The Iron Age 1942-09-24: Vol 150 Iss 13

t Engi brary SEPTEMBER 24, 1942 SEP 25° 1949 to keep ‘em flying . . . nothing rolls like a ball SAE UMC ME ee) eT CeCe CLT DTD NUT a ODL UNO that men can fly unerringly to a speck in the ocean thousands of CSE) AL MUS Loe CD It is the absence of the drag of friction that does it — the free rolling motion of anti-friction bearings such as New Departure Fe ee ae Me keeping mechanisms cool. New Departure, Bristol, Connecticut. for anti-friction wherever a shaft revolves — NEW DEPARTU Naa — a es Positive, Continuous Operation- i“ CLEVELAND OWNERS give you the Low-down Vital Then-—Indispensable Now! More than 12 years ago an Eastern manufac- turer selected Cleveland Worm Gear Speed Reducers for the important drives through- out his large Mill, and now tells us:— “Cleveland Drives have given positive and continuous operation.” For over 12 years— 24 hours a day — 355 days a year— not just one Cleveland but more than 50 of them have kept this manu- facturer’s machines in steady production. Install Clevelands and you will keep your machines in steady production too—with assurance of continuous, trouble-free per- formance through many years to come. Your Clevelands will never let you down! The Cleveland Worm & Gear Company, 3252 East 80th Street, Cleveland, Ohio. Affiliate: The Farval Corporation, Centralized Systems of Lubrication In Canada: PEACOCK BROTHERS LIMITED CLEVELAND © THE IRON AGE, published every Thursday by the CHILTON CO. (INC.). Entered as second class matter November 8, 1932, at the Post Office at Philadelphia under act of March 3, 1879. $8 yearly in North America and South America, Foreign $15. Vol. 150, No. 13. a eden SEPTEMBER 24, 1942 VOL. 150, NO. 13 © J. H. VAN DEVENTER wan President and Editor Cc. S. BAUR el Vice-President and General Manager ° ° ° Managing Editor, T. W. LIPPERT News & Markets Editor, J. A. ROWAN Technical Editor, F. J. OLIVER Associate Editors D. R. JAMES G. F. SULLIVAN D. C. MacDONALD Art Editor, F. J. WINTERS Editorial Assistants M. M. SCHIEN G. B. WILLIAMS J. 1. BUTZNER S. H. BARMASEL R. E. BENEDETTO Resident District Editors L. W. MOFFETT T. C. CAMPBELL Washington Pittsburgh DONALD BROWNE W.A. PHAIR Washington Chicago ¥._E. £EO¥D S he BRAMS Cleveland Detroit OSSOOD MURDOCK San Francisco Editorial Correspondents W. P. DEARING ROBERT G. McINTOSH Buffalo Cincinnati G. FRAZAR R. RAYMOND KAY Boston Los Angeles HUGH SHARP JOHN C. McCUNE Milwaukee Birmingham F. SANDERSON ROY M. EDMONDS Toronto, Ontario St. Louis C. H. BACON Seattle °e ° ° A. H. DIX, Manager Reader Service ° ° ° Advertising Staff mer prrerson Findley } 421 Union Bldg., Cleveland B. L. Herman, Chilton Bldg., Philadelphia H. K. Hottenstein, 1012 Otis Bldg., Chicago R. Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. H. E. Leonard, 100 East 42nd St., New York Peirce Lewis, 7310 Woodward Ave., Detroit C. H. Ober, 100 East 42nd St., New York Wd Btzgesald } 428 Park Bldg., Pittsburgh D. C. Warren, P. O. Box 81, Hartford, Conn. O. L. Johnson, Market Research Mgr. B. H. Hayes, Production Manager. R. E. Baur, Typography and Layout. ° ° ° Member, Audit Bureau of Circulations Member, Associated Business Papers Indexed in the Industrial Arts Index. Pub- lished every Thursday. Subscription Price North America, South America and U. S. Possessions, $8; Foreign, $15 a year. Single copy, 35 cents. Cable Address "‘lronage N. Y." ° ° ° Owned and Published by CHILTON COMPANY (Incorporated) Executive Editorial and Offices Advertising Offices Chestnut and 5éth Sts. Philadelphia, Pa._ New York, N.Y. U.S.A. U.S.A. OFFICERS AND DIRECTORS Cc. A. MUSSELMAN, President JOS. S. HILDRETH, Vice-President GEORGE H. GRIFFITHS, Vice-President EVERIT B. TERHUNE, Vice-President J. H. VAN DEVENTER, Vice-President C. S. BAUR, Vice-President WILLIAM A. BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS L. KANE, G. C. BUZBY, P. M. FAHRENDORF, HARRY V. DUFFY CHARLES J. HEALE 100 East 42nd St. This Week in Editorial How to Lose the War Technical Articles File Hardness Glass Fiber Insulation Used sen — Sunde. Casting of High Speed Steel . : Sodium Light Improves Microscopic ieapection 44 Success Brings Japanese Industrial Problems. 45 Seamless Steel Tubing Steel Milled Faster with Negative Rake Carbide Cotter 50 100 Million Volts to Extend Radiography..... ree Wine FN ease «s+ 5 vias .. & How to Figure Arc Welding Speed 54 Removing Broken Drills by Welding Technique. New Equipment Features Assembly Line Washington West Coast Fatigue Cracks Dear Editor News and Markets This Industrial Week News of Industry Personals and Obituaries Non-Ferrous Metals Machine Tool Activity Scrap Markets Iron and Steel Scrap Prices Comparison of Prices *Finished Steel Prices Warehouse Prices Index to Advertisers Copyright, 1942, THE IRON AGE SO ree 46 2 ° ° ° ° ° by Chilton Company (tee.) | from RAW STEEL to the BATTLE LINES! “™ But Ryerson Cuts the Corners T’S a long way from raw steel to finished tools of war—from plates, structurals, bars and sheets—to planes, tanks, ships and guns! Helping to keep steel moving quickly and smoothly to all of the thousands of operations that must come ahead of final assembly is Ryerson’s part in the war production job. Ten big Ryerson Steel-Service Plants, conveniently located to serve the nation, provide a reliable source for emergency steel — quickly available to keep arteries of war production flowing. This is the vital function these steel warehouses are performing. And, in spite of today’s emergencies, when required stocks are not always immediately available, Ryerson engineers, laboratory technicians, and steel-service men usually find a way to supply industry’s war needs. Time and again, Ryerson stocks and Ryerson ingenuity, have been able to supply steel vital to the steady flow of war production when at first it seemed impossible. Whatever your steel requirements — in line with the W PB system—the experience and resources of this cen- tury-young steel-service organization are yours to com- mand. Phone, wire or write to the nearest Ryerson plant. You'll get quick action at once. Joseph T. Ryerson & Son, Inc., Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City. RYERSON STEEL-SERVICE How to Lose the War