Norton Abrasives at Work in Industry

Grinding as the Common Denominator of Mass Production

BY ARTHUR POUND ¹

I

THIS series on twelve great fabricating industries began on the note of Precision and Perspective. The first article, that on General Motors, bore that phrase for a title. Each of the subsequent articles presented various phases of the relationship between precise manufacturing methods and the satisfaction of public needs through improved goods and services. The series ends, with this article on the Norton Company, on the same note of precision and perspective. Purposely this article has been held for the final position because Norton products — abrasives in many forms — enter directly or indirectly into all the complicated fabricating and processes which have been discussed.

Grinding is a common denominator of refined fabrication. In metals it has become the essential element of machine practice, both in the creation of better machines for all lines of production and in the operation of those machines in the quantity output of consumers’ goods. The automobile, steel, electrical, and paper industries, in their later phases, all owe to abrasives a large part of their ability to supply quality goods at low cost, while the efficiency of the other industries studied depends largely on machine equipment ground and finished to better than hairline precision. The shining stainless pipes of the modern dairy, the massive steel beds on which plate glass is carried under the polishing pads, the trim machines which shape and test tin cans in endless procession, the presses which give shape to asbestos products, the mighty valves which control the passage of oil through the refinery, and the steel rolls which turn wheat into flour — all these take shape and depend for repair upon grinding machines and grinding wheels. There is scarcely an aspect of modern industry which could function at its present speed and effectiveness if grinding had failed to advance with other branches of applied science.

II

The use of abrasives is as old as the hills which provided primitive warriors with stones on which to grind their arrowheads. You use abrasives when you bring a lead pencil to a point on a piece of sandpaper. Hardly a dwelling or a piece of furniture stands in the world that has not felt the smoothing touch of an abrasive. But the natural abrasives in the hand of man could not cope with all the grinding tasks set up by the delicate requirements of modern industry as it developed increasingly hard materials and advanced to new’ standards of precision. In this transition the Norton Company of Worcester, Massachusetts, through its research, inventions, and policies, has earned a proud place in American industrial history by pioneering in the manufacture of artificial abrasives and their machine use at high speeds.

The centre of this great business, now basic and world-wide in scope, remains in Worcester, where it took root many years ago as a pottery. F. B. Norton, however, was a potter willing to flirt with a new idea; and when one of his employees suggested making a grinding wheel out of emery, in 1873, he agreed to back the effort. After six years of trial and error, finally crowned with success, the Norton emery wheel came to market. Another six years and Norton Emery Wheel Company was formed, just fifty years ago. With Mr. Norton at that time were John Jeppson, master craftsman, who almost singlehanded mixed, fired, trued, and sold the early output, and Charles L. Allen, bookkeeper, later General Manager for forty-eight years, then President and now Chairman of the Board. This group was joined by two professors of science from Worcester Polytechnic Institute, Milton P. Higgins and George I. Alden, who gave the Norton Company the benefit of their trained minds and accurate knowledge while continuing their teaching careers, and later became active in Company affairs. Their influence brought Norton into the orbit of applied science at a time when most American industries were still following rule-of-thumb methods, and left with the institution a tradition of exact methods. In 1886 the Company built at Barber’s Crossing, north of Worcester, a modest building forty-two feet by one hundred, which still stands as part of the vast Norton factories on the present site.

Scientific aid proved timely, for revolutionary changes were in train for all American industry and particularly for the abrasive arts. By the end of the century the possibilities of the natural grits, emery and corundum, had been exhausted. The industry turned to two types of artificial abrasives, both products of the electric furnace. First in the field was silicon carbide, made from silica sand, coke, and sawdust. Possessing hard, sharp, though somewhat brittle crystals, it was suited to grinding the materials low in tensile strength. Its limitations soon became apparent. The next great gift to the industry was an aluminum oxide abrasive, produced by fusing the mineral bauxite, a Norton development which was trade-named Alundum. Manufacture of the abrasive which was to become so successful in the working of steel and steel alloys began at Niagara Falls in 1901.

