The Iron Age 1940-09-12: Vol 146 Iss 11

SEPTEMBER 12,1940 VOL. 146 NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager C.E.WRIGHT J.A. ROWAN T. W. LIPPERT Managing Editor News Editor Technical Editor Machine Associate Associate Editor Editor Editor Art Editor Editor Emeritus Washington Editors L.W MOFFETT JAMES ELLIS Resident District Editors CAMPBELL ROBERT BINGHAM Pittsburgh Chicago Cleveland Detroit Editorial Correspondents DEARING ROBERT McINTOSH Buffalo Cincinnati FRAZAR CHARLES POST Boston San Francisco HUGH SHARP JOHN Milwaukee Birmingham SANDERSON ROY EDMONDS Toronto, Ontario St. Louis LEROY ALLISON Editorial Preparedness Technical Articles Tool Crib Dolling the Iron Fatigue Cutting Steel With Carbides. Semi-Permanent Molds Quenching and Quenching Media................... Grinding and Sanding Castings Without Dust........ New Welding Equipment Feature Reports the Assembly Line Washington News News and Market Reports Personals Metal Working Activity...... 101 Comparison Prices 102 Summary the Week.. 103 The Industrial Pace 104 District Market 106 Fatigue Cracks Products Advertised Index Copyright, 1940, Chilton Company DIX, Manager Reader Service Advertising Staff Emerson Findley Robert Blair Herman, Chilton Bldg., Philadelphia Hottenstein, 1012 Otis Bldg., Chicago Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, East 42nd New York Robinson Don Harner, 1595 Pacific Avenu Beach, Cal. Long Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price: United States and Possessions, Mexico, Cuba, $6.00; Canada, $8.50; Foreign, $12.00 year. Single copy, Machine Tool Non-Ferrous Metal Market Scrap Market and Construction Iron and Steel Pig Iron Warehouse Prices Sales Possibilities Owned and Published CHILTON COMPANY (Incorporated) Publication Office Chestnut and 5éth Sts., Philadelphia, Pa. Editorial and Executive Offices 100 East 42nd St., New York, Y., U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, Vice-President GEORGE GRIFFITHS, Vice-President EVERIT TERHUNE, Vice-President VAN DEVENTER, Vice-President BAUR, Vice-President WILLIAM BARBER, Treasurer BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY V. DUFFY CHARLES J. HEALE 110 112 114 121 122 Over the wires ten great Ryerson plants comes ever- growing demands for steel meet the strict requirements America's defense program. Industry knows, from years experience, that Ryerson strong first line support when good steel needed quickly. It's matter seconds from your plant the Ryerson order department. matter seconds for you tell Ryerson just what you want. And matter seconds for your order its way the Ryerson lightning- fast order handling system that gets steel shipped the day it's ordered. Bars, plates, sheets, shapes, beams stainless steels and alloys 10,000 differ- ent kinds, sizes, and all stock for 26—THE IRON AGE, September 12, 1940 instant service! And all Ryerson Certified quality, your positive insurance against shop losses due faulty steel. Ryerson Certified Steels are closely controlled chem- ical content, accuracy, and finish, without the slightest increase cost you. you don't know Ryerson you're work- ing defense orders other RUSH business, and you need steel, touch with Ryerson today!" will our full share, with little extra besides, back American industry with the steel needs and must have promptly, efficiently and the uniform quality necessary high speed mass production. The Ryerson Stock List—the Guide America's Largest Steel stocks—will sent request. Joseph Ryerson Son, Inc., Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleve- land, Buffalo, Boston, Philadelphia, Jersey City. | | Vy ESTABLISHED 1855 Preparedness and Prices still uncounted millions looming for our defense program, our National overhead bound rise sharply. Already high be- cause staggering National debt. And this overhead can liqui- dated only one two ways—increased taxation inflation which the forerunner national bankruptcy. Inflation can avoided only one way; keeping prices down. Every business man will accept this statement truthful generality but some will say “our case exception.” Friends, the necessity avoiding price rises during the coming months, there are exceptions. matter self preservation for you avoid price rises and discourage them elsewhere. will tell you why. Your normal business has been making and selling peace time prod- ucts. And that what you expect after this present abnormal emergency. You have spent thousands upon thousands dollars educating your customers buy and use these peace time products. Over period years this represents large investment, whether you make and sell cigarettes sewing machines, automobiles baby carriages. some- thing happens that will get your customers accustomed going without your products using them less freely, this investment has been ma- terially damaged. These customers yours have certain incomes spend, whether they individuals corporations. The more that they are required spend, the way taxes, for non-productive implements war, the less they will have spend for peace time products. They will begin learn without. This year, for example, five billions dollars are being taken away from normal purchasing power and this only the beginning. Five billion dollars year means lot doing without. Think that over. you then add this merchandising obstacle another hurdle the way price rises, you are cutting off your market both ends. There are exceptions. Any man who raises his prices, whether pins peanuts push carts, helping cut down your market even though his business remote from yours. Self preservation for your business means refraining from price rises your own back yard and discouraging them other people’s. | SEPTEMBER 12, 1940 REJECTIO CUT difficult draw! Heart the newest Automatic Gear Shift thisvacuum cylinder, diameter cup, drawn toa depth. And the call for 8000 parts per day. Ordinary sheets caused tremen- dously high breakage rates. acceptable rejection figure was fixed three per cent. When Inland Sheets were used, the breakage was brought down average less than one per cent! That kind performance nothing new with Inland Sheets. That’s why manufacturers come depend Inland Sheets reduce production costs. They the job better. They cut waste the bone. They help you keep output right schedule. Inland metallurgists are available work out similar economies for you. Write today. SHEETS STRIP TINPLATE BARS PLATES FLOOR PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS 28—THE IRON AGE, September 1940 Production cost went down when Inland Sheets were used form this vacuum cylinder. First draw. Blank and cup. Trim flash. Second draw. Draw inches. Embossed, punched and drilled. 4 q ~ GAYLORD THOMPSON Madison, Wis. can shop obtain maximum benefit from the use carbide tools? The proper place initiate many changes the tool crib; for there the management sets its own house order and establishes frame mind that carries through the shop. The result minimization waste, faster and more satisfactory performance, and lowest possible costs. This article describes how these objectives may approached through proper tool crib control. ARBIDE tools, when sort curiosity mechanics. Characteristic human nature, new article object usually receives careful handling. But, when daily routine demands constant use the article object, there dency toward laxity its proper care. The old saying, “familiarity breeds contempt” very accurately describes the morale the machine operators shop that flooded with carbide tools. The respect the mechanics for the value carbide tools cannot ex- pected when the management shows its own indifference the tool costs and control. Machine tool operators must made feel that carbide tools are hard get, that carbide tools repre- sent many five, ten, and twenty- dollar bills circulation the shop, and are entitled the same amount business skill and trust obtain from the tool crib obtain cash from bank. sloppy When mechanic comes the tool- crib window for carbide tool, what does see? Does the attendant keep the tools some dilapidated group bench drawers trays where they are piled like junk? are the tools kept neat appropriate cabinet with properly labeled draws compart- ments? The first condition naturally encourages carelessness ence, while the latter creates im- pression value—something solicits trust from all concerned. The proper psychological effect upon the mechanic the tool crib window important dividend paying factor. Make mistake about that! the tools are handled disorderly man- ner the tool crib, all the missionary work and instructions the mechanics the shop the proper use carbide tools, their care value, will not convincing. The management must first put its own house order. There are any number styles and types cabinets that would prove very appropriate for the storing filing away carbide tools. The drawing, Fig. shows style cabi- net that has proved very con- venient. has capacity about 4000 assorted tools. About the capacity this cabinet would serve plant employing about 1000 men the machine-tool industry and leave room for per cent expan- sion. The cabinet about in. high. has shelves, each shelf contain- ing seven drawers all in. deep in. long. The first drawer in. wide. The next two are 434 in. wide each, the next three are in. wide each and the last drawer in. wide. The drawers are made gage steel spot welded. There need for airtight seams. The shelves consist two studs, each in. long over which placed in. pipe spacers in. long and which attached angle iron frame end pieces uprights. sheet No. gage steel fitted across each shelf serve floor,” provide smooth sliding surface for the drawers. The numbers the top the cabi- net serve merely identify each vertical row drawers. The numbers the left are the style numbers the tools that are kept the horizontal row drawers the right. (The style numbers and their application were covered article THE Iron May 9.) Note that the first horizontal row reserved only for style No. tools, the second row for No. tools and the third row for No. tools and on. Note also that the first drawer reserved for tool sizes and that this same reservation applies all the respective tools these styles and sizes shown the vertical column headed No. For example: No. refers tool having shank size in. long; No. refers tool having shank size 5/16x5/16x in. long; No. in.; No. in. long. style No. tool measuring would then identified No. 101 tool. This same method numbering applies the other sizes. The first drawer then, the first row, and THE IRON AGE, September 1940—29 Jat y 7 ° ° ° cabinet which very useful for the filing carbide tools. Scale: 30—THE IRON AGE, September 12, 1940 for each the next series drawers down until style No. reached, there are that many styles. The drawers the right the first drawer each horizontal row contains tools similar styles except that Soft jaws shank are larger progressively with each drawer. tool style No. in., will assumed that this size shank known No. 13. This tool would, therefore, identified No. 1301 and would found the top drawer vertical column No. Note that each vertical row reserved for its respective sizes tools while layout shown Fig. The layout folded that one side shows the TC- sketch and the other side shows the worded description. | This tool could because cut feet the reaming operation MATERIAL CHECKED IG. 2—First copy tool 339 = the horizontal rows are reserved for each style tool. This makes very convenient filing method for carbide tools. Tools Are Controlled Now that arrangement has been made for proper storage filing carbide tools the tool crib and the tools are place for distribution, the next step the actual distribution the tools the shop. Certainly there should inclination hand the tools out promiscuously merely for the asking, exchange for tool check. “Ya gotta control them identified 101-401 would contain all four the above-mentioned sizes PART tools. The next drawer underneath would contain the same sizes tools but different style. This continues DWG. NO. 97324 For control necessary have man that knows the machines the shop—one who has had good deal experience machine tool set-up and THE IRON AGE, September - understands speeds and feeds and ca- pacities machines and can talk the machine shop language with any mechanic. man like this avail- able, then becomes necessary make one. Pick out man that has the fun- damental qualities and then turn him loose one department section the shop. Let him accumulate data machine and speeds and tool- ing facilities and acquire knowledge the personal habits the workers and the general routine mechanical tolerances and machining methods. Let him make number lay- outs carbide tool set-ups until such time his knowledge the mechan- ical equipment will permit him make layouts from blueprints the office. The form and style layout can designed suit the purpose each individual plant. One style layout shown Fig. wherein the for coupling, part No. A-7434, BELOW 4—Template made from 20- gage sheet copper. The brass screw for use handle. Full size. there necessity for maintaining relativity dimensions. All that desired the sketch the respective tools that constitute the set-up that particular operation and the number that identifies each individual tool. illustrating and numbering MATERIAL NAME PART Front tool post OPERATIONS description the sub-operations and the listing the speeds and feeds and cut-feet and the tools used that par- tool number shown the illustra tion the tool and also tied with PART NO. OPER. NO. DWG. NO. MACH. CUT T.POST TUR.| FEET PART NO. Brass screw template 32—THE IRON AGE, September 1940 ABOVE IG. 5—This shows how the tem- plate forms the outline the tools used the layout. the description the sub-operation. This layout made triplicate. The original kept the office file, the tool crib for its files and the third copy sent the time-study department for its use make rate changes be- cause the installation carbide tools. The envelope containing the dupli- cate copy for the tool crib shown Fig. The layout folded that one side shows the sketch the tools used and the other side shows the worded description the sub-opera- tions and their respective speeds and NO. | | — | | | | . T + + _ fy 4 + + + = ©) 9 ° ° ° 4 feeds. The layout shown ficti- tious and not example actual operation. merely for illustration. Attention called the apparent in- consistencies the cut-feet rates shown the extreme right column the layout Fig. This due the DATE MATERIAL NAME PART Chuck Rear tool Post Front tool post OPERATIONS CHECKED speed for operating carbide tools some machine tools. Usually there gap between speed changes that makes imperative that the next best speed 150 r.p.m. which makes cut-feet 200 and the next speed change would PART NO. OPER.NO. DWG. FEED CUT PART NO. 6—This shows how the tools appear when the finishing lines are filled in. fact that where simultaneous opera tions are performed, the operation having the largest diameter the con- trolling factor the speed that par- ticular group operations. For ex- ample: Operation No. performed with one independent tool, namely TC- 805-1, and consequently can take the full 325 cut-feet capacity. Operation three operations designated and which work simultaneously. Operation has the largest diameter, therefore all other operations are con- trolled that operation The same applies operation No. where the same condition experi- All simultaneous operations are shown the alphabetical designation listed after each operation number. not always possible establish the correct and most efficient cut-feet FOR PC. NO. OPER. NO. 250 r.p.m. and would produce excessive cut-feet, then natural that the 150 r.p.m. speed would chosen. Considerable difficulty has been ex- perienced because the limitations machine speeds acquiring the full efficiency carbide tools. Time study departments that practice the setting rates standard cut-feet speeds are often error because the limitations speed changes machines not always permit the equaling bettering the cut-feet data used establish- ing piece rates. Referring again the matter layouts, might well mention how the layout man can adopt some kinks help his own efficiency. As- suming that provided with drafting table, the first thing required would some material covering that would hard and would withstand the imprint the pencil and produce clear cut carbon copies. piece plate glass 24x36 in. makes excellent foundation upon which draw the layouts triplicate. The glass not only cleaner but also has the added advantage transparency that layout data all kinds can conveniently placed for quick reference. The layout forms are held place the glass adhesive tape. well wind several wrap- pings the tape around the straight edge hold off the paper that the moving the straight edge does not smear the carbon copies the layouts. Glue small piece wood each triangle irregular curve that used. This will facilitate move- NAME PART Coupling Turning tool Description of Tools in Tray degree chamfer tool Boring Reamer other tools the machine 7—This card lists the tools used for the coupling. inserted the envelope shown Fig. THE IRON AGE, September 1940—33 \\ 7 | tity Tool Kept Drawing 06-3 Straight turning tool 02-2 04-1] D-276 ment the parts without smudging the copies. The layout man will find that tools and tool holders used some ma- chines, especially turret lathes, will re- peat themselves with rather consistent regularity. evident therefore that some form template will produce quicker results, and will much more convenient than the use the straight edge and combination angles and protractors. Fig. shows template made from No. gage sheet copper. brass screw soldered the center came aware the new carbide tool set-up. Then too, free hand sketching did not prove any too legibile when blueprinted. drawing table re- sorted to, then more economical and prompt make carbon copies which entail additional cost other than the material used. When drawing layout has been completed the layout man, writes long hand the operations and other data that should appear the copy matter the bottom portion the layout form. This then given the typist who types the operations TOOL REQUISITION Date Fic. 8—Tool requisition form for presentation the tool crib attendant. act handle lift the template from the drawing and shift into various positions. This, too, avoid smudging carbon copies. Fig. shows how the template forms the outline the tools used the layout. The numbers the template corre- spond the numbers the tools out- lined, just matter convenient reference this illustration. Fig. shows how