Have heard so much and read so much on the subject of how to win the war that I am fed up on it. And I believe you are, too. Columnists who have never shot off a gun; ex-majors who have never had command of a regiment are busily telling the Administration, the War Department, General MacArthur and the rest of the world just what should be done to win this war. I think you will welcome a change, so I am going to tell you how to lose it. And I have gathered that information just from looking out of my office window. My office happens to be at the corner of 42nd Street and Park Avenue, New York City. From one of my windows, I can see the 42nd Street front of Grand Central Station. It's a fine building. It probably has 40 or 50 tons of copper on its roof, in case we might need it, but copper and brass, as yet, are not critical materials. Number one heavy melting steel is a critical material, however, and I can see some of that from my window. Labor, especially the kind of labor that can fabricate plates suitable for shipbuilding is a critical ss item also, I am told. Then, there is that matter of time, the most precious material of all. SEPT. 24, 1942 if we can call it a material. “So much to do, so little time to do it.” Ah, those moving slogans! ° ° For the past six weeks, I have observed a gang of structural steel ESTABLISHED 1855 workers numbering from three to six, dismantling and remantling the steel canopy over the eastern 42nd Street entrance to Grand Central. ° 0 Roughly, this canopy measures some ten by forty feet. If I were hard up for cash, as I usually am, and had not recently won a daily double, I would like to take a contract to do that job with three men in two weeks. Yet it is not half done. With what tenderness and loving care these structural workers pat the rivets with their hammers, reluctantly driving them to and from their home! And with what delicate brush strokes they apply the red lead to the structural members. It is something to see and admire — if you are a friend of Hitler. Now don't get me wrong. I! like the New York Central and have commuted on it for thirty years. But I understand there is a war on and that a war needs skilled labor to win it. Skilled labor of steel workers in shipyards, tank plants and munition plants — not on canopies over railroad stations and hotels to keep Mr. and Mrs. Jones from getting a trifle wet when they leave their taxicabs after an evening at the theater, but to give at least a fair fighting chance to our boys overseas who are risking their lives and losing them for the folks back home. I would hate to have these boys see what I see from my window! (fWlewbsima “Send us more scrap— and, we’ll make more steel” “We steelmakers can make more steel, if you'll 9,000,000 pounds of scrap in 24 hours? That’s 9,000 send us more scrap! We are appealing to you be- old autos a day —and they are just not coming in cause we need the help of American industry more anvwhere near that fast. than ever before. : y “That is why we are looking to industry to send Do you know there is no longer such a thing as a scrap stock pile at the mill? We are charging scrap as it comes in from day to day. If scrap should suddenly stop reaching us we would be down to 50% of capacity within 24 hours. us more scrap. Forget you’ve ever put on a drive. Start a new one now! Send to us, as soon as possible, that old building steel, unusable machinery, dead stores, and obsolete dies, jigs and fixtures. “It’s so easy to look outside of industry at all the scrap that could be gathered— old autombiles and the like. But, do you know that there is only about 1,000 pounds of scrap in an old jitney, and that “We steelmakers will make more steel for victory, only one of the Inland banks of furnaces melts when you send us more scrap.” “America is waiting for steel —our fighting men are waiting for ships, tanks, guns, shells. SHEETS STRIP ° TIN PLATE BARS . PLATES FLOOR PLATE ¢ STRUCTURALS PILING - RAILS TRACK ACCESSORIES REINFORCING BARS 38 S. Dearborn Street, Chicago a Sales Offices: Milwaukee, Detroit, St. Paul, St. Louis, Kansas City S a simple instrument for the A testing of hardness of tech- nical matter, the file ante- dates probably any other. Alvaro Barba in his “E] Arte de los Me- tales’”’ (published in 1637) states that he used the file scratch test to differentiate between precious and ordinary stones—admittedly a very daring criterion for the value of some crown jewels. Irrespective of this early appli- cation of the file test, practically no developments nor even attempts were made for nearly three cen- turies in clarifying the logical question “how hard is file hard?” A review of existing literature in- dicated only the few appended ref- erences, all dating back less than a decade. Complaints in this direc- tion have appeared before technical societies, and it is with this in mind that some accumulated data is be- ing presented at this time. According to modern tool engi- neering, files are classified as edge tools. The multiple edges or “teeth” of the file must, therefore, be pro- duced from such metal and with such treatment which permit re- peated use without rapid dulling by wear or breakage. This prerequi- site has been met by the manufac- turers of modern files by choosing steel of the following general char- acteristics: Per Cent Carbon 0.90 to 1.49 Manganese 0.25 to 0.50 Silicon 0.15 to 0.35 Phosphorus Maximum 0.03 Sulphur Maximum 0.03 Vanadium 0.10 to 0.15 (if specified) Test files made from this type of material are ordinarily of rather fine “cut,” 6 to 8 in. long, and are usually made to “bite” material of Rockwell C-63 to C-65. Several rep- utable manufacturers offer test files of C-66 to C-68 Rockwell hardness. The production of these special files depends largely on the successful File Hardness Testing BY JOHN H. HRUSKA Chief Inspector, Electro-Motive Division, General Motors Corp., LaGrange, Ill ... A modern answer to the question, "how hard is file hard?"; a clarification of file hardness testing by the most up-to-date methods including the characteristics and selection of test files, preparation, standardization and calibration of results, taking into consideration the element of human