The Iron Age 1915-06-10: Vol 95 Iss 23

SