The Iron Age 1940-06-06: Vol 45 Iss 23

Editorial Technical Articles Hardness Conversion for Hard Metals................. New Graphitizing for Ladle Additions................. Deep Draw Test for Sheet Metals..................... Special Tooling for Machining Die Castings........... Design and Welding Fabricated Machines.......... Case Carburization Contour Sawing Railroad Shops................... New Machine Tool Design.................. Feature Reports News and Market Reports News Industry Non-Ferrous Metal Market Personals and Obituaries 100 Scrap Market and Prices May Pig Iron Production Fabricated Steel JUNE 1940 Comparison Prices 104 Reinforcing Bars....... Summary the Week 105 Iron and Steel Prices....... The Industrial 106 Ferroalloys, Pig Iron District Market Reports 108 Warehouse Prices VOL. 145 NO. Machine Tool 114 Sales Possibilities ) O ) » ) ) President and Editor Just Between Two Index Advertisers BAUR Vice-President and General Manager Copyright, 1940, Chilton Company Managing Editor News Editor Technical Editor Machinery Editor Art Editor Editor Emeritus Associate Editors DIX, Manager Reader Service Owned and Published (Incorporated) Washington Editors Advertising Staff L. W. MOFFETT JAMES G. ELLIS wit ae Publication Office Editorial and Resident District Editors Herman, Chilton Philadelphia Philadelphia, Pa., 239 West 39th St., CAMPBELL ROBERT BINGHAM U.S.A. New York, ittsburg Chicago Leonard, 239 39th New York JAMES SHERMAN Peirce Lewis, 7310 Woodward Ave., Detroit Cleveland Detroit Ober, 239 39th St., New York FRAZAR CHARLES POST Beach, Cal. EVERIT TERHUNE, Vice-President Boston San Francisco VAN DEVENTER, Vice-President HUGH SHARP CLYDE ENNIS Member, Audit Bureau Circulations BAUR, Vice-President Mil Birmingham Member, Associated Business Papers ilwaukee the Industrial Arts Index. Pub- WILLIAM BARBER, Treasurer SANDERSON ROY EDMONDS lished every Thursday. Subscription Price: JOHN BLAIR MOFFETT, Secretary Toronto, Ontario St. Louis JULIAN CHASE, THOMAS KANE, .00: Canada, 50: Foreign, LEROY ALLISON Single copy, cents. Annual Number $1.00. BUZBY, FAHRENDORF, Newark, Cable Address, HARRY DUFFY CHARLES HEALE Bare & 39 46 ¢ 11S > 120 125 126 128 75 j | | ty 7 Guide Largest Steel Stocks STAINLESS 67 mm 2 THE NEW RYERSON STOC steel New new analyses new more reference tables and helpful improved mechan- ical features—all combine make the new Ryerson Stock List outstanding manual for steel users. What- ever your need steel and allied lines, you can rely the Stock List dependable guide Immedi- ate Stock Shipment uniform high quality products. Over 10,000 kinds, shapes and sizes Ryerson Certi- fied Steels are available from large, fully-equipped RYERSON STOCK Many New Products Cold Forming Plates, Inland Hi-Steel Cold Rolled Stretcher Leveled Sheets, Pluramelt Stainless Steel Sheets, SAE 4815 Hot Rolled Alloy Rounds, W. D. X4130 Hot Rolled and Cold Rolled Rounds, and SAE X4340 Hot Rolled Alloy pve 4 2 on ruses GET IT! plants. Every pound steel carried stock Ryerson represents the highest quality available each partic- ular classification. you have not received your copy this new book, write for today. you have one, keep handy, use often, profit repeatedly. Joseph Ryerson Son, Inc. Plants at: Chicago, Milwaukee, St. Louis, Cincinnati, De- troit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City. 36—THE IRON AGE, June Rounds are among the new products listed this new book. Handy Reference Tables and Charts SAE Standard Specification tables, physical properties charts showing physical prop- erties and ings of over 50 steels, weight tables, numerical equivalent charts and other important data are included the 1940 Ryerson Stock List. LIST buying LIST INCLUDES Complete Description Many Lines Over 10,000 kinds, shapes and sizes Certified steel are shown. These turals, bars, plates, sheets, cold finished steels, heat treated al- loys, tool steel, high tensile steel, stainless, mechanical tubing, babbitt metal, welding rod, reinforcing bars, bolts, nuts, rivets, etc. Mechanical Features product index, the new book has improved thumb tab margin index. Eye-condi- tioned paper assures easy reading. A new type of me- chanical binding has been adopted the book will lie and pages turn easily. i = | JUNE 1940 ESTABLISHED 1855 Columns ROOSEVELT, his “fireside” chat last week, neatly put all his New Deal Critics into the “fifth column” together with all non-New Deal Democrats. Which brings the question what fifth column and does. The name was coined during the late civil war Spain. Nationalist General Mola was advancing upon Madrid and was asked the strength his attacking force. have four columns the march outside the said he, “and one column inside that will act when the time From then on, the term column” seemed one that was made order describe the effective German policy planting saboteurs neighboring countries ready act when the time came. doubt the sabotage these enemy sojourners played consider- able part overcoming the resistance the English and the French and allowing such unprecedented German successes taking planned objectives. But there was another kind sabotage work that was tremendously more damaging. Sabotage can deliberate and intentional unintentional. can imported domestic. And equally damaging whatever label you give it. The weakness France and England, contrast the strength Germany, primarily due unintentional domestic sabotage. the lack the right men the right places. lack organization for preparedness and lack the kind men who were capable visual- izing what was needed and putting effect. What was needed visualized several years ago was that Ger- many was organizing its industries for highly mechanized war. That Germany doing this was putting men charge its armament pro- gram who through experience and force character were capable producing the goods the time they would needed. The young soldiers England and France who are now dying the Belgian are not paying with their lives because German “fifth They are paying the price benevolent but ineffective political administrations recent years their home countries. That should indeed lesson for us. Our great need for top authority the hands people capable quick and right