The Iron Age 1944-05-25: Vol 153 Iss 22

VAN DEVENTER President and Editorial Director BAUR Vice-President General Manager ° ° Editorial and Advertising Offices Johnson, Market Research Mgr. Hayes, Production Manager. Baur, Typography and Layout ° ° Regional Business Managers LEONARD New York 100 East 42nd St. East 42nd St. ROBERT BLAIR FITZGERALD Cleveland Pittsburgh 1016 Guardian Park Bidg. Chicago Chilton Bidg. 1134 Bldg. PEIRCE LEWIS WARRE RAYMOND KAY Los Angeles 2420 Cheremoya Ave. ° ° Owned and Published CHILTON COMPANY (Incorporated) Executive Offices Chestnut and Sts. Philadelphia 39, Pa., U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH GEORGE GRIFFITHS EVERIT TERHUNE BAUR WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE THOMAS KANE HARRY DUFFY CHARLES HEALE Vice-President Vice-President Vice-President why nder glad —or indexed the Industrial Arts index. Pub lished every Thursday. Subscription Price North America, South America and Possessions, $8; Foreign, $15 year. Single Copy, cents. | ° ° ° IRON AGE Vol. 153, No. Editorial Another Inch Toward Freedom ° ° Technical Articles Mm. Mortar Shell Production Technique Automatic Tapper Applied Heavy Work Steel Separators for Gun Mount Bearings Machining the Barrel for the Light Carbine Radiography Applied Welding Pneumatic Swagers for Tubing Perfected Radius Broaching Turbine Buckets May 25, 1944 Annealing Aircraft Parts Pan-American Shops Features News Front Assembly Line Washington West Coast Personals and Obituaries Fatigue Cracks Dear Editor This Industrial Week News Industry News and Markets Civilian Steel Alottments Veteran Rehabilitation Survey Geneva Steel Co. Gets Price Relief “Must” Lag Steel Wage Hearings Foundry and Forge Labor Problems War Contract Termination Plan Machine Tool News Non-Ferrous Metals News and Developments Non-Ferrous Metals Prices; Scrap Prices Iron and Steel Scrap News and Prices Comparison Prices Year Finished Iron and Steel Prices Steel and Warehouse Prices Semi-Finished and Tool Steel Prices Steel Pipe and Tubing Prices Wire Product Prices Pig Iron and Coke Prices Railroad Material and Stainless Steel Prices Ferroalloy Prices Index Advertisers 134 136 137 138 140 143 144 145 146 147 148 149 150 213 | | | | 74 | ° 90 Member, Audit Bureau Circulations Member, Associated Business with THE Only employing facilities complete as those ct Mahon can these massive assemblies be produced. To insure absolute full size wood pat- terns built carefully studied before fabrication begins. = MARINE DIESELS Crankcase and cylinder block assemblies for marine diesel engines now are being fabri- cated from welded steel plate. Less weight. Greater strength. marked saving pro- duction cost. This only one many uses which welded steel construction has been adapted the building war materiel. turning out this work, Mahon engineers have acquired extensive knowledge that can untold value industry ... and the broad possibilities peacetime applications. ; Machine Bases and Frames and Many Other Welded Steel Plate ESTABLISHED May 25, 1944 VAN DEVENTER President and Editorial BAUR and General Manager DIX Monager, Reader Service Editorial ° ° ° Associate Editors WINTERS LLOYD BARMASEL Editorial Assistants SCHIEN WILLIAMS ROGERS Regional News and Technical CAMPBELL Pittsburgh 428 Park Bidg. POST Chicago 1134 Otis Bldg. MOFFETT DONALD BROWNE EUGENE HARDY Washington National Press Bidg. MacDONALD Cleveland Guardian BRAMS Detroit 7310 Woodward Ave. OSGOOD MURDOCK San Francisco 1355 Market St. Editorial Correspondents ROBERT Cincinnati PENLEY Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ont. RAYMOND KAY Les Angeles JOHN McCUNE Birmingham ROY EDMONDS St. DOUGLAS Another Inch Toward Freedom the four famous freedoms, copyrighted and merchandised the New Deal but “swiped” from other and more ancient originators, freedom speech the most important. Unless you have that, you have nothing. Once falls down, all the rest the freedoms topple with it. Until recent years, America has been, England still is, the land freedom speech. There were strings it. One could express his opinion anyone anything without the fear going jail, provid- ing his expression within the limits decency and the libel laws. Then Senator Wagner opened his Pandora’s box produce the National Labor Relations Act and begin the process taking away freedom speech from minority group. Through the instrumen- tality the National Labor Relations Board, one class American citizens was deprived this traditional liberty. was just entering wedge but wedge has enter somewhere applied all and once entered one can tell how far will go. The point this wedge pierced the freedom small minority, which was then politically unpopular and perhaps somewhat the doghouse general. This the historical process extirpation rights which can never successfully begin with politically powerful groups majorities. Government did not say Protestants Catholics atheists: “It will hereafter illegal for you present your views attempt make converts.” did not say labor leaders: “You must not send out workers plants letters purporting come from the President, saying that the President wants you join the union.” Nor did say them: “You must not hereafter cast aspersions upon employers, nor can you present unorganized workers the superlative advantages paying tribute you for the right hold job.” indeed, for these things would have been political suicide, not also say inexpedient. the least articulate group America, the employers, became the target for the entering wedge. They were told: “No matter how good your record has been the past respect labor relations, shall henceforth illegal for you present your case your employees attempt refute any charges, however unfair, directed you professional union organizers. Keep your mouths shut, jail.” should gratifying know that inasmuch are prodi- gally spending our blood and money establish the four freedoms broadcast throughout the world, freedom speech has finally been restored America. The entering wedge has been removed, not the Administration that inserted but the decision the Third Circuit Court Appeals Philadelphia. From now on, the employer has the same right free speech has anybody. > i- ; | | | 4 