About the turn of the century occurred two seemingly unrelated happenings which were to join forces with tremendous vigor. The automobile, after several false starts, swung into its stride with the initial commercial success of Olds Motor Works at Detroit. At the same time Charles H. Norton was designing his first cylindrical grinding machine at Providence, Rhode Island. He found a willing backer in the grinding wheel company at Worcester and in 1900 the Norton Grinding Machine Company was established.

Here was precisely the medium the automobile industry needed to shape interchangeable parts to close measurements from tough stock at low cost, an abrasive that could stand the gaff and, properly bonded, grind the common metals down to a thousandth of an inch, thereby eliminating expensive lathe work. Here, too, was a machine on which grinding wheels of greater breadth could be mounted and moved transversely, under accurate and mechanically controlled guidance, across securely held metals. From the start the combination of Alundum wheels and Norton machines was ideal for grinding the all-important crankshafts and camshafts. For years leading automobile makers sent camshafts to Worcester to be ground; but gradually, as Norton machines and wheels became more common and more mechanics mastered the art of grinding, this practice lapsed, until to-day every automobile factory has in its shops employees equal to the most delicate tasks required.

Norton has never been content to rest on its priority in past performances, or to attempt quick profit at the expense of industry as a whole. Its superior knowledge of the grinding art was early placed at the service of manufacturers and mechanics, and education of the men behind the machines the country over has always been one of its chief concerns. Norton has for years presented technical lectures and demonstrations in industrial towns and cities so that a more intimate and comprehensive knowledge of abrasives and grinding-machine manufacture might be passed along to supervisors and operators interested in their application. That is perhaps one reason why Norton innovations encounter so little resistance in the shops among men naturally conservative. Here is registered Norton’s faith that every improvement in grinding widens the field for abrasives and that this ever-broadening use more than makes up in the long run for decrease in immediate sales caused by wheels that last longer and do more work.

III

Artificial abrasives are born in the electric furnace. Norton established its first electric furnace plant in 1901 at Niagara Falls, where cheap current was available, and its second across the Niagara River in Chippawa, Ontario, in 1910. The Chippawa plant is now the largest electric-furnace operation in the world for the production of abrasives, with an annual capacity of 50,000 tons of Alundum and Crystolon abrasives.

In this great plant one sees bauxite ore being transformed into Alundum abrasive in long rows of Higgins watercooled, arc-type pot furnaces, invented in 1904 by Aldus C. Higgins, now President of the Norton Company. Mr. Higgins received the John Scott medal for this basic improvement, which made the steel furnace capable of holding and utilizing heats which otherwise would have destroyed the shell. Out of these furnaces come huge white-hot ingots, the core of which is almost pure aluminum oxide, ready, after cooling, for granular division into the various abrasive sizes.

Crystolon, or silicon carbide, the other standard abrasive for high-speed work, is made in resistance furnaces from sand, coke, and sawdust. The sand is almost pure silica; the coke, source of carbon, is the best grade obtainable; the sawdust is hardwood residue from lumber camps, and effective chiefly in lightening the mix to permit easy escape for gases. Under electric heat the mix cooks long and thoroughly, shrinking the while; and when the core has been cleared of sinter the humble coke and sand have been transformed into a mass of iridescent crystals, running from light blue to black-green, which in the course of time will be buffing leather, grinding metals and wood pulp, smoothing automobile finishes, and cutting granite.

IV

Ever since Charles H. Norton built his first cylindrical grinder in 1900, a feat which years later was recognized by the award of the coveted John Scott medal, the Norton Company has been building, in the best New England tradition, machinery for use in the abrasive arts. For a century Worcester has enjoyed a reputation for machine design and construction and Worcester workers have been nurtured in a tradition of machine precision. In the beginning the Norton grinding machine was an important element in opening the market for Norton abrasives; where other abrasive manufacturers could offer only the materials for the new grinding technique, Norton offered both materials and machines, thereby clearing the path to increased efficiency at one sweep. At once a close and enduring relation arose between Norton and the users of Norton abrasives. Through the years Norton leadership grew naturally out of this union of machine building and abrasive production.

