The Iron Age 1942-09-03: Vol 150 Iss 10

51.30 56.00 46.55 43.00 7.60 $51.30 58.90 51.30 9.00 Ton 54.00 22.00 1942 Total Depth Case .038 in., depth .35 car- bon .030 in., depth excess carbon content Ist .005 in. turned from surface 1.034, 2nd in. .807, 4th .005 in. .639, 5th .005 in. .509 (100X) Case .047 in., depth case .35 carbon .040 in., depth case excess bon in. Carbon content .005 turned from sur- 2 005 in. 1,007, 3rd .005 in. .846, 4th .005 in. .752, 5th Total Depth Case .038 in., depth .35 bon .032 in., depth excess carbon Corbon content Ist in. turned from surface 1.007, 2nd 3rd .005 .823, 4th .005 .670, Sth in. .35 carbon .030 in., depth case excess in. content ist .005 turned from sur- 3rd .005 in. 4th .005 in. .660, Sth .005 is SEP RAPID PENETRATION COMPLETE WATER SOLUBILITY PERCENT LESS WEIGHT PER CUBIC FOOT The TYPE CASE produced these baths indicated the series photo micrographs, shows tectic structure and Rockwell hardness equivalent pack carburizing. With modern equipment these baths operate costs LESS than solid gas carburizing, and have added advantage lower initial investment. SEVEN BATHS Holden Light Case No. 50- 100-200-300 For temperatures from 1450° 1750° All specimens carburized hours—temperature 1650° Stock—1 inch round inches 1700-1750° and for the same periods, casing depths will increased from 25%. For example, bar half-inch diameter placed the bath one hour 1700° will case harden .025 inch depth Sales Literature Request THE HOLDEN CO., New Chemical and Furnace Division, Richard West Haven, Conn. Commercial Heat Treating Division, 200 Ave., New Hoven, 3.00* 4 2.907 12.50 Glorious news keeps coming in.. .“‘pro- months.” Every day saved the production front means American lives saved the battle front. this “war production” the quick, efficient handling materials vital; and Whiting are the thick it. There’s time now wait for gim- cracks and extras...Whiting bending every effort turn out cranes the shortest possible time... Victory Cranes that have been designed for just one purpose—to the job! Long yes. Smooth operation? Economy?...of course. But more possible de- livery. Whiting Corporation, 15601 Lathrop Ave., Harvey, Illinois. ak | FOR send for the new book just lished containing for the safe tion Traveling STEP US OVE) 50 , just ining safe ling SEPTEMBER 1942 VOL. 150, NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager Managing Editor, LIPPERT News Markets Editor, ROWAN Technical Editor, OLIVER Associate Editors JAMES Art Editor, WINTERS Editorial Assistants BENEDETTO Resident District Editors Washington Pittsburgh DONALD BROWNE PHAIR Washinaton Chicaao OSGOOD MURDOCK San Francisco Editorial Correspondents Buffalo Cincinnati FRAZAR RAYMOND KAY Boston Los Angeles HUGH SHARP JOHN McCUNE Milwaukee Birmingham SANDERSON Toronto, Ontario BACON Seattle ROY EDMONDS St. Louis DIX, Manager Reader Service ° ° ° Advertising Staff E Findl Herman, Chilton Philadelphia Hottenstein, 1012 Otis Bldg., Chicago Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, 100 East 42nd St., New York Robinson Warren, Box 81, Hartford, Conn. Johnson, Market Research Mgr. Hayes, Production Manager. Baur, Typography and Layout. ° ° Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price North America, South America and Possessions, $8; Foreign, $15 year. Single copy, cents. ° ° ° Owned and Published CHILTON COMPANY (Incorporated) Executive Editorial and Offices Advertising Offices Chestnut and Sts. 100 East 42nd St. Philadelphia, Pa. New York, U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, Vice-President GEORGE GRIFFITHS, Vice-President EVERIT TERHUNE, Vice-President VAN DEVENTER, Vice-President BAUR, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY CHARLES HEALE THE IRON IRON Editorial Less Paper—More Head and Foot Work Technical Articles Foolproof Gaging System Armor Plate Planer Made Structural School Systems Aid Industrial Training......... Electronic Controls Guard Furnace Atmospheres Hardenability Steel Scaling Heat-Resistant Steel Cupola Practice with Briquettes Soap Used Tungsten Ore New Equipment: Machine Tools Features Washington West Coast Fatigue Cracks Dear Editor News and Markets This Industrial Week News Industry Personals and Obituaries Non-Ferrous Machine Activity Scrap Iron and Steel Scrap Prices Comparison Prices Finished Steel Prices Warehouse Prices Products Index Index Advertisers Copyright. 1942. by Chiften Company (ine.) 136 140 166 216 ° ° has that OUTGROWN ITS MAYBE YOU ALREADY KNOW WHY! can used any position. can used for all types fabrication welding, but especially for light sheet metal work and other jobs requiring low heat input work. diameters. meets code requirements A.W.S. and A.S.T.M. Tentative Electrode specifications for classifications E-7010, E-7011, E-6012 and E-6013. Flexarc “SW” electrode was developed especially for welding light sheet steels, and particularly for use with low capacity a-c welders. And how filled the bill! Any reason- ably skillful welder could make good sound weld sheets burn-through. But that’s not all. Users found equally well adapted heavy gauge metal and all types general steel welding. They liked its uniform metal transfer, its easy arc strike. Then when they found could used all different positions using a-c d-c, they demanded larger diameters. That’s why you can now get diameters from Try it! Westinghouse Electric Manufacturing Company, East Pittsburgh, Pa., Dept. 7-N. J-21195 *To describe the job was de- signed welding... Meet the rest the family with a-c and d-c for fillet posi- tion and general purpose high-speed welding low and medium carbon Flexere high-speed rod a-c d-c for downhand posi- tion heavy horizontal fillets and finished beads. AP—Use for all position welding low- to-medium carbon steels get minimum spatter. Reverse polarity d-c. Castingweld and Free- machineweld—F welding iron castings. Latter type can machined. Hardentough—F hard- surfacing parts chinery. For Special chrom, Nickelmang. ghouse 42—THE IRON AGE, September 1942 ELECTRODES Less Paper—More Head and Foot Work HIS country has capacity for producing steel, and performance too, that greater than all the rest the world. inconceivable that uses