J | | 40—THE IRON AGE, May 25, 1944 TON FINISHED STEEL REQUIRES Have hand—2,800 pounds iron ore; 16,000 pounds air; 480,000 pounds water; 87,000 cubic feet gas; 1,600 pounds coal; 825 pounds limestone; 4,300 pounds steam; pounds steel scrap—also fluxes, electric power, sulphuric acid, acid, fuel oil, and furnaces capable develop- ing 27,000,000 for each ton steel shipped. Making ton steel complex method and equip- ment, well the number, and quality ingredi- ents, supplies and utilities. Inland these complex processes are controlled large staff metallurgists working laboratories and the plants, and specially trained engineers who constantly investigate and design new mechanical methods and equipment. Basic ingredients—ore, lime- stone, coal and fluorspar—come from Inland owned mines and quarries—selected and blended meet the needs critical steelmakers. All other supplies are obtained under rigid specifications. The Inland “know how” for making each ton steel giving America quality steels for will help supply the quality steels for America peace. INLAND STEEL COMPANY Dearborn St., Chicago Illinois Cincinnati Detroit Kansas City Milwaukee New York St. St. Paul J But America Makes. Millions Tons Year COAL—1,600 LBS. LIMESTONE—825 LBS. AIR—16,000 LBS. Front May 25, 1944 The Administration's Surplus War Property Administration heading for gressional trouble. Principal points attack are decentralization and lack any uniform disposal policy. Congressional critism that there will more than 150 offices throughout the country which will not operating uniform procedures and which will un- doubtedly conflict from region region and city city. its contribution uniformity, the War Department has issued single standard contract termination form used all its contracting services. like the S., finding some surplus stocks building certain industries, but attacking the problem typical realistic manner. ment department has been set for collecting stocks and storing them central warehouses. Further manufacture these products are prohibited and all are filled from the warehouses. This practice follows the British method the first World War, which, for instance, Aircraft Disposals, Ltd. took over all aircraft material from the Ministry Munitions, and gradually released the material the ensuing years. identical system has been proposed the Material Section Wright Field, but far they have been whistling the wind. While manufacturers this country recognize the dangers heavy surplus stocks, their inclination ignore the matter, hoping meanwhile that someone will figure out some uous method throwing the material into the ocean. Less than per cent value was received from surplus materials sold after the last war. Estimates current surpluses this country high $35 billion, rise $50 $75 billion depending the length the war. Idle and excess government owned machine tools are not likely channeled back into regular production plants through WPB screening. These idle tools will probably withheld from the regular market and doled out urgency contract holders only the most critical variety. The North American two-engine, medium bomber, the Mitchell, improve- ment the plane that bombed Tokyo, now the most heavily armed airplane existence. carries mm. cannon and .50 cal. machine guns. Japanese mineral production essential steel production during 1943 fell short quotas according reports the Japanese Mines Control Association. Production iron ore was per cent the quota; iron sand ore, per cent; chromium, per cent; and tungsten, per cent. Manganese output was per cent over the quota. Overall average output "steel ores" was per cent new test beds, capable taking aircraft motors 5000 hp. and propellers ft. diameter, have been completed the Curtiss-Wright Corp. Caldwell, aircraft motor 2200 hp. the most powerful unit censors permit being mentioned this country. The British are gettine little fed with American advertising. The managing director Vokes Ltd. recently stated that was rather tired Americans claiming originate everything major importance. singled out the Philco Radio Corp. advertisement claiming origination Radar; and Packard Co., which produces Merlin engines under license, claiming that the Hurricane, Lancaster and Mosquito are fitted with Packard Merlin engines. Manpower and component shortages have resulted "must" production losses least 220 plants the Cleveland area. Programs hardest hit are: Farm imple- ments, parts the aircraft component program, mica, truck parts. trailers, some hand tools, road equipment and railroad needs. When X-raying welds, fast film has been found obliterate welding defects. Fine grained film and carefully controlled darkroom procedures result ac- Curate images, introducing "phony" faults and minimizing real defects. The guaranteed annual wage phase the steel wage hearing has been termed fantastic. Without guaranty steel customers, such plan would guaranty nothing except insolvency, Boal Andrevs Steel Co. insisted. = | ¢ é > | | Blank steel and finished mortar shell. ULLINS MANUFACTURING CORP. learned how make mm. high explosive mortar shells about the same way many per- sons acquire the art swimming— the company was literally thrown and had learn quickly and without premeditation. Late 1943 the War Department notified Mullins that needed new method making mortar shells. They 42—THE IRON AGE, May 25, 1944 hoped that stamping method could devised order avoid forging, machining casting. One the best previous methods made use rolled blank that was curved press form two halves which were then welded together, but even this had improved upon. Plans were drawn Jacques Stan- itz, William Swertfager and the writer, and the final details the HARRY HECKATHORN Vice-President, Mullins Mfg. Corp., Youngstown ° ° ° process the presses were worked out. complete set sample shells was Washington nine days after the original request was received. Briefly the process starts with circular blank steel 4.503 in. diameter, 0.670 in. thick, blanked out mechanical’ process from S.A.E. 1010, killed hot rolled steel. cup- ping process, three draws and ing and reducing operations, all per- formed mechanical presses, pro- duce pear-shaped shell, 5.156 in. long, 2.429 