Norton’s first grinding machine removed one cubic inch of metal per minute, with greater accuracy than ever before known. Both in quantity and in quality of work it more than met all the inventor’s claim for economy, becoming a cutting tool as well as a finishing tool. Since then Norton machines have been developed to the point where capacity for removing metal has reached twelve cubic inches per minute, while accuracy of grinding has risen from a thousandth of an inch to a fraction of a ten-thousandth. Divide a cross section of a hair of your head thirty times and a Norton grinder will match that minute measurement in repeat operations. The trend has been away from the original general-purpose grinder toward specialized machines to cope with the growing refinement in shop practices; at present Norton makes approximately one hundred machines of various sizes and types. Among recent developments are lapping machines, which bring ground surfaces to still further smoothness by removing the microscopic marks left by grinding wheels.

Throughout the entire industrial world, but particularly in the ironworking industries, the grinding machine has become indispensable to quantity manufacture in a degree incomprehensible to the hurrying public that daily uses its products. It is one of the decisive hidden factors in the low cost and high output of machine tools, automobiles, locomotives, woodworking machinery, automatic refrigerators, armament, printing presses, cash registers, typewriters, adding machines, linotypes and monotypes, and agricultural equipment from simple hand tools to mammoth combination reapers and binders. The automobile industry, dependent for its amazing advances upon complete interchangeability of machined parts, could hardly have reached its present volume but for the steady increase in accuracy at low cost made possible by the grinding machine. No machine development of the past century has affected more profoundly the efficiency of manufacturing precision goods, and through them the way of life of the people.

V

Norton research, now represented by three staffs, has played a master rôle in the development of abrasives ever since the industrial developments of the turn of the century brought precision grinding into new importance. The Norton conception of research is eminently practical, in natural reaction to industry’s unremitting pressure for better grinding tools and materials. An example was the demand which the automobile industry raised when the practice of buffing solder placed labor in danger of lead poisoning in an industry highly cautious against that menace. In response, the Behr-Manning division research staff developed waterproof grinding disks, in order that dangerous dust could be wet down and washed away by water at every point in the operation.

Another research rescue by Norton followed the development of the socalled cemented carbides. Tools made of these new products were of superior hardness and cut extremely well; but they were difficult to condition. Norton met this challenge by creating the diamond (bort) wheel, the abrasive consisting of crushed diamonds of commercial grade. These wheels immensely widened the field of utility for cemented carbides; in addition, their use penetrated other industrial processes of most precise nature, rendering commonplace certain refined operations in grinding which had never been commercially possible before.

The above were special quests, undertaken to relieve distressed customers and meet the more demanding requirements of advancing industry. An equally important class of research problems arise through the chronic dissatisfaction of research scientists with existing products and processes. At first these may be general quests, originating with an individual’s idea that improvement is possible; but as the search proceeds it involves teamwork of all members and sections. In each branch of science experts carry the search along until what was at first merely an idea has been materialized, manufactured, tested, and sold.

A new product discovered through this indirect approach is Norbide, the trade name for Norton boron carbide, a compound of such extreme hardness that it ranks next to the diamond in the hardness scale. The research staff at Chippawa, constantly experimenting with various carbon compounds in their electric furnaces, found new ways of combining carbon and boric acid. Norbide is making its way in powdered or grain form as lapping material for tasks requiring extreme precision, and in moulded forms, such as nozzles for sandblasting, where utmost hardness is needed to resist intense wear. However, no one knows how far any new material will go in industry once the formula has been found for its successful manufacture. The artificial abrasives which are now the foundation of the grinding art were once highly expensive; but with increasing demand ways were found to cheapen them until they could become the backbone of quantity production. This may be equally true of Norton’s new find under changing conditions.

More meaningful from the standpoint of immediate acceptance on a broad scale, because it could be applied promptly to large use, is the now famous ‘B’ bond.

Norton’s experience with bonds ran back fifty years, to the pioneer days when grinding wheels occasionally burst under stress, and extreme precautions for safety marked the rise of the company. In the meantime Norton had developed and adopted shellac, silicate of soda, Bakelite, and rubber bonds for special purposes, but the standard bond for grinding wheels remained vitrified bond, a clay bond which under the intense heat of firing turns to glass, tough, highly resistant glass capable of holding abrasive grains under tremendous stresses. These clay glasses offer a wider range of materials and qualities than the other bonding materials; if the ideal materials existed they would probably be discovered in this field. Before these were found, however, between two hundred and three hundred different glasses were made and studied until at last the correct formula was reached and industry was given a superior cutting tool.