this precious metal are curtailed, should not have enough available for all war purposes. Eighty million tons steel more year lot steel. Enough build 240 first class battleships—if wanted them—or merchant fleet cargo ships four times the total tonnage Great float- ing merchant marine empire. ° ° Putting all into M-4 tanks, could make 2,660,000 them, enough tanks stretch, end end, nearly half way around the globe the equator. Putting this annual steel output ours into three-inch shells would give enough fire one per second for the next 250 years. course, want that way, but these comparisons will give you idea what our steel capacity qnd production amount terms war material. Hitler would sell his soul have were that questionable asset his not already sold the devil. With this tremendous and enviable capacity produce, why that are encountering shortages? Maybe because, working out the channels flow the steel that have, are depending too much paper work and too little head and foot work. That has happened plenty times before private industry, SEPTEMBER 1942 most any practical production man can tell you. One the foremost our past American “efficiency engineers” put some years ago into Midwest manufacturing plant. ESTABLISHED 1855 Theoretically, the foundry, forge shop, machine shop and other depart- ments this plant had sufficient capacity meet all demands for parts for shipments. But deliveries were from three six months behind and bottlenecks were daily happening. The expert installed dispatch boards, production slide rules, red sing tags, green tags and white tags plus the most complete and elaborate system paper forms that one could imagine. And deliveries got still further behind. 74. Then the practical-minded general manager organized staff Trouble men who knew what things were about, who “lived” the departments and who came the front office only when things went amiss and needed attention. Shortages and bottle- necks then began evaporate together with slide rules and fancy forms, and delivery dates were met Sometimes it’s not what you've got that’s not enough, but what you with what got. And such cases, head and foot work beats paper work all pieces. 4 J ] J é The freighter Block, unloading ore the Indiana Harbor works Inland Steel Co. Capt. Kizer the bridge. eet Breaks Records Carrying Ore the Mills for War Production Every freighter the Inland Steel Co. fleet has broken its all-time cargo-carrying record since the opening spring navigation. The Block, flagship the fleet, recently docked with 16,348 tons iron ore—a new tonnage record for the Inland freighters. Before mid-summer the Block already had made round six which set new tonnage records. This performance the Inland fleet answer the tremendous wartime demand for steel. Not only must enough ore, limestone and coal delivered Indiana Harbor maintain present above-capacity ingot production—but enormous additional tonnages must put huge stock piles for ready use during the long winter months when navigation closed the Great Lakes. The men who sail the Inland lake freighters, like the men who tend the Inland furnaces and rolling mills, are working day and night their part winning the war. They will bring down more ore— make more steel—until those who threaten liberty have been conquered. SHEETS STRIP TIN PLATE BARS PLATES FLOOR PLATE PILING RAILS TRACK ACCESSORIES REINFORCING BARS D Ly, wy, “Ui 3% Indiana bridge. NEALEY HILE civilian industry has long boasted its manu- facture interchangeable parts mass production basis, made possible dimensional con- trol, the manufacture certain military weapons requires even greater degree accuracy than ordinarily used production civilian industry. Faced with this problem, the Ordnance Department has carefully developed new sys- tem gaging. The system admirably suited the manufac- ture Ordnance materiel which subject approval Ordnance inspectors using Ordnance inspec- tion gages. There little doubt that this system the best yet developed any country the world. Many factories working mili- tary items have adopted this sys- tem gaging and are loud its praise. with the idea ex- plaining this system industry general that the following detail given. Proved Experience Take, for example, the experience world famed producer fire- arms. The Ordnance Department recently gave this concern $80,- 000,000 contract for equipping plant and producing 0.30 and 0.50 cal. machine guns. There are well over 300 major parts this gun, which involves 3500 machine opera- tions, large proportion which must gaged. The Ordnance sys- tem gaging was adopted this corporation and was found enormous benefit actual ser- vice and worth more than any in- conveniences which may have been experienced its first application. Foolproof Gaging System Developed Army Ordnance Arms plants are now using improved system gaging developed the Army Ordnance Department. With this system dimensional control, all gage tolerances are within the limits set the work instead being centered the upper and lower limits. Furthermore, the tolerances the in- spection and work gages have been set with respect each other assure positively interchangeability components mass production. Because the scientific soundness the Ordnance gage system, likely that will replace present commercial practice throughout American industry the near future. All drawings for the gun, to- gether with the drawings for the Inspection gages, were fur- nished Ordnance Depart- ment complete all details. has been found that, ignoring minor discrepancies, the gun when made strict accordance with the Ord- nance Department drawings func- tions with unbelievable reliability. For instance, gun picked ran- dom has been fired 26,000 rounds without any malfunction whatso- ever and without breakage serious wear any part. The Ord- nance Department was also great assistance the procurement machine tools, and the Small Arms Section the Office the Chief Ordnance has been, and being, constant help the solution technical problems which arise connection with the production. The War Department general has thrown open the company all its resources. For example, the gage inspection laboratory this particular plant patterned