The Iron Age 1926-12-16: Vol 118 Iss 25

THE IRON AGE New York, December 16, 1926 ESTABLISHED 1855 VOL. 118, No. 25 Fixing Costs for Gray Iron Castings Analysis of Elements in Jobbing Foundry, for Varying Production—Taking Adequate Profit Into Consideration BY H. P. PARROCK* HAT the cost of any casting may be most closely approximated when each pattern is assumed to be . the only pattern in use is the theory of this analy- sis of the cost of gray iron castings in a jobbing foundry. This presupposes sufficient duplicates to en- able the standard quota of molders and core-makers, and other necessary labor, to return a day’s work. Expense sheets have been compiled for a shop of 100 molders, on the assumption that, during different periods, each molder would produce 100, 200, 300, 400 and 500 Ib. of good castings per day; it is also assumed that one core-maker is required for every four molders in’ all instances. The figures are based on the follow- ing units of cost of labor and material, and on going rates for other items, listed in the details: Cost of Materials and Labor Materials Iron Pehl tiie aid 6:20 bre % $26.88 per gross ton delivered ht Neth nn ik ola ig bia 10.00 per net ton delivered Stone oo PLR Pea 5.00 per ton delivered Sand ....$4.00, 5.00 and 6.00 per ton delivered Ee ree 0.60 per gal. delivered Compound 40.00 per ton delivered Labor Molders Je an dale ate i 90 c. per hr. for 8 hr Core-makers ......... 90 c. per hr. for 8 hr Helpers ....... ae teiee 55 c. per hr. for 8 hr Labor ts ae eee . 50 c. per hr. for 8 hr Cupola Se os ela ee 60 c. per hr. for 8 hr OE eee Satan 62.5c. per hr. for 8 hr *Engineer, 64 Francis Street, Brookline, Mass Fig. 1— Main Divisions of c Costs in Foun- : dry Operation, with Mini- mum Profit Added to Make a Fair Selling The major divisions of cost are as follows: Metal in ladle: iron, melting loss, coke, stone, labor, power, interest, maintenance. Labor, except that for metal in ladle: molders, helpers, core-makers, common, clean- ing, inspection, shipping, stores, production, time, carpenters, pattern making, pattern storage, office, supervision, maintenance, polic- ing, trucking, administration, sales. Fixed charges: interest, depreciation, taxes, water and sewer charges, power and light, fuel, insurance. General supplies: sands, oils, compounds, molders’ tools, maintenance supplies, fuel, miscellaneous. Sales expense: traveling, advertising, but not labor. Defectives: defective castings returned by the trade. Metal in Ladle Metal in ladle is not a fixed figure for any given iron and coke market. It varies with the yield of good castings per 100 lb. poured into the mold, and also with the total melt for any melting equipment. Assuming a melting loss of 4 per cent, Table I shows the probable variations in most jobbing foundries. Figures for 50 per cent and 40 per cent yield are derived from the 60 per cent yield costs by making proportional increases. The table appears to justify the opinion that the cost of metal in the ladle increases markedly above the average figure usually assumed in practice, when the pounds per molder-day decrease and when the yield of metal poured falls off. Grouping all other items of expense, as shown in Table II we obtain the total cost, and arrive at a fac- tor or ratio applicable to direct labor to return this It will be noted fe. that the cost Price. This Molaing i ‘ iM F xi0), iin of metal in drops sharply Expense’ 10-62 ase ele shows as output per eer I i a : only a_ slight molder-day in- Hy drop as a creases ye - © 647 put gains. 1d 2.69 Nearly the en- 5. cohen . . : : , Metal in | k ; ULL ARBOR IIZILITI ieee LaLa IIIT LILES, —j — advantage ladle AGS . TRON j : 160 comes from ee 4 he ia a: other (rela- a KVV 3 V UV IV s s 1.25 Pounds per Molder-Dau tive) savings 1681 2 RR a 0 — ‘ a pl el ee eee ee ae 1682 general expense when estimating costs. Metal in ladle for a 50 per cent yield is used for convenience. WORDONELED NE vambeePELAGAEONDANDAs 1 tELOORLLOOLEHOUNUROOHNEY DONSULOOEOREEDL 1440 CAHERELBOGSOUUERREOERROREAEDSOAERT ONORLAONERODENL SU DELED HH oovueeebece oti cUL geateuet Table I—Metal in Ladle Melt, net tons, 60 per cent SE. “60 %.5 Wish ds & a a 8.3 16.7 25.0 33.3 41.6 Good castings produced, Ib.10,000 20,000 30,000 40,000 50,000 Pounds per molder-day.... 100 200 300 400 500 Iron, c. per Ib..... ere 25 1.25 1.25 1.25 1.25 Expe nse, 60 per cent yield DE: Bic nc nkkes uke ees 0. 61 0.46 0. 39 0.34 0.30 Metal in ladle, 60 per cent a Se ons, 1.86 1.71 1.64 1.59 1.556 Metal in ladle, 50 per cent BN a hia re ie ah oan 1.96 1.79 1.70 1.65 1.60 Metal in ladle, 40 per cent : evecehéesane nates 2.06 1.96 1.77 1.70 1.65 Details of the Item “Expense” in Table I Follow: Melt, tons 60 per cent basis 8.3 16.7 25.0 32.3 41.6 Good castings, Ib.......... 10,000 20,000 30,000 40,000 50,000 Pounds per molder-day.... 100 200 300 400 500 Coke, 0: me ...kssss OR 0.24 0. 21 0.19 0.17 Stone, c. per Ib.. 0.01 0.01 0.01 0.01 0.01 Labor, am per Ib.. 0.19 0.12 0.10 0.09 0.08 Power, c. per Ib. 0.03 0.02 0.02 0.01 0.01 Interest, c. per Ib. 0.08 0.05 0.04 0.03 0.02 Repairs, c. per lb. 0.02 0.02 0.01 0.01 0.01 Expense, c. per lb.... 0. 61 0. 46. 0 39 0. 34 0.30 Proportional increases in the costs of Metal in “Ladle cor- responding to decreasing yields are determined as follows: 7 60 per cent yield Expense for 60 per cent yield, 0.61c., times —————_____ — F ; 50 per cent yield Expense for 50 per cent yield, 0.71c. Expense for 50 per cent yield, 0.71c., plus Iron, 1.25c. — Metal in Ladle for 50 per cent yield, 1.96c. VULL;UUTDONDDDOAREDNOYCDEDOO. SPR ONAA DURCH EEDNRE HoDeRSROGAARaNON SUUOREDENLEDNN TONED LN.seemNy erieesi ony /tanenene The cost of labor (Table II) is determined from the estimated number of men necessary to produce the various tonnages. Allowance is made for the fact that, under the conditions inherent in any plant of fixed dimensions and equipment, reduction in labor cannot be carried beyond a certain minimum. Labor is added to take care of the extra work involved as the tonnage increases. The numbers of men on the payroll for the different tonnages are as follows: Good castings per day, 1b.10,000 20,000 30,000 40,000 50,000 Pounds per molder-day... 100 200 300 400 500 Molders ...... eseeess 100 100 100 100 100 : Helpers .... age 30 32 35 40 45 Core-makers 25 25 25 25 25 Helpers .. 