in. the widest point, tapering 1.980 in. diameter the larger end and 1.3 in. diameter the smaller end. Side walls are about 0.2905 in. thick except the fuse end where addi- tional metal built and the tail end where the metal only 0.261 in. thick. The opening the tail end, where THIRD ORAW The circular blank, cupping operation and three drawing operations are shown above. Figures indicate dimensional changes during the various operations. hi, ; 3256 ala ------->| 2852 Wia- - -2562 ala 24/2 aa | no ‘ ! sor » FIRST DRAW / UN vv i\ | 4 | BLANK the reducing operations take place, closed with machined plug 0.762 in. diameter, 0.750 in. high, with groove cut near the top around which silver solder ring fits for brazing the plug the shell. Tolerances outside diameters average 0.020 in., but ances the press work must held 0.015 in. except the tail where the hole for the plug reamed within 0.004 in. specifications. Following step-by-step discus sion the process and the equipment involved: All press operations, including the blanking 250-ton press, are done with double dies, producing two pieces time. The blanks are then forms cup 3.236 in. diameter, in. high with wall thicknesses 0.645 in. All pieces are washed auto- matically they pass through the dies and into conveyor tubes that drop below the press floor. washing chamber hot water sprayed with operations from the circular blank through all the drawing, piercing and reduction oper- ations, the finished mortar shell. This pressing technique was devised the Mullins plant order avoid forging, machining and casting operations, that production mm. mortar shells could rapidly increased. considerable pressure, removing the lubricating oil used the draw. Per- fect cleaning all pieces necessary because the annealing process that follows nearly every press operation, any oil left the metal would cause charring and might leave carbon deposit the steel that could affect further drawing operations. Annealing done gas-fired conveyor furnace 1240 deg. F., and this followed pickling bath remove scale. The first, second and third draws which follow the cupping are all per- formed the same press. This ma- chine, 900-ton mechanical unit, holds three sets double dies, turning out six pieces time. Six conveyor tubes carry the pieces through the wash chamber and deliver them back the press floor where they are packed the annealing baskets. The press has large bed that once held dies for making pressed steel kitchen sinks. Four six persons work one time, loading the dies and intricate system controls pro- vides for complete safety. The three drawings result cyl- inder with round end approximately 5.75 in. long and 2.50 in. diameter. After the third draw the shell rough trimmed length Reed small piece multi-tool production lathe and then sent through pre-head- ing operation that tapers the corner the closed end, and work hardens the metal slightly. The end then pierced 250-ton press, with THE IRON AGE, May 25, <a e rr <a ° ° ° lls er a ip- re- er- ro- in. nt, ick di- the ere % 00642005" Q0x3 -Q020" Remove burrs 0636 solder ring purchased from the plug assembly, showing the dimensions and manufacturing outside. Silver brazing carried out tolerances. induction furnace. tool steel die that produces 1.250 in. diameter. The metal pierced slightly under in. thick. This the last work done Mul- lins the large end the shell and from this point the shell loses its cylindrical shape and begins ap- proach the pear-shape. First in. the open, unpierced end the shell annealed Selas, gas-fired conveyor furnace tem- perature 1100 deg. After pickling, the ends the shells are reduced, still two time, 200-ton press that reduces the end from 2.410 in. diameter 1.500 in. and increases the wall thickness this point. The next anneal hits only in. the end, and the second reduction another 200-ton press works the end 1.270 in. diameter. The an- neal following this operation only the last three-quarters inch, leaving the metal above this point slightly work hardened. The end then put through restrike opera- tion 450-ton press where flat taper ending neck 0.656 in. long, with nearly parallel sides duced. The neck thus formed, which the last the press operations, then reamed receive the plug. Both the plug and the silver solder ring are purchased outside facilities not exist Mullins for producing them. The solder ring fitted around the plug hand and another hand oper- ation fits this assembly into the shell. Silver brazing done induction furnace until the silver flows capil- lary action throughout the entire joint, forming perfect weld. Final work includes two testing operations for every piece and one extra test for specified number each lot. First 150-lb. air pres- sure test water check the braz- ing the tail plug. Then weight one foot dropped the plug further check. The speci- men test calls for load 30,000 applied the tail plug. The pieces are then stencilled and packed after final inspection. Machining the outsides the shell and threading the two ends done elsewhere. The machining operation reduces the rough shell assembly weight from 2.53 1.67 Ib. Automatic Tapper Applied Heavy Work UBSTITUTING two vertical au- tomatic tapping machines for one horizontal machine resulted 300 per cent production increase turn- buckles made the Edward Daniel Co., Cleveland. The machines now used are Model heavy-duty, leadscrew machines manufactured the Cleveland Tap- ping Machine Co. and are equipped with special casting mounted the column support sliding index fixture which holds two turnbuckles. While one being tapped, the other lever. Two machines are operated threads, the other tapping right-hand threads. The previously used horizontal ma- chine was tapped through the turn- buckle, dropping the tap out its 44—THE IRON AGE, May 25, 1944 holder re-inserted for the next operation. the present setup the tap automatically reversed through the hole, saving much time. Tap wear has been considerably decreased, tap breakage has been eliminated and thread (job requires Class fit) has been greatly improved, due leadscrew operation. many 10,000 holes per tap achieved the new setup. Additional advantages are that now possible accurately estimate the time required for