decisions and strings attached. The four industrial members the Advisory National Defense Com- mission, Knudsen, Stettinius, Hillman and Budd, are first rate caliber. are not qualified express opinion the others. But have had advisory commissions and committees galore first rate caliber dur- ing the past several years and their advice has gone out the window. that should happen now, Hitler will not need “fifth column” America. | Suh or i 125 eye j | | | ~ 4 Production cost went down when Inland Hot Rolled Sheets were used form this vacuum cylinder. Heart the newest Automatic Gear Shift cylinder, 4-inch diameter cup, drawn toa depth. And the call for 8000 parts per day. Ordinary sheets caused tremen- dously high breakage rates. acceptable rejection figure was fixed three per cent. When Inland Hot Rolled Sheets were First draw. Blank Second draw. and cup. Draw inches. used, the breakage was brought down average less than one per cent! That kind performance nothing new with Inland Sheets. That’s why manufacturers come depend Inland Sheets reduce production costs. They the job better. They cut waste the bone. They help you keep output right schedule. Inland metallurgists are available work out similar economies for you. Write today. SHEETS STRIP TINPLATE BARS PLATES FLOOR PLATES Trim flash. Embossed, STRUCTURALS PILING RAILS TRACK ACCESSORIES punched and drilled. REINFORCING BARS IRON AGE, June 1940 if hardness conversion charts presented here differ from their predecessors notably the ab- sence the warning, “approximate only.” Deletion this customary phrase justified the substitution more specific limitations the use the data and giving more de- tailed information the source data than heretofore. This action was taken only after thorough study hardness tests, seeking fundamental objections the use conversion re- lations. Comparing Rockwell and diamond pyramid hardness values obtained hardened steels and cemented car- bides, consistent relations were obtained each material, but the numerical values the same hardness one test were widely different the other test. This fact was attributed the large difference elastic modulus be- tween these metals and shown natural consequence the method evaluating impression area used the two tests (A. paper, Chicago, 1939), there being much larger elas- tic “spring back” effect tests mea- suring depth impression those measuring diameter. that the elastic modulus has prominent effect conversion rela tions means, course, that conversion charts for the different types tests mentioned can accurate only when restricted metals approximately the same elastic modulus. Accordingly this restriction here replaces the less HOWARD SCOTT Westinghouse Electric Mfg. Co. specific one previously used “approxi- mate Other properties than elastic modulus and composition can vary enormously without changing the conversion relations materially. Other justifications for publishing new tables may mentioned low. All hardness tests were referred the same reference test having long range high accuracy, namely the diamond pyramid hardness test. Hardness values other tests were made when possible the maker the instrument question. The ERE are hardness con- version equations and charts which application assumption that they are only approximations. The data shown apply steel and cemented carbides, and can used quickly and with con- fidence. ness the Brinell ball used speci- fied eliminate common cause diserepancy hardness conversion tables. Finally, the tabular values are calculated from empirical equations which express accurately the observa- tional data, the spacing between rows representing the same hardness inter- val the reference scale high low hardness. The equations used obtain the tabulated values for steel follow. The symbols appearing there are also de- fined, excepting DPH which stands for diamond pyramid hardness sured the latest model Vickers hard- ness testing machine. measured with 150 kg. load the diamond brale. 2.430 over DPH range 240 1040 DPH. 119.0 over range 240 1040DPH. THE IRON AGE, June 1940—39 | x 5, 9 | +. 2 2 TABLE I—HARDNESS CONVERSION CHART FOR HARDENED STEELS Minimum thickness inches stock required for accurate readings tests noted (Values given are ten times depth impressions) Rockwell Rockwell DPH Test Brale Test Superficial BHN, Ball, DPH Kg. Kg. 150 Kg. Kg. Kg. Kg. 300 0.0140 0.031 0.012 0.134 200 0.0170 0.038 0.072 0.041 0.015 0.040 0.197 Superficial (Wilson Chart No. 38) Hardness, Kg. Load Diamond Pyramid Seale, 150 Brale Penetrator Seale, Brale Penetrator Monotron Load Scale Value Divisions) Monotron tests all hardnesses can made 0.018-in. stock over. | | Scleroscope numbers vary with size—relations given are for in. Hardness 40—THE IRON AGE, June 1940 1020 70.2 86.4 94.6 86.5 78.1 Tungsten Carbide Hultgren Ball, Standard Ball, ensile 980 69.2 85.9 94.2 85.5 77.0 99.3 Strength 920 67.6 85.1 84.0 95.8 BHN mm. BHN mm. BHN mm. 840 65.3 83.8 82.0 72.4 90.8 95.9 746 2.24 820 64.6 92.0 81.5 71.7 89.5 93.8 735 2.26 800 63.9 83.2 91.7 81.0 71.0 88.2 91.6 723 2.28 780 63.2 91.4 80.5 86.9 89.5 710 2.30 760 62.4 91.0 79.8 69.3 85.6 87.4 698 740 61.6 81.9 90.7 79.0 68.5 84.2 85.2 685 2.34 | 680 59.2 80.6 89.5 77.0 65.5 80.0 78.8 640 2.43 601 2.50 2.55 640 57.4 88.6 75.5 63.5 77.0 74.5 602 2.49 578 560 316 620 56.4 79.1 88.2 74.5 62.3 75.5 72.4 584 565 549 2.615 306 580 54.2 87.2 72.8 60.0 72.4 68.1 546 537 525 2.67 279 560 53.1 86.6 71.5 8.7 70.8 66.0 527 521 2.68 510 269 540 51.9 76.7 86.0 70.5 57.2 69.2 63.9 508 506 2.73 496 260 520 50.6 76.1 85.4 69.5 55.7 67.5 61.7 489 489 481 2.79 250 500 49.2 84.7 68.3 54.2 65.8 59.5 471 2.81 473 465 2.84 240 480 47.8 74.6 84.0 67.0 52.6 64.0 57.4 452 2.87 454 448 2.89 230 460 46.3 73.8 65.5 51.0 62.1 55.2 433 2.94 437 2.92 432 220 420 42.9 81.6 62.5 47.3 58.3 51.0 395 3.07 399 3.05 398 3.06 200 360 36.8 68.8 78.6 57.0 52.0 44.6 339 342 3.30 342 3.30 170 340 49.8 42.4 320 3.40 323 3.39 323 3.39 161 320 31.8 76.2 53.0 34.5 47.4 40.2 301 3.50 304 3.48 304 3.48 151 300 29.0 75.0 50.3 31.3 45.0 38.1 283 3.60 285 3.59 285 3.59 141 | | | Rockwell superficial hardness kg. load, brale. v ins DPH range 240 1040 DPH. DPH range 240 1040 DPH. Same 15-n except kg. load. 3.132 DPH range 240 1040 DPH. 10-mm. ball with 3000 kg. load. 0.951 (DPH) for standard steel ball over range 200 400 DPH. 0.951 (DPH) for Hultgren steel ball range 200 450 DPH. (DPH) for tungsten car- bide ball over range 200 700 DPH. Tensile strength determined standard test speci- men ductile steel. 