closely after the laboratory one the arsenals, whose personnel cooperated unstintingly provid- ing the necessary information. The Ordnance Department sys- tem controlling gages also em- ployed with great success. Travel- ing gage inspectors make frequent checkups gages use and keep detailed records wear, that gages may not only replaced the proper time, but also records may built from which the life all gages may accurately predicted. For example, certain thread gages have been found wear the point unserviceabil- ity periods short four five days, and obvious that un- less frequently checked, gages may accept great deal defective work. maintaining careful control such danger points, the gages may withdrawn from the job and replaced with new ones time prevent the acceptance bad work. Needless say, this very important factor insure interchangeability the component THE IRON AGE, September 1942—45 ° ° f 4 4 a | | 4 5 | 010°0 900°0 100°0 a t uJ a uJ | uJ SSS wo parts and maintain the high de- gree precision required the Ordnance Department. New and Old Systems Compared the Ordnance system, the dif- ference between work and inspec- tion gages predicated very logically and carefully planned sys- tem wear allowances and toler- ances, rather than the tion arbitrary differences. This system based tne fact that gages cannot built exact fig- ures but, like all other things, must made within permissible toler- ance accuracy; also the fact that they are subject wear. Therefore, the system takes into ac- the tolerance required the dimensions for the gagemaker, well allowance for the wear which will inevitably occur when the gage use, with the purpose mind controlling both these factors that satisfactory com- ponents can still produced. goes further that recog- nizes the fact that work gages, general, will wear more than in- spection gages due their greater usage, and that some difference must allowed between the inspec- tion gage and the work gage other- wise, the part which passes the work gage after has been use short time may not pass the in- spection gage, due the normal wear which the work gage subjected. The system worked out the greatest detail for all common kinds gages such snap, ring, plug and flush-pin types, and for all the usual toler- ances encountered part drawings small arms components. The Inspection gage designed that the necessary gagemaker’s tolerance producing the gage applied within the dicated the component drawing; and addition, wear allowance provided, also within the toler- ances shown the component part drawing, that the gage may have reasonable length useful life before must retired due wear. See Chart The work gage designed that also has gagemaker’s toler- ances and wear allowance applied it, not only within the limits shown the component part draw- ing, but also within the limits shown the inspection gage, that the work gage may have reasonable life usefulness before worn the point where will meet exceed the size the in- spection gage noted Chart facilitate the control the work gage, marked such way that when the actual measurement taken the gage inspector, has reached the amount indicated the marking, the gage must re- tired. The gagemaker’s tolerance and wear allowances are both charted for all the component tolerances 0.001 in. For example, Fig. “Go” and “Not Go” snap gage be- ing provided measure com- ponent with tolerance 1.750 1.755 in. The older practice would have been provide snap gage the figures the component toler- ances without ances wear allowances shown This obsolete system not sufficiently accurate for present day Ordnance materiel. due the fact that the gage theo- allow. toler. toler. 10.0006 [0.0001 [0.0004 |0.0002 [0.0002 [0.0005 0002 10.0015 10.0016 0016 .0016 AND RING Oo on miro Oo olo A Clo ADJUSTABLE GAGES AND FLUSH PIN © EE ae EE nis EB Post ‘ WMI So PO Giro oO © a =) a nA folie) OQ © Sis Oo retically can used only once (since with every use some wear occurs); also limit accuracy specified which the gage maker must work. such gage could possibly produced flat figures with tolerance accuracy what- soever, except enormous expense and then discrepancies few millionths per inch size would usually found under laboratory conditions. Work Gages The development the work gage shown directly below the inspection gage Fig. Although the figures ultimately arrived for the work gage are within the inside limits the inspection gage, for convenience use, the work gage chart wear allowances and gage- maker’s tolerances based the figures shown the component drawings. Consulting Chart reveals that DIMENSIONS ADD ALLOW. AND APPLY TOLER GO: SUBTRACT ALLOW. AND APPLY TOLER SUBTRACT ALLOW. AND APPLY ADD ALLOW. AND APPLY TOLER ADD MIN. SUBTRACT FROM MAX NOT GO: ADD MIN MARKINGS FOR MARKING ADD SUBTRACT FROM, THE PLUG ADD SNAP(PLAIN AND ADJUSTABLE) SUBTRACT SUBTRACT TYPE ADD MIN FLUSH PIN TYPE FROM MAX FOR MARKING “NOT ALL GAGES: USE ACTUAL SIZE NOT (GAGE MAKERS TOLERANCE NOT INCLUDED) THE IRON AGE, September 1942—47 4 0.000 0.002 0.003 0.005 0.006 0.009 0.010 0.014 0.015 0.016 0.10 | for component tolerance 0.005 in., the wear allowance for the side 0.0007 in. and the gage- maker’s tolerance in. Starting with the maximum com- ponent limit 1.7550 in. and con- sulting the chart, find that the wear allowance for the tracted, and that the 0.0002 in. gagemaker’s tolerance ap- plied minus direction. There- fore, subtracting 0.0007 in. from 1.7550 in., get 1.7543 in. and this figure shown the work gage drawing the side with tolerance minus 0.0002 in. accordance with Chart II. found that the work gage wear al- lowance the Not side 0.0002 in. and that the gagemaker’s tolerance also 0.0002 in. this case they are both applied plus direction. The 0.0002 in. wear allowance therefore added the minimum component limit 1.7500 in. give the size which the Not side the gage must made, this example 1.7502 in. plus 0.0002 in., shown the illustra- tion figures for the work gage are within the figures the inspection gage. Referring again Chart II, found that the side the work gage should marked 0.0005 in. less than the maximum component dimension and that the Not side the gage should marked the actual size the Not