2 3 4 5 6 Common labor ; 10 12 15 20 25 Cleaning .. ; 20 25 30 35 40 Trsp., shipping, stores 3 4 5 6 7 Production and time $ 4% 5 5% 6 Carpenters se ee 1 2 2% 3 3% 4 Pattern makers 2 2% 3 3 iy * Pattern storage 2 2 2% 2% 3 RG Week eae 2 oak 4 4 4 4% 5 Supt. and foreman 9 9 10 11. 12 Maintenance 3 3% 4 4u 5 Watchmen .. 2 2 2 =_ Teamsters 1 1% 2 2 3 Administration 2 2 2 9 2 Selling l 1 1 1 1 Men on payroll, except for z ae ar. _ melting wc 222 235%, 252% 273 295 Men on melting .. 4 i 7 Total on payroll 226 240% 258% 280 3023 High 25.00 Fig. 2—High and Low ' = - ‘ , oe 4 Points of Costs as Estab- 1.90 lished by Analyses of Sev- eral Foundries Operating » 7 on Different Varieties of iJ . . sc ( astings ° 2 {0 ¥ © i? f\ i Vv ———— a 7 ) n : Qnn 0 100 «= 200s 300s 400 s«O500 000 100 800 900 Pounds per Molder-Dau THE IRON AGE December 16, 1926 SAE/OLbOOUOOREEDADSEEDSERDOGOCRBEORERDOOAAELOGOEOOONG:LUQNERELUOAEDOOORELOOROEDONER LAU OtHLLUGANODESOEELL ONDE CURE COOROEENUEALE susuesercsenennes Table 11—Total Cost and Ratios Good castings per day, »- 10,000 20, eee 30,000 40, eee 60, eee Pounds per molder-day.. 100 300 00 Metal in ladle, c,.......-- 1.96 1.79 1.70 1.65 1.60 Labor, except melting..... 14.48 7.57 5.34 4.25 3.60 Fixed CRArBOS.....cccsees 2.12 1.13 0.81 0.65 0.55 General supplies.......... 0.42 0.28 0.25 0.25 0.25 PN” . cn weep ean shes 0.25 0.12 0.08 0.06 0.05 Selling charges....... ‘<ne e 0.06 0.05 0.04 0.04 ee OR, on anew kale ad sues be 19.33 10.95 8.23 6.90 6.09 Less metal in ladle........ 1.96 1.79 1.70 1.65 1.60 General expenses ........-- 17.37 9.16 6.53 5.25 4.49 Direct haber Stde ice eh eae ie . 9.00 4.50 3.00 2.25 1.80 { General expense ‘ 2.18 2.34 2.50 Ratio) Direct labor 1.93 3.08 Pre HONNUARADONEDELDUSDDEAE DED OASHRAGSERLAIDSAAGGARS /LEsooED The item of fixed charges (Table II) is determined as follows, the yearly amounts being reduced to a per- day basis, on the assumption of a 300-day production year: Good castings, Ib......... 10,000 20,000 30,000 40.000 50,000 Real estate and buildings, 250,000 @ 6 per cent. $50 $50 $50 $50 $50 Equipment, $125,000 @ 10 cae naa ene nee ee 42 42 42 42 42 Inventories, $50,000 to $100,000 @ 6 per cent. 10 12 15 18 20 Taxes, local and State $6,000 20 20 20 20 20 Water os efiwerase. $900 eh ES 6 Wb on oo Wee: 3 4 5 6 7 Power and Onght, $9,600 to SIR. 6.5045 5.009.0 00.0% 32 39 46 53 60 Heat, $3,600 to $4,800. 12 13 14 15 16 Insurance, Broperty....... 5 5 5 5 5 EME 6 60 wea s-0 8 28 ko 28 30 32 34 36 Liquid capital, g6e.o00 to $100,000 @ per cent 10 12 15 18 20 Fixed charges per day.. $212 $227 $244 $261 $276 Per pound good castings, c. 2.12 1.13 0.81 0.65 0.55 The item for general supplies (not including melting sup- plies) has been deduced in the same general way. Direct labor is the molder + core-maker wage, per pound, for work requiring one core-maker for four molders. The general expense ratio varies, increasing as the pounds per molder-day increase. It does not, in our opinion, remain a fixed ratio, such as 2%, commonly used, except through a narrow range of work. Minimum Profit The profit to be added to these cost figures should not be less than that which will net a safe return on the money invested. For this analysis the amounts invested at different outputs, and the per pound margin necessary to a safe return, are shown in Table III. The per cent profit increases as the pounds per molder-hour decrease; or, assuming perfect production from a pattern, as the cost per pound increases. For this analysis, these are the lowest margins that will return 10 per cent on the invested capital. Adding these profit figures to the costs as determined, the sales prices are recorded in Table IV. It has been stated above that the ratio of general expense to direct labor is a variable, not a constant NELLA NTHLENOROOOREROONERDUONEALOUNELERONOTOREOAETUONONLOOENTEREOENREDOctL ii etecesecurnnecen scien Table III—Invested Capital and Minimum Profit to Net 10 Per Cent Good castings, lb.. 10,000 20,000 30,000 40,000 50,000 Pounds per molder- Gl? sican eau 100 200 300 400 500 Real estate and : _ buildings 250,000 $250,000 $250,000 $250,000 $250,000 Equipment ...... 125,000 125,000 125,000 125,000 125,000 Inventories ...... 50,000 62,500 75,000 87,500 100,000 Liquid capital.... 50,000 62,500 75, 000 87,500 100,000 Invested capital. . 10 per cent return - $475, 000 $! 500, 000 $5 25. "000 $550,000 $575,000 per day .. $158.00 $167.00 $175.00 $183.00 $192.00 Per pound, c..... 1.58 0.84 0.58 0.46 0.38 Per cent of cost. 8.17 7.59 7.16 6.67 6.24 SUED OONDUOUEHODENEDOOEELOOUONEDODCORROTONREADONDEODOOEERDONOEROROOHErIOnerTOONccrooNeneRaneNS na 375 Taking the costs as a whole, Low the different cases examined m0 came nearest to uniformity WN at an output of about 470 Ib. per molder per day December 16, 1926 factor. The use of one factor is a common one, but we believe that greater accuracy in bidding may be reached if molding, core-making and cleaning each have factors through which the general expense should CHLANENL AULA AEUUYAOEDEUEOOOGRLELE OED ATERUETONSUAEEA ANON oA LAnUUrTUNEGEERONLONENANTOOREULL OLD ONDOAUNONEYTURORETANLANRREED TONES ONOTL TENE) URONET SO URNEDEEREDLaNEUOTOLOCeOsoO reer UOT ENEE Table I1V—Minimum Sale Prices; One Core-maker for Four Molders Good castings, Ib......... 10,000 20,000 30,000 40,000 50,000 Pounds per molder-day... 100 200 300 400 5 Metal in ladle, 60 per cent,c. 1.86 1.71 ; f 1.55 General expense, c........ 17.37 9.16 6.53 5.25 4.49 Minimum profit, c........ 1.58 0.84 5 0.38 Sale price, 60 per cent SN Miten dn as des owe 20.81 11.71 8.75 7.30 6.42 Sale price, 50 per cent SS Pare 20.91 11.79 8.81 7.36 6.47 Sale price, 40 per cent 8.88 7.41 6.52 SOS eso aren exiwese 21.01 11.86 be estimated. We have not endeavored to deduce the factors for core-making and cleaning, but in Table V have used generally accepted factors, to arrive at a molding factor. Under this plan the errors that often creep in may be reduced to a minimum. Separating the cleaning costs in this way will facilitate the estab- lishment of piece rating, or tonnage contracts, in the cleaning room. It will also uncover difficult cleaning jobs. THE IRON AGE 1683 Having established a set of factors such as these in any shop, the estimator should follow them closely in the cost records, to note variations under changing conditions. Large-scale curves regularly plotted are a valuable aid in this detail. The principal facts are that molding, core-making and cleaning are separately handled; that the variation between costs of fast and HOHCTeNe CODENTE LPR ENREE PENRO OONRRRROREEER Table V—Ezxpense Ratios Good castings, Ib.......... 10,000 20,000 30,000 40,000 50,000 Pounds per molder-day... 100 200 300 400 500 Cleaning expense, R—=2\.. 