given job and unskilled operators can employed. The operating time sec. tap in. hole turnbuckle, for ex- ample, can consistently maintained. Several sizes turnbuckle are being made, with holes and in. dia. They are drop forged steel, representing heavy work for automatic tapper. | | na Ca ce or ; m OL a Ww r¢ Steel Separators For Gun Mount Bearings rolier separators for bronze separators sulted weight saving large size tnrust and radial bear- ings made the Bantam Bearings Division the Torrington Co. for naval gun mounts. tor the in. cal. single gun mount, the weight re- duction per cent and for each mount 224 lb. critical bronze the rough casting saved the thrust bearing alone. For the radial bear- ing the saving not great per- centagewise, but 112 lb. bronze the rough conserved. Similar savings have been achieved the thrust and clip bearings for the in. cal. gun mount. General- ly, reduction weight, use cheaper material and manhours have also resulted ap- preciable cost reductions. The idea the possibilities stamped steel separators ously been gained the Bantam Bearings Division’s design separa- tor and retainer for the balls the mm. Bofors azmuth bearings. Here cast bronze machined separator rolled channel shaped steel retainer ABOVE ring weighing lo., which pro- roiled from tiat strip steel, holes per- forated bail pockets and ends welded. both the and 5-in. gun mounts the thrust bearing separator was eight sections, clamped together radial bolts. Each the bronze separators was carefully ma- chined and partially enclosed the rollers, which carried the cage weight. the pressed steel ABOVE pressed steel separator, about in. SV eight sections clamped together. Weight compared with 176 for the machined bronze retainer, made weighing 224 Section A-A Section B-B view pressed steel sepa- rators for the thrust and radial bearings in. cal. naval gun mount. RIGHT 1G. 2—Further details the pressed steel sepa- rator for the thrust bearing the in. gun mount, showing the method bolting the sections together. trated, tne separator not carried the but riaes projecting shoes stamped tne lower plate that contact the raceway. The effort turn this separator with its rollers place considerably less than with the bronze separator. shown section the upper and lower halves are held together brass rivets with U-shaped spacers separating them. the rollers are straight, they tend run tangent the roll paths the races and hence flat surfaces are provided the retainers for the outer end well both sides each roller. These surfaces are merely formed lips. Before assembly the halves each section, the parts are heavily plated. The steel cage kept concentric with the race rings vertical flange.drawn downward from the lower stamping seen section BB. Section C-C P Yyy iff THE IRON AGE, May 25, 1944—45 1G. the barrels length hyper milling operation performed with negative angle carbide end mills. Note equalizing type fixture. OST small turers began production with what facilities were hand, much which was obsolete according today’s standards, but even the case new facilities, many the machine tools available the begin- ning the war were not suited the latest concepts high speed pro- duction. When the Underwood Elliott Fisher Co., Hartford, undertook the manufacture the cal. 0.30 M-1 car- bine, found use about per cent its peacetime machine tools for this work. For machining the barrel, however, was necessary procure about per cent new equipment and was found desirable modify many these new ma- chines meet production schedules. The main purpose making these modifications was apply cemented carbide tools wherever feasible and most instances this meant speeding spindles and This goal could readily achieved the manufacture the barrel where turning and drilling boring operations predominate. Hence, some the more important opera- tions the barrel will described bring out specific applications the principles involved which resulted new production records. While out- increasing power. most 46—THE IRON AGE, May 25, 1944 put cannot disclosed, can said that production Underwood its peak far exceeded that any other rifle manufacturer and addition this company supplied the finished barrels several other carbine pro- ducers. the process stepping pro- duction many ingenious methods were developed. Operations were also sim- ° ° FRANK OLIVER Technical Editor, The Age plified order that the barrel could produced with unskilled labor. The principal operations required ma- chine the barrel are shown the ac- companying table and some the more unusual procedures lined below. Heat Treating Practice The barrel, Fig. forging made WD1350 special carbon man- ganese steel. very important pro- cedure the heat treatment the forging before machined. Lind- berg Super-Cyclone electric bath type furnaces are used heat the forg- ings which are loaded vertically basket holding 116 pieces. column super-hot air driven high veloc- ity from the heat source through the basket charge the ‘feature this furnace. Heating solely with fan- driven hot air builds tempera- ture with rapid uniformity through- out the barrel forgings. Since radiant heat reaches the charge there one-sided heat cause distor- tion. The heat treating cycle consists Grind cylindrical back taper center below solid carbide blank brazed end larged end view shows the clearance provided, tube. / FA! ARG LIVNLARG END VIEW the the tes que has cro ing tan Bec enc inst pell men mac cula elim carbide & 7a edae must he 2209020000 | on? J Flute DE SECTION lenath of @on ly Sangh / 1072 +0 105° ke S O06" Landa the usual soak, quench and draw with the metallurgical control tests. The barrels are brought 1550 deg. F., held for hr. and then quenched oil. Particular attention has been paid the quenching opera- tion order obtain the desired mi- crostructure for machining. Quench- ing time min. and the tanks are equipped with program clocks govern this part the cycle. Because the large number pieces the basket there was some difficulty encountered first getting cool oil into the center the pile. Following installation two “Lightnin” pro- peller type mixers agitate the quenching oil bath, marked improve- ment was immediately noted the machining operations. Thorough