the tools appear when fin- ishing lines are filled in. This tem- plate has proved great time saver and eliminates the tedious annoy- ance manipulating triangles and protractors. Some may question the feasibility making layouts triplicate, offer- ing perhaps the alternative blue- prints. This was tried. Free hand drawings were made the layouts and then these drawings were sent the blueprinting department. There was too much delay the receipt the blueprints. Jobs would finished before the time-study department be- 34—THE IRON AGE, September 1940 and tool information shown. This done with the three copies the layouts still intact. addition this, card typed listing the tools used, shown the layout. This card the envelope containing the layout that goes the tool crib. When the tool crib attendant re- ceives the layout, envelope, etc., re- moves the card and files according the part number standard 4x6 in. card file. The envelope containing the layout then filed another ap- propriate file according part num- ber. These records remain their respective files until called for the shop, explained later. Time Study Procedure When the time study department re- ceives the third copy the new car- bide tooling layout shown checks the rates and makes notations the operation cards that the respec- tive operation has been provided with carbide tools. This notation may con- sist star letter affixed the operation affected and denotes the shop that the operation card can presented the tool crib for carbide tools assigned that operation. order prevent the possibility some mechanics acquiring carbide tools surreptitiously, the card shown double check. When the tool crib at- tendant receives the tool requisition form, properly filled out the foreman, gives the layout the worker the window and files the card No. under the number the machine which the tools are used. This arrangement better than personal charges through the medium checks, especially where several shifts workers are another worker presented requisition for the same layout tools, the tool crib attendant would know the presence the card No. under the machine number that one set tools was out. If, however, the worker perform the same operation simul- taneously with another worker, the tool crib attendant can issue dupli- cate set with clear knowledge that the tools are not being requisitioned without authority. ticket attached the card No. until has served its purpose and then can filed for future reference destroyed. The use the ticket shown Fig. compels the attention and cooperation the foreman. conclusion, any tools that are broken mechanic cannot re- turned him the tool crib ex- change for another without written note from the foreman explaining how the tool was damaged destroyed. The percentage damage posted the note the man charge the carbide tools after which turned over clerk for calculations dol- lars and cents loss. This amount then listed under the name the man who caused the damage. This only memo charge order keep rec- ord the tools damaged each worker. Where the charges are con- sistently high, steps can taken correct the trouble. Here where foremen can give good service the They should keep their ears open for tell-tale dull carbide tools and their eyes open the burnish pol- ish that likely denote the same condition. Workers, naturally, hate stop production piece-rated jobs long the tool will “push” the mate- rial off. The foreman can stop costs broken carbide tools considerably insisting tool changes. Tools Desired layout Rec'd Check No. 3/7 Other Tools Being Returned per layout Were Used Part No. Oper. No. LZ Foreman Dolling-Up the Iron Horse ECENTLY the Reading Railroad stainless steel passenger train from the Edward Budd Mfg. Co. and was faced with the problem dolling two conventional 4-6-2 Pa- cific type coal burning locomotives and their tenders conform with the ap- pearance the lightweight cars. How the work was done the Reading shops pictured the right. The 18-8 stainless steel sheets, furnished the Budd company, were fastened framework angle and bar iron with self-tapping screws. The frame- work, fabricated electric weld- ing, was bolted and some instances welded the locomotive superstruc- ture and the tender. Without this method arc welding, the fabrication the supporting framework would have required considerably more cumbersome structure and the cost would have been greater. Longer ser- vice life expected result from the rigidity structure effected. The framework for the rear canopy the tender entirely electric arc welded light weight steel I-beams and angles. has four hooks fitting into four receptacles mounted the rear the tender permit the re- moval the canopy will. This canopy makes possible attach the tender either end the five-car train without turning the train around, the end cars this train are de- signed run either direction. RIGHT RONT end the engine showing pilot and front hood arc welded frame- work place. Photos courtesy the James Lincoln Welding Foundation. BELOW IRST stepin sheathing the ten- der with stainless steel sheets was arc weld bar steel the side the loco- motive tender form the framework shown. This view also shows the top sheet framework welded THE IRON AGE, September 22, = the effects stress raisers the fatigue strength metals and alloys are particularly important these days with many service parts highly stressed. the first part this correlated abstract last week the author presented data the fatigue strength notched specimens, and the effect corrosion fatigue strength. Herein, conclusion, information given chafing fatigue, and the effect surface working the fatigue strength the presence stress raisers. HAFING FATIGUE: tween the surfaces two metals that are pressed together with certain force usually asso- ciated with wear, particularly the softer metal. Small particles are re- moved from the metal surface and transformed oxide the sliding ac- tion takes place common atmos- similar process occurs be- tween two closely fitting machine components, when subjected vibra- tions; and this “fretting” has long been source considerable trouble. The fitting surfaces become pitted irregular patches and usually some 36—THE IRON AGE, September 