The Iron Age 1943-07-15: Vol 152 Iss 3

NGTON ANGELES > 4 VORKS, ITA iVISION ER CO., HICAGO HICAGS RTLAND BAL TIMG® LING APOLS iSAS CHF ST. RSEY For All Types TOOLS For PREHEATING High Speed Steels for heat treating water oil hardening steels—1300° 1750° VORKS, WORKS, [LAND PLY For HARDENING High Speed Steels any type any alloy steel from 1750° 2350° "VELAND OLUMBUS QUENCHING unit for High Speed Steels Alloy Steels. LLENTOWN PITTSBURG DENCE HARDENING DECARBURIZATION 75% Less Floor Space for Same Production WRITE FOR BULLETINS Al00 POT FURNACES HY-SPEED CASE DEFENSE TOOLS BRIGHT TEMPER A104 LIQUID CARBURIZING MANUFACTURERS HOLDEN PRODUCTS CANADA PEACOCK BROTHERS LTD., Box 6070, Montreal, Canada JULY 1943 JUL 1943 & | ip 3 a | if é electric ere used for toolroom work plant. Today they are still that toolroom, tools, knock out the Axis. The equipment con- sists box furnace for carbu- rizing, cyanide pot, lead pot and oil bath. The importance tools rightly heat- furnaces prewar days, these Hoskins need heat-resistant castings, rolled material, our Alloy 502 the 35-15 type. melted high-frequency induction that guarantees uniform composition. Glad give you design suggestions. - THE IRON AGE, published every Thursday the CHILTON CO. (INC.) Philadelphia under act March 1879. yearly North Entered second class matter November America and South furnaces, you meet that vital need. The heating elements are made durable ribbon, and perform faithfully meeting today’s hard you need good, dependable heat-treating equip- ment, send for Catalog 58. Company, Detroi treated obvious. With Hoskins electric Michigan. 1932, the Post Office America, Foreign $15. Vol. 152, No. q 4 | 4 VAN DEVENTER President and Editor BAUR General Manager and Advertising Offices 100 East 42nd New York Y., Johnson, Market Research Baur, Typography and Layout. Regional Business Managers New York New York 100 East 42nd St. East 42nd St. ROBERT BLAIR FITZGERALD Guardian Bidg. 428 Park Chilton Bidg. 1134 Otis Bidg. PEIRCE LEWIS WARREN RAYMOND KAY Los Angeles 2420 Cheremoya Ave. ° ° Owned and Published CHILTON COMPANY (incorporated) Executive Offices Chestnut and Sts., Philadelphia 39, Pa., OFFICERS AND DIRECTORS MUSSELMAN, JOS. HILDRETH GRIFFITHS VAN DEVENTER Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary CHASE THOMAS KANE HARRY DUFFY CHARLES HEALE Vice-President Vice-President Vice-President Member, Associated Business Papers North America, South America $8: Foreign, year. Copy, cents, Annual Number, ° Office Vol. 152, No. This IRON AGE Editorial Forgotten Technical Articles Bearing and Tool Damage Induction Hardened Parts for Desert Warfare Ford Reclaims Tungsten Carbide Tool Tipping Procedures for High Speed Material Handling War Finishes Dominate Electroplaters’ Convention The Annealing Steel New Equipment—Small Tools Features Assembly News and Markets Army Revises Property Disposal Methods Six-Months’ Steel Output Sets Record. Scranton Prepares for Industrial Warehouses Permitted More Details CMP Reg. Coalition Bloc Decentralize Steel Severe Blow Dealt Grade Personals and Obituaries Machine Tool Non-Ferrous Metals News and Developments Non-Ferrous Metals Prices; Scrap Iron and Steel Scrap News and Finished Iron and Steel Stainless Steel, Tool Steel Semi-Finished Iron and Steel Prices. Pig Iron Prices Ore and Coke Prices Ferroalloy Prices Index July 15, 1943 104 105 106 120 123 142 146 154 156 158 159 160 162 163 164 165 165 168 169 170 243 ° ° ° & vn é “Share the Campaign Will for Reduction Inventories and Elimination Duplicate Stocks The cooperation all manufacturers using steel being sought the WPB, cut inventories and gain 2,000,000 tons steel. Working through its Regional Offices, Steel Division officials have been sent the Washington Office work with consumers, effort see steel supplies hand will permit the elimination deferment third and fourth quarter orders producers’ books without interfering with the produc- tion important war equipment. This effort the successful, will permit the diversion tonnage other manufacturers war products who need it. each manufacturer will check his inventories against requirements carefully and avoid duplicate stocks, this government program may accomplish its purpose and make available the extra two million tons steel needed during the last six months the year. Stocks steel the hands commercial warehouses strategically located serve all manufacturers help overcome the necessity for large individual inventories and many duplicate stocks. These steel service plants with long experience stocking, cutting and shipping steel notice—are definitely the answer the problem. Throughout the history America, peace and war, they have served this very purpose. And now, this national emergency, they are carrying the burden—and stand ready even more make safe and practical reduce high inventories, eliminate duplicate stocks, and lower the overall tonnage idle steel. JOSEPH RYERSON SON, INC. Steel Service Plants at: Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City. 50—THE IRON AGE, July 15, 1943 | | 5 ~ FORGOTTEN PEOPLE ESTABLISHED 1855 ° President and Editor BAUR Vice-President and General Manager “forgotten man” lately has been somewhat neglected. During the hard times was the subject considerable political com- ment. Much was said about him, although less was done about him until Mars took him over and put him work good wages. This original forgotten man was the fellow who couldn’t get work because there were not enough jobs around during the depression DIX years. Whoever whatever was responsible for this lack jobs has Manager, Reader Service not yet been determined and perhaps never will be. But very rightly Government undertook help out these unfortunates and did, although Associate Editors MacDONALD BARMASEL some the methods employed may have been open criticism. shall always have forgotten people with us, even during periods News, Markets JAMES Government assist them when they cannot help themselves. Technical Editor......... OLIVER Art WINTERS Today, the forgotten people are even more numerous than they were 1930 1933. But they are not the same kind people. The forgotten ones today are the white collar workers and the retired