2.25 1.41 1.13 0.98 0.90 Core - making expense, MOOR SOR. on cba ae 2.25 1.50 1.12 0.90 Molding expense, R—=Var.. 10.62 5.50 3.90 3.15 2.69 General expense........ 17.37 9.16 6.53 5.25 4.49 Molding ratios. . ; 1.48 1.53 1.62 1.75 1.87 ean emenennnnen: serrrsscornenvene sete oun ' £00) :08as eee aeUDND etree setae rnnNNRNIRD slow, or heavy and light, castings is alloved for; and that the variation in melting expense permits proper charges for high and low-yield pieces. Fig. 1 reproduces the four main items of the cost of jobbing castings, adding the minimum profit to show the sales prices. The use of such a chart is an aid to the appraisal of cost of small, light, slow-running jobs. (To be concluded) Billet-Piercing Mill Manipulator Device Carrying Two Mandrels, One Being in Action While the Other Is Being Unloaded ! ANIPULATORS to increase production of rolling mills have found an extensive application in this country. It is rather surprising in view of this that the billet piercing mill has been more or less neglected, notwithstandig the fact that a comparatively simple manipulator such as described here might permit an increase in production per mill—possibly as much as 75 per cent. One source of delay in piercing billets in such mills as the Mannesmann is due to the necessity to wait until the pierced tube has been stripped off its mandrel, be- fore another billet can be pierced. This is due to the fact that only one mandrel at a time is employed in each piercing machine. The present device is designed primarily to eliminate this delay, and thus to increase the output of the mill. This is accomplished by the employment of two mandrels and the control of the operation through the medium of a movable, preferably revolving, frame, in such manner that, while one mandrel is being stripped off its tube and made ready for the next cycle of op- eration, a new billet is being pierced on another man- drel, the whole operation being so planned as to insure the minimum of delay and lost time. The device consists of a casting A, which carries a semi-circular runway B, extended by member C, the purpose of which is to hold in position the revolving frame, consisting of lower part E and upper part F. The two parts of this revolving frame are held to- gether by bolts, and in their turn hold between them rigidly a cylindrical frame member J. Frames E and F also carry, respectively, guide forms K and L. Co. acting with them are guide forms M and N, carried on hinged arms O and P. To understand the operation, assume that a biilet, R, Fig. 2, is in the initial stage of being pierced. As its piercing continues, the first pierced portion en- ters between the guide forms K and M, and in doing so pushes back the collars T, U, etc. At the end opposite to the piercing point (hereafter referred to as the outward end) mandrel S carries a fitting V capable of engaging into socket W contained in a ball or roller thrust block X movable in and outward between ways Y and Z by cylinder 2A. The socket W is brought to engage with fitting V before the start of the piercing operation. When the latter has been completed, cylinder 2A is stroked outward (i. e., away from the piercing mill), thereby withdrawing mandrel S and tube R (made from billet R), bringing the fitting V to position Va, Fig. 2, whereupon rod 2B ejects fitting V from socket W. This is one of the novel features of the present device and works as follows: Rod 2B is attached to the bottom of 2C of the sta- tionary frame, of which part is constituted by the ways Y and Z previously referred to. In withdrawing the mandrel S and tube R, cylinder 2A travels away from the piercing mill, dragging with it, as part of the mandrel, fitting V held in socket W. This continues until a certain position is reached at which the tip of fitting V abuts upon the rod 2B freely passing through thrust block X. Cylinder 2A continues then to move, while fitting V is prevented from doing so, and is conse- quently ejected from socket W. At this time the actuating device 4C (electric motor or compressed air cylinder) is brought into action. It releases the locking pin 2D and then turns the frame E-F through an angle of 180 deg. This, among other things, causes fitting V to travel in the grooveway 2E until it reaches the mandrel-withdrawing clutch 2F, an important element of this device. Construction and mode of operation of this man- drel-withdrawing clutch are as follows: It slides back and forth over guide rod 2G and is carried on guide shoe 2H and arm 2K, which latter is in its turn car- ried on piston rod 2L of the air (or hydraulic) cylinder 2M located in the center line of the manipulator. As shown in the drawing, the fitting V is in the clutch 2F; spring 2N is in compression, and presses clutch cover member 2P (shaped somewhat like a wide staple, and freely sliding on clutch rod 2R) against abutment 2S forming part of grooveway 2E above referred to. As cylinder 2M moves outward, it carries with it arm 2K; as clutch 2F moves at the same time, spring 2N forces clutch cover member 2P over the clutch 2F. This covers the opening through which fitting V en- tered the clutch, thus making it impossible for fitting V to slip out again until cover member 2P has been a — 1684 THE IRON AGE ) moved back into the position shown in Fig. 3. In mov- ing outward, cylinder 2M, acting through clutch 2F, withdraws the mandrel from the tube, while the latter is held by guide forms L and N. The purpose of the next operation is to get the tube out of the guide forms. To do this, the operator twists handle 2T, Fig. 2, connected with rod 