1940 dark powder This pro- cess differs from ordinary wear the fact that occurs contact surfaces which are supposed fixed re- lation each other, such fits and shrink fits. has been found, however, that any such system rela- tive movements between the surfaces occur the vibrations exceed certain limit, while below this limit all strains this compound system are purely Similar relative movements have also been observed rolling friction. The tangential force which has transferred, for example, the wheels the rails locomotive, GEORGE SACHS Case School Applied Science, Cleveland strains the particles the surfaces contact, first elastically, ally and finally causing The force required break off these par- ticles wear the metal the sliding friction. While the effects different notch shapes and corrosion agents the fatigue strength have been extensively studied, only few investigations have been carried out the present time strength aluminum and magnesium considerably reduced any chafing action, such present press fits, hubs jaws (See Fig. 7). alloys,” is has been furthermore shown that rotating bending tests with cylindrical specimens yield results corresponding those obtained with other types chafing. offers therefore, simple procedure for determining chafing fatigue strength values. Besides, chafing appears exert similar effect particularly sharp notch and thus yields desired IG. break and chafing magnesium alloy aircraft pro- peller. ‘ a | ; ! : Annealed Wrought Cold worked Heat treated castalloys (Basis 100 million cycles) Cast (heat treated) Annealed Heat treated worked Regular fatigue strength, Ib. per sq.in. Basis 500 million cycles) limiting condition (See last week.) the relation between notch fatigue strength and chafing fatigue strength should more definitely es- tablished, such fatigue tests cylin- drical specimens may also replace the fatigue testing notched specimens which are difficult Thus, again, benefit derived from alloying, heat treating strong chafing action has been found, the contrary, that the chafing strength annealed metal may considerably higher than that the same metal the cold worked the heat treated condition, illustrated for some aluminum alloys. Cast alloys are usually wrought alloys regarding the chafing Aardened RIGHT IG. Stress- cycle diagrams normalized cast and wrought mild steels reg- ular and chaf- ing fatigue. Broke between jaws Cycles, millions 100 1000 LEFT 8—The re- lation between the chafing fa- tigue strength and the regular fatigue strength for various alu- minum alloys. fatigue strength (Fig. appears that the loss fatigue strength due chafing again increases with the tensile strength (See Fig. regular fa- tigue strength (See Fig. the particular alloy within certain alloy However, the level which approached the high strength alloys different for the various conditions. the group wrought aluminum alloys (See Fig. the highest chafing fatigue strength values are obtained with annealed, and still higher values with cast, heat treated alloys, while cold worked and wrought heat treated alloys have chafing fatigue strength values that are about per cent lower. Regular specimen > Stress, Ib. per sq. in. Chafing broke outside grip LEFT Rela- tion regular chafing fa- tigue strength for annealed and cold worked dura- lumin. ——chafing -regular ° ° ° Forged stee/ 100 1000 Cycles, millions with regular fatigue strength below certain limit (de- pending upon the condition) are little affected chafing (See Fig. 8). Their regular and strengths are almost identical; and cylindrical specimens, therefore, gen- erally break outside the section which subjected the stress raising action. limits, however, are rather low, and such behavior has therefore, only been observed the pure metals and the case low strength alloys. The chafing action, however, re- duced any alloy zero, the stress THE IRON AGE, September 4 “0 | 0.1 w fon) nN La) Unit pressure grip, 1000 10.0 LEFT IG. grip pressure the fatigue strength cylindrical, canti- lever type specimens. (Thum and Wunderlich). etc. the gripped section (See 11). Surface films metallic nonmetallic nature have effect the chafing fatigue strength, while they reduce the wear mation the oxidized powder the area contact. However, intermediate layer vielding has been found produce 30,000 25,000 15,000 With thick collars 5000 With thin rods corrosion Chromium Cycles, millions sufficiently high (See Figs. and 10). The branches the stress-cycle diagrams high stresses are usually identical for the regular and the chaf- ing fatigue; they separate certain stress, depending upon the nature the metal and its condition, and gradu- ally spread apart towards low stresses. similar behavior has ex- pected for the notch and the corrosion fatigue curves, both not prac- tically affect the tensile strength (rep- resenting the stress for number cycles 1). The infrequent results published for low strength alloys also indicate that their fatigue strength may not reduced either notches corrosion, previously discussed. The extent the reduction chaf- ing increases with the which exerted the press fit, bearing, 38—THE IRON AGE, September 1940 ABOVE effect various stress raisers the chafing and cor- rosion types and the ef- fect surface rolling the fatigue charac- teristics magne- sium propeller alloy. RIGHT 13—Device for curface roll- ing. with collars anal fresh-water increase the chafing fatigue strength (See 14). Effect Surface Working The damaging etfect stress raisers can reduced certain mechanical surface treatments. has viously observed that the decrease fatigue strength will vary appreciably for threaded parts, depending upon the method The reason for these variations has not yet been explained, but according some periments the deformations and resid ual stresses produced cutting™ materially with the machining condi tions. layers considerably improves the fatigue strength cases where ence notches, grooves, surface defects, corro sion and attack. screw generally has much strength rolled vantage applies for thread machined same Over- size and finished roll- However, | } | + + Q / Vv ut | Surface rolling also will consider- ably improve the chafing Fatique strength polished test