people who live fixed incomes. There very little that Government can for the latter these two groups except prevent inflation stealing through their windows and robbing them part their capital. think that Government BENEDETTO really trying prevent this, although the record has not been altogether Editorial Assistants successful. With respect our white collar workers, think the Government not only not helping them, but that hurting them. Certainly Regional News and Technical CAMPBELL not giving them the consideration that gives the men and women wage earners our factories. Many progressive managements would like help their white col- lar workers keep their heads above water the rising tide living costs. They know that, despite the fact that “Rosie the Riveter” and 1134 Otis Washington Notional Press BROWNE Washington National Press “Willie the Welder” are doing fine job war production the plants, there would not any production all were not for the ideas, knowledge and leadership displayed their foremen, engineers, production experts, metallurgists and office people who are fixed weekly salaries regardless the hours that they work. many in- stances, these people put just many hours per week the hourly paid workers, yet spite supposedly superior qualifications, 1016 Guardian draw less money. BRAMS Progressive management would only too glad correct these Detroit 7310 Woodward Ave. OSGOOD MURDOCK San Francisco 1355 Market St. Editorial Correspondents ROBERT injustices, but finds its hands pretty well tied Government adminis- trative restrictions. These skilled and experienced people are not unionized and have collective political voice. But they are the very yeast the home front war effort. Their ideas, knowledge and initiative furnish the larger part the push the war effort. Unless something done help them meet the squeeze, many them will tempted swap their white collars for overalls, that they can take home much money our semi-skilled shop workers and the ’teen age industrial newcomers. And then would certainly HUGH SHARP find ourselves out luck. SANDERSON Toronto, Ont. RAYMOND KAY Los Angeles JOHN McCUNE ROY EDMONDS Louis JAMES DOUGLAS Seattle ¥ | q sheets are used ghter aerial bombs blitz cans that carry You Find American Fighters Find Inland Sheets Many months before Pearl Harbor great quantities Inland sheets were flowing manufacturing plants that were beginning make war equipment and supplies. America was stores tough little jeeps that war materiel—and shipping some the nations that verywhere, reckless speed today are our Allies. War products made Inland sheets have been moving the four corners the earth—to Arctic Regions and blazing deserts, remote continents and islands. Fighter squadrons take off from landing mats Inland steel. Troops are fed, bombers and mobile units are fueled, and explosives and ammunition are safely stored containers made Inland sheets. Yes, wherever you find men fighting for Democracy, you will landing mats, from which find products made Inland sheets. INLAND STEEL CO. motorized that forms lifelines Armies action. Sales Offices: Detroit St. Paul St. Louis Kansas City Cincinnati New York | News secretive and highly efficient manufacturing operation the use 500,000 12-15 volts flash weld trench mortar and artillery shells (not cases). Two are pressed from plate, and the welding area often exceeds sq. in. Production has Airplane engine manufacturers are now going into production 3350 cu. in. displacement motor, job developing h.p. much plus has await the capture the Germans intact engine. OPA processing Kaiser's petition for establishment West Coast base prices semi-finished steel. Ingots may set high $40 gross ton, against $31 now talking with some American suppliers about building and setting tinning line Argentina. Probably the plan, basically little silly view the lack continuous coils steel, will die quick death. Speaking South America, American exporters looking for post war market there will delighted learn that Rio Janiero has just raised minimum wages 45c. nonth $15.45. All the government's metal recovery corporations (steel, copper, aluminum) will soon out the window. Time Magazine last week lauded Kaiser's first small (merchant ship hull) aircraft carrier, unique idea personally rammed down the Navy's throat with Presidential Forgotten was H.M.S. Battler, first number merchant ship hulls converted "escort carriers" (Woolworth carriers) which Ingalls completed for the British over year ago, and which Churchill credited with the recent drop Atlantic submarine sinkings. The German Iron and Steel Institute, meeting recently, concluded that the basic bessemer converter would almost fully replace the open hearth the post-war period. Belly turrets bombers will soon passe. future, belly gunners will inside the ships with remote controls and sights, while guns with range superior the old turret guns will hang from brackets below the ship's belly. Vast numbers minute but true welds, constantly being made and broken, are major bearing friction and result more harm than all other wear causes combined, recent studies indicate. German investigators are the same track, agreeing also that destructive contact follows impairment oxide film. Exhortations South America industrialize are bearing fruit. Sao Paulo, Brazil, alone there are ten concerns making imitations certain well known American Representatives some large coal mine operators met with couple Ickes' boys Pittsburgh last Thursday explore just what meant the Federalization coal that has been proposed Lewis; i.e. does the Government pay the taxes, take care depreciation, there any profit for the companies involved, Renegotiation has been going for 100 years under the name piece work price cutting, with industry the other end the renegotiation, Lincoln, president Lincoln Electric Co., told the House Naval Affairs Committee recently. called greatest error management ever made. The Pacific Northwest will shiver the verge power shortage autumn 1944, according Bonneville Power Administration, which advocates third giant dam the Columbia Basin and additional storage dams for Grand Coulee and Bonneville. Fuse production can now controlled 100 per cent with developed Motors for testing fuses anti-aircraft shells. The action the Shell flight simulated spinning process. Manhours required for standard liberty ship have been reduced West Coast Yards below 250,000 per vessel, less than half the bogey 510,000 which contracts originally based. One the best records belongs Kaiser Portland ratio women workers also highest the country. Because production, one large explosives plant has been shut down and others are curtailing output drastically. q 3 § q ff q f 3 q j 4 q q d n aga. writer has previously pre- sented some ideas regarding the causes bearing surface dam- age together with some suggested remedies.