with the gagemaker’s tolerance disregarded, this case 1.7502 in. Some confusion arises from the fact that the gage limit stamped the side the work gage does not corre- spond with the figure which the or, first glance, with anything else. However, refer the side the inspection gage and note that the illustration the figure 1.7547 in. minus 0.0002 in., mak- ing possible for this side the gage either 1.7547 in. 1.7545 in. any point between. Insofar work passing the work gage and not passing the inspection gage concerned, the worst figure would 1.7545. Referring once again the marking the work gage, the figure 1.7545. other words, this example, 1.7545 in. the figure beyond which the side the work gage should not 48—THE IRON AGE, September 1942 allowed wear work passed tion gage. Therefore, the marking the work gage sort red signal the gage inspector that may know without further refer- ence the chart anything else, that once the gage has worn the figure marked, must returned and replaced. Inspection Gages The development the tion gage for this example shown tolerance 0.005 in. the com- ponent drawing, found re- ferring Chart for inspection gages that component tolerance 0.005 in. carries wear allow- ance 0.0003 in. the side the gage and that the gage- maker’s tolerance the side the gage 0.0002 in. Starting with the maximum component figure 1.7550 in. for the side the gage, the 0.0003 in. wear allowance subtracted leaving figure 1.7547 in. The gagemaker’s tolerance minus direction this case. This the direction which will keep the gage figures within the tolerances indicated the component draw- ing. The dimension and gagemak- ° ° ° IG. female gage di- mensions worked out for inspec- tion and work gages line with the new system Ordnance gag- ing. shown gage dimen- sioned under the old system. Obsolete system gage Component tolerances a Inspection gage 1.7545 Work gage er’s tolerance designated the side the gage made the gagemaker 1.7547 minus 0.0002 The Not side the inspec- tion gage starts with the minimum component dimension 1.750 in. wear allowance provided the Not side the inspection gage the part seldom enters it, but the gagemaker’s tolerance 0.0002 in., shown the chart, applied this case plus direc- tion. This the direction safety within tolerance shown the component drawing. Therefore, the figure which the gagemaker will make the Not side the inspection gage 1.7500 plus 0.0002 in. additional reason for not us- ing wear allowance Not gage that wear allowance would have outside the component limits which would contrary good manufacturing practice. will noted that the plus tolerance the Not gage diminishes the metal for wear, while the minus tolerance the gage adds metal the wear allowance. should therefore clear that the side the inspection gage can either 1.7457 in. 1.7545 in., any point between which the gagemaker may work. Since the maximum component dimension 1.755 in., the gage can wear 0.0003 in. the gagemaker has worked the high side his tolerance, 0.0005 in. has worked the low side, before the gage will exceed the maximum limits the figure shown the component drawing and pass part which incorrect. Fig. shows the relationship the tolerances the inspection and work gages with respect each other and the com- ponent tolerance. The have dwelt entirely male component parts and female gages. However, clearly evident that the ap- plication the data contained these tables female parts and male gages, and applying the data the opposite direction (that is, plus the gage and minus from the Not gage) satisfactory results are obtained, those already alluded to. Gage Laboratories The arsenal gage laboratories are responsible for the initial checking and acceptance all tools, jigs and fixtures used the manufacture war materiel, well all work a ‘ q ? the and are being Inspection the present emergency. The largest and best these labo- gage ratories are models which are copied L755 ec- r free from vibration, but sealed, air-conditioned and also air filtered ( prevent moisture from corroding ere actua Wear the gages and instruments. The Gage makers temperature the air main- Work tolerance how the work tained deg. and the tem- w ' e the same temperature the pre- ( cision instruments used take the applies especially for measuring ! long lengths. For example, dif- uld ference temperature deg. Worki long would result error Inspection approximately 0.0003 in., based gage per deg. Precision these laboratories were furnished and microscope which direct tal ocks universally used gage with the finest measuring equip- readings may within ing are ment obtainable, which include some 0.00001 in. available since the start the war. trical means amplification in- i 2 yr area « ich ards, gage block measurements are list the equipment these based their actual measurement laboratories includes the following precision gage blocks are the stand- measuring me- magnification 10,000:1 that standard measuring 0.0001 in. the work shows ard all Ordnance gage labora chine provided with vernier scale his tories and insure that Ordnance movement dimensional inspection based across the dial. the United States legal standard (c) optical projection com- measurement. the years prior parator with magnifications rang- 4 ay 7 = . . i j fr 9 iz - the emergency, through the fore IG. Actual application ing steps from 100 diame sight the Ordnance Department, type gages shown Fig. ters. This machine has visual artillery shell cases. THE IRON AGE, September 1942—49 | a screen upon which the magnified image the component projected for accurate measuring compar- ison with magnified outline the component. (d) universal measuring mi- croscope for contour, coordinate angular measurements which are sere very carefully ground and polished until one surface each fectly flat within .000002 in. addition, includes one set master precision gage blocks, and monochromatic light one color and wave length similar neon light. This light wave equipment 4—This type multiple contact electric not only reads many eight diameters more glance terms over, under size, but also eliminates the necessity for setting inspection gage tolerances and wear allowances. taken means cross hairline