error. attainment of uniformity in sur- face hardness and toughness in heat treatment. To illustrate, com- pare the results of averages of Rockwell hardness tests made on five test files furnished by the three largest file makers in the United States (see Table I). The usefulness of high-grade files as testing tools depends, in addi- tion, upon certain design factors such as tooth contour, up-cut and over-cut angles, number of teeth per inch, etc. These characteristics of test files are summarized for five different specimens in Table II. Great strides were made in the file industry during the last two dec- TABLE | Surface Hardness of American Test Files Average Rockwell Hardness Nominal | File Number Length, In. Tip Middle 14 In. from Tang H-1 4 66.5 | 66.8 66.0 N-1 6 66.9 | 66.8 65.8 H-2 6 66.8 66.2 65.8 D-2 R 66.5 66.8 66.5 D-1 8 66.3 66.7 66.2 TABLE Il Characteristics of American Test Files Average Nominal Maximum Maximum Tooth Number Type of Length*, Width, Thickness, Distance, Teeth File Number File In. In. In. In. per In. H-1 Mill 4 0.437 0.094 0.0218 42 N-1 Pillar 6 0.484 0.146 0.0160 60 H-2 Pillar 6 0.409 0.195 0.0150 60 D-2 Pillar 8 0.562 0.188 0.0248 38 D-1 Mill 8 0.750 0.126 0.0186 50 * Length measured from tip to tang. _ THE IRON AGE, September 24, 1942—35 ades in the perfection of these de- sign factors. The uniformity of product was checked repeatedly and the modern test file is certainly a reliable tool for the purposes in- tended. Micrographic examination of the face and sides of such files indicates best the precision under which they were produced. Photomicrographs, Fig. 1 and 2, represent average conditions of such test files. Fig. 1 indicates that the teeth are very sharp as fur- nished and it is only logical that care should be exercised not to abuse such test files in actual ser- vice. Fig. 2 indicates the top view of a test file depicting also the rela- tive angles between up-cut and over-cut. In commenting on these charac- teristics of test files, it should be borne in mind that their purpose is definitely not the removal of stock but rather the production of a multiple scratch on the test ma- terial. Analysis of the fundamen- tals governing the mechanics of a scratch indicates that perhaps the most important of factors is the shape and hardness of the pene- trating edge. The entire problem may, of course, be simplified by producing a sharp point of known LEFT IG. 1—Photo- micrograph profile of 6-in. test file enlarged to 50 diameters. RIGHT ISG. 2—Photo- micrograph face view of 6-in. test file enlarged to 50 diameters. or measurable hardness. In order to utilize this thought effectively, round or square bars may be heat treated to a _ definite hardness, ground to a 65 to 90 deg. point and used subsequently for the determi- nation of actual scratch hardness expressible in Rockwell “C,” Vick- ers, or Brinell numerals. In order to facilitate handling of a smooth bar, it was found more convenient to use a round or even square file which prevents slippage in the fingers and thereby enables the operator to apply a somewhat heavier pressure against the point. Successfully used files of various hardnesses ranging from C-45 to C-66 are shown in Fig. 3. Actually obtained correlation between the drawing temperature and Rockwell “C” hardness is presented in Table TABLE Ill Effect of Drawing Temperature Upon Rockwell Hardness of Round Files Used for Scratch Hardness Testing Drawing Temperature, Deg. F. 80 210 400 480 550 630 750 860 Nominal Hardness Hardness Hardness at Point Near Shank 66 65.8-66.5 66.5-66.8 64 64.0-64.0 64.5-64.5 63 62.8-63.5 62.8-63.2 60 60.2-60.4 60.4-60.8 58 58.0-59.0 58 .8-59.2 55 55.0-55.2 54.0-54.0 48 47.5-48.5 48 .0-48.5 45 44.4-44.8 44.4-44.8 All specimens were held at temperature for 20 min. and ccoled in still air outside furnace. 36—THE IRON AGE, September 24, 1942 Ill. These figures are graphically represented by the diagram Fig. 4. Selection of Files The file scratch test has definite value in ascertaining surface hard- ness of irregular parts or of ex- tremely small areas thereof. Pro- duction requirements necessitate, however, the knowledge of uniform- ity over larger areas of heat treated parts. In order to verify average conditions, it is much more de- sirable to have a series of such scratches produced and thus check the average conditions rather than minute spots. Whenever possible, multiple scratches, such as _ pro- duced by the application of a suit- able test file, are much more infor- mative. sy following the same principle as that given above, test files may be selected which are more conve- nient in size or design to suit spe- cific requirements. In many cases, the standardized dimensions, tooth size or length may be more suitable if standard test files or even stand- ard files of available dimensions are heat treated to a hardness which will cover specific hardness ranges. Most commercial test files are C-65 to C-68 in hardness. These limits indicate only the actual grouping of tested material, either above or below the hardness of the test file. It has been found by actual mea- surements that usefulness may only be attained if the files are compar- atively small in length and cross- section. Lengths from 4 to 8 in. O- have been found most convenient. In addition, the design of the file should definitely permit a checking of the file material at various spots by means of conventional hardness testing methods, such as the Rock- well, diamond pyramid, or Knoop procedures. This consideration makes the pillar file of about 6 in. long perhaps the most desirable of all test files used for practical pur- poses. The file should not be de- stroyed for verification of its hard- ness and, therefore, the sides of the pillar file have been found most convenient if practically smooth, without any teeth. Fig. 5 shows the face of three test files and Fig. 6 the sides ground smoothly, prepar- atory to making five Rockwell im- pressions on the entire length of the tool. The preparation of test files under strict metallurgical con- ditions has been conducted in the following manner: A dozen 6-in. pillar files has been secured and the fact established that all files were produced from the same heat