494 (DPH) 7000 over range 200 660 DPH. Monotron load seale value for penetration units. 0.107 (DPH) over the range Sel hardness deter- mined with recording instrument square specimens. Over 133.51 (DPH) 1440 over the range 200 1040 Table gives the values for the sev- eral tests calculated these equations for point steps DPH. Values be- yond the range accuracy these equations are taken directly from plot- ted curves. Also given are minimum values stock thickness which re- liable hardness readings can taken, upper right corner Table com- mon cause inaccurate readings insufficient thickness stock for the test used. The only other material than steel extremely high hardness whose TABLE Hardness Conversion Values for Sintered Carbides DPH 1750 80.1 1700 79.5 91.9 1650 79.0 91.6 1600 91.3 1550 91.0 1500 1450 76.5 1400 75.8 89.4 1350 75.0 1300 74.2 89.0 1250 73.3 1200 72.4 1100 70.4 1050 69.3 1000 950 66.8 85.2 900 hardness frequently determined the sintered carbides, mostly tungsten carbides. Having the extremely high elastic modulus 79,000,000 per sq. in., this metal requires different con- version relation from steel. set carbide specimens having wide range hardness was obtained through the courtesy Judkins the Firth Sterling Steel Co. The relations be- tween two Rockwell scale readings and DPH were determined specimens and yielded the following equations measured with 150 kg. load the diamond brale. DPH the range 900 1800 DPH. Ry = Same as R. except 60 ke. load. DPH over the range 900 DPH. Values and bonded car- bides for 50-point steps DPH be- tween 900 and 1750 are given Table The test (60 kg. load) quite popular testing this material because the lessened possibility cracking the diamond indenter. Note that the value carbides 900 DPH 1.6 points lower than steel the same DPH. value obtained conversion can better than the direct observa- tion, accurate conversion data are value unless the original observa- tion accurate. Accordingly, de- sirable mention the more common causes inaccuracy inconsistency, namely (1) Failure check testing instru- ment frequently. (2) Carburized decarburized skin. (3) Depression anvil with depth measuring test when testing thin ma- terial. (4) Test impressions too close (the separation should least five times the impression diameter spite all these precautions, in- consistent conversion relations are still possible one particular case, namely shallow hardened steel, although the depth uniform hardening deeper than specified for accuracy Table Under this condition the observed Rockwell “C” hardness given DPH value may much two points higher than that obtained conversion from DPH. This effect attributed the high residual stress known exist shallow hardened steels when the hardness has not been reduced greatly tempering. THE IRON AGE, June i ' ay. : rie Sy ay 4 AS A HERE the present time generally accepted form test for the deep-drawing qualities sheet metal. Various forms test have been proposed from time each has had its champions critics, and there sufficient evidence show that each satisfactory under certain conditions and unsatisfactory under others. approaching the problem se- lecting test procedure for deep-draw- ing sheet necessary examine the conditions involved the drawing operation and ascertain the simplest combination properties amenable test which these conditions bring into play. general three different types strain are involved deep-drawing operation. The three types action—bending, stretching, and drawing, occur together most types press operation, but varying degree. the three, bend- ing appears present little difficulty practice, though the subject Stretching may occur without drawing certain shallow pressing operations, but drawing does not occur without stretching under any normal condi- tions, and when material fails during pressing almost invariably fails region subject stretching dis- tinct from drawing. Cupping Tests This fact has naturally led the conception that the most suitable mate- rial for drawing purposes one which can subjected most stretching without fracture. This has led turn the use criterion drawing quality, either the elongation meas- ured tensile test the depth penetration cupping test. rough indications, capable distin- guishing between good and bad mate- rial, these tests have served useful purpose, but they are very much under cloud where close comparisons are required between materials able and just unsuitable for exact- ing operation. This failure the part the cup- ping tests particular unfortunate, for they have several attractive fea- tures. They are simple and inexpen- carry out, they are intrinsically multi-directional, and therefore bring into evidence any directionality the material, they afford indication grain size and surface appearance, and they lend themselves autographic load-penetration records with (hitherto 42—THE IRON AGE, June 1940 undeveloped) possibilities detailed interpretation. defence the cupping test should pointed out that there intrinsic disability the test itself, and provided form chosen which elim- inates parasitic influences has been demonstrated provide reliable and sensitive measure that particular type ductility which required stretching operations. Indeed, closely simulative such operations that failure correspond with prac- tical pressing results purely stretching character can only logically attributed want consistency the impressed conditions. The Drawing Test The cylindrical cup-drawing test has several attractive features, including almost all those associated with the cupping test. closely simu- lative many common forms pres- sing that its acceptability criterion the suitability material for such pressings can almost There little scope for personal errors the part the observer, and the completed cup forms its own permanent record the result the test capable providing consider- able amount information apart from the primary dimensions; readily reveals