setting comparison with one the standard graduated glass scales magnified which are mounted suitable ad- justable cross slides. Results are read through two spiral micrometer microscopes with accuracy 0.00005. circular table for ro- tating the work around vertical axis and dividing center for loca- tion around horizontal axis are provided. (e) One the most accurate measuring facilities the light wave measuring equipment, consist- ing two semi-quartz optical flats clear hard glass, neither having any magnifying power, which are 50—THE IRON AGE, September ideal for checking flatness, par- allelism and the size small parts, and for detecting worn spots the anvils precision measuring devices, etc. When the optical flat placed measured, interference light and dark spaces will visible through the flat, caused the fact that the light reflected from the surface the work interferes out phase with the light re- flected from the under surface the flat. The dark bands indicate comparative vertical distances the work, which determined the width and straightness the bands, resulting definite meas- inch the work per dark band, eight bands 0.0001 in. Straight bands indicate flat surfaces and curved bands may indicate convex concaved surfaces. Interference bands seen with daylight are series colors similar the colors the rainbow. The arsenal have other more commonly known measuring facilities which include toolmakers’ microscopes, vertical optimeter, visual gage capable 5000 magnifications, Rockwell hardness tester, Rockwell super- ficial hardness tester, and finally large toolmaker’s microscope. New Types Gages new instrument for gaging, recently developed under the guid- ance the Ordnance Department, known the multiple purpose electric contact gage. Instead routing component part through number inspection stations, each gaging different surface, the gaging all these surfaces per- formed one instrument which gages all surfaces simultaneously. Flashing tell-tale lights indicate the operator their color whether not the part will pass. does not pass, warning light designates exactly which point surface fault. master light shows when all points are correct. This gage great time-saver and its use industry rapidly. This type gage em- ployed for shells, cartridge cases, primers, fuse components, etc. simultaneously practically all external toleranced dimensions components inspection rate that compares favorably with the highest production rates. Pneumatic gaging devices for the type fuse have been developed and procured for use all facilities this fuse. Pneumatic devices for gaging gun bores have been developed and are now use arsenals and inspectors facilities producing small arms and cannon. Pneumatic gun bore gages permit faster and more accurate inspection than star gages and not require highly skilled operators. dial indicator gun bore gage has also been developed for cannon. obvious from the foregoing that gaging history being made the Ordnance Department the Army and contributing mightily our armament effort. and nvex ence own lude tical well per- Armor Plate Planer Made Structural Shapes HROUGH the use tural steel shapes and welded -fabrications, the armor plate grinder pictured here was designed, built and shipped division General Motors less than 100 days. Weighing 25,000 used less than one-half the critical mate- rials that might needed for machine similar capacity but more conventional design. The machine ft. long and ft. wide and shown set skel- eton frame for test purposes. When actually installed, its I-beam track rails and grinder unit will mounted concrete foundation. The machine, which was built the Vonnegut Moulder Corp., con- sists stationary grinder unit and twin traveling tables running 45-ft. tracks. The machine intended bevel the edges ar- mor plate preparatory arc weld- ing into the shells armored cars and combat tanks. Hence there provision for adjusting the angu- larity the tables means heavy screws provide for edge bevels deg. While one table unloaded, loaded and set up, the other table traverses the work past the grinding wheel. Tables travel ball bearing roll- ers upon hardened steel tracks set angle resist grinding whee! forces. Feed actuated cable drive and can varied from 25, ft. per min. Each table connected disconnected from the cable quick acting clamps. The grinding wheel segmen- tal type, in. diameter and supported 6-in. diameter spin- dle tapered babbitt bearings, with ball bearing thrust collar. Drive eight V-belts from 40-hp. motor. There also 1-hp. motor for driving the coolant pump. 4 * AKING the frame this 45-ft. long armor plate edge grinder welded structural steel saved much time fabrication and reduced the weight materials required. 4 j EAR view the machine, showing the cable drive for the work tables. Cable power supplied 3-hp. motor driving the cable drum through pair reversing friction clutches, reduction gears and roller chain sprockets. THE IRON AGE, September ent, ugh the sly. her ght ght : ive res ate rs. grading workmen pro- vide for instruction these men their own foremen eve- ning classes held public schools, with the factory lab- oratory. This plan being very effectively used the Peoria plant LeTourneau, Inc., employing ap- proximately 2000 men arc weld- ers, machinists, and allied trades, meet the company’s increased requirements for trained men. The part which the public school considerable. Approximately months ago, the Federal Govern- ment set aside funds used Federal, State, local, and privately for the purpose war education. The idea back this appropriation was that there were some way which the education indus- trial workmen could removed from the factory and placed the already existing educational insti- tutions, more effective use could made the production facilities already existing factories. progressive vocational educa- tion program the high school level was already operation the Peoria public schoo) system. cooperation with the local advisory board for National Defense Educa- tion, the Peoria system set night school classes the indus- trial subjects which they were pre- pared teach virtue equip- ment and facilities. These were opened the general public the