pieces LEFT limit’. Thus, surface rolled and magnesium are used com- mercially certain extent. effects sur- while sandblasting essentially face rolling with grinding process. has also been different pres- claimed that the former processes have fabric layer The factor factors associated the localized surface deformations in. dia properties not yet quite ap- rods. provement the properties the sur- Roll pressure, surface layers (See Fig. 15) which render the metal more resistant the quent heat treatment eliminates these +5000 improvements from rolling. stresses similar beneficial effect can ob- locally deforming the critical surface region subjected fatigue some mechanical treatment. Such surtace working, however, does not materially increase the fatigue strength polished cylindrical least not degree that obtained for the surface working notched parts parts subjected corrosion chafing fatigue. RIGHT has been found, for example, that the fatigue resistance parts with per sq. appreciably increased plastically deforming the metal the vicinity these grooves with special tools. -20,000 IG. stresses oped mag- nesium alloy rod surface rolling. ? The same beneficial improvement obtained cylindrical parts which are and corrosion attack still water and salt water (See Fig. 12). treating the surface with one sev- eral rolls, which produce close spi- ral indentation, the corrosion fatigue strength can increased approxi- mately the value the polished parts commercial prac- tice can accomplished large -10,000 lathe equipped with special rolling +5000 stresses -5000 device. Such tool can made steady rest with hydraulic regu- lation the pressure (See Fig. 13). The rolling such the shape the rolls, the pressure and the rate advance have ad- (See Distance from center, inches THE IRON AGE, September 1940—39 Distance from center, inches } ity effects stress raisers The residual stresses steel springs ging” also generally improve their low fatigue strength”. However, the ef- fect residual stresses introduced general cold work quenching has been found rather Bibliography Fink, Trans. Am. Soc. Steel Treat., Vol. (1930), pp. 1026-1034. Gough, Proc. Inst. Mech. Eng., Vol. (1939), pp. 223-349: Metal Progress, Sachs, Zeit. Angew. Math. Vol. (1924), pp. Maschinenbau, Vol. (1923-24), pp. 168-175. Sachs and Stefan, Am. Soc. for Metals, Convention 1940. Matthaes, Luftfahrforschung, Vol. (1935), pp. 176-179. Schraivogel, und Eisen, Vol. pp. 1189-1193. Sachs, Metallkunde, Vol. Berlin 1934, 207. Ruttmann, Maschinenbau, Vol. (1936), pp. 557-560. (1931), pp. 714-717. Thum and Wie- gand, Ver. Deut. Ing., Vol. (1933), 1061. Horger, Applied Mechanics, Vol. pp. Doering, Metallwirtschaft, Vol. (1930), pp. 781-786; Vol. pp. 435. Meyer, Wiecker and Koch Mitt. Woehler Inst., No. 18-20 1934). Thum and Ochs, Ver Deut. Weibel, Trans. Am. Soc. Mech. Vol. (1935), pp. 501-516. Frye and Kehl, Trans. Am. Soc. for Metals, Vol, (1938), pp. 192-218. Eisen, Vol. (1933), pp. 1330-1332. Seeger, Ver Deut. Ing., Vol. 698. and Steel Inst., Vol. 133 (1936), pp. 427- 453. Rockefeller, Wire and Wire Prod- ucts, Vol. pp. 373-377, Cutting Steel with Carbides Older Machines adoption cemented carbide tools for machining steels increase productive capacity machine tools, considerable parently still exists the usability older types machine tools. There reason why older machines good condition—such turret lathes and boring mills—cannot adapted the use carbide tooling provided the machine able run fast enough—and smoothly enough that faster speed. with carbides the main objective kept mind that cutting speed should high enough forming “built-up” edge. This means average cutting speed the neighborhood 200 ft. per (The lower the carbon usually, the higher the speed. check the adaptability any piece available equipment use carbides, the following general considerations suffice REQUIREMENTS: takes speeds required—to remove metal faster rate. takes more power, also, cut steel than non-ferrous metals cast iron. Therefore, the machine horsepower must checked. Horsepower requirements may readily calculated the following Hp. per tool Depth cut inches Feed inches Sur- face speed feet per min Pow- constant. The power constant varies from 40—THE IRON AGE, September 1940 JAMES LONGWELL Chief Engineer, Carboloy Co., Inc. 10, depending the steel cut, Power SAE Clas- Power sification 1010-1025 6 3115-3130 S 1030-1095 3135-3450 1112-1120 4130-4820 5120-52100 T1330-T1350 9 6115-6195 10 2015-2520 Cast Steel 2330-2350 9 The power required operate the machine idle must added, course, obtain motor horsepower. This re- quirement usually figured per cent the horsepower required for cutting. \Vith the power requirements for ma- chine speed take full advantage carbide tooling determined, neces- sary check belts, clutches, for ability transmit the horsepower the spindle. Clutch fingers should adjusted prevent slipping and stall- ing. Where machine equipped with flat belt, sometimes desirable stock removal high cemented carbides makes advisable use anti-friction tail stock cen- ter. SPINDLES: Spindles checked for adequate the higher speeds which they will operate. Posts AND Rocker tool plates should eliminated and shims should also provided main- tain the tool proper cutting height. available handle the ume chip production. Sheet metal chips are apt clog. Chip breakers can used where size openings demand production small chips. with cemented carbide tools, machines should checked for excessive clear- which would cause chatter the higher cutting speeds. bear- ings, slides, and ways should cor- rected. Where found impossible impractical tighten the machine tion, certain amount chatter can corrected the incorporation negative rakes the tools. With these simple considerations, there reason why any machine cannot used effectively for cutting steels with carbides, particularly where single point cutting tool used. the machine capable handling the horsepower required the higher speed and can tightened and chatter, trouble should en- ductivity per machine with cemented carbide tooling. | } | Semi-Permanent Molds NMALL foundries can materially designed castings such bushes, large Washers and nuts, handwheels, small propellers, the