work to 
 showing special ways of doing things better, more cheaply and more rapidly than usual. As 
 a result the advanced methods of representative establishments of the world arc placed at the 
 disposal of the reader. --" 
 
 i reader. This book shows the proprietor where large savings are possible, and how 
 products may be improved. To the employee it holds out suggestions that, properly applied, will 
 dvancement. No shop can afford to be without it. It bristles with valuable wrinkles 
 
 hasten his ac 
 
 ___________________ No shop can __________ ____________ _. ________ ______ 
 
 and helpful suggestions. It will benefit all, from apprentice to proprietor. Every machinist, at any 
 age, should study its pages. 
 
 AMONG THE CONTENTS ARE: 
 
 Lathe Speed; Lead Screw; Grinding Lathe Centers and Spindles; Cut-off Centers; Tube Centers; 
 Centers Right and Wrong; Testing Centers; Alignment of Centers; Setting Lathes; Bell Chucks: 
 Spring Chucks; Milling Vise; Tool Clamps; Tool Holders; Gauges; Center Drilling: Combination 
 
 Drill and Countersink; Center Reamer; Centering Devices; Chasing; Curve Boring; Turret Lathe 
 Tools; Special Tool Holder; Squaring Up Connecting Rods; Turning Vulcanized Fibre; Turning and 
 Key Seating Shafting; Counterbalancing Cranks; Slide Rest; Making Reamers; Step Reamer; 
 Standard and Adjustable Reamers; Planers; Quick Return, Open Side and Holding Work; Planer 
 Chucks; Hollow Planing and Large Work; Planer Parallels and Gage Blocks; Cutting Gears on Planer 
 and Slottor; Boring Cylinders and Large Holes; Boring Bars; Work on the Drill Press. Clamping Jig 
 Mid Clamps; Starting aiid Centering Drills; Drilling Hard Steel; Drilling Glass; Splicing Drills, etc.
 
 JUST PUBLISHED 
 
 FOURTH EDITION, REVISED AND ENLARGED 
 
 Its Selection, Annealing, Hardening 
 and Tempering 
 
 By E. R. MARKHAM 
 
 400 Pages (5x7 J^) Cloth Binding 
 
 168 Specially Prepared Illustrations 
 
 Price $3.OO 
 
 This work was formerly known as "THE AMERICAN STEEL WORKER," but on the pub- 
 lication of the present edition, the publishers deemed it advisable to change the title to a more comprehensire 
 3ne, viz: "Steel, Its Selection, Annealing, Hardening and Tempering." 
 
 THIS book tells how to select and to know the steel best suited to various purposes ; gives reasons 
 for the different steels ; how to heat in the making of everything in the way of tools made from 
 steel ; how to proceed in the making of taps, reamers, drills and milling cutters ; how to harden 
 dies and punches from the largest to the smallest; about the tempering of springs, from watch 
 springs up; about saws, chisels, and other wood- working tools; about pack and case hardening; 
 how to anneal; about heating apparatus, the kinds to use for the best results, and how to make such 
 heating apparatus right at home if it becomes necessary; gives formulas for mixtures for baths for 
 different purposes, and gives good reasons why each is best adapted to its special work. In fact, 
 there isn't a thing that a steel worker would want to know that isn't included within its pages. 
 
 Mr. Markham has been selecting, annealing, hardening, tempering and studying steel for nearly 
 thirty years and is still at it. There's a reason for every failure you have and a remedy. You'll 
 find them both in this book; and it will be mighty handy to have a copy to look over when something 
 goes wrong and you want to get it going right without any delay. 
 
 There are new Sections on High Speed Steels, High Carbon Steel, Electric and Salt Bath Furn- 
 aces and Ovens. This makes the book more valuable than ever. A copy ought to be in the hands of 
 every wide awake mechanic and in every shop library in the country and it will be when its value 
 is fully realized. Its pages are full of practical information that you cannot find elsewhere. 
 
 AMONG SOME OF THE SUBJECTS TREATED ARE 
 
 The Workman Steel Methods of Heating Heating Tool Steel Forging Annealing Hard- 
 ening Baths Baths for Hardening Hardening Steel Drawing the Temper after Hardening 
 Examples of Hardening Pack Hardening Case Hardening Spring Tempering Making Tools of 
 Machine Steel Special Steels Steel for Various Tools Cases of Trouble Welding High Speed 
 Steels High Carbon Steel Electric and Salt Bath Furnaces and Ovens. 
 
 WHAT IS SAID OF THIS BOOK: 
 
 We are glad to note the appearance of this excellent book. No tool maker or steel worker can 
 make a mistake in buying a copy of this publication. American Machinist. 
 
 Contains 400 pages of solid information. American Blacksmith. 
 
 Every machine shop superintendent and tool-room foreman ought to possess a copy of this 
 valuable book, and engineers in charge can save their firms money by circulating it in their work- 
 shops where fine steel tools are made. The Canadian Engineer. 
 
 All who are interesteu in the subject should secure a copy of this work and from it learn all 
 that is to be known regarding steel and its use. 
 
 This is among the best technical books published, and will prove a valuable aid to every one 
 who has anything to do with the making of steel for any purpose whatever. National Builder.
 
 Practical 35 Cent Books 
 
 These are Monographs in which thoroughly practical men give definite in- 
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 are full of just the practical points you want to know; they are well printed 
 and bound in handsome paper covers. 
 
 TURNING AND BORING TAPERS 
 
 By Fred H. Colvin 
 Associate Editor "American Machinist" 
 
 There are two ways to turn tapers; the right way and one other. This treatise has to do with 
 the right way; it tells you how to start the work properly, how to set the lathe, what tools to use 
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 Price 35 cents. 
 
 DRAFTING OF CAMS 
 
 By Louis Rouillion 
 
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 THREADS AND THREAD CUTTING 
 
 By Colvin-Stabel 
 
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 threads, catching threads, use of hobs, etc. Contains a lot of useful hints and several tables. Third 
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 COMMUTATOR CONSTRUCTION 
 
 By William Baxter, Jr. 
 
 The business end of any dynamo or motor of the direct current type is the commutator. This 
 book goes into the designing, building, and maintenance of commutators; shows how to locate 
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 BRAZING AND SOLDERING 
 
 By James F. Hobart 
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 O IT .C; L/ 1 A 1-f V^rrr/IX. if or dered at one time, on receipt of $1.50.
 
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