2U, which re- Fig. 1 (Lef View) ZIs a { Toss - Sect ( of the Manip- tor, with j Bar En- ering at S and Finally Leaving Ove) 3-P from Po- fion B-B. Fig. 2 (right) 1 top vt th a detail fhe sna We J Fr Ze ») by pin 2W, Figs. 2 and Pin 2W slides off the end of arm P. The weight of the tube, which is considerable, bears then on arm P and forces it downward, whereupon the tube 3M rol out, as shown in Fig. 1. The arm P is then returned to its original position by spring 2X, Fig. 2, and the locking pin 2W is likewise returned to its original posi tion by spring 4X. t i leases the catch constituted Mandrel S has now moved, as has been described above, into the position shown at 2Y, and will be desig nated henceforward by this latter number, to prevent possible confusion. It is now located far outward, and has to be returned into a position where fitting V would be located opposite grooveway 2EF, so that the frame E-F could be turned through another 180 deg. To per mit this, cylinder 2M is stroked inward, i. e., toward the piercing machine. Cover member 2P comes then to bear against the abutment 2S, whereupon it compresses spring 2N and gradually uncovers the opening through which fitting V is enabled to pass into grooveway 2E. While the tube was being pierced, and later on while the mandrel was being withdrawn, the collars T, U, ete., were gradually shifted into the position To Canvass World Trade Movements in Iron and Steel WASHINGTON, Dec. 14.—Review of the trade in the iron and steel merchant products throughout the world, together with a report on the effect of the formation of the European steel entente is asked for in a ques tionnaire sent out by Acting Chief Marshall T. Jones of the Iron and Steel Division, Department of Com- merce. The questionnaire has been sent to all Depart- ment of Commerce offices and to consulates in countries where the department has no agents. The reports ars to be mailed not later than Feb. 1. It is intended to combine them for issue as a trade information bul letin. The review asked for will deal with the calendar years 1926 and 1925 and include any unusual events that have taken place to affect the trade concerned, together with price trends and in a general way, the sources of supply of the material involved in case loca December 16, 1926 shown in Fig. 2. A special device which will not be described here has been designed to re-distribute them rapidly and certainly into the proper positions for a new piercing operation. The revolving mechanism 4C is now brought into action again to unlock and then turn frame E-F through an angle of 180 deg. When guide form L-N was opened, as described above, tube 3M rolled out and dropped into position A-A, Fig. 1. But as the arm 3N of frame E moves through the turn of 180 deg. in the direction of the arrow, tube 3M is gradually carried upward until it reaches a level above the horizontal, whereupon the tube begins to roll toward the center and eventualy comes to occupy the position shown at B-B, Fig. 1. On the next half revolution the tube will roll from position B-B onto runway 8P and then out of the machine. The device described above was designed for a western mill by Leon Cammen and Robert S. Haydock, New York. manufacture does not control. By “merchant prod- ucts,” the questionnaire says, is meant such items as pig iron, bars, shapes, rails, sheets, tin plate, pipe, tubes, wire, nails, etc. Pennsylvania’s Increasing Contribution of Coking Coal WASHINGTON, Dec. 14.—In the 10-year period, 1916- 1925 inclusive, Pennsylvania’s ratio of the total coking coal consumed in the United States increased from 32 to 41 per cent, chiefly because of the installation of by-product ovens in the Pittsburgh and Ohio districts, according to a summary issued by the Bureau of Mines. West Virginia’s contribution dropped from 42 to 26 per cent, and Kentucky’s share increased from 10 to 15 per cent. The report presents a table showing replies of operators as to the origin of the coal used in the manu- facture of by-product coke in 1924 and 1925. at ee Sas 2 x SOTGAL Bea Coat Me Chromium Plating Is Expanding Application to Steel Gages Notable—Hardness and Brightness Are Features—What the Process Is and Its Advantages BY DR. WILLIAM BLUM“ UDGED by the interest displayed and the publicity attached to this subject, chromium plating might well be called the sensation of the last few years in the field of protective coatings, a field in which there have been but few other radical changes in the last decade. Among questions that are no doubt now in your minds, and in those of many chemists and engineers, are “What is the future of chromium plating?” “Is it a practical process?” “What is its probable value when applied to engineering materials?” “In short, can we use it?” In this informal talk I will attempt to answer, or at least to discuss, some of these questions, especially from the standpoint of the mechanical engineer. In doing so I am limited principally to the experience and contact of the Bureau of Standards, because so little authentic information has been published on this sub- ject, especially in this country. As, however, a large number of industrial research laboratories are now en- gaged in the study of chromium plating, and hundreds of firms are trying it out for various purposes, it will no doubt be possible within a few years to make much more definite statements than are now justified. Process Has Some Definite Advantages In order for any new process or product to compete permanently with the established procedure, it must have certain definite advantages. It may, therefore, be well, before discussing methods and applications of chromium plating, to consider those properties of the metal which make it of special interest. The outstanding property of chromium, when de- posited under appropriate conditions, is its extreme hardness, as measured, for example, by its resistance to scratching. A bright chromium deposit, when tested in the Bierbaum apparatus with a sapphire point and a given load, yielded a scratch with a width of about 0.7 micron (the narrowest scratch of any metal thus far examined), while the cold-rolled steel on which it was deposited yielded a scratch about 2.2 microns