basis two 3-hr. class periods per week, the instructional material which was supposed supplement the work which the workmen who attended the classes were already doing. The cost these courses was met the Federal Govern- ment. Because the specialized na- ture its work, and the relatively rapid growth the LeTour- neau organization Peoria, the 52—THE IRON AGE, September WALTER BROOKING Director Plant Education, LeTourneau, Inc., Peoria, plant already had well-developed system for the education its em- ployees the job. This consisted lied workmen being trained from the start the job. They started regular employees the com- pany full pay until they could perform the work required the plant. Supplementing this on-the- job training was program home study courses based the use text book and the answer- ing series questionnaires. Employees were informed the nature these voluntary courses, their subject matter, length time that would normally required the studying and answer the questionnaires. The questionnaires were made up, cor- rected and discussed instructors closely allied with the actual work centage the workmen plant took these courses. Quicker Education Needed fulfill the purpose the national defense gram the public schools, plan was envisioned reduce the bur- den education industry and speed the educational process. courses the factory, placing them public school classrooms where they were taught foremen supervisors from the factory. During the summer months this plan was experimentally and coop- eratively tried the Le- Tourneau Co., and the Peoria public classes use text books and meet the shop for practical expe- rience. This group learning shop mechanical maintenance. 2 LJ school system. Evening classes machine tool operation, weld- ing, flame cutting, and acetylene welding, blueprint reading, and shop mathematics were organized, ork based the home-study texts and outlines, but expanded teacher- the student personal contact the classrooms. They were held one the local high school buildings, three hours night, two nights the week for weeks. They covered the work which had previously been lan covered from weeks. Qualified foremen and supervisors from the LeTourneau organization were examined and certified the state board education teachers for the courses. When the home- study classes for LeTourneau em- ployees were discontinued careful program plant publicity was undertaken familiarize the work- men thoroughly with the new courses. Classes were open, not plan which ties the facilities and supervisory ex- perience the public school system with the foreman and shop facilities Peoria plant speeds upgrading war workers. only LeTourneau employees, but anyone the Peoria area who was engaged similar work. Each course was administered the Peoria Board Education, whose director vocational edu- cation was assisted the director plant education the LeTour- neau plant. Good Response New Courses The response these experi- mental classes was very good. First, was found that there was wide interest the subjects presented, both the part the men the LeTourneau plant, and men man this class spends three hours week the lathes the high school machine shop, and three hours theoretical study with text book. working other plants the com- munity. All classes were set the theoretical semi-theoret- ical basis because those who at- tended were already working the field being studied and was thought that they could correlate six hours theory week that subject considerable advantage. This automatically course men who were already doing the type work being stud- ied; and therefore became strictly supplementary, upgrading class. The workmen did not seem reluctant come school build- ing study the theoretical side their daily work. The attendance was quite regular from class class, and was found that about per cent, rather creditable percentage, those who started course continued its completion. The number men enrolled each class varied from 30, though was looked upon the ideal class for most work. The attitude the men attending these classes towards the school building, its equipment and grounds was very good. From purely administrative point view, the courses tried the classrooms the local high school during the summer months could have been set and con- ducted factory premises. They through the Peoria public school system but the contribution the local school board allowing the use the school building itself for these courses was one consider- able importance. classrooms were not already available plant, the setting aside space large enough for one several class- rooms the average industrial THE IRON AGE, September = ‘ 7 might very difficult, even impossible. Further, the prob- lem getting blackboards, desks, chairs and tables, and other fix- tures suitable for classroom; the arranging for lighting, drinking water, and toilet facilities must adequate for classes from two three hours duration would one considerable mag- nitude for the average plant. the interest speed getting the classes started and economy their completion, the use already ex- isting schooling facilities was ob- viously the most effective solution the space and furnishing problems. The fact that they were made available this cooperative basis was considerable contribution the present vital educational effort. The experimental classes held the summer were successful that somewhat expanded program was undertaken for the fall months, October through December. addition the regular classes which were being taught under the war program the local high school the following classes were set up; taught supervisors and foremen from the LeTourneau com- pany, and open the attendance and any other emplovee the Peoria vicin- ity who was interested, far the the class could ac- commodate them: Two classes machine tool op- eration. Two classes blueprint reading. mathematics. Four classes theory welding and arc welding control symbols. One class flame cutting and acetylene welding. One class elements inspec- tion. Two classes first aid and fac- tory safety. One class heat treating. One class time study for fore- men and supervisors. the 15, five were set the premises the LeTourneau