any directional properties the material the formation ears, can made give indication grain size and finish under both stretching and and provides means for measure- ment the tendency the material change thickness under drawing action. such test can accepted with (1) must proved sufficiently consistent under fixed con- ditions provide sensitive means differentiating between different mate- rials. (2) must not sensitive such changes testing conditions are inevitable practice. (3) Conditions introduced exigencies practical testing which bring into play other properties than those under direct consideration, such, for example, local ironing, bending action over the die radius and surface condition affecting friction, must F | § é : | | | TAL... CRITICAL and highly appreciative audience assembled Birmingham (England) several months ago for the deep-drawing symposium organized the Institution Automotive Engineers. This paper was the high spot the meeting, and least England the data presented Professor Swift will likely accepted the standard work deep drawing for some considerable time. the extended abstract herein, from Sheet Metal Industries, par- ticularly interesting note the conclusion that maximum blank diameter which can drawn successfully sensitive and consistent function the drawing qualities metal. Also great value are the data lubrication. sults. order ascertain what extent the virtues this drawing test can preserved practice, what precautions are necessary ensure reliable results and what testing con- ditions and details punch and die necessary have complete knowledge the mechanism the drawing process and the influence cedure. work described this paper was undertaken primarily with the purpose determining ability the cylindrical cup pressing drawing test and ascertaining proper conditions test, but the in- vestigation naturally touched cer- tain matters more general nature the mechanism the deep- drawing process, and this connec- tion results significance are included. designing apparatus produce cups experimentally was thought well that the apparatus should sufficiently large enable reliable measurements made displace- ments distortion and eliminate the effect minute inequalities, but small enough inserted ordi- nary testing machine and avoid un- necessary waste material testing. was thought desirable for experi- mental purposes that the apparatus should capable wide variations the speed operation, that should give autographic record punch loads, and should enable the drawing process interrupted, required, examine partial pressings. was also necessary ensure accurate re- production the conditions test, and incorporate means for the ready adjustment clearances accommo- date blanks different thickness. Autographic Sub-Press The autographic sub-press shown Fig. was designed and constructed with these features mind, produce cylindrical cup in. internal di- ameter from flat circular blank. For this purpose punch case- hardened steel was provided, having diameter 2.000 in. and (normally flat working end with radius round the edge. This plunger slides ireely the vertical direction cylindrical guide formed the cast-iron cover the machine. The circular blank for pressing inserted between the lower face the cover and the upper face the body the press, which, the normal form the machine, are kept mined distance apart means suitable spacing ring, and clamped means studs passing through this ring. The inner diameter the spac- ing ring in. The body the press mild steel and has central bored hole, in. diameter, provide clearance for the punch and pressing. hardened steel inner ring inserted the body forms the essential lower por- tion the die, determining the radius over which the sheet shall bent and (by its inner diameter) the radical clearance permitted without iron- ing the cylindrical pressing. The normal curvature the ring (in sec- tion) in. radius, and several inner diameters have been employed, varying from 2.067 in. 2.094 in. for blanks 0.036 in. thick. order enable the punch load measured and recorded the body the press takes the form annular in. outer and in. inner diameter, mating with piston integral with the rigid cast-iron base. The annular space between piston and body filled with light oil and communi- cates with modified engine indicator, the oil pressure operating the piston and pencil the indicator. The indi- cator drum actuated cord which passes round small pulley the cover the press and attached arm projecting radially from the upper end the punch. this way vertical movement the punch re- produced horizontal movement the indicator diagram. Special Attachment Used overall height the press be- fore action 1134 in., and order ensure truly axial thrust ball- loaded top and bottom. The machine can operated according conveni- ence either means hydraulic lever testing machine, inserting any commercial type press which sufficient space available. order ensure central location the blank the die annular piece thin sheet metal employed, hav- ing outer diameter exactly the same in.) the inner diameter the spacing ring and inner diameter the same the diameter the blank tested. will seen that, the form THE IRON AGE, June 1940—43 ; £ j x | 3 ON | | : ring plug described, the machine does not exert any specified pressure the blank, but merely limits the puckering thick- ening the blank according the clearance provided the spacing ring. For tests where holder pressure required attachment has been designed and con- structed which can substituted for the head the existing sub-press and means which prescribed blank- holder pressures nearly 10,000 Ib. can applied during pressing. Hydraulic (oil) pressure supplied the upper face floating annular piston which transmits the pressure the upper surface the blank through loose replaceable plate hard steel. The oil pressure controlled means the ground plunger which kept float- ing during test replenishing any hand-operated plunger. normal this leakage screw sure throughout the process, but suitable elaboration could arranged vary this pressure The blank-holder pressure at- tachment does not the auto- graphic recording arrangements any way. The plate interposed the piston and the blank and the die plate