use semi-permanent molds, accord ing recent article Hudson Trade Journal. The best results are obtained on the more simple bronze, gunmetal brass castings, free trom intricate cores, machine molding facilities and short skilled labor derive particular advantage from this method production, order obtain maximum cast- ing solidity and reduce the need feeding risers much possible, the mold should have high thermal con- ductivity and this can obtained the use silicon-carbide graph- ite base material. order obtain the highest yield castings the mold important that the method running should removed from the good taper should given parallel faces any appreciable depth. shows suggested method making simple mold for gun- metal disk. That part the mold forming the center hole well sprigged and given good taper. should noted that molding boxes are not required, and the semi-perma- nent mold can initially rammed quently removed. Locating pins and sockets can inserted during ram- ming up. The mold should well vented wire right through the casting face and air vents should also precaution. shows the method making mold for motor boat this instance the casting poured horizontally through large runner- head the center boss, and facili- tate removal the top part oil- sand insert fitted prior each pour that the necessary clearance can obtained after casting. tively weak red-sand core employed sufficiently friable enable the runner-head drawn through the top part. important note that the head should only filled with metal within in. the top. permanent molds per cent dry silicon-carbide sand (fire sand) and increase production suitably ABOVE Fig. mold for gun- metal disk. RIGHT Fig. 2—Method making mold for motor boat pro- peller. we per cent concentrated cate. The sodium silicate diluted with equal part cold water be- fore adding the silicon-carbide and mixed rapidly the consistency green sand. the mixture appears too dry, temper accordingly. Use immediately—if drying out takes place, the final strength the mold markedly reduced. This mixture possesses enough green bond strength for most the molding operations entailed. Greater plasticity can ob- cent bentonite, but the presence clay decreases the thermal conductiv- ity and the strength after and should therefore avoided far possible. Should the addition clay found necessary, the percentage sodium silicate will probably have increased order get ade- quate dried strength. Additional so- can also employed increase the strength clay-free material this required. Molds are rammed the nor- mal manner. instances, will found most make the bottom-half first, and then dry it. The pattern and the top part rammed up. The whole assembly should then turned over and leaving the other half ready for drying. This enables the satisfacto- rily handled without requiring much green bond strength with the conse- quent production strongest structure after drying. Moreover, results obtaining two perfectly con- tiguous faces the mold joint. Be- fore drying, all molds should well through the pattern face order get maximum permeability. The VENTS FEEDER refractory wash used casting pro- duction subsequently seals any small vents the casting face. The use resisting parting powder the pattern and mold faces recommended, especially when wooden patterns are employed. Molds bonded with sodium silicate should dried slowly first, other- wise swelling and blistering are likely occur. accordingly advisable keep the oven temperature just be- low 100 deg. for the initial drying period and until most the moisture has been removed. Subsequent tem- peratures can increased the max- The surface semi-permanent molds made from silicon-carbide ture inclined rough, and the required degree casting finish obtained treating the mold with suitable surface dressing. The con- sistency the applied wash should such fill the small cavities present. suitable wash for this pur- pose can obtained from plumbago graphite made into cream with water containing per cent sodium silicate. Care should taken when applying the first dressing may tendency for the mold sur- face soften and rub the drying temperature has not been sufficiently high. Once the first casting has been obtained from the mold, cause. The mold surface should redressed when necessary. Washes containing clay are not advised for semi-permanent mold work, although cereal oil binders can necessary replace the sodium silicate mentioned Old molds can crushed broken down for re-bonding with sodium sil- icate used for packing filling space behind the mold face. THE IRON AGE, September 12, Refractory application vitreous enamel steel may said dependent upon three major factors: The frit enamel, the kind and surface condition the steel, and the means which radiant heating applied for fusion. The first two factors are largely controlled the purchase suitable oxides and steel sheets from suppliers who are well acquainted with the rig- orous demands the enameling in- dustry. The third factor, however, function the furnace equipment used for vitreous enameling, together with the method handling mate- rials under high temperature condi- tions. generally conceded that direct ROSS Furnace Engineer, Electric Furnace Co., Salem, Ohio radiant heat required for the fusion the vitreous material used enam- el. Careful consideration the means cure the best enameling therefore required. Since large portion all enam- eled parts now being hung from overhead conveyors continuous enameling furnace equipments, the problem securing uniformity temperature throughout the conducting refractories over the entire area exposed the ware being enameled primary importance. The quality the finish, the per- fection the adhesion ground coat depends not only the means heating but large degree upon the uniformity and intensity the heat. Recent enameling tions have achieved rapid and uniform heat flow the ware being enameled the application series ver- tical refractory tubes. This ticularly true furnace equipments utilized for the enameling sheets hung double relationship where uniformity heat pieces must assured. view the refractory radiant tube enameling furnace, showing details bridge carrying ware both before and after