and bar respectively, thus assuring uniformity of the file metal. The chemical analysis of one of the previously annealed files gave the following results: Per Cent Carbon 1.22 Manganese 0.32 Silicon 0.29 Sulphur 0.023 Phosphorus 0.016 Chromium 0.03 All samples used later were ground parallel on the narrow sides, that is, on those sides without any teeth. One of these test files was then broken into specimens about 1 to 14% in. long and drawn at va- rious temperatures. In order to eliminate the question of cooling rates during slow furnace cooling, all samples were held for 20 min. at various drawing temperatures, removed from the furnace and per- mitted to cool in still air to 80 deg. F. After this heat treatment, the sides of the specimens were smoothed on emery cloth and four Rockwell tests made. The average of these determinations was then recorded as resultant hardness for the corresponding drawing temper- atures. Practically the same proce- dure was followed with the actual test files. Ten files were thus pre- pared by drawing and testing them for hardness as indicated in Table IV. The hardness data of both series of tests were combined graphically and indicated against the rather smooth curve shown as Fig. 4. For convenience, conver- ABOVE IS. 3—Pointed scratch test files. Note the ground surfaces for penetration hardness testing. RIGHT IS. 4— Effect of various drawing temper- atures upon the hardness of com- mercial files. BELOW IS. 5 — Face view of three 6-in. test files. ROCKWELL “C” HARDNESS 600 500 400 300 BRINELL HARONESS 200 200 600 1000 1400 TEMPERING TEMPERATURE — DEG. FAHR 600 500 400 300 200 DIAMOND PYRAMID HARDNESS THE IRON AGE, September 24, 1942—37 sions were made, permitting the use of these files for determining Rockwell, Brinell or diamond pyra- mid hardness. File hardness testing is pri- marily a rapid shop control test, and for reasonably precise work some thought should be given to standardization of this procedure. In carrying out this effort, two principal factors enter into consid- eration or into the informative value of the test, namely, the file and the operator. The above de- scribed procedure seems to give a fair uniformity to the file. On the other hand, the much heralded im- portance of the operator has been definitely overemphasized. In order to obtain unbiased in- formation, the test files were given to eleven different operators with no actual experience in the han- dling of test files. Table V sum- marizes these observations. It is quite evident that there is practi- cally no difference in the results and in the effect of previous ex- perience, or the lack of it, on the part of these operators. Before making final reports as to hardness of parts tested by the file scratch method, some means of as- certaining the nominal hardness from the “feel” should be applied. Perhaps the simplest method of checking commercially secured files, drawn to various tempers, is by heat treating representative sam- ples of the stock to be tested to various hardness ranges. These test pieces should be of the same gen- eral type of metal, identical con- tour, such as flat or round, and 38—THE IRON AGE, September 24, 1942 similar in size and surface finish. The usual method of calibration is for the operator to make a few very short strokes on the surface being tested, and to determine from the reaction of the piece, the approxi- mate surface hardness of the same. Another suggested method of calibrating test files has been by heat treating a small round bar of high carbon steel of about 34 to ™% TABLE IV Effect of Drawing Upon the Hardness of 1.22 Per Cent Carbon Test Files Test Made Drawing Rockwell with Test Temperature, Hardness | Pieces (T.P.) Deg. F. ses and Files 80 (no draw) 66.1 File 1 219 65.7 T.P 410 62.5 TP, 449 62.1 File 2 506 60.2 File 3 521 60.0 File 4 541 58.6 File 5 550 57.9 T. P. 580 58.0 File 6 645 54.6 File 7 650 54.0 aoe 750 50.6 File 8 760 49.5 Laue 805 47.0 wales 830 | 45.0 TP. 855 44.4 File 9 901 41.8 | es 960 38.1 ase 1020 32.8 T. P. 1065 29.5 TP. 1090 27.7 T. P. 1150 23.6 ise 1200 21.5 oe 1248 19.7 cr 1480 14.0 tales IG. 6—Side view of three 6-in. test files showing the smooth side prepared for pen- etration hardness test- ing. in. diameter and 4 in long. The treatment is carried out in such manner as to obtain a gradation from C-65 or C-67 on one end of the round, with hardness tapering down to C-55 or C-57 on the oppo- site end. The intermediate hard- nesses between these two ends are verified by actual Rockwell or Dia- mond Pyramid hardness tests made accurately on a 1, in. wide, ground flat, on the entire length of the calibration bar. The actual test results obtained from the hardness penetration are etched next to the corresponding test mark made by the Rockwell or Pyramid hardness test. In order to use this bar, comparisons are made by attempting short strokes in that hardness area for which the test file was intended. The Human Factor Micro-hardness measurements made recently on the tips of the file teeth indicate that files of C-67 Rockwell hardness will definitely bite steel of C-64 to C-65. This difference in resistance to scratch is somewhat less pronounced at lower hardnesses—an observation similar to that made by geologists when scratching minerals of the various hardness ranges defined by the Moh scale. In the past, no attempt has been made to utilize the file to define numerical hardness. Even the cali- bration was much simpler, as ordi- narily, a standard test piece mea- suring % x 3/32 in. of 1.30 per cent carbon steel, was hardened and to of 2S n- + ie drawn to 375 deg. F. This opera- tion produced a hardness of C-63 to C-64 and a good file was expected to bite this test piece easily. In order to verify how much lower the actual hardness of the piece tested was, the operator had to use con- siderable judgment and experience was, no doubt, necessary for such testing. The knowledge gained in the use of files of various hard- nesses seemed to place experience of the operator distinctly in a sub- ordinate position, and it was with this viewpoint in mind that the above summarized attempt has been made to eliminate the human factor in file hardness testing. The relative file