different forms plate can substi- ‘Two testing machines have been em- ployed conjunction with these sub multiple-lever machine capacity, fitted with vari able-speed motor, has been drawing speeds from 0.05 in. per presses. min., 1.5 per min., the ing constant throughout the hydraulic press seven tons capacity, IRON AGE, June 1940 graphic sub-press with spacing ring. which has been used for higher speed work, enables tests made drawing speeds about ft. per min. order obtain systematic mea- surements changes thickness different parts partial, complete, and broken pressings special jig has been designed and constructed, suitable for the type pressing under investiga- tion. This jig, while entirely for measurements the walls and not capable giving reli- able readings thickness radius near the base the cup, re- gion which some the most impor tant changes actually occur and where the danger fracture most real. Measurements this region have been made means traveling micro- scope diametral section the cup embedded wax. the course the present investi- gation nine different metals were used: mild steel, two brasses, nickel silver, three grades aluminum, alumi num-bronze, and electrolytic copper. Experimental Results The sequence the experimental work was determined some extent the material available and the prog- ress construction the apparatus and accessories, but the results may conveniently grouped for discus- sion follows: (1) Relationship between blank di- ameter, punch load cup (3) Effect drawing conditions; blank-holding, clearances, curvatures, speed, Auto- Owing mainly the absence knowledge regarding the stress-strain conditions present not possible put forward theoretical treatment the drawing process which could aspire comparison with experimen- tal data, but descriptive account the mechanism radial drawing can developed from certain simple as- sumptions regarding the havior the material and the condi- tions restraint. Such treatment outlined appendix the au- thor’s paper and the main conclusions which leads are: (1) Hoop compressive stresses are substantially greater than correspond- ing radial tensile stresses. (2) These radial tensile (drawing again drawing proceeds. (3) The maximum drawing tension bears approximately linear relation- ship the blank diameter for given Punch Loads Important the experimental work was established that the maximum blank diameter which can drawn successfully sensitive and tent function the drawing qualities speed pressing showed that six mild steel blanks, 4.10 diameter, all drew successfully, while six blanks, 4.15 in. diameter, all broke approximately the same stage the draw. six blanks, 4.125 in. diameter, four failed and two drew successfully. This order consistency was revealed through out the testing work when the condi tions drawing were kept constant. this connection should men- tioned that all blanks were machined the outer diameter and were actually centered the die means adaptor rings; neglecting observe these precautions led inconsistent results. Closely related the successful drawing that punch loads. the absence ironing, the punch load wall strength the partially fracture will occur. The relationship between blank diameter and maximum punch load therefore primary portance, this kind for various metals are shown will seen that the relationship each case closely systematic, re- mentioned above and encouraging confidence Cover | ring | Af, hi, of AA Af / Wy / plug the method testing. The relation- ships are approximately linear, with slight tendency convexity most cases. Comparative Tests this stage may appropriately inquired whether the drawing test does fact measure different prop- erty from the cupping test compar- ing maximum blank diameters with the Erichsen numbers the various metals available. The results comparative tests show that proper relationship exists between these quantities, that neither test can used predict the results the other. interesting note, however, that comparison the Erichsen values with the depth punch penetration which fracture occurred with oversized blanks the drawing test showed reasonably sat- correlation, not unexpected result view the similar types strain involved and one gests that cupping test might con- veniently carried out with the same apparatus and dies the drawing test. cases where the drawing test regarded proof test only necessary, course, demonstrate that blank particular specified diameter will draw successfully. But where required ascertain the actual value the maximum permis- sible blank diameter more than one test necessary and the linearity the polation and reduces the number tests necessary determine the limit. most cases three tests would sufficient; one with small blank and one with larger but safe blank, define the tic, and one with oversized blank determine the ultimate punch load. But although with most the metals tested the punch load rupture was found substantially the same for any oversized blank within reason, this was not true one two cases, not- ably with the half-hard this case the punch load which fail- ure occurs oversized blank measurably lower than that which properly sized blank will carry successful draw and the larger the oversized blank the lower the failure load. This due the observed fact that when half-hard aluminum blank fails drawing fails early when the metal carrying the punch load oblique the line ac- tion that load and therefore sub- ject radial “toggle” action. notable fact that all the metals examined half-hard aluminum differs S IG. 2—Relation- ship between blank diameter and punch load; punch and die radii: H.B.B. grease lubri- cant. Maximum punch draw, pound most widely its behavior between the drawing test and the cupping test, and doubt the lack ductility under pure vealed the cupping test explains the early failure and consequent low load unsuccessful drawing test. the other hand, the behavior the half-hard aluminum under the com- pound drawing strain superior that either the soft qualities the same metal. Strains and Stresses order give concise form idea the actual strains which develop different parts simple cup pressing the three principal strains five representative points are shown Table TABLE Representative