cir- culation the oil has done much eliminate “gummy” centers necessary ABOVE 3—Grinding instructions for drill with carbide tip. RIGHT with carbide enhanced maintaining oil pressure 500 and over the drill this Pratt Whitney machine. “ the speed and power standard machine tools and using carbide tipped tools has resulted considerable increase output. Use carbide drills with high pressure coolant and coarse tooth reamers has helped speed bore machining, together with broach rifling and automatic chambering operations. For data the machining other components the carbine other plants, the reader referred articles the April and Aug. 26, 1943, issues The Iron Age. the barrel forgings and produce bet- ter finish the bore. The barrels are not allowed cool below 225 deg. the quench and are immediately cleaned free oil high temperature cleaning compound and rinsed boiling water before being put the draw furnace. The drawing operation consists bring- ing the basket barrel forgings heat 1135 deg. for hr., after which Rockwell hardness test run across section must read between and “C”. example negative rake mill- ing with carbide tools found the first machining operation facing the end the barrels in. Cin- cinnati duplex automatic milling ma- chine. equalizing fixture, Fig. used which clamps four the bar- rels securely during the operation. Carbide tipped end mill cutters are operated dry 238 ft. per min. with 4.25 in. table feed. These millers are over years old and flywheels have been added the arbors pre- vent vibration and backlash. Cutter life between grinds 1400 barrels. Machining the muzzle end the « an) | iC - . > ls ~ n- THE IRON AGE, May 25, 1944—47 barrel another high speed opera- tion. This turned Lipe Carbo lathe using follow rest and ball bearing tail stock center. carbide tipped cutting tool with deg. front clearance, deg. side clearance, deg. top rake and deg. side edge cutting angle held rigid posi- tion with three set screws tool operation. The tool shank rests slot deg. angle for the rough cut. The effective side edge cutting angle thereby becomes deg. the roughing cut. The lathes operate high speed (1395 r.p.m.) correspond- ing 250 ft. per min., with 0.010 in. cutting feed and reduce the muzzle from 0.875 0.660 in. finish diameter. holder especially designed for this coolant using Quaker 18:1 soluble TABLE Operations Barrel Operation No. Operation Machine Test run-out rollers and straighten Foot press Heat treat and draw Lindberg Super-Cyclone furnace Test for hardness Rockwell motorized tester Mill length Cincinnati duplex miller Center both ends Double end centering machine Turn muzzle end full length Lipe Carbo lathe with follow rest and bearing tail stock cen- ters breech end, major dia. Reed-Prentice lathe with ball Rough turn breech end, minor dia. Drill First ream Re-center Finish turn breech end—minor dia. Finish turn muzzle end Finish turn breech dia. Mill both sides barrel rear end Mill flat rear and straddle mill gas cylinder lug Mill corners gas cylinder lug demagnetize and attach Mill track left side Mill track right side Remove burrs from flats and corners Break corners cperating slide slots Hand mill clearance for slide lug Shave clearance left slide way bearing tail stock centers Reed-Prentice lathe with bearing tail stock centers deep hole drill machine Baush deep hole reaming machine Two-spindle drill press Hendey speed geared head lathe Lipe Carbo lathe with follow rest Hendey speed geared head lathe Cincinnati duplex No. Milwaukee miller Hand miller unit Becker-Brainard miller Becker-Brainard miller Belt lap High speed bench grinder Hand milling machine Remove yellow tag and finish form barrel No. Sundstrand Rigidmil Grind muzzle end Spline mill front sight key way Stamp draw line Form undercut Mill threads Second ream Hand counter sink and rifle Chamber Hand mill for extractor Hand mill clearance for bolt lug Drill gas port hole Straddle mill gas cylinder lug Counterbore gas cylinder hole Ream out burr from gas port hole Countersink gas cylinder hole Machine tap gas cylinder hole Norton in. plain hydraulic grinder Taylor and Fenn spline miller Simmons turret lathe Coulter thread milling machine Baush deep hole reaming machine broach machine Krueger chambering machine Hand milling machine Hand milling machine Special machine Becker-Brainard miller Two-spindle drill press Bench tapping machine Special Machine Haskins tapping machine Cut off surplus material muzle end Becker-Brainard miller Finish end length and chamfer Single-spindle drill press Remove burr from gas port hole inside barrel Assemble thread protector and plugs Sand blast Parkerize Hand tap gas cylinder hole Hand ream cylinder hole Stamp identification Bench Sand blasting cabinet Bench Bench fixture oil used the cutting tool and ap- proximately 300 barrels are turned before the cutting tool resharpened. When grinding the Kennametal single point lathe tools guide block with the tool produce the proper angles. Drilling with Carbide One the mest outstanding opera- tions the method applied drill- ing the barrel. Solid carbide deep hole drills, Figs. and 38, are used Pratt Whitney double spindle hori- zontal drilling machines, Fig. Note that the solid carbide blank, in. long brazed steel drill shank, Fig. which few thousandths smaller diameter. bores this small size, success was obtained with inserted tipped variety car- bide drills which have been used suc- cessfully 20-mm. barrel drilling.’ Note that when this drill ground, Fig. the cutting edge radial but the point the drill off center. “Cemented Carbide Gun Drills,” Iron Ace, Aug. 13, 1942. These deep hole drillers normally operate 1760 r.p.m. but special pulleys are used gear the machines run the unusual high speed 3100 r.p.m. Feed 0.0008 in. and 500 lb. oil pressure applied that the drill runs oil film which results low tempera- ture drilling, high penetration and longer life the drill. Tests have shown that the output could fur- ther increased with 1000 oil pres- sure applied the cutting tool, but coolant pump could found stand against this pressure. The cutting compound used has per cent sulphur and cutback per cent with good paraffin oil. Each machine can drill 7.5 barrels hour and one man tends three drilling machines and turns out ap- proximately 372 barrels hr. The success this drilling opera- tion largely depends upon the way the carbide tipped drill ground, Fig. The operation grinding the drill very simple. Only three rotary cuts are required ordinary cutter grinder. Resharpening consists re- moving approximately 0.010 in. from the face the drill. 