* The serious effects weld- ing, perhaps more commonly called “galling,” likewise been stressed. Continued careful ex- See the article, “How Smooth Should Bearing Surface Be,” THe Ace, issue Jan. 1942, 40. amination damaged plain bearing surfaces has reinforced the belief that such welding far greater source detrimental bearing conditions than commonly supposed. Indeed, believed that practically all metal surfaces that rub together are harm- more welding than all other causes combined. course, welding not the only source damage bearing and tool surfaces. Undoubtedly, turned and ground surfaces are covered with partially loosened minute splinters metal produced the tearing and splitting action the removal chips lathe tool, the inef- fective cutting angles grinding grits. Such splinters are completely freed during the early part opera- tion become loose abrasive parti- cles. Some them are gradually washed out the bearing causing certain amount erosion pass between the surfaces, and some may become more less deeply fixed the softer the two surfaces. Where soft bearing metal such babbitt employed, the particles may become almost completely embedded with only their tips projecting. this case they usually cause im- provement the shaft smoothness mild abrasive action. They will burnish the shaft surface better operating finish condition. When harder bearing metal, such bronze, used, the particles seldom become deeply embedded. Instead, they may fixed just deeply enough hold them place, when they have little tendency produce smoothness. More often, rather deep scoring the result. Roughness, such turning grinding ridges, undoubtedly has some cutting action the mating surface, especially during the early stages operation. Until the ragged, splintery 54—THE IRON AGE, July 15, 1943 portion the ridge tips has been re- moved, this cutting may somewhat important. Yet experience has shown that this effect soon dies down be- cause the tips rapidly become dull. Such are the processes wear usually described contributing the most damage bearing and tool surfaces. Under comparatively mild operating conditions, where metal metal contact might better de- scribed approximate rather than actual, that may the true picture. Yet, except where particles become wedged between the surfaces cause scoring, should noted that the general tendency these kinds wear produce increased smoothness and better geometry the surface. Any burnishing action wear resulting from interlocking irregularities cannot help but re- duce high spots first, and thus result increased roundness and smooth- ness. Unless there other actions than these, the greatest detrimental result roughness would seem and uncontrollable clearance dimensions. Unfortunately, known from ex- perience that other damaging proc- esses must effect, because bear- ings very often not improve smoothness with continued operation. All the evidence that the writer has seen indicates very definitely that the chief cause increased rough- the previous article* three con- ditions were described necessary for welding occur. First, the mate- rials employed must have some degree affinity for each other. Second, the surfaces must become absolutely clean. Third, the surfaces must come into close enough contact that they are within the field molecular at- traction. Heat not all necessary for welding occur, although always present some degree, and does greatly increase the amount damage done. All metals employed for tool and bearing purposes have sufficient affinity for one another weld, but they vary considerably the degree that affinity. Minute areas are very often wiped clean enough, and into sufficiently close contact, par- ticularly during state boundary (deficient) lubrication. When the re- quired close and clean metallic con- Bearing and Tool Damage tact does occur, just true weld takes place that produced that perfect, because liquid metal would make more continuous contact, and flux would cause more perfect cleanliness surface. Never- theless, galling sufficiently per- fect welding action cause great deal damage. Welds Are Very Small most mechanics the world “gall- ing” instantly brings mind com- paratively large surface defect; one that easily seen, and which may even stop the motion. However, the vast majority welds are very mi- nute size and instantly break apart with perceptible effect the rota- tool parts. (See Fig. The energy consumed the making ing these welds undoubtedly important part the total effect call- “friction” and contributes the heat developed thereby. The ultimate load carrying capacity its ability resist serious galling. Because most often microscopic extent, the restriction bearing capacity galling easily overlook- ed. Just because the results this. action cannot always seen easily does not prove them unimpor- tant. Galling three dimensional tion; involves both area and depth. The area the weld will depend upon the contour the surface and upon the softness the metal. the roughness the surface sharp, the area will small; but soft enough deform under the ap- plied pressure, the area will become correspondingly larger. Other condi- tions being the same, combination metals low affinity for one an- other will result fewer and smaller spots welding, and this the most important reason for the continual search for improved bearing metals and alloys. The depth which particles are torn out, welds break apart, dependent upon the softness and tility the metal. Very hard and brittle surfaces will not deform allow large area contact and will flake off very thin Soft and ductile