Strains Cylindrical Cup (The figures show the final dimensions unit cube unstrained metal) Walls Directions Base Radius Top Hoop 1.10 0.66 0.50 Radial 1.30 1.30 0.70 0.80 1.33 failure most likely occur where thickness most reduced, which corre- sponds regions where the radial strain large and unaccompanied any important compressive hoop strain (which the saving feature the upper parts the walls). interesting observe that the produc- tion cup more than one stage facilitated the fact that the region incipient necking changed each stage, that the region which thinnest the first operation subjected “compressive hoop drawing” the second quent stages. Changes thickness the base cups the particular shape under test were relatively small and uniformly distributed. worth recording, how- ever, that these are affected the speed drawing. cup drawn one minute from 4-in. diameter blank (corresponding drawing speed 1.5 in. per min.) the base thickness had diminished mm. (about per cent) and stretcher strains were visible, while similar cup produced with drawing speed it. per min. the diminution ness was only mm. (about per cent) and stretcher strains were still developing. Ed. Note:—Next week the author will conclude this interesting discussion with detailed data stretcher strains, lubri- cation, etc. THE IRON AGE, June 1940—45 oO broken Blank diameter, inches hardware and trim parts are die cast from zine alloy exceedingly large quantities the new plant the Alemite Die Cast- ings Mig. Division the Electric Auto-Lite Co., Woodstock, keep step with this production, has been necessary provide for rapid and accurate machining the parts. This, turn, requires even though large proportion the operations are drilling and tapping and none requires heavy cuts. few the operations and the tools used are herein described. RIGHT 2—Arbor press setup with tools for shearing fin from the parting (at right-angles beads around the center opening) tail-light casting. BELOW square pin which fits cored hole, while another hole right angles the pin drilled. 46—THE IRON AGE, June 1940 hole cored for insertion steel shank after casting. necessary drill through hole right-angles the cored hole. The setup used quite simple and shown Fig. which fits the hole snugly, being pressed and locked with quick acting clamp. pair pins locate the curved end the handle make sure that the hole drilled comes the correct diameter. the drill fed down- bushing and passes through hole pro- vided the square pin. After drilling, the piece pushed off the square pin four pins actuated hand lever the right. doing, any burrs left the drill the faces the square hole are sheared off and not bother subsequent Use pedal leaves the hands for loading and unloading upper left, through sight feed and and onto the bristles brush contact with the Dodge tail-light housings have three beads around the light opening and the use pair slides the casting die. This, course, leaves parting line across the center —_, 1 mas HERBERT CHASE ° ° ° & = IG. 3—Rocking fixture used for holding die casting which requires that two holes drilled and tapped each the two positions which the fixture rocked. the piece. remove the fin and the parting line itself the piece mounted hand arbor press. clamp holds the piece each the two positions successively and when the shaped tool the upper half the die lowered the hand wheel the flash sheared off around the beads and along the side the piece. After one such operation the right half the fixture, the piece versed and set the left half that the tool can enter from the other side. Another simple trim press operation required shear flash from the large central opening and from ery the piece. After the foregoing operations necessary drill and tap four holes for fastening screws applied sequent assembly the piece the car. the piece fits against warped surface, the axes the holes are angle that the main opening and would make the casting die too complex and expensive core these screw holes. Since they have tapped anyway, requires very little time drill them just before tapping. The holes are spotted the casting using small conical projections proper points the die surface, the angle the cones being such that they clear the piece the latter with- drawn from the casting die. similar procedure followed many cast- ings which have fit against warped IG. 4—In this line, holes are drilled and tapped odd angles while the casting held the fixture. Other holes are after- ward drilled and tapped normal the face casting. surfaces and require holes odd angles. Drilling and tapping the Dodge tail-light housing done the setup shown Fig. The piece fits into light fixture which rests pair pins below the center line the piece. There pair shorter pins each side the fixture and also its two lower faces. These six pins make possible tilt the fixture each side the center line, first one way and then the other and thus bring the piece correct position for each pair holes drilled and tapped. The pins, course, raise the fixture slightly above the bed that chips not bother. After drilling, the holes are tapped un- der the spindle second Delta drill press, the two presses being set carry plate forming common bed. With this setup, four holes are drilled and tapped 300 pieces hour one man. Another somewhat similar setup used for drilling and tapping spotted holes three different angles Willys headlamp adapter ring, Fig. this case, however, the fixture has Y-shaped holding portion for the casting, this part the fixture being mounted ball joint carried base. The latter slid along the table from drilling tapping positions, required. bracket attached one side the base made that sup- ports the Y-shaped holes each the different angles required for the different holes. With this fixture, single operator drills and taps three holes different angles 125 pieces THE IRON AGE, June 1940—47 | ‘ x 5—Setup for simultaneous tapping three cored holes head- lamp bezel and subsequent drilling and tapping angular hole rear face boss. press equipped with cam-operated die for simultaneous punching holes the die cast instrument frame for Plymouth car. 48—THE IRON AGE, June 1940 hour. Aiter removal from the jig, which has snap catch hold the