firing. This view also shows the method using cross arms for handling small pieces, well hook arrangement for handling larger pieces ware without the use cross-over arms. 42—THE IRON AGE, September 12, 1940 | Cc ° re) > interesting installation special design has recently been placed ser- vice the new plant the Porcelain Metal Products Co., Pittsburgh, for the enameling large flat sheets and The accompanying photographs show the appearance and operation equipment. Designed for enameling miscellane- ous flat steel shapes, such large ad- vertising signs, the equipment equal- suitable for use with pressed drawn steel shapes suitable for suspen- pended burning tools. Sufficient burner capacity provided for approximately 4500 material, enamel and burn- ing tools, with operating tempera- ture approximately 1650 deg. The fusion chamber proper provides unrestricted cross-sectional loading area ft. in. wide ft. high, measured the door. The actual chamber width ft. in. with effective chamber length ft. in. measured from the inside the in. long charging throat the rear wall. locking suspended type provided with slot along the center line the fur- nace. Muffle effect within the fusion cham- her provided means firing be- neath the flat tongue-and-groove type silicon carbide working hearth, and exhausting the products combustion through vertical silicon carbide radiant tubes spaced approximately 9-in. and drawn shapes, etc. —Fuel fired furnace with recuperator type heat exchanger and silicon carbide radiant tubes used for enameling flat ware, centers along each side the cham- ber. Each tube sealed indi- vidual bottom support block containing lar section flue the top the cham- ber, which flue leads directly stack, this case, heat inter- changer the recuperator type, means which waste heat the flue gases may reclaimed for the purpose supplying heated air drying booth the plant heating system. One such flue accommodates the tubes along each the sides the furnace. The firing chamber beneath the spaced support piers, between which the various burners are fired. Tem- perature control two zones ar- ranged for modulated proportioned supply gas and air the burners accordance with the quirements each zone. The open end the furnace pro- vided with hydraulically operated split type doors arranged for horizontal opening any predetermined width like vertically opening door, the split type arrangement may opened just sufficiently allow the charging discharging material into the cham- ber with resultant economy lessened heat loss during the open in- terval. designed, the furnace equipment readily adaptable fork charging. However, series trolley convey- ors, together with movable charging bridge, have been installed this in- stance facilitate the handling material into and from the fusion chamber. Each trolley arranged for oper- ation upon monorail, which when position before the furnace chamber allows the trolley and load moved forward over stationary rail located over the slot the furnace arch. Closure the slot the arch ac- overlapping seal plates, which are self- adjustable upon vertical rods attached each trolley. These seal plates move with the trolley, and when the trolley upon the stationary monorail over the furnace chamber rest upon slide castings either side the arch slot. Closure the slot when trolley over the furnace accomplished means set plates which auto- matically slide into position over the slot the trolley withdrawn from the chamber. portion the seal plate retaining rods extends downward through the slot and into the furnace chamber, where each rod provided with hood end. These rod extensions form the suspension members for burning tools within the fusion cham- ber. The features rapid and facilitated handling materials into and from the fusion chamber are provided bridge front the furnace, which carries movable crane equipped with two monorails, either which may moved into position for charging THE IRON AGE, September 12, 1940—43 | — | } = : | a ‘ = = “ar. discharging trolley material into from the fusion chamber. The transverse travel the crane, together with the movement trolleys from the crane the furnace and vice versa, hydraulically operated under direct control the furnace operator. Additional stationary rails outer side bridge and crane provide suitable cooling stations, loading posi- tions trolley storage space. Essentially fuel fired furnace, the equipment may designed for use with natural manufactured gas with oil. The operation the equip- ment and the capacity remain the same with any these fuels. The handling system described only one many possible applications batch type means handling mate- rial suitable the fusion chamber. Similar type equipments the double- ended variety are also utilized for con- tinuous enameling, using endless chain conveyor operating upon monorail, with suitable entrance and exit vestibules place doors. noted that the use radiant heating tubes provides the full utilization the bottom and side wall areas source radiant heat. Comparative- rapid flow heat the work with- the fusion chamber provided the increased conducting and radiating surface well the highly conduc- tive silicon carbide construction the tubes and hearth, with resultant high fuel efficiency, lower combustion ber temperature and increased furnace materials life. The design and construction the silicon carbide tubes permit moval all stress strain the refractories, the tubes are carried floating relationship the arch and side walls, thus insuring freedom from breakage, warpage and the resultant leakage the products combustion into the firing chamber. 44—THE IRON AGE, September 1940 IDE view refractory radiant tube enameling furnace, showing door oper- ating mechanism, arrangement burners, controls and fans for combustion air. This view also shows the loading trolley and method hanging ware and also the recuperator mounted above for reclaiming heat from flue gases. Design provides for removal one more tubes for replacement re- pairs without disturbing any others, causing costly shut downs for reset- ting muffles. The optional use recuperators supplied with this equipment makes possible the inexpensive supplying relative large volumes p