In this long search all sections of the Norton laboratories coöperated. The microscopic section studied glass samples with the petrographic microscope, which reveals the shape and nature of crystals, identifies the elements in the compound, and shows the distribution of the elements more clearly than chemical analysis. Physical chemists ran qualitative tests; industrial physicists studied the new bond with relation to the plant problems of mixing, refining, and firing. Ceramic engineers considered the application of the new products in factory processes; mechanical engineers experimented with the machine phases of the problem. When the time came to put ‘B’ bond into production, Norton followed its usual procedure of keeping the development research in control of those particular factory processes until the new materials had been manufactured, shipped, and tested in use in the production plants of its customers. Not until the worth of the new bond has been proved up to the hilt under widely varying conditions in actual commercial work is a Norton innovation left to the usual factory control staff. In this case five years elapsed between the conception of this research problem and its materialization as a fully tested and standardized Norton product definitely proved to be dependable and superior in grinding precision.

‘B’ bond overcomes undesirable features which unfit ordinary vitrified bonds for precise tool and cutter work — chemical reactions which occur during burning in the kiln and physical strains which develop during subsequent cooling. These affect adversely the internal arrangement of the grains, or abrasive cutting points of the wheel, and also the strength — uniformity of the bond. Gripping each individual abrasive grain uniformly, ‘B’ bond makes for slow wearing and cool, free cutting.

A grinding wheel may weigh anything from ten tons to ten grams, and its work may be anything from grinding logs into pulp to slotting a fountain pen. But, whatever the size or material, all wheels consist of three factors — the abrasive which removes the material, the bond which holds the abrasive in place, and the pores or air spaces which permit the chips to escape during the grinding operation. The relation of these three factors determines the serviceability of the tool both in quality and quantity of work and in length of life. If their relationship changes even slightly during stress of work, the result is something less than perfection. Variations were not important in the early days of industrial grinding; but with the growing use of harder and more expensive steels, and the pressure toward greater accuracy, every grinding improvement became a vital step in industrial efficiency.

Control of structure is another contribution of Norton research, through which the actual spacing of the abrasive grains — the tiny cutting particles — is accurately regulated. Each spacing of the grains — each structure — is designated by a definite symbol and can be specified and duplicated at any time, just as grain size and grade are specified. The result is ability to provide customers with wheels more rigidly standardized than wars possible before.

Once a Norton product has been standardized for production and sale, its control passes from research to the general inspection staff, which continues the routine work of inspection along lines laid down by research, referring to the latter department only special cases. The research department, however, maintains a check of all Norton products made in the foreign plants. From the Canadian plant at Hamilton, Ontario; the French at La Courneuve, near Paris; the British plant at Welwyn Garden City, near London; the German plant at Wesseling, near Cologne; and the Italian plant at Corsico, near Milan, samples are sent to Worcester for elaborate tests in order that Norton products may be kept to rigid quality the world over, establishing the same confidence among foreign users as at home.

VI

Norton’s foreign plants, situated in the great industrial nations, are becoming vital links in a world-wide system. Each is the answer to a commercial necessity arising out of tariffs, variations in exchange values, quota systems, or some other factor interfering with the flow of American-made abrasive products in foreign trade. Norton would have preferred to keep all this work at home, but under present world conditions this is impossible. The products from the Norton abrasive plant are transferred to Worcester, where they are crushed to commercial grain sizes and separated into various sizes for further manufacture both at home and abroad. The finished material of the Chippawa plant becomes in turn the raw material of the Worcester plant, and part of that volume, as semifinished material, goes abroad to become the raw material of overseas operations. Part of the work has been saved for American labor, and at the same time each of the leading foreign industrial countries is assured of safe domestic production of abrasives, a matter of such moment to industrial welfare and national defense that abrasive manufacture would have gone forward there in any case, whether Norton had coöperated or not.

VII

As the Norton Company advanced from emery toward the more competent artificial abrasives, it shortened its name; and through astute national advertising has managed to make the word Norton synonymous with abrasives. To give complete abrasive service, Norton entered allied fields through combination with Behr-Manning Corporation at Troy, New York, and the Pike Manufacturing Company, now the Norton Pike Company, situated at Littleton, New Hampshire.