in width. The great hardness of the chromium, and the fact that this as well as its other properties may be varied by the proper choice of plating conditions, at least justifies its consideration wherever hardness is an essential factor. Another property of chromium that is distinctive is its resistance to tarnish or oxidation under many con- ditions of exposure. Thus it will stay bright for long periods, not only in an ordinary atmosphere, but also when exposed to a high humidity, to salt air, to fairly elevated temperatures, to molten tin and zinc, to many laboratory fumes, and to concentrated nitric acid. It is readily attacked and dissolved, however, by hydro- chloric acid, and more slowly by sulphuric. This re- sistance to tarnish, therefore, justifies its consideration wherever a bright surface is necessary, as on mirrors, even though the reflecting power of chromium is some- what less than that of silver. Although chromium itself resists tarnish, it does not necessarily protect an underlying metal such as steel against corrosion, if the steel is anywhere exposed. Thus it may be readily shown that chromium-plated steel quickly corrodes at any points where there are pores or pin holes in the deposit. In this respect chro- *Chemist, United States Bureau of Standards, Washington, and president of the American Electrochemical Society Contributed by the Machine Shop Practice Division for presentation at the annual meeting, New York, Dec. 6 to ¥ of the American Society of Mechanical Engineers (a)Trans. Am. Electrochem. Soc., vol. 37, page 49, 1929 1685 mium is similar to nickel and copper, and unlike zine and cadmium, which latter will protect small areas of exposed iron because the zine and cadmium dissolve more readily than the iron. Any superior protective action of chromium plating on steel above that of nickel plating must depend upon producing more nearly im- pervious deposits of chromium than of nickel. From present indications it appears probable that for such uses chromium will generally be applied over nickel plating of good quality, in which case the chromium is chiefly useful for its hardness and tarnish resistance. With the definite advantages it possesses, it is no doubt surprising that chromium plating has been such a recent development. This condition is not the result of any lack of interest in the subject, but from inabil- ity until recently to so define and control conditions that consistent results may be obtained under indus- trial conditions. Chromium was electredeposited by Sunsen as early as 1854, and since then numerous pa- pers and patents have been issued on this subject. Of the more recent papers, that published by Sargent (a) in 1920 is probably of greatest interest, as most of the methods proposed since that date represent modifica- tions of Sargent’s solution, or of his operating condi- tions. Sargent recommended a bath of which the major con- stituent is chromic acid (CrO,) in a concentration of about 2.5 M or 250 g. per L. (33 oz. per gal.). To this he added a small amount, 3 to 5 g. per L. (0.4 to 0.7 oz. per gal.) of chromium sulphate, Cr.(SO,),. From such a bath, Sargent and others have obtained good chromium de- posits, but frequently the results have been erratic. H. E. Haring, from a study at the Bureau of Stand- ards (Chem. and Met. Eng. vol. 32, page 692, 1925) concluded that in such a bath it was necessary to regu- late the acidity. This is accomplished practically by having present in the bath a colloidal suspension of chromium chromate, which may form ‘automatically or may be produced by the addition of any basic or reduc- ing substance. Deposits Are of Three Types Even more important than the exact composition of such a bath is the control of operating conditions, especially the temperature and current density. These have an appreciable effect in all plating operations but in chromium plating relatively small variations in these factors may change entirely the character of the de- posit, or even prevent deposition entirely. Three prin- cipal types of chromium deposit may be _ produced, though of course these shade gradually into each other: (1) At too low a current density or too high a temperature, a “milky” deposit is produced This is relatively thin owing to the very low cathode efficiency under such conditions (2) At the appropriate temperature and current density, e.g. at 45 deg. C. (113 deg. Fahr.) and 10 to 20 imp. per dm* (100 to 200 amp. per sq. ft.), a bright deposit is produced (3) At too high a current density, or too low a tem- perature, the deposit becomes “frosty,” gray and ‘burnt.” Of these deposits, the milky form is the softest, and the bright is the hardest, as measured by the scratch test. With an appropriate solution, temperature and cur- rent density, it is a relatively simple matter to produce bright, hard deposits of chromium upon those articles where a nearly uniform current density may be se- SE at a ik 25 Ae er ee nr ot “* ~e- Pua ele 1686 cured, for example, upon nearly plane surfaces, cylin- ders, etc. Upon irregularly shaped articles, and espe- cially those having deep recesses, it is very difficult to get a continuous deposit of chromium of uniform proper- ties. Thus it may then be found that no metal is de- posited in the recess, or else thé deposit on the project- ing parts is gray and spongy. The latter type of coat- ing is hard to buff to a bright surface. This poor throwing power of the chromium solu- tion is due principally to the fact that the current effi- ciency decreases rapidly as the current density is low- ered. Thus at 45 deg. C. (113 deg. Fahr.), the cathode efficiency at 20 amp. per sq. dm. (200 amp. per sq. ft.) is about 18 per cent, while at 5 amp. per sq. dm (50 amp. per sq. ft.) it is only about 7 per cent, and at slightly lower current densities it is practically zero. This limitation appears to be an inherent defect of baths containing chromic acid, and while minor im- provements in the throwing power may be effected, there is little reason to believe that it can ever be made to approach that of a nickel plating bath, much less that of a cyanide copper solution. Another factor which may affect the introduction of chromium plating on a very