hardness is a function of the actual hardness ex- pressible in Rockwell, Brinell or Diamond pyramid hardness of the file material. Accordingly, softer files are useful criteria for rela- tively softer materials. Toward the end of the last century it was, therefore, assumed that file hard- ness would not exceed C-50 to C-58 Rockwell. With increasing knowl- edge of metallurgical properties of steels, this fact was accompanied by improvement of manufacturing processes, thus raising the mini- mum hardness at which a test file would “bite” well above C-60. Under present circumstances, the gener- ally acknowledged minimum limit would be C-63 to C-64. The pre- viously described methods broaden essentially the degree of file hard- ness to almost any desirable value. For purposes of precise specifica- tions, it will, therefore, be ad- visable to designate “file hardness” equivalent to corresponding pene- tration hardness numerals. Bibliography Nicholson File Co., “Hardness Test- ing With a File a Useful Art Easily IS. 7—File hardness test set, showing com- parative Rock- well C hardness numerals at the end of handles. TABLE V Test Results with Three Files by Different Operators Estimated File Hardness by Rockwell “C’’ Conversion Specimen “A” Specimen “B” Specimen “C” Operator (Round) (Flat) irregular) Metallurgist. . 62 62 66 Engineer... 62 64 66 Inspector. . 60 62 66 Pyrometer engineer 62 64 64 Secretary (female) 62 60 66 Blacksmith. . . 62 62 66 Laborer. .... 60 62 64 Factory worker (female) 62 62 66 Machinist. . . 60 62 64 Toolmaker 60 60 66 Welder..... 60 62 66 Actual measured hardness (average) C-61.4 C-63.1 C-65.5 Learned,” Metal Progress, Vol. 22, December 1932, pp. 15-18. Morton, H.T., “File Hardness Test,” National Metals Handbook, 1939, pp. 125-126. Hamilton, W. C., “Note on File Scratch Test,” Metal Progress, Vol. 32, September 1937, p. 265. A.S.T.M., “Proposed Method of Test for File Scratch Hardness of Metallic Materials,” A.S.T.M. Bulletin, October 1937, No. 88, p. 26. Buxbaum, B., “Gage for File Test,” Metal Progress, Vol. 23, June 1933, p. 48. Glass Fiber Insulation Used for Brass Furnace ) 1TH mica listed as one of / the nation’s critical mate- rials, the Western Car- tridge Co. has successfully used Fiberglas tape in place of mica as coil insulation in the primary coil of induction-type brass fur- naces. The 38 furnaces of this type in- stalled in the Western Cartridge Co. plant have a_ sleeve-shaped form composed of ceramic mate- rial which retains the helical flat copper coil. Fiberglas tape is spi- raled between turns in the coil to form a double helix composed of alternate layers of copper and Fiberglas tape. Insulation be- . tween turns in the coil is required to prevent short circuiting. It is said that the use of the Fiberglas tape insulation made it practicable to increase furnace temperatures to the point where it was possible to produce five pours of 1500 lb. each during each 8-hr. shift, whereas with the mica insu- lation the limit was three pours of 1500 lb. each during each 8-hr. shift—an increased production of 300 lb. per shift, per furnace. The cost of the glass fiber insu- lation was 50 per cent less than the mica it replaced. The number of man-hours required to install the Fiberglas insulation was less than half that required for the installation of mica. Approximately 1000 of the in- duction-type furnaces are used by the large brass companies. Most of these companies follow the practice of rebuilding their own cores when such rebuilding is necessary. THE IRON AGE, September 24, 1942—39 Casting igh Speed Steel By W. F. SHERMAN Both sand and centrifugal casting methods, using perma- nent molds, are employed at the Gorham Tool Co., De- troit, in casting high speed steels. Such steels, when cast in rough too! shapes, are easily and economically finished, and are unusually resistant to abrasion and wear. NEW electric steel foundry A designed especially for quan- tity production of cast high speed tool steel, including both sand cast materials and centrifugally cast materials produced in perma- nent molds, has been put in service by Gorham Tool Co., Detroit. It is producing an unusual abra- sion resistant tool steel that liter- ally bridges the gap between the conventional high speed tool steels and the cemented carbides. The casting process makes it possible to pour this special high speed steel directly into tool blanks or into shapes which are _ subsequently made into tools without any mill working operations. In addition, experiments by L. C. Gorham, president of the company, point in the direction of possible success in the casting of cutters with teeth formed in them. Such tools are already in use in an ex- perimental way. Modern, progressive type layout is displayed by the foundry, which incorporates an extremely up-to- the-minute materials handling sys- tem used in conjunction with two 200-lb. furnaces of the Ajax induc- tion type, one 30-lb. Ajax induction furnace, and two 50-lb. Detroit rocker arc furnaces. The two lat- ter furnaces have been used for a major part of the experimental work and for the production of this type of high speed steel since about 1938 when it was first offered to the trade. As in the accompanying plant layout diagram, the foundry 40—THE IRON AGE, September 24, 1942 includes a pattern shop, standard sand handling equipment, a con- crete-imbedded rail system for transporting molds to the pouring floor, and a well-designed cooling and shake-out area. A _ two-ton overhead crane services the entire working floor of the foundry. The pattern shop is small, compact, and efficient; and is admirably fitted to the type of work it has to do. The casting technique, as men- tioned above, makes use of sand molds or permanent molds, for con- ventional pouring or for centrifu- gal casting, depending upon the size and contour of the parts being cast, and the quantity. Sand and Binders Early in the experimental stages of the development of this cast high speed tool steel, it was learned that a selection of a proper mix- ture of grades of sand and binders was one of the big problems to be overcome for successful casting. The main difficulty was the elim- ination of porosity in the castings. The