Behr-Manning makes sandpapers and other coated abrasive products in bewildering variety, using as its abrasives flint (really quartz), emery, garnet (from the Adirondacks), Alundum and Crystolon grains (supplied by Norton). Itself a merger of the Herman Behr and Manning interests, this company maintains decisive leadership in its field. In a plant filled with originally designed machinery, the chief exhibit is the electro-coating or ‘Lightning’ process, by means of which high electrical charges automatically sort abrasive grains into even spacing at minute distances from each other and draw them into the bonding glue in the upright position where they perform best. Until one visits Behr-Manning, he never dreams how complicated the abrasive business is, even with as apparently simple a commodity as sandpaper.

The Norton Pike Company can trace its ancestry back to 1823, when the Pike Manufacturing Company was established for the purpose of converting New Hampshire rock into scythestones. As time passed, products made of natural stones found in half a dozen different states and several foreign countries were manufactured to meet specific sharpening requirements. Of these, the most distinctive products are those made from the Arkansas novaculites, used for sharpening surgeons’ and engravers’ tools. With the introduction of artificial abrasives, the widely known India oilstones, made from Norton Alundum abrasive, were brought on the market, followed by others made from the silicon carbide abrasive Crystolon. Thus all abrasive demands from the hardware trade and the household user have been included in the Norton line.

In addition to these standard products, Norton markets a broad range of abrasive goods in other forms. For the building trade it manufactures nonslip floors, tiles and treads in a wide variety of colors and designs, providing sure traction. Or it will sell you Alundum aggregate and tell you how to mix it with terrazzo and cement for walkways where traffic is heavy. Its porous plates, practically indestructible filters, are used not only in laboratory work but in the activated sludge type of sewerage disposal plants. Abrasive grains for polishing can be bought in all sizes. Norton bricks and sticks are available for all manner of cleaning, smoothing, and polishing jobs. The high resistance of Norton abrasives to heat makes Norton refractories available for many furnace operations beyond the range of ordinary firebrick. The huge Norton pulpstones are converting logs of the forest into pulp for newsprint. These materials represent as yet only a fraction of Norton’s production, but they are part of the Norton plan to anticipate market needs by research and development, providing complete coverage in abrasives even though new products are brought out in advance of effective demand.

VIII

These are among the tangible factors in the manufacture of Norton abrasives. But in industry, as in life itself, intangibles are equally important. We have seen, in other chapters of this series, how great corporations function in welfare work, employee education, labor-relations plans, insurance protection, following lines of thought and action directed toward individual improvement and community betterment.

Norton also has done its share in these directions, but it has succeeded better than most in avoiding both complexity and paternalism in these group relationships. It has relied chiefly on keeping alive and effective under modern conditions and increasing size the spirit which was so strikingly evident in its early days, when bosses were artisans as well as employers and when every workman knew what everyone else in the business was doing to advance the general welfare of the group. A pleasant custom of celebrating festivals together comes down from a time when the labor staff was small enough to gather with management around a table for Christmas dinner. Growth of numbers rendering this impossible, Norton now gives a Christmas turkey to every employee — 4000 employees, 4000 turkeys. Through a service director the company guides work in education, recreation, sanitation, dental care, safety, health, and nursing, and coöperates with employee groups interested in housing, insurance, mutual loans, agriculture, photography, and sports.

The Norton spirit — the intangible behind the tangibles of production — is materialized artistically in Norton Hall, in the heart of the big Worcester plant. On the walls of Norton Hall are a series of ten impressive murals by Arthur Covey, each panel illustrating labor’s part in the rise of the abrasive industry. And occupying the end of the room is a graphic tree of Norton history, containing the names of all the men who, from bench to desk, contributed outstandingly to the beginnings and rise of the company. There is preserved, for the eye of future generations of Norton men and women, recognition of the part played by personalities and loyalties in the rise of this enterprise to leadership in the intricate business of making abrasives a key factor in America’s industrial advance.

Copyright 1935, by The Atlantic Monthly Company, Boston, Mass, All rights reserved.