large scale is the rela- tively large power cost involved. Ordinarily in electro- plating the cost of power is negligible, or of the order of ic. or less per sq. ft. With chromium, however, the power cost may be from five to ten times as great. This is due to several factors, especially (1) the low electro- chemical equivalent of chromium in chromic acid, in which it has a valence of six; (2) the low cathode effi- ciency of chromium deposition, generally about 15 per cent, and (3) the higher voltage, generally 8 to 10 volts, required by the use of insoluble lead anodes and high current densities. Cost of Chromium Is Not Prohibitive The cost of the chromium itself is not prohibitive, as the metallic chromium in chromic acid at 40c. per lb. costs about 80c. per lb. as compared with nickel at 45c. A coating as thick as 0.025 mm. (0.001 in.) rep- resents only about 3c. worth of chromium per square foot. The total cost of chromium plating is certain to be somewhat greater than that of nickel, as the in- vestment, the power, and the labor cost are all higher in chromium plating. On those products for which the chromium has unique advantages, and especially where the general labor cost represents a large part of the entire expense, the greater cost of the chromium plat- ing may be fully justified. Among the possible applications of chromium plat- ing, those dependent upon its great hardness are espe- cially promising. One interesting example is its use on plates for printing currency and securities at the United States Bureau of Engraving and Printing, where the process and conditions developed by H. E. Haring at the Bureau of Standards are in successful operation. Some years ago the Bureau of Standards cooperated in the design and installation of a plant for reproducing these plates electrolytically. The plates produced by this process have a nickel surface, fol- lowed by alternate layers of copper and nickel, finally sweated to a steel plate. These plates are “intaglio,” that is, the designs are below the plane surface, and before each impression the plate is inked and rubbed first with burlap and then with the hand. As all inks contain some abrasive particles, there is considerable wear on the plates. As was expected, the plates with a nickel surface did not last so long as the case-hard- ened steel plates that were formerly used exclusively. By the application of about 0.005 mm. (0.0002 in.) of chromium to the electrolytic nickel plates, it was found that their useful life may be increased to about four times that of the nickel or twice that of the hard- ened steel plates. The impressions are usually sharper, and through the use of a smaller number of plates, greater uniformity and security of the product is ob- tained. In other branches of the printing industry, it has been found that when very long editions are required, (b) H. J. French and H. K. Herschman Preprint 18 of the American Society for Steel Treating, September, 1926 THE IRON AGE December 16, 1926 as of labels and soap wrappers, chromium-plated elec- trotypes may be used to produce from three to six times as many impressions as can be made from the nickel electrotypes. Chromium Increases Life of Gages Of more direct interest to engineers is the applica- tion of chromium to gages. In a recent study at the Bureau of Standards (b) the performance of chromium- plated plug gages was compared with that of hardened steel gages. In these comparisons a wear testing ma- chine, devised by the above authors, was employed. By its use, two gages were automatically moved up and down in hardened steel rings, and the wear was meas- ured after a determined number of such gagings. From this study the following tentative conclusions were reached: When exposed to sliding friction, with no abrasive present, the chromium-plated gages resisted wear about five times as well as any of the steels tested. When, however, abrasives such as fine emery were present, the chromium-plated surface, while still su- perior to the steel, was only 30 to 60 per cent better. This latter result does not, however, mean that the chromium plating is unsuitable for resisting wear by finely divided abrasives such as emery under all condi- tions. Thus it was found in lapping wear tests that the chromium resists wear from two to four times as well as the customary gage steels. It is at least prob- able that, by depositing the chromium under different conditions, coatings may be produced which are best suited to resist each particular type of wear. For all those conditions of service in which chromium-plated gages may be found applicable, they have the advan- tage that a relatively soft steel may be used as a base and thus dimensional changes with time may be avoided. In the experiments thus far conducted at the bu- reau, a relatively thick chromium deposit (about 0.02 mm. or 0.0008 in.) was applied, after which the sur- face was ground and lapped to the desired dimensions, leaving a somewhat thinner coating of chromium on the gage when it was tested. A simpler and more eco- nomical procedure would be to apply a relatively thin chromium layer (e.g. 0.005 mm. or 0.0002 in.) to a finished, accurately under-dimensioned gage. The lat- ter could then be used directly after plating and, after a pre-determined length of service during which about half the chromium would have been removed, the re- maining chromium could be readily dissolved off and a new coating applied. Whether such a procedure will prove practicable remains to be seen. While both lab- oratory tests and plant practice have indicated that chromium plating may not be universally advan- tageous on gages, the results are certainly sufficiently promising to warrant further investigation and trial. The experience with gages at once suggests the ap- plication of chromium to other steel surfaces exposed to wear, and which now require special hardening processes. A few observations indicate that chromium plating on certain cams is practical and advantageous. On gears, it may be difficult to produce satisfactory deposits in the depressions, and the wear on the teeth is much more likely to detach the chromium coating. On stamping dies or other surfaces exposed to severe impact, it