metals will tear out to a case, becon note dama sof tively great meta more score tent worn meta furth mech parti torn will place agai they | v weld liquid nuous more per- great one may the mi- apart rota- nergy call- alling. scopic earing rlook- this easily mpor- ac- depth. lepend and sharp, ap- ecome condi- nation maller most metals are and and out Galling considerable depth. either case, the metal torn from one surface becomes ragged defect welded upon the other. is, however, very important note the difference the extent damage done the mating surface weld torn from hard and from metal. The weld compara- tively large area, and very much greater depth, torn from metal will obviously produce much more extensive damage. will surely the mating surface some ex- tent before becoming broken loose worn off. Too often will pile metal ahead the point where movement stopped, and say has “frozen.” Most the shaft and tool scoring, usually ascribed the presence foreign particles, caused this process. The thin flakes smaller area, from hard brittle surface, will naturally have the same tenden- cy, but the extent damage will very greatly reduced. the first place, the hard welds will rubbing against ‘the hard metal from which they were torn, with small probability ° ° HEMINGWAY Chief Metallurgist, International Machine Tool Corp., Foster Division, Elkhart, Ind. ° ° Welding far greater source detrimental bearing condi- tions than commonly supposed. The author examines the reasons and theory galling, and gives pertinent data how this action can minimized. Bearing metals, and other important data bearing performance also are discussed scratching deeply because that hardness and their extreme thinness. Any metal removed the weld from the hard parent surface will finely divided, and will not pile any extent ahead the weld. The very minute welds from hard metal tend ride over the parent surface in- stead gouging into the case with soft metals. There reason believe that hard steel sur- faces will weld less readily than soft ones, but those welds will very much smaller, both area and depth, with comparatively very little dam- age done; and herein lies the chief reason for the better performance hard steel shafts compared soft ones. Frictional heat greatly increases hub gear bearing. Both small welds (right), and those large enough stop rotation (center), are shown. All the scoring, across the entire width the bearing, was caused welding. Most galling still less extent. the amount damage galling. expands the affected area, forcing into still greater pressure and rise temperature. promotes greater cleanliness frying away the oil. Worst all, considerably increases the softness and ductility the metals with the detrimental results just described. heat allowed develop through inadequate lubrica- tion, other causes, the possibili- ties for serious damage are enor- mously increased. Grinding exceedingly valuable process for the production dimen- sions sufficiently accurate for prac- tically all purposes except such tools gages. Indeed, modern mechanical efficiency can said date from the development the production grind- and synthetic abrasives. Never- theless, there are features ground finishes which are very undesirable bearing and tool surfaces. (See Fig. The pattern ground surface con- sists helix winding around cylindrical part composed suc- cession ridges several times long their widths. This helix plainly visible, and everyone fa- miliar with its appearance. addi- tion these spiral semi-continuous ridges, all ground surfaces contain some degree longer pitch waviness, which seldom can seen, and which not revealed the Profilometer Brush Analyzer. They are caused mechanical defects the grinder, the heat produced grinding, and perhaps still other causes. For ex- ample: loose spindle will produce “flats”; slight looseness the head stock will cause parallel, chatter, particularly with certain types drive; lack sufficiently rapid cool- ing the grinding solution will re- sult feed spirals. Apparently, grinder will produce perfect ge- ometry surface. Another detrimental condition pro- duced grinding annealing THE IRON AGE, July 15, ox n “burning” hardened steel sur- face. Such annealing may include only the surfaces the ridges, but some- what deeper the tips; may include the complete cross-section the ridge and some depth into the body the part. Unfortunately, such annealing causes the supposedly hard bearing tool surface re- semble soft surface its perform- ance. may eventually wear down sufficiently expose real hardness, but considerable scoring will result before that condition secured. Oil Film Imperfect Wear galling ground surfaces begins upon the tips the highest ridges upon the crests waviness. These few scattered ridges are the actual load carrying areas, and the only ones. important that this picture visualized: That, unless the oil film pressure sufficient sepa- rate the surfaces completely, the en- tire bearing load carried upon the peaks the highest surface regularities. practice very seldom that the oil film will separate the surfaces all times. these very small areas come into rubbing contact with the mating surface, they very often are wiped clean enough, and forced pressure into close enough contact, for weld- ing take place. When the weld broken apart, the height the ridge from which was torn reduced the amount metal removed. Fur- ther, the-weld particle will scratch score more less deeply the sur- face from which was torn depend- ing upon the hardnesses the two surfaces. Metal thus removed kind machining action the rough weld particles, and welding 56—THE IRON AGE, July 15, 1943 RIGHT Sanded crank bearing. Aviation engine main bearing, which has been sanded, then partially Super- finished. Hollows, produced sand- ing, have almost completely been re- moved. BELOW Grinding defects. ground pilot bar shown, the defects which have been exposed very short ap- plication Su- perfinishing stone. Completion the operation move these defects surface geometry, together with frag- mentation and an- nealing. =<: 4 4 “ transfer from the other. Attrition this sort continues, and first the highest ridges are moved exposing spots continuous surface the crests