molding technique, as well as the material, has been developed in detail and varies from that ordi- narily employed in casting. For in- stance, the layout or the “pattern” of individual tool blanks in molds has been found to require excep- tional molding experience. In at- tempting to cast a dozen or more tool blanks at one pouring, the problems to be overcome were many. Under such conditions it is necessary to obtain rapid solidifica- tion of the cast materials in order to get the desired grain structure, but the solidification has to be very uniform to prevent cracking from strains set up in cooling. Such cooling cracks have been a leading cause of tool breakage, and it mat- ters not whether the cracks are set up as a result of heat-treating or in the casting of the tool. While Gorham cast high speed steel was first made available com- mercially about four years ago after four or five years of experi- mental work, Gorham’s experience with cast high speed steel extended back to World War I when at- tempts were made with some suc- cess to cast tungsten high speed steels. At that time the goal was simply cost reduction through the quick production of a low priced tool. It was the advent of molyb- denum steels that stirred interest because it was apparent that some of the difficulties encountered in casting tungsten steels might be overcome by the use of a molybde- num analysis. Working with mo- lybdenum alloys, he introduced a variant from the typical moly tool steel analysis by adding boron. Abrasion Resistance A small percentage of boron has the faculty of giving these steels a greatly increased resistance to abrasion. It also gives the steel a resistance to the formation of a decarburized surface and soft skin. Of no importance in the cast mate- rial, but quite a factor if there had been an attempt to forge the tools, is the fact that a higher boron con- tent decreases the forgability of the material. Therefore, the most satisfactory method for producing Ca- ler ry om ch ng at- set go ri- ce ed ic- ed as he ed ‘b- st ne be le- \O- ol an alloy with a high boron content is to use the casting process. This high speed steel has the fol- lowing analysis: Molybdenum 8 per cent, chromium 4 per cent, vana- dium 2 per cent, cobalt 8 per cent, and boron 1 per cent. It is pro- duced in the electric furnaces by charging mild steel scrap and the proper alloy additions. When mo- lybdenum scrap is available, a large percentage of it is used in the charge. It requires 45 min. to melt and prepare a 200 lb. charge for pouring. It appears that the resultant alloy is a material that fits into the physical range between the forged high speed steels and the cemented carbides, with some of the physical characteristics of both incorporated in the new material. Producing finished tools from this cast steel appears to offer no unusual problem. The castings are annealed for easy machining, mak- oo the Ajax furnace for a heat of high speed tool steel. The 200-Ib. ing possible the production of com- plex tools without extensive mold outlay since the annealed blanks charge requires 45 min. for each heat. are machined as readily as though 7 . , made of ordinary high speed steel. The blanks are machined by boring, BELOW Tena hating tae ae Yate ultra-modern foundry layout is for the casting of molybdenum high ——s Se ao speed tool steels of a special analysis, including boron. The plant includes for finish grinding after heat treating. Cast-to-form blanks which pattern shop, core department, modern sand mixing equipment, up-to-the- minute material handling system, Ajax induction type electric furnaces and Detroit Rocker Arc furnaces, and special spinning equipment for centrifugal casting. j SAND BIN | CORE DEP'T. iJ Oe Mold benches Da x Bd ox Scrap bins 0 _| ss Sand car track FLASK STORAGE Mold car track Bee S| Sand mixer J oe machine Shake out sand a = Cj Spinning Snagging 2-2001b. Ajax furnaces Ladle sass ger Sand blast FURNACE PLATFORM _ — 50 b CEMENT FLOOR {ax GENERATOR ROOM SS 33 bh > dd Annealin ! 50 lb. Rocker furnaces y Soca + Denise cesestialia catenin 0 6 4' 8 12’ 16° 20 24' 28° 32' 36 40 EOS o_o —— 7HOpOND a THE IRON AGE, September 24, 1942—4I Lr haaahahahaannhanhhnnhanhnhachnhahachnhhahchhchnhchchchahachchahnhchnhanhnhchchchcahchchahadchchhhchhhchahhchchhchhhhhahhbchhh hhh bbbddh hbbbbhbbbbdbbbkbikd ) II SY PATTERN SHOP | | | | creer ego high speed tool steel. Molds are transported on trucks on the rails embedded in concrete A few feet from the pouring area the weights and clamps are removed, adjacent to the storage place for the weights and clamps. reduce the amount of machining also are being produced, as men- tioned elsewhere in this article. Finishing Heat treating schedules have been worked out by which any de- sired hardness from 60 to 70 Rock- well “C” can be obtained with no decarburization and a minimum of distortion. The finish grinding and resharpening operations are car- ried out with standard grinding wheels on standard equipment, the strength of this material permit- ting either machine grinding or hand grinding, and giving an ex- cellent cutting edge without sub- sequent honing or lapping. In gen- eral, the same cutting clearances are used on cast steel as on the forged high speed steels, but be- cause of the inherent wear resist- ing properties, rubbing clearances such as concave on the sides of cut- ters, etc., can be removed or mate- rially reduced without disturbing the over-all efficiency of the tool. For the material thus produced, an unusual red hardness is claimed H's speed steel is centrifugally cast in this horizontal spinning machine, a result of extensive experimentation over a long period of years. 