is at least probable that a light chromium coating would furnish little protection against the deformation of a soft steel base. If, however, chro- mium can be made to adhere permanently to a case- hardened die, it would preserve the details. On dies used in molding plastic materials, the application of chromium will probably be advantageous. More exten- sive experience than is now available, or at least pub- lished, will be required before a final conclusion can be reached regarding these and similar possible appli- cations. Uses of chromium dependent upon its resistance to some specific corrosive condition include such applica- tions as the following: Molds for vulcanizing rubber may be chromium-plated to prevent sticking of the rubber to the mold. The resistance of the chromium to sulphur or many sulphur compounds, which leads to the above use, has also caused its consideration on The resistance of chromium oil-cracking equipment. December 16, 1926 to oxidation has suggested its use on glass molds, and on rollers for making plate glass. So far as is known, the latter two uses are still in the experimental stage. Chromium Plate Makes Good Reflectors The luster and permanence of chromium plating warrant its consideration for reflectors, especially those that are exposed to sulphur fumes such as in locomo- tive headlights and flood lights. Even though its re- flective power is only about 60 per cent as compared with 90 per cent for silver, the rapid tarnishing of the silver more than compensates for this initial difference. Whenever a bright surface is required, that is not exposed to severe corroding conditions, the application of chromium directly to steel will be advantageous, for example, on rules and scales for shop use. Where, however, steel articles are to be exposed to the weather, it will be found desirable to apply a coating of chro- mium (0.005 mm. or 0.0002 in.) over a substantial nickel coating (of 0.025 mm. or 0.001 in.) or still bet- ter over a coating composed of a copper and a nickel layer, or a nickel, copper and nickel layer. In the auto- mobile industry great interest is being shown in such applications of chromium plating, and one make of car is now made with chromium plating on the radiator. As previously indicated, the value of chromium under such conditions depends largely on its luster, and its Considers Standardization of Frame Dimensions for Motors A general conference to determine whether the standardization of certain dimensions of electric motor frames shall be undertaken was held under the auspices of the American Engineering Standards Committee, Dec. 10, at the Engineering Societies Building, New York. The conference was called by the A. E. S. C. at the request of the National Machine Tool Builders’ Association, and was attended by a number of repre- sentatives of organizations interested in the project. C. E, Skinner, chairman of the A. E. S. C., presided. Correspondence of the A. E. S. C. with a number of important organizations is said to indicate that there is considerable interest in the standardization of motor frames which would secure interchangeability between motors used for driving certain mechanical devices, such as machine tools, pumps, hoists, etc. The status of foreign practice in the matter was outlined by John Gaillard, mechanical engineer of the A. E. S. C., who said that the question was discussed at a recent conference in Zurich, Switzerland, of standardization experts from German, French and Swiss industries. It was brought out that in Ger- many, a standard series of shaft heights for electric motors has been established, and for some kinds of motors, standard distances between the bolt holes have been adopted in addition to the standard shaft height. Among those speaking in favor of the project were E. F. Du Brul, general manager of the National Machine Tool Builders’ Association; E. J. Kearney, secretary of the Kearney & Trecker Corporation, Mil- waukee; B. P. Graves, designer, Brown & Sharpe Mfg. Co., Providence; T. R. Jones, Cincinnati Milling Machine Co., Cincinnati; and a representative of the Association of Railway Electrical Engineers. J. M. Hipple, representing the National Electric Manufac- turers’ Association spoke in opposition. It was recommended that the scope of the work include the following five items: A series of standard dimensions for the distance from the base to center of shaft (shaft height); a series of standard distances between bolt holes, at right angles to the shaft; a series of standard distances between bolt holes, parallel to shaft; certain definite combinations of a shaft height with any or both of the distances between bolt holes as mentioned under the first and second items; and an attempt to establish maximum diameter and length of motor for a given horsepower. It was moved to appoint a special committee of three to consider sponsorship. This committee, ap- THE IRON AGE 1687 resistance to tarnish and abrasion. There is little rea- son to believe that the chromium will materially in- crease the resistance to corrosion of the steel under severe conditions of exposure. On brass articles, such as plumbing fixtures, where there is little tendency for the base metal to corrode, the chromium may be plated either directly on the brass, or on a nickel-plated surface. In the latter case, however, it is essential that the nickel plating should be very adherent, otherwise it will peel during the chromium plating. The more rapid adoption, or at least trial, of chromium plating for such fixtures is undoubtedly hampered by the poor throwing power and the greater personal attention required for consistent production. With so many research laboratories engaged in the study and development of chromium plating, it seems safe to predict that even though no revolutionary de- velopments appear probable, at least with the present type of bath, a fund of experience will scon be gained, upon which will be based the application of chromium plating to those many purposes for which it is espe- cially suited. Chromium plating is not a panacea; it will not replace all other forms of plating. It will serve, and indeed has already served, many purposes better than other metals, and