waviness. Finally, even waviness itself may eroded away multitude sepa- rate galling and scoring actions. Just abrasive wear embed- particles very soft bearing surface, the general tendency gall- ing wear produce better degree ness. The welding begins its attack the highest points the surface. However, while abrasive wear Will sometimes result greater smooth- ness when the bearing metal soft and has little affinity for the shaft metal, galling wear will almost variably produce scored rings are usually deeper ridges. This particularly true the shaft soft has been usual extent. Once visible all control over the com unit ove tan of fee enc the wil but > wh dis ste ing the are waviness. may sepa- ons. embed- bearing gall- degree wavi- attack surface. vear will soft the gs whieh grinding true anneal- scoring the quality surface and clear- ance dimension has been lost. Several abrasive processes are that are applied after the grind- ing operation remove fragmenta- tion and annealing and produce greater smoothness. For these pur- processes sanding have reasonably successful, but they most often increase waviness beyond that produced grinding. The writer has seen many parts finished strip and has never yet seen one that did not have hollows developed surface that process. There can little doubt but that smooth waviness more difficult force through oil film, into metal- contact, than grinder ridges. Yet, the smooth area does come into such contact under excessive pressure, the damage very likely more simply because larger, more continuous area involved. The that comparatively large veld will form are greater, and the weld particle will plough through longer, continuous extent continuity scoring action. Con- metal can thus piled thad the original weld. course, the same line reason- ing applies still greater degree asmooth surface perfect geometry without waviness. However, the perfection surface shape be- comes greater, the actual effective bearing area also increased. The pressure becomes equalized all wer the bearing area, and the proba- metallic contact under seri- pressure becomes very much less. Another consideration the fact that mooth and perfectly shaped surfaces fitted with the very minimum thus avoiding shaft de- within the bearing, with con- localization pressure the ends the bearing. Other factors remaining the same, the smoother and more perfect shape surfaces are made, the greater will their load capacities long adequate lubrication supplied, but the greater will the damage metal metal contact does oc- Fortunately, there are means which lubrication can improved and galling decreased during boundary conditions. Among the items that contribute that direction and more uniform bearing pressure are: (1) Use bearing metals low for the shaft, which usually (2) Use bearing metals contain- contaminants. (3) Use lubricants containing elements which form surface films. (4) Use second surface finish- ing operation after grinding that will produce the following effects: (A) Improve the shape geometry the shaft tool surface. (B) Produce pattern minute oil grooves all over the shaft surface. (C) Increase the actual load carry- ing area production finer and, therefore, greater number surface ridges. (D) Break up, minutely, the con- tinuity surface smoothness. (E) Remove fragmentation sur- face, smear metal, and annealing, all which are produced the heat reasonable. Babbitt metal, ex- ample, does not readily and widely known have little tendency score. Others believe that those similar crystalline lattice readily, and those considerable dif- ference not. Another (Underwood) thinks the position Mendeleeff’s periodic system has much with these theories may have, the writer believes the essential thing recog- nize that scoring originates welding, and that such welding will less serious the shaft and bear- ing have low affinity for one another. investigate the conditions wear metallic surfaces under the action sliding friction, and different temperatures, Radeker used special arrangement which the test sample could heated and cooled extraneous means. this work, described fur das Eisenhuttenwesen, tests were ducted over temperature range from 190 deg. 700 deg. C.; the relative speeds the surfaces contact were and per second. With the materials investigated, unalloyed steels with 0.04 0.73 per cent cast iron, non-rusting and Cr-Ni steels, and manganese steel, the wear most cases was found diminish the temperature was raised and then increased again beyond certain critical temperature. Wear was three types: (a) Flaking, (b) removal surface layers, and (c) abrasion. Wear under (a) was very marked and due direct contact between the metals; this effect could considerably reduced increase tempera- ture; (b) only occurs when the outer layers the materials con- tact are high temperature, whether produced artificially actual friction; this type wear very pronounced soon the oxide surface punctured removed. With the oxide skin un- impaired the wear was very slight. The third type wear due the simultaneous occurrence high temperatures and slight deformation the surfaces sliding friction. There is, course, series transition stages between these three types. The author found certain relationships between the temperature effect and amount wear and the loads and the relative the sur- faces contact. and the violence with which grinding grits remove metal. outside the scope this paper discuss bearing metals any length. Little more can done than point out the fact that considerable variation exists the affinities dif- ferent metals and alloys for steel, which almost universally used for shafts and tool parts. Where bear- _ing metal used which has low affinity for steel, entirely logical expect that galling will correspond- ingly reduced. the search for new bearing met- als with lower scoring tendency, many theories have been advanced giving reasons for the variations ex- pected that respect. Some people, for instance, believe that the proba- bilities scoring can gaged the ease with which the bearing met- practical test, this appears Bronze bearing metal containing around per cent lead has very good anti-scoring properties. The lead does not alloy but properly exists