180 grit dia- mond finish wheel used grind the angles. prevent the drill from dig- ging in, 1/64 in. flat ground the cutting edge the drill which can seen the illustration Fig. For grinding the drills special fixture was made and shown the top Fig. The used check the angles gage show same tion ing six Fig. lieve clear rean in. than men tion able hole two and feeds high prod time vent in. ‘ 48—THE IRON AGE, May 25, 1944 shown the lower portion the same illustration. Special Reamers Used Perhaps the most important opera- tion the barre! reaming. Baush spindle hydraulic deep hole ream- ing machines are used, Fig. with six fluted push reamers. The reamers, Fig. have three alternate lips re- lieved in. from the end for chip clearance. The barrel hole rough reamed in. and finish reamed 0.300-0.302 in. diameter the uncon- in. per min. This feed three times faster than generally recom- mended for this opera- tion and the remark- able feature that the hole with two reams where formerly required three and four reams. These feeds have been run high in., but there was gain production due down time waiting for the (Storage hole) line (Back side) line 7 tit IG. used for diamond lapping the carbide drill point shown Fig. The angles and deg. are complementary the drill point angles and deg. re- spectively. BELOW 6—Battery spindle Baush barrel reaming machines. e § \ i 2 | Re \ \ | } in. fix his ar- ‘ uc- n Scribe / = | | ers arre oz ~ Stane renterc ore cerrers > 2 9 erore grinding ~ Je ~ nA» ) grooves ” 8 Wide x 446 ACEp must nor FUP | nto tlyfes SECTION B-B 2nd Grind FIG. 7—Details push type reamer. operator load and unload. Under- wood engineers favor push reaming over the old method pull reaming because the chips drop out gravity and are not forced the entire flute length when the reamer pulled through. One the primary func- tions the design shown that the flutes must smooth Relieve thus Half the straight flutes are removed for in. greater chip reamer long enough whipping. Lardex (23 per cent lard) used cutting oil and 100 barrels are reamed between sharpen- ings. The muzzle end finish turned Reed-Prentice and lathes using follow rest and carbide tipped FIG. 8—Duplex milling with shell end mills replaces two slab milling operations. 50—THE IRON AGE, May 25, 1944 cutting tools held holders similar those used the rough turning except that the shank slot the tool holder right angles the work axis. The size the motors driving these machines was increased order double the spindle speeds. this operation spindle speed 1196 r.p.m. used with 0.015 in. cutting feed. Unique Milling Fixture Both sides the gas cylinder end the barrel are straddle milled in. Cincinnati duplex machine shown Fig. ingenious fixture, Fig. was designed hold the bar- rel during the milling operation. The barrel muzzle end placed center the right end the fixture and the breech part the barrel clamped between vertical equalizing jaws the left end the fixture, using the pull rod lever and cam lock manipulate and center. The equalizing clamped and locked through double cam actuated through lever The whole clamp assembly then rigidly held the binder clamp lever This assures lining the barrel from the centerline. Angular location obtained work locator shown bearing against the projecting gas cylinder lug the barrel. The locator kicked out dog and roller the end milling operation shown facilitating unloading. Two shell end mills are used straddle mill the sides. This method milling decided improvement over the slab milling applied one side the barrel time, with relation the bore the barrel. the broac able mach fix durin actua 41.4 used the cen The end tion, and speed center the makes slide neve becaus could rack Coul are barrel, Prod the rifle broach: ing The 4 J 7 = 5 = “ - >) ly at — 6 A~ B-ind | 5 Straight flutes ( Uv / -0 ( 005 land-> = 7 -o° & | SECTION A-A ist Grind Center must concentric with r 9—In this the time this equipment was installed, broaching machines were not avail- able for this type operation. The front sight slot key way spline milling operation which machined Taylor Fenn millers. fixture used hold two barrels during the milling operation and the actual production each machine 41.4 barrels per hr. plug gage used check the size the slot, and the position the slot with relation center line limited tolerance +15 min. The shoulder and undereut the end the barrel skiving opera- tion, employing tangential feed tool, and done Simmons micro speed lathe, which the turret merely used for supporting the live center. draw collet used hold the barrel place and form tool makes the cut. Although the cross slide operated hand screw feed, nevertheless very fast operation because depth control eliminated. could made even faster using rack and pinion motion. Coulter thread milling machines are used mill the threads the barrel. The threads must concen- tric with the bore within 0.001 in. Broach Rifling Production has also been stepped the rifling operation. The complete rifle broaching setup includes Illinois broaching Fig. 10, sharpen- ing machines and inspection fixtures. The broaches, Fig. 11, are made pairs and two passes are required rifle barrel. The broaches are pulled through the barrel bore and their own lead. exterior devices for turning besides freely rotating puller are required. The ability the broaches follow their own lead created the sides the broach teeth and helical chip breakers each tooth. the past rifling was done spe- cial machines using single point tool correct width and positively controlled helix angle. The criticism this process was the time expended finishing barrel and the necessity — ——_T he} \ = 4+ o ~ = Machine table fixture, applied the miller shown Fig. the work located from the bore. the left, cam actuated jaws clamp the work and are turn clamped the fixture frame. for skilled handling