piece, the latter passed second operator using second pair drill presses. drills flash from eight holes cored normal the flat surface the piece and taps these holes, jig being required. large proportion 1940 cars have headlamps recessed and use die cast bezel alloy which buffed and plated. These bez- els fit crowned and, with many other castings, re- quire some holes odd angles. The bezel shown Fig. however, has only one such hole, the three remain- ing ones being countersunk and cored parallel the axis the lens opening. These holes are tapped simultaneously the holding fixture the left, using special multiple-spindle head the drill press. The piece then turned over and placed successively the sim- ple fixtures shown for successive drill- ing and tapping the angular hole. Housings which the instruments for Plymouth cars are assembled are light-wall castings having large cen- tral opening and two smaller openings the side. the first operation after casting, this part placed die which shears the flash from all open- ings and from the periphery single stroke the press. then passed station where the back edge sanded, burrs removed and any straightening required done. The casting then placed the cam die shown Fig. and small holes are punched simultaneously various points around the side walls. Punches are hidden the lower die block but are actuated the angle cams seen the upper half the die, after remov- ing the piece from the die, the press operator turns around reams, counterbores and taps hole for jewel (subsequently put place for use combination with pilot light). These operations are performed three light drill presses not shown the illustration. Six Delta drill presses set for drilling, tapping and spot facing oper- ations the tail-light housing, are shown Fig. Tables the presses are joined strip steel serving common bed along which some the fixtures are moved. Seven holes are drilled and five them tapped, some odd angles. One drilling op- eration performed the station which the drill head inverted, this making easier clamp the casting quickly the required position than the drill head were above the table. Two men operate the entire line and perform all the operations named ° ° ° IG. 7—Six-station drilling and tap- ping setup, using rocking fixture first stations. Invert- press drills boss. ground shown the rocking type, the two lower faces be- ing disposed such angles that, after drilling holes normal one, the piece rocked bring the second face par- allel the table for drilling other holes. The piece held place spring-operated catch seen the right end the fixture. Remaining fixtures are simple holding types, one which arranged for sliding along the bed required bring the piece into tapping. Numerous other machining opera- tions performed other castings pro- duced this plant might described, but the foregoing are fairly typical. give good idea the general character work required and the good tooling which facilitates doing rapidly. New Graphitizing Alloy for Ladle Additions HESE three fractures show the effect SMZ alloy white cast iron. alloy, com- posed essentially and Zr, developed Electro Metallurgical Co., New York, for ladle addition cast iron. This alloy, iden- tified SMZ, said especially effective converting normally hard white iron into high strength gray iron. also reduces the chill gray iron, minimizes wall sensitivity and improves microstructure with resultant betterment physical properties, claimed. The effect SMZ alloy white cast iron shown the accompany- ing photograph. The base iron used make the chill blocks illustrated analyzed approximately follows: 1.00 1.10 and 0.30 Mn, and was melted commercial air furnace. When enough SMZ alloy was added raise the silicon content the iron approximately 1.60, the iron became almost completely gray except near the chilled edge. When enough the alloy had been added raise the final silicon content 1.90, the iron had throughout. Addition sufficient SMZ alloy white iron running 2.66 TC, 1.15 and 0.36 boost the silicon 0.50 per cent, resulted gray iron having the following physical proper- ties: Tensile strength, 51,700 per sq. in.; transverse strength, 3800 deflection, 0.415 in., and Brinell num- ber, 207. THE IRON AGE, June 1940—49 BAG 4 ) draulic press 400-ton capacity good ex- ample the proportions obtainable for well bal- anced design. this first section two-part article the author discusses whether machine should should not welded and, so, what are the design and welding problems involved. Data are given for those structures which must withstand high total static dynamic loads. advantages the fabrica- tion machinery welding have become well known recent years that each machinery man- ufacturer must face the problem “shall welded not?” Very often the ultimate future his busi- ness rests the proper answer this question fabrication. Not only sufficient visualize duplication fabrication his product which present casting, but must also consider changes design which will fabrication. Such decision must approached with critical analysis all pertaining his particular product. The final result which may consist fabricated steel castings, rolled steel plate and rolled sections, combination all three, usually due fundamental changes the thinking his engineering and manu- facturing personnel. such case the change-over seldom done radical manner. chine tool equipment, required addi- tional equipment, yearly volume, stock hand, and necessity for training 3—The ap- pearance large bull dozer design personnel properly realize the advantages fabrication are all factors which must considered. Fortunately for the industry these factors were appreciat- various fabricating concerns well qualified this type work. Such concerns furnish services which first analysis seem parallel the services foundry. The services furnished qualified steel fabrica- tor not only must the services rendered foundry but must even farther mental engineering. Presuming the machine tool manu- facturer has reached decision that his product warrants change steel fabrication, what steps should take realizes that spite the volume fabrication gas cutting ing, his engineering staff should take advantage knowledge rather than attempt