plant, and given the afternoons from two days week for the benefit the men night shift. All these classes were well attended. Observations There were over 15,000 hours actual classroom study completed voluntarily their own time employees engaged defense in- dustries. The amount theory which they can absorb theoret- 54—THE IRON AGE, September 1942 >, school drawing desks and blackboards contribute materially the effectiveness this class blueprint reading. a.ong work, allows correlate what tney know and increase vastly their effective- ness and adaptability the job. training and upgrading importance the present time when personnel many plants state flux due military service absorbing men, and new types work being brought into factories. has been found that members class which goes from the classroom into the plant examine certain phases the subject study how their department re- lated other departments, often develop very desirable interest parent that weeks such class vastly superior effec- tive learning value any home study course taken the average man. classroom course, taught man who supervising the type work under discussion gives the workman ask many question concerning the work which normally may not able ask his daily work. Foremen supervisors teaching such classes frequently find quali- ties and capacities men which they may not have recognized their daily contact with them. The men these classes come know the supervisor workman and also teacher and human being. This has great advantages the and cooperative personnel within plant. Men from other plants than the one from which the teaching foreman and perhaps the majority the class come, bring their con- tribution new ideas and discus- sion because varied experience, and profit the exposure new ideas and different ways doing things. instructor these classes learns more than anyone else his class. The fact that men and vested with the teaching them the finer points and the broader aspects the job which they are doing, usually requires him some studying which might not other- wise do; and which probably get The fact that his relation the course that paid in- structor also may motivate him more conscientious and thor- ough job. The experience conduct- ing class contributes noticeably fidence, self-esteem, ness most the instructors, not only teachers such courses, but their regular iobs. For this reason, plan heing carried out far possible pass the ex- teaching such classes from one supervisor another the end the second three months’ teaching period. the ding than hing con- cus- nce, new sses the the ing, yme ion in- bly on- ve- not his hs’ Such classes these must kept strictly practical basis. The text books (which are purchased varying part each course, depend- ing upon its nature. most these classes text book looked upon general outline upon which the practice the plant may super-imposed; with which the knowledge the people the class may correlated. The heat treat- ing class, for example, uses text book which rather wide its scope because the LeTourneau plant builds all its own furnaces. Therefore, study refractories, furnace construction, pyrometry, steels different kinds, different heat treating processes and some elementary considerations metal- lurgy rightfully find their place the course. All study done dur- ing class time—there home study any the courses. Text books for blueprint reading and for shop mathematics are rather stand- ard because these two subjects are elementary almost any kind shop work, and have, therefore, been carefully studied the past. Examinations are not given very often, nor there much emphasis upon the grading the men the course from day day, although the end the course there grade assigned each man based his accomplishments class and his faithfulness attendance. Both the examinations and the grading are considered secondary importance. The essen- tial thing these courses have men attend the class who, virtue being the class, back their daily work better work- men. able write good examination may not indicate that the man will back his job and apply what has learned. There- fore, the emphasis laid upon presentation material, correla- tion with daily work the plant, and continual service from the instructor the man the class his own ground. de- gree which the man goes back the plant and applies what learns the only valid criterion which these courses may evaluated. This cooperative method wherein the public school system contributes its supervisory experience and its classrooms, blackboards and other equipment for the purpose in- dustrial education; where industry supplies the teacher, the organized subject matter, and offers its plant laboratory for inspection, dem- onstration some actual work; and where industrial workmen may come study, free charge, the work which they are doing from regular factory foremen and can all their studying the class- room concentrated 12-week course study effectively takes much the burden factory training off the shoulders indus- try. exceedingly important contribution the war program. Electronic Controls Guard Furnace Atmospheres SPECIAL tube, providing continuous check the purity the hydrogen gas flowing over steel atmosphere furnaces, has been developed Westinghouse electronic research engineers. Such control important where the dew point the treat- ing gas must maintained the critical region —40 —94 deg. for precise furnace condi- tions such required for bright annealing, for chemical pro- cesses using purified dry hydrogen similar controlled gases. Steel often heated at- mosphere highly purified hydro- gen that practically free moisture and oxygen. Ordinarily, measure moisture the gas where dew points are less than deg. F., cooled and polished metal plate inserted the gas stream and the temperature noted when condensation first occurs. 