some that other metals cannot serve. pointed from the floor, includes a representative of the National Machine Tool Builders’ Association, the National Electric Manufacturers Association and the Association of Railway Electrical Engineers, respec- tively. The committee is to meet and transmit its report to the chairman before Jan. 15. The report will then be submitted to members of the conference for letter ballot. Foundrymen to Hold 1927 Convention in Chicago in June The 1927 convention of the American Foundrymen’s Association will be held in Chicago the week of June 6, according to a decision made by the board of direc- tors at its annual meeting in that city Dec. 7. It has already been announced that this convention will be held without an exhibition, the latter having been post- poned to the spring of 1928. The board of directors at the same meeting deferred the selection of a loca- tion for the 1928 meeting until later. A feature of the meeting of the board last week was a luncheon in honor of Alfred E. Howell, who was retiring after a continuous contact as a director for 17 years. President Root had appointed past presi- dents R. A. Bull, B. D. Fuller and G. H. Clamer as a committee on resolutions. These, beautifully illu- minated, were mounted in a leather case and presented by Major Bull. Mr. Fuller then gave to Mr. Howell a writing set and Mr. Clamer presented a cigarette case, all suitably engraved. Name of Ulster Iron Works Unchanged The Ulster Iron Works, Dover, N. J., which was recently taken over by a new management, has not changed its corporate name to the Dover Iron Works, as was indicated in THE IRON AGE of Nov. 18, page 1449. The latter is the name of a holding company formed at the time of the transfer of ownership, but the name of the operating corporation remains the same as heretofore. The names of the new officers of the Ulster Iron Works, together with a brief review of the company’s history, were published in THE IRON AGE of Dec. 2, page 1560. The Pittsburgh Foundrymen’s Association will hold its annual Christmas dinner and entertainment at the Fort Pitt Hotel, Pittsburgh, Monday evening, Dec. 20. | | ~~ Teen eee = — mea cee at it Copper and Brass Manufacture Discussion of Methods of Rolling and Heat-Treating for Producing Non-Ferrous Wire Sheets ILLIAM R port Brass Co., Bridgeport, Conn., copper and brass industry Association in New York. He took relation of the industry efly in THE IRON AGE of Oct sts of abstracts from his paper (ake copper, the principal product opper refining pliant, 1s used ne ] irpose ‘ y ’ y sneets nese Cakes are ast Various s$1Zes rccordiny I specification require- Che re heate i brigh ind passe De vee! nea I | 4 reduce tne r ( CKI ~ \ eing roll il I me require eng For certain pu ‘ ea sn give! Tul ( sning 1! ing cold, whic] i a stiffer nd improve and appearance. UT ma mportance to tne trans rtation industry 1s the wire Dar. “his we gns ordinarily about 200 Ib. nd is some 4 in. square by 4 ft. o1 ng After being heated rig red, wire ba re reduced ne not-roliling operation to a I id, usually having a diam- eter of % in These are reduced to wire D drawing through a succes y t ; For some purposes, where strength is a requisite, such as trolley and telephone line wire, the finished wire left in the hardened condition drawing process. purposes, fiexi- ty s desired, it is annealed by proaucea Dy the where g to a red heat. There are ee Se) ee dl WEBSTER, vice-president Bridge- recently before the Metropolitan section of the American Electric Railway What follows con and Other Materials innumerable variations in requirements, which govern the treatment to be used. For large quantity production, the electric furnace has almost completely supplanted the crucible for melt- discussed the up particularly the ing copper and zinc in making brass. The furnace transportation, as reported shown consists of a cylindrical shell with a top opening, a side opening and a pouring spout. It is lined with refractory material to form a cylindrical vessel, de- pending from the bottom of which is a V-shaped channel formed in the refractory lining. When the furnace is partially filled with molten metal this channel becomes a closed metallic circuit and forms the secondary of a _ trans- former, the primary portion of which is built into the body of the furnace. If an alternating current is passed through the primary, an induced cur- rent is set up in the secondary. This heats the metal composing the latter and at the same time pro- duces a violent circulation of super- heated metal within the body of the furnace, by means of which the pppfpfHf SSF SAP DKG teetetey / Y ‘ rd A hh i gases i . ; | charge of solid metal, introduced = LL from time to time, is melted. Fh hp nh ar ag —"_H oucalnn inion Ja LITA pL ALL fp Seamless Tube Making CLLLLL . For making tubes by the hot- KK , rolling or piercing process, the range CTT, of brass alloys capable of being CLL Lf worked at a red heat is limited, but ty oe for some purposes brass is perfectly ee suitable. Heated billets are entered into the tube-rolling mill, which con- Elementary Diagram of Wyatt Electric sists of a frame in which are mounted horizontally a pair of axially inclined rolls of somewhat the form and dimensions of a beer keg. These rolls are mounted axially at an angle so that, as the billet Heating Element Application of heat at the bottom of the mass of metal causes a circulation which draws the colder metal continuously to the bottom and in this way effectively distributes heat throughout the mess. A violent propulsion of metal from both legs of the lower triangle thoroughly mixes the charge and carries the heat to all parts of the bath lf ln cs Ne Hot Billet Entering Piercing Mill After Leaving the Heating Furnace at Left. The billet is subjected to the cross-rolling action of three rolls placed at an angle to its axis and in such a way that the point of contact describes a spiral drawing the billet forward. billet leaves the rolls it encounters a Just as the hardened point over which it is forced to travel and the function of which is to open up the billet and form it into a tube 1688 December 16, 1926 enters, it is given a rotating motion and also a motion