finely dispersed minute globules the metal. The writer believes that when frictional developed, the lead melts and partially oxidized. The lead oxide wiped between the bearing surfaces and acts con- taminant, preventing true metallic contact and thus also eliminating welding and scoring. Cast iron much better bearing metal than steel the same combined content, and this due its porosity. Sufficient oil (plus the pos- sible effect graphite) contained the graphitic areas tide bear- ing over considerable period ex- cessive pressure. The very minute quantities oil contained the po- rosity cast iron are sufficient contaminate the surfaces and prevent THE IRON AGE, July 15, 1943—57 “3 = > | > 4—Internal grinding defects. Shows ridges and chatter found practically all ground holes. Surface has been incompletely Superfinished. welding, degree. The writer conducted extensive series tests several years ago determine the proper metals use seal surfaces: operating under high pressure and considerable speed. very large number combinations bronzes and steels were tried. Even high carbon, high chromium, high speed, and nitrided steels were en- tirely unsuccessful. Finally, cast iron was resorted to. Close grained and chilled iron were better, but the most open grained iron available solved the problem. Where all other combinations had failed, two open grain iron surfaces running together actually were better condition after 180 hr. continuous operation. Sprayed Metal Bearings Another type surface that has desirable qualifications sprayed metal. While care must exercised that deposited the proper kind roughness hold it, because does not actually bond the surface upon which sprayed, will operate with minimum welding. cross-section spray- steel examined under the micro- scope, will found structure very minute droplets steel sur- rounded iron oxide. is, there- 58—THE IRON AGE, July 15, 1943 fore, weak and brittle and somewhat porous. However, the oxide not only polishing agent, but has affinity for steel. Consequently, its tendency polish the mating sur- face and never gall. The minute areas exposed steel will tend gall just would any other steel, but any individual weld cannot progress very far because that action will broken the oxide film surrounding it: The porosity sprayed metal un- doubtedly acts similar that cast iron holding the lubricant. All bearing metals instantly begin oxidize upon exposure the air. were possible maintain per- fectly such oxide films during bearing operation, there could galling because oxides have affinity for metals. They must scraped off the bearing motion for welding oc- cur. Experiments have been made where the lubricated bearing oper- ated under blanket nitrogen and oxidation thus could not take place. Under that condition, was found that galling was increased consider- ably because any protecting film oxidation already formed was not re- placed. Thicker and thus considerably more permanent films can secured chemical action, either separate process activated lubricant. Instead oxides, such films may chlorides, sulphides The result will the same; they have affinity for metals and thus prevent welding long they persist the surface. Such tion surface films sometimes ployed ease bearing through the wearing-in period, particularly those cases where heat other have tendency produce un- predictable alteration the bearing shape. While the “extreme pressure” activated lubricants are sometimes resorted case necessity, there can doubt but that attention surface finish shaft and tool surfaces offers the most hope sub- stantial improvement. faces, plus improved bearing metals, seem the aim every facturer precision mechanisms, Since galling seems the most destructive kind wear, appears reasonable consider very carefully how distribute the bearing load uniformly over the greatest possible area and lubricate and contaminate that area with oil the most certain manner. Absence areas high unit pressure, together with efficient distribution oil, should result the minimum metal metal con- tact and the least damage when does occur. Uniform bearing pressure can secured only production bearing surfaces perfect geometry and amount clearance. The yardstick which the desirable accuracy ometry and clearance should mea- sured the dimension the most efficient oil film, which somewhat less than ten one-millionths inch. The perfect bearing assembly would have surfaces perfect smooth- ness, with deviations from perfect cylindrical planes their shapes, and approximately 0.00001 in. clearance. would never come metallic con- tact. the present time, there appears fection will ever reached. mechanical process can visualized which will not result some degree waviness bearing surfaces. Un- der boundary lubrication, certain some degree metal metal contact. All that can hoped for minimize the results such contact. previously pointed out, the best way that make each point contact subject the least amount pressure and render lacking metallic cleanliness possible the best distribution oil. the evidence accumulates from many clear heavi This ducti cann' than tren gre ahe cal many sources, becomes reasonably clear that system minute oil grooving must provided all over heavily loaded shaft bearing surface. This most easily done the pro- duction very fine scratch pattern. These scratches must very closely spaced because appears that oil cannot wiped over more than very minutely short space smooth area. The spacing oil supply and actual bearing area should exceed- ingly fine, preferably surface with Profilometer reading more than Thus the chances keeping the scratch tip contaminated are bet- ter; and, they are not completely, the weld will confined ex- tremely small area. The minute scratch pattern tiny ridges and valleys important for another reason. Not only the weld confined extreme smallness, but its further detrimental effects are thus restricted. weld occurs con- tinuously smooth surface, has much greater chance piling metal ahead it, often many times the bulk the torn out weld itself. occurs the scratch pattern, must pass over broken surface and will soon completely detached will more than minutely scratch for short time before becomes worn first degree