2—This simplified sche- matic wiring dia- gram the dew point electronic con- trol apparatus. However, below —40 deg. F., this method becomes largely guess work and even skilled testers dis- agree the values the same gas. This new electronic method insures reliable and accurate de- terminations the moisture and oxygen content hydrogen dis- associated ammonia gas. operation, the flows through two-element tube, shown Fig. containing tungsten filament and plate. The wiring diagram for the control shown Fig. Electrons flying from the hot filament the plate con- tinually bombard the gas. the gas pure dry hydrogen, all electrons reach the plate; but any oxygen water vapor the gas immediately pick some the electrons and form negative ions, thereby reducing the electron cur- rent. This change current the plate circuit indicates the de- gree impurity*in the gas. I—A continuous sample the hydro- gen gas used atmospheric heat treating furnaces flows the top this tube and out the base. moisture oxygen mixed the gas, the tube passes less current, and the current volume passing through the tube measures the gas purity. THE IRON AGE, September 1942—55 | % § 4 ° ° FOCKE Research Metallurgist Diamond Chain Mfg. Co., Indianapolis ° ° concluding this series three articles, which the concepts involved measuring hardenability and the test methods employed have been outlined, the author corre- lates the test data and gives practical example its application choosing substitute steel. the standard Jominy test the cooling rate terms distance from the water quenched end shown Fig. 25. The “L” bar curve shown this chart, used primarily for shallow hardening steels, discussed be- low. From this chart possible plot hardness-cooling rate curves (H-CR Curves), shown Fig. 26. Usually the cooling rate plotted logarithmically order cover the entire range. The SAE its proposed standard suggests form such shown Fig. which automatically provides the correlation between distance from the water quenched end and cool- ing rate, and also the pertinent data the steel and test proce- dure. The writer has revised the standard form slightly include columns for recording treatment and the values. Then with set curves such shown the hardness-traverse (U) curves. From these curves, more di- rectly from chart such shown Fig. 29, possible trans- pose Jominy end quench data into ideal critical size vice versa. For example, the data the curves Figs. and and the curves Fig. 28, the Rock- TABLE Rockwell Hardness Cooling Rate Chart for SAE 3140 Steel Rockwell Hardness From Cooling Rate from Fig. Fig. Test Piece, In. Quench Surface Surface Midway Center 56—THE IRON AGE, September 1942 well hardness-cooling rate curve for 3140 steel can developed shown Table VI. These are the data plotted for 3140 the upper curves Figs. 24, and 27, but all the 1045 in- formation these three figures was obtained from actual Jominy end quench tests. The values from the Jominy information were obtained using the chart shown Fig. and the calculated values were obtained the Gross- mann using nominal analysis for the 3140 but actual values for the 1045. Finally, return the first example the 3140 part for which 1045 was substituted, possible using this infor- mation predict not only whether not the 1045 would show satis- factory surface hardness but also within reasonable accuracy just what the hardness would the surface and any point within the part. Also, comparing the hardness distribution obtained the ac- tual quench with that obtained equivalent rounds flats pos- sible with fair accuracy deter- mine the surface hardness and dis- tribution across the section which would expected more dras- tic quench were utilized. the gear which was chosen example for the first part this article, was stated that the surface hardness quenched was only when the gear was made 3140. From Fig. 27, clear that hardness 3140 was obtained cool- ° ° Distance from quenched end jominy test bar, 25—Cooling rates determined experimentally for standard Jominy test bars. ing rate about deg. per RIGHT sec., and obvious that this Data same cooling rate would only de- from Fig. velop about Rockwell 1045. plotted ona From Fig. cooling rate modification deg. per sec. would obtained the SAE pro- oil the surface three- posed standard inch round, and for purposes form approximation then would vides possible consider the gear tion between the the equivalent distance from the round that water quench water quenched had been used, the surface cooling end and the cool- rate could expected about ing rate and also 400 deg. per sec., which would gives data the have been more than sufficient steel and test > Rockwell hardness 26—Hardness cooling rate curves based Figs. and 25. ° ° ° Cooling rate, deg. per sec. hardness Distance from water-quenched end jominy provide hardness the surface procedure. sixteenths inch 1045 excess the Rock- But, assuming that cross sec- tion the 3140 gear showed minimum hardness and was felt that would necessary keep this value above 30. From uench similarly quenched would only show about Rockwell Again THE IRON AGE, September 1942—57 | | for ‘igs. in- niny vere inal tual first for ted, for- ther also just ac- ter- dis- "as- sen the rily the 4 »0 Cz | 0.2 2 ls 0 3 oO Distance critical hardness from water-cooled end, in. end quench data can transposed into ideal critical size vice versa, means this chart (Gross- mann). LEFT 28—Chart for using hardness-cooling rate curves pre- dict the actual hardness which would obtained various Cooling per sec. 1300 deg. could seen that the gear had cooling rates similar those which would developed three-inch round, that even the 1045 were quenched water satisfy the surface hardness re- quirement, the minimum core cool- ing rate would not over deg. per sec., that the core hard- ness would only about Rock- well For shallow hardening steels such the 1045 described, the “L” bar shown Fig. may substituted. Because its shape, the faster rates cooling are stretched over greater length and provide, therefore, greater sensitivity. The cooling rate-dis- tance from the end the speci- men for this bar are shown the upper curve Fig. 25. data are taken bar, care must exercised prevent confusion transposing other units keeping everything directly terms cooling rates and not de- pending upon transposition charts such Fig. 27, which are pre- pared for the standard bar. For small sections from which would not possible prepare the standard Jominy test piece, the SAE recommendation includes variation the standard water orifice and pressure heigh