the tool. Barrels Rifled Broaching,” Iron June 19, 1941, presents diagrammatic description the broach- ing operation. mum production with this method was per hr. the present time. With the present method broach- ing cutting lubricant supplied under high pressure. The pressure built chamber which slipped over the broach after the broach has FIG. 10—Rifle broaching the barrel broaching machine. D,,// ull roa ha rd, le A re - Cam lock { machine ar na ine ire, ar- : 1 a willl THE IRON GE, May 25, IG. rifling broach, showing the small diameter grinding wheel used hollow the tooth rake been inserted into the barrel. Locked into position, the pressure chamber confines the lubricant and forces over the broach and through the bar- rel. The construction the broach facilitates the passage large amounts oil. Besides acting lubricant and coolant, the oil removes the chips from the cutting edges and accumulates them the back the preceding tooth. this broaching operation the cut has small enough cause the chip roll off accordion fashion. Heavier cuts would produce more solid chips rolling the form spirals which cannot accommodated tween cutting teeth the broach. The chip space purposely made large avoid crowding the chips since any resistance the free flow the chips would detrimental the finish and tool life. The rifle broaches are made reg- ular high speed steel, hardened about Rockwell This hard- ness desirable from the standpoint tool life, since cutting chips 0.0002 0.0004 in. thick alloy steel the hardness the carbine barrels sub- jects the cutting edges considerable abrasion. Although the broaches are expensive, costing $290 per pair, the average life approximately 1600 1800 barrels. Broach Sharpening Practice Rifling broaches require sharpening after average passes and about regrinds are possible before the cutters become undersize. The principle the rifle broach sharpen- ing machine similar other broach sharpening machines except that small diameter, high speed wheel used generate hollow rake sur- face and equipped steady rests, interchangeable grinding and polishing spindles and diamond wheel-dressing device. also has means for quick indexing from tooth tooth. The rifling broach inspection ture which part the broaching setup, provides for visual inspection through microscope times en- largement. The size and steps the broach teeth are checked snap FIS. Krueger automatic chambering machines. 52—THE IRON AGE, May 25, 1944 gage inspe the up. ing dulln broac eter teeth. chine Borin and plete vertic bined tion. from about chine rels drillin signed heads loadin tions that angle decide this been ing tween with 0.0005 The tapped diamet con barrel machin barrels the origina tion applica this press, 185 the With — | gage indicator arrangement. Visual inspection the broaches determines they have remained free from pick- up. Inspection follows every sharpen- ing ascertain that every trace dullness has been removed. Sharpened broaches must checked the diam- eter well the face the teeth. For the Krueger multiple spindle automatic machines, Fig. 12, are used. The ma- chine has loading station and nine different tools complete the operation. Boring tools for the chamber are posi- tioned five stations; three reaming and one burnishing operation com- plete the chambering cycle. these vertical machines, the tools are sta- tionary and are fed upward com- bined mechanical and actua- tion. Work rotated and indexed from one work station another about vertical column. Each ma- chine geared chamber 112 bar- rels per hr. special machine, Fig. 13, for drilling the gas port hole was de- signed which three Delta drill heads are used. The machine has one loading station and three drilling posi- tions and requires steps drill two different size holes. fixture used hold the barrel that the hole can drilled angle deg. This machine decided improvement over the two- spindle drill press formerly used for this operation. similar unit has been devised for reaming and bottom- ing these holes, the concentricity be- tween which held within 0.001 in., with tolerance the diameter 0.0005 in. The gas cylinder hole machine tapped Haskins pneumatic tap- ping unit. The tap used has pitch +0.0026 diameter 0.4797 and must concentric with the bore within 0.001 in. fixture used hold the barrel during the operation and each machine can tap approximately barrels hour. conclusion, attention called the operation for crowning muz- zling the end the barrel. This was originally considered lathe opera- tion and was performed that way. application special jig this operation has been put drill press, Fig. 14, and production boosted 185 barrels per hr. This type the crowning not done concentric the bore, wild shooting barrel four Delta drill heads have been arranged this special unit for step drilling concentric gas port holes two diameters. will result. The drill press barrel regards this operation used Underwood proved give was possible with the old lathe method good perhaps better quality and much faster. drill press setup for crowning the barrels does better and faster job than the former lathe operation. THE IRON AGE, May 25, 1944—53 a e p { with several other methods fabrication, the reliability the products the welding industry other variables. The surface ap- pearance weld will give lot information, but does not tell all. any job necessary for the welder establish and maintain the complete confidence his cus- tomer. establishing this confidence, the opposition those favoring more traditional methods fabrication may have overcome. Some people will often refer isolated cases the failure welded assemblies and use them undermine confidence the welding method. However, ducing X-rays the welder can guar- antee job that above suspicion. One the main functions radi- ographers help create the great- est possible confidence in-welding. The reason for the existence all testing procedures prove that materials are what they are represented be. natural, therefore, that X-rays should used prove the pur- chaser welded product that the welding the quality called for. ¢ i 4 % < 54—THE IRON AGE, May 25, 1944 for the radiographer see that whatever has been written into the contract fulfilled. general this function covered written codes A.S.M.E. boiler code. However, written codes are more than gen- eral guide and the radiographer must have knowledge welding and the function the welded article be- fore can interpret these codes rea- sonably. the same token, helps great deal the welding engineer knows something radiography. For instance, considerable benefit the welder understands the advan- tages good radiograph over poor radiograph and knows where and when X-ray can used most effec- tively. Practical Aspects Radiography Radiography method produc- ing film picture the internal structures opaque object. welding, the opaque object consists the weld metal and the base metal adjacent it. The factors that mat- ter most are: 1—What can made visible the IG. Radio- graph thick weld. Porosity in- dicated black dots. graph precisely same area shown Fig. but made Porosity dots grain- iness film. q q film? What things visible images? 