importance the geometrical accuracy any bearing tool surface. the pressure carried the crests waviness, the unit pressure such points will many times what should be, with much greater probability welding. (See Fig. matter whether the shape concerned round everything humanly possible should done make that surface minute- perfect its geometry. bearing assemblies, fortunate that proper shaft surface provides much the greater percentage the im- provement possible. This because the bearing metal usually much softer than the steel shaft, and the shaft surface largely determines the quality which the bearing will assume operation. Nevertheless, the same attention the bearing surface will produce still better results, ofttimes surprising degree. The perfection secured the shape shaft bearing has direct rela- tionship the fineness desirable the minute seratch pattern. has been shown that welding the tip minute ridge seldom seriously damaging, particularly truly hard. after the ridges have been completely eroded away and con- tinuous spots surface have devel- oped the crests waviness, that galling becomes really serious. Con- sequently, the pattern minute oil grooves preserved after waviness has disappeared, they must still deeper than the waviness. the more minute the scratch pattern the more efficient becomes, this another reason for improved ge- ometry. last important point the fact that the finest scratch pattern will result the greatest total actual load carrying area. Study parallel scratch patterns has shown them similar cross-sectional shape, matter what abrasive process was em- ployed. is, therefore, reasonable assume that the tip each ridge has the same bearing area regardless Master- shaped abrasive. Shows Superfinished stud and stone used that operation. Note the large area contact, mokes possible the removal flats, ridges and feed marks. This ex- tremely smooth fin- ish ideal for tools. the other dimensions. other words, fine ridge has the same load capacity large one, because the actual tips are all the same size and approximately the same included angle. surface having great many fine ridges will thus have greater load capacity than one with fewer coarse ridges. However, here again the necessity for improved geometry ap- pears. These ridges must contain- the same plane they are effective. Nevertheless, the ad- vantage still lies with the finer ridge, even though some waviness does exist, because lesser amount metal would removed galling from higher ridge before another came its assistance. The required pattern minute oil grooving possible produce grinding. However, previously de- scribed, grinding also results sever- effects that are very detrimental, indeed. Dirty oil, full fragmented particles due the violence stock removal grinding grits, can undo all the benefits derived from other- wise proper surface finish. Galling damage immensely increased the annealing produced grinding. attempting produce surface low Profilometer reading grind- ing, there always tendency produce “smear metal.” The heat de- veloped sufficient flow. the rough- ing grinder ridges fill the val- leys. The writer has recently seen several such instances the surfaces aviation instrument parts. While grinding the most efficient means producing accurate dimensions, far from suitable for production final tool and bearing surfaces. additional, milder process seems neces- sary produce the most desirable quality surface for these purposes. Experience has shown that the use abrasive process which applies many more finer grits over area instead line contact, and with greatly reduced speed, most ef- ficient. Very much less work thus done each grit, resulting prac- tically heat, annealing, frag- mentation. The stock removal should only sufficient remove these defects produced the previous grinding operation, usually one two tenths thousandth. The abrasive area, which con- tact with the work, must rigid master shape (See Fig. 5); and must large enough cover suf- ficient surface insure the removal chatter, feed marks, flats and other waviness. The abrasive either should applied loose metal master surface, bonded master shape. THE IRON AGE, July 15, ides, and they em- uses un- ring here ition { sub- sur- tals, | nbly fect and nee. con- per- ized Un- such out, the ness tion One applied line contact, means emery cloth sand paper, can never produce improved ge- ometry. the present time, there are two processes which can satisfy the de- scribed surface requirements regard- ing geometry and removal anneal- ing and fragmentation. They are metallic master laps and Superfinish. Careful lapping this type pro- duces most excellent geometry, and surface the proper kind every respect except scratch pattern. Seratches arranged random direc- tions are produced with comparative- smooth and large areas between them. There reason believe that the oil contained the scratches can- not sufficiently contaminate and thus prevent galling the relatively large areas between them, under severe loading. The closely spaced scratch pattern previously described seems much more efficient that respect. Superfinish not only gives the neces- sary correction geometry and re- moval annealing and fragmenta- tion, but can controlled produce almost perfect smoothness well the desired scratch pattern for shaft bearings. For many tool purposes, such cartridge punches, piercing punches and reamers, the surfaces cannot too smooth. Superfinish meeting these requirements better than any other process. Indeed, many people have come believe that the only type surface for which Superfinish useful. Such not the case. When scratch pattern for shaft bearings deemed necessary, one any desired Profilometer read- ing easily secured proper trol, and use the correct grain size abrasive. Complete removal waviness also easily accomplished the rigid, master shaped bonded abrasive used Superfinish. Induction Hardened Parts for Desert Warfare Army Ordnance recognized publicly the part induction heat treatment has played the manufacture tanks, because the resistance wear inductively hardened 26-in. bevel gear shafts and 30-in. drive sprockéts used English tanks the Eighth Army North Africa. These two large components the drive