pro- ceed more less blindly. represen- over the line equipment and make recommendations the par- ticular parts which can most readily changed and produce the able results. Drawings these particular parts are submitted the gineers, who make estimates either duplicate the part fabri- Corp. Warren, Ohio majority cases also fabricating economical avail themselves outside fabricating large precentage the fabricating business today. question which most often pre- change design extreme impor- uneconomical practices have been per- petuated because possible limitations foundry practice limitations moval such limitations opens new vista thinking. The personnel fabricating con cern must have intimate knowledge the requirements the machine tool manutacturer order properly weight reduction must adequate- avoid vibration. design loading, the fabricator the factors are only part the spe- IG. 2—This welded press quite similar that shown Fig. one difference being the clear ance hole the inner wrapper plate for the clamping ram. sented the fabricator the ma- chine tool who wishes use fabricated steel “How can assured obtaining the advantages fabricated design and costs with minimum trouble?” The answer this question many sided one and the balance this article will devoted the factors which make possible satistactory solution. steel for the machine tool industry may classified the three following major groupings Structures which must withstand high total static or dynamic loads. marily tures bases for machine same bull dozer fully finished. tools and often have secondary containing coolant tanks. Miscellaneous gas cut shape gas cut and welded. Having properly classified any job under consideration the fabricating engineer must have working knowl- edge the direction and magnitude the stresses the case Group full awareness the importance appearance and knowledge coolant paths the case Group and background ingenious economical design for Group Group Consideration any structure fall- ing under the Group heading will indicate the portions which contain the highly stressed sections weld metal and parent metal. These sec- tions must have properly worked out bevels, contours, and weld-metal cross- sections obtain uniform unit stresses magnitudes consistent with proper safety factors. good welded design uses min- imum weld metal. While welded joint, properly made and treated, the equal homogeneous piece parent material, the cost per pound deposited weld metal will average 50c with normai overhead. Economical design therefore must carefully watch the poundage de- posited metal. Factors tending keep weld metal minimum are the generous use gas cut parts and brake bending eliminate welded joints, elimina- tion excessively large bevels, use intermittent welding and arrangement parts structure that the welds carry minimum loads may smaller. structures this group are C-frames and tie rod frames for presses, brakes and shears. Literally hundreds these have been made, varying size from few tons ca- pacity several thousand tons ca- pacity. examples this type con- struction, consider machines construction makes very efficient use the weld metal. The upper and lower platens rest the inner sur- faces the C-frames and the weld metal carries very little the machine load. The outer wrapper plate gives stiffness the C-shaped side plates resist buckling. Some idea the proportions for well balanced design may obtained from the dimensions for the 400-ton hydraulic press shown Fig. The side plates are in. thick, the inner wrapper in., the outer wrapper in. and the lower platen 434 in. Such box section can also provide convenient hydraulic oil sump. This press frame was fab- ricated for the Kewanee Boiler Co., Milwaukee, and weighs 11,500 Ib. fabricated plates almost identical thicknesses those shown Fig. The main feature difference the clearance hole the inner wrapper plate for the clamping ram. This joggling press weighs 33,000 and was built for Charles Elmes En- gineering Works, Chicago. Figs. and are and finished photos No. bull dozer fabricated for the Ajax Mfg. Co., Ohio, for railway car work. The machine equipped with alternating current motor, dual reversing clutches and mitting stoppage the ram any part the stroke. Some idea the may gained the fact that the machine will bend cold the 434 in. radius ft. ore car doors. The inner wrapper for this frame in, thick and welded the end sections 100 per cent welds. welding such rigid structure use bevels, welding sequence and weld metal proper type avoid either excessive distortion one hand cracked weld metal the other hand. trouble from properly designed structure after were not previously present. should noted that this frame the bear- ing housings are steel castings. These four examples are typical single job orders for special machine frames, and maximum cost and are where noprevious patterns exist. Three four week deliveries are normal for these structures and are distinct benefit since machine tool manufac- turers are often under considerable pressure for short-time deliveries. time-of-delivery This type job requires more care design and manufacturing than the other groups avoid contours and techniques causing bility fatigue failures. Ed. Note: Next week the author will conclude with data the design and welding structures falling Groups and Lead-Sodium Master Alloy Available EAD-SODIUM alloys, metallurgical work and drying agents for inflammables, are being manufactured commercial quanti- ties, according announcement from the Chemicals Depart- Co. One the alloys being made Pont marketed under the trade name Hydrone. solid lead- sodium alloy containing approximately per cent sodium virgin chemical lead. can easily melted dry 52—THE IRON AGE, June 1940 iron crucible and diluted with molten lead prepare alloys lower sodium content. The preparation per cent sodium-90 per cent lead alloy can carried out this manner. This avoids addition pure sodium lead, operation requiring special appara- tus. alloy was said have demonstrated superior qualities safe drying agent for inflammable liquids place metallic sodium. Lead-sodium alloy now used considerable extent master al- loy metallurgical work harden, modify grain structure, deoxidize and smoo