2—How can these images iden- tified and described that the engineer will know their im- portance, cause and cure? 3—What action should when the image has been iden- tified often said that radiograph just shadowgraph, but this not | very good analogy. When hand placed between light and screen black and white image obtained, but the shadow obtained from thick hand blacker than the shadow thin one. However, hand placed between X-ray tube and fluorescent screen, the bone clearly distinguished from the flesh, and the thin sections are distinguished from the thick. The powers let through stop X-rays depends both the nature the material and the thickness the material. The reason that bone can revealed inside flesh, that the power the bone stop X-rays much greater than that the flesh. technical language, the absorption the bone much greater than the absorption the flesh. X-raying weld, the weld bead usually thicker than the base plate and for this reason casts visible image. there cavity the weld, there local reduction thickness and can cast image. the cast and only the absorption the included material different from that the steel. because slag has less power absorb X-rays than that slag inclusions can revealed. When metal fastened dif- ferent metal such copper brazed iron, X-rays can reveal how far the one metal diffuses into the other. Un- steel there seldom sufficient differ- ence the composition the plate and the rod allow X-rays show diffusion. Anything weld that gives rise things include porosity, slag, cracks, lack eut. degre many how thi On weldi relati their tinua fast scree] obtail illust weld black ties. used. Fig way, fast Visibl comm was netwo white tion is dou the real great The req and Visor, ~ | ° ° » . ¢ lack fusion, inclusions and eut. However, whether they are re- vealed not depends tremendous degree the X-ray equipment and the technique. all probability many welding engineers not realize how much valuable information lost technical factors that may appear them quite trivial. Technical Factors One the principle features welding defects that they are all relatively small and many cases their images consist fine lines small spots. Welding engineers con- tinually demand the use the fastest available films, not realizing that fast film the inevitable coarse grain obscures many defects. intensifying screens are used, the grain the screen likewise will limit the results obtained. Fig. has been chosen illustrate this technical factor. This weld containing some porosity. The black dots are the images the cavi- ties. rather fine grain film was used. Fig. shows precisely the same area the weld radiographed the same way, but using popular brand fast film. The porosity almost in- visible this film. X-ray picture the microshrinkage defect that common magnesium castings shown Fig. The original picture was magnified times. The black network consists cavities and the white dots are due segregation. Fig. shows exactly the same condi- tion X-rayed another film. Prac- tically the entire picture obliterated the grain pattern the film. course also vitally important process the films under the most carefully controlled conditions. This doubly true because carelessness the darkroom will not only spoil the real images, but will produce great number false defects which may lead unnecessary rejections. The operation X-ray darkroom not trivial foolproof procedure; requires full knowledge the pho- processes and great care and diligence the part the super- Two illustrations will help em- LESLIE BALL Assistant Technical Director, Triplett Barton, Inc., Burbank, Cal. Information the quality welds can obtained only proper choice number technical factors which apply radiography. The author emphasizes the need for reciprocal under- standing between the welding engineer and the radiographer X-ray problems that standards acceptability can set up. This report has been abstracted from paper presented the author recent A.W.S. meeting Los Angeles. phasize this point. Fig. simple pressure mark caused thumb nail. Its appearance very similar the cracks welds that occur the points where the rod changed. This false defect can caused carelessness loading the film carelessness placing the film the hangers. rather pretty example electrostatic image shown Fig. This “phony” caused pulling film against the black paper. and can misinterpreted. X-ray Equipment The source X-rays consists the X-ray tube, the transformers sup- plying high voltage and the auxiliary production mi- croshrinkage cast magnesium made very fine grain plate showing segregation tion identical with X-ray shown Fig. but made or- dinary X-ray film. Grain pattern the film obliterates the picture (50X). controls such water cooling. The equipment requirements for X-raying thin welds are course very much simpler than those for X-raying thick welds, but all cases the convenience with which the X-ray equipment can placed position great im- portance both cost and the quality the work. known that weld X-rayed, accessi- bility should considered from the day that the first plan the assem- bly made. good example this certain war project which Triplett Barton, Inc., X-raying every inch 125,000 ft. welding. This job has been planned that the welds the base certain large tanks will X-rayed while the struc- &