mechanism are, accord- ing reports, lasting three times longer. Further, they have been in- ductively hardened this country per cent under former costs. This was revealed Miller, chief engineer the Buckeye Trac- tion Ditcher Findlay, Ohio, which using regular Tocco process induction equipment developed for this ordnance job Crank- shaft Co., Cleveland. the use the induction process harden these pieces, distortion and the subsequent straightening opera- tions once required the gear shafts are eliminated. After hardening, only finish grind necessary. This removed growing out the extra handling formerly required. has meant that skilled workers could released other jobs. said that heat treat- ing costs dropped per cent, while reports reveal that the life these pieces three times greater. Example how large parts are now being treated these small hardening machines, the gear shaft has overall length in. and SAE 4820 carburized steel. Three areas the shaft are hardened in- 60—THE IRON AGE, July 15, 1943 ductively—the spline section and two needle bearing races. The spline area extends for in. along the shaft with diameter 115/16 in. Hardening continuous. special hydraulic fixture 40-kw. one-station machine, holds the shaft perpendicular above the induc- tor. The piece passes downward for heating and water quenching “C” obtained. Located either side the spline are two roller bearing races, each inductively separate operations. The depth hardness in. Uniformity marks all treated areas and heat-treat re- jects are negligible. addition the 30-in. transmis- sion sprocket which 1045 steel plate, 27%-in. sprocket also Tocco hardened. SAE 104 drop-forged steel in. thick. The larger sprocket in. thick. Each sprocket contains teeth. positioning 26-in. bevel gear shaft the inductor hardened. This gear shaft part tank transmission mechanism. The spline section, in. Jength, hardened sec. 59-61 the left hand corner are drive sprockets also Tocco treated. | from quanti tools essent The used claim have usable The hr. acid deg. acid slight bide slight brazi remo parts and they clean they ent nace titan acqu tung light can rate the amo take the are and veri ham mat reci ‘ | UNGSTEN one the stra- tegic metals, being produced chiefly from from China, and since tremendous quantities are used for cutting tools and other purposes, very essential that all scrap reclaimed. The process described now being used the Aircraft Engine Division Ford Motor Co. recover re- claim tungsten carbide tool tips that have chipped badly non- usable regrinding. The first step the removal the carbide tip from its steel shank. This accomplished keeping the tool for hr. concentrated bath nitric acid temperature about 150 deg. then removed from the acid bath and washed water, and slight tap then will loosen the car- bide chip. The chips usually are slightly contaminated with iron and brazing material, which are readily removed bath composed equal parts nitric acid, hydrochloric acid and water. Next the chips are bath ammonium hydroxide, after which they are tumbled ball mill them. Titanium and tantalum carbide chips must removed since they are not recoverable the pres- ent method resintering. This accomplished passing the chips through hydrogen-atmosphere fur- nace 1650 deg. F., which the titanium and tantalum carbide chips acquire brownish color, while the tungsten carbide tips retain their light gray color, that the former can readily recognized and sepa- rated out. While still the hydrogen atmosphere, the chips are pushed into the temperature allowed drop about 1000 deg. This limits the amount oxidization that might take place upon withdrawal. After visual grading and separation the chips are passed through modi- fied mercury flotation process order assure final separation the titanium and tantalum grades which are lighter than the tungsten grades and float the mercury. The carbide chips are hammer, which operates approxi- mately 250 strokes per min. hard- ened steel mortar and pestle are used this hammer. reciprocates through packing gland that prevents the escape carbide Ford Reclaims Tungsten Carbide Chips ODIFICATION Bradley hammer for pulverizing the car- bide chips steel mortar and pestle. The packing gland re- quired keep the dust from escaping. dust. (See illustration). The carbide fed into the mortar through iron standpipe, and the pulverized product drawn off the air current centrifugal exhauster, through cloth filter. The dust settles trap from which recovered. The pulverized tungsten carbide now put into carbon boats and placed 1500 deg. for min. reduce any oxides that may present. The powder then put through 400- mesh sieve, and the portion that passes through ready for further use. The part that does not pass through fed back into the power hammer and repulverized. consisting cent solution paraffin wax trichlorethylene added the powdered carbide, and this mixture dried oven 140 deg. for approximately hr. now ready for forming into shapes. From this point on, the process similar that used the manufacture new carbide tips from powder. The mixture com- HAMMER COLLECTING TRAPS pressed suitable steel molds under gives somewhat higher density, also tends cause laminations, and for that reason necessary use the lower pressure range most cases. The tungsten carbide thus com- pressed placed carbon boats and covered with aluminum oxide. After careful preheating drive off the wax, “soft-sintered” 1600 deg. for min. After this soft-sin- tering process the carbide “chalk- like” and may cut any shape with saw, file grinding wheel. The stock cut per cent over- size all directions, allow for the shrinkage which occurs the final sintering This final sin- tering done carbon boats, which the carbide shapes are covered with flake graphite through hydrogen-atmosphere fur- nace 2760 deg. for min. The tungsten carbide shapes are now ready for brazing tool shanks, into die holders, etc. Infra-Red Used Skin Dry Sand Molds PORTABLE infra-red skin drier which will dry sand molds quickly, uniformly nomically has been developed Infra-Red Engineers, Inc., 812 Huron Road, Cleveland. These units will handle molds any volume in. long, in. wide and in. high. Time required skin dry mold said about min.