42—THE IRON AGE, September 24, 1942 in addition to wear resistance. Ex- perience indicates that it is partic- ularly valuable on two types of applications: (1) Cutting opera- tions at speeds well in excess of the speed at which such forged steels break down, and (2) on difficult operations at normal speed where abrasion dulls forged high speed tools at an excessive rate. Under average conditions, it is claimed that the cast material will perform satisfactorily at surface speeds above those possible with the forged material, this ability opening up a field of application lying between the accepted fields of the forged high speed steels and the cemented carbides. Normal cutting speed limits for cast and forged high speed steels and for cemented carbides are shown in Table I. Where intermittent cut- ting must be done, the cast mate- rial will operate at high speed, withstanding severe shock condi- tions and cutting faster than is pos- sible with forged high speed steel, according to the Gorham company. In this connection it is pointed out that the cast material is not a cure-all and does not make it pos- sible to step up all production sim- ply by use of the material. It is the opinion that forged high speed steel will remain the most econom- ical tool material on jobs where it performs acceptably and where it is impossible to take advantage of the increased production possibil- ities of a higher surface speed be- cause of the limitations of the ma- chine tools or the design of the part being machined. Likewise ce- mented carbides will continue to be the best tool material on those jobs where it is possible to establish the ideal condition for their use and the surface speed can be stepped up high enough for satisfactory tool life. Between these two fields is the place where the cast high speed steel will find its economic application. Examples of these applications include current use on tank armor plate and extensive use on alumi- num. The material shows ideal re- sistance to wear even on aluminum pistons, which have a high silicon content and traditionally are very rough on tools. Certain operations, such as the ‘milling of keyways in axleshafts, where the width of the cut must be maintained in spite of repeated sharpening of the cutter, are ideal situations for cast tools. This is true since concaves and clearances — — oa \v el N a vertical axis, high speed steel is cast cen- te molds prepared to avoid porosity in the cast- trifugally in this spinning machine by the Gorham Co. In this and the machine shown in photo at bottom of opposite page, permanent molds are employed. that are essential to free operation of forged tools can be almost en- tirely eliminated on these cast tools. Because the cast material is not severely affected by abrasive oper- ation, sharp corners are maintained on the tool and the part and dimen- sions are held to close tolerances throughout the tool life. Where complicated form tools are required, the cast material has proved to have exceptional advan- tages. In such instances, the cost of making and maintaining irreg- ular formed tools and cutters of cemented carbides is excessive, even if surface speeds could be increased enough to suit such applications. The fact that the Gorham cast high speed steel is as easily machined as the forged type, but will operate at much higher speed under difficult ings of tool blanks (the latter shown in front of the open mold). Small diameter welding rod is also being cast of this material, by this method. conditions, makes it a desirable ma- terial for use in such cases. Principal limitations are in the manufacture of extremely small or thin tools that are difficult to cast economically. However, these tool styles that are not adapted to the casting process are infrequent. The cast material has the un- usual characteristic of being vir- tually free from hardening distor- Approximate Operating Speed Limits of Forged and Cast High Speed Steel and Cemented Carbide Tools. Approximate Surface Speed,* Ft. Per Min. Hardness Range, Tool Rockwell Cast Cast SAE SAE SAE SAE SAE SAE Material —— Aluminum | Bronze | Copper Iron Steel 1112 1020 2320 3135 4340 6145 Forged high speed 62 to 65 300 | 100 | 200 | 60 | 50 | 80 80 60 | 60 60 60 steel 1000 300 | 600 | 90 | 140 140 140 | 125 | #12 | 12 125 Gorham cast high | 60 to 70 300 | 100 | 200 | 60 | 60 | 100 |, 100 | 80 | 980 80 | 80 speed steel 1000 350 | 600 | 150 | 200 225 200 175 | 175 175 175 Cemented carbide 70 to 81 300 150 | 200 | 80 125 500 375 225 225 275 225 1500 500 600 350 250 600 400 275 275 325 275 * These surface speeds indicate stints limits aaa pamela mani must ai waseian “i to oui ih anon pastes bis fluencing the best operating speed are: Capacity and condition of machine tool, method of holding work, size and type of tool, and naterial and type of work being machined. THE IRON AGE, September 24, 1942—43 VARIETY of cutter blanks and cast-to-form cutters is shown here. The cutters in which teeth are formed in the casting have been ground to final size and finish, nothing more. tion. This is important in the production of unground form tools and* cutters since coupled with freedom from decarburization, it permits the use of the material on jobs that require accurate forms but are not economical to grind to shape following heat treatment. An outstanding example of such an application is the use of cast high speed steel in the manufacture of unground serration cutters in the wider sizes. When these cut- ters are made of forged steels, there is a strong tendency for the blanks to bulge in the center with a consequent error in the cumula- tive pitch dimensions. Serration cutters of cast high speed steel are regularly produced with a cumula- tive pitch error of only 0.001 in. over a width of three to four inches. Similarly, unground form relieved cutters come through the harden- ing operations with much less dis- tortion of the form than is possible with the use of forged steels and with no appreciable decarburized skin. The cast material is being used for a variety of purposes besides cutting tools. For instance, center- less grinder work rests of this ma- terial have been used, with results almost exactly comparable to the results achieved with cemented car- bide wear strips and similar work rests. Centrifugally cast bushings of this material also are in use, and cast welding rod, made of the same material, is being used with acety- lene torches for applying wear re- sistant welds wherever required. Since this material has air harden- ing properties, it can be tipped onto shank steel and used for cutting tools without further heat treating. A 1's in. thick layer under such conditions will give a 63 to 64 Rock- well “C” reading. On thicker welds the surface Rockwells at 63 to 64, but the hardness decreases through each layer of weld to about 50 Rock- well “C”’ on the lowest layer. In some applications, of course, such thick layers do need subsequent an- nealing and heat treating. Heat treating can be accom- plished in any equipment normally used for treating high speed steel and the technique is very similar to that used regularly with other material. Gorham uses electrically heated controlled atmosphere fur- naces. Sodium Light Improves Microscopic Inspection HE use of sodium light in the microscopic inspection of small parts has proved effective in increasing worker’s efficiency for the detection of mi- nute flaws, pits and cracks, ac- cording to recent information de- veloped by H. A. Breeding, of the General Electric Illuminating Laboratory, Schenectady. The unusual perception of de- tail under sodium light is due to the monochromatic nature of the . light as the eye, in common with other lenses, actually focuses only one narrow wave or color band at a time, according to Mr. Breeding. Other colors which may be pres- ent in the light only tend to fog the clarity of the image. Thus, 44—THE IRON AGE, September 24, 1942 minute detail may be lost in exam- ination under multi-color light while clearly perceptible under monochromatic light such as so- dium livht. An additional factor is that ‘ne human eye has always been accustomed to seeing more yellow-green objects than any other color and has gradually de- veloped a visual affinity for light in this color band. Consequently, the pale golden yellow of the so- dium light falls very near to the spectrum band where maximum eye sensitivity occurs. In using sodium light for in- spection it has been found that a broad distribution of the light is better than concentration in a bright spot. In this way an undis- torted view of both the size and shape of the flaw is obtained. The level of illumination should also be comparatively high. In searching for small blow holes and cracks the use of a light-absorbing or light-reflecting dye has also proved helpful. The dyed surface serves to increase the contrast between the flaw and the surrounding surface to such an extent that much smaller flaws can be detected. A caution in the use of sodium light is to eliminate as much light as possible from other sources so that the maxi- mum benefit can be obtained from the monochromatic nature of the sodium light. ad eS a- ts ne r- rk of Success Brings Japanese Industrial Problems GERMAN view of the prob- A lems which Japan will have to face in the near future as a result of her plans for an East Asian Co-Prosperity Sphere is given by Dr. J. W. Reichert in Stahl und Eisen. The article, which calls the lack of intercommunication and transport facilities in the hinter- lands the most serious obstacle to the rapid and successful exploita- tion of heavy industry in Japan’s conquered territories, appeared in Germany March 26 and has been abstracted in the British Jron and Coal Trades Review. During the first four months after Pearl Harbor, Dr. Reichert points out, Japan extended her con- trol to an area of nearly 3,250,000 sq. miles, inhabited by 400,000,000 to 450,000,000 people, while Old Japan, excluding Formosa, Korea, Kwantung and south Sakhalin, cov- ered an area of only 143,000 sq. miles, with a population of about 70 millions. Transportation facilities are, of course, adequate in the coastal re- gions, where they have been devel- oped for decades by Europeans. But the greater part of the Chinese massif has only the most primitive forms of transport, and even good roads are absent in vast areas. If these areas are to be developed on modern industrial lines, or even de- fended against invading forces, roads must be built and a compre- hensive system of intercommunica- tion provided. One phase of the transport problem is sea communi- cations between the widely-scat- tered parts of the new Japanese empire. To meet the enormous de- mands of the war at sea against the chief maritime nations of the world and to provide shipping for normal trade operations, Japan needs a merchant navy which must be sev- eral times greater than the one she now possesses. Her shipyards are working to capacity, but Dr. Reich- ert considers that it will take ten years before her present tonnage is even doubled. In 1934, the author made an analysis of the Japanese iron and steel industry and suggested that the supply of raw materials and the security of her communications with the Asian mainland, her in- dustrial and economic mainstay, were the twin Achilles heels in Jap- anese plans for future hegemony in Eastern Asia, i.e., in her ability to wage war successfully. He now sees the position in a different light with Japan standing astride a conquered empire, and he suggests that indus- trially Japan is totally unprepared to shoulder the burden of exploiting it. Her inability to expand com- munications to the level needed, owing to the general backwardness of existing transport facilities and the absence of a large mercantile marine, has already been mentioned above. On the industrial side, the same picture appears, for the new Japanese empire cannot be ex- ploited without a vast army of ma- chines, and at the moment Japan is quite incapable of building these machines in the numbers required for her large empire. Steel Industry Expansion No effort has been spared in the past to create a large iron and steel industry in Japan. First, many years ago, came the Godo plan, then in 1938 a five-year plan was drawn up to cover also the metallurgical industries of Man- churia and North China, under which production was to be stepped up annually to 1941. A develop- . ment company to exploit the iron ore and coal resources of Manchuria was formed, and has made good progress; the Krupp Rennver- fahren was introduced at several works to make sponge iron from the low-grade ores available. Steady progress was made with these plans, and increasing outputs re- ported up to the entry of Japan into the war. Current coal and lig- nite output of greater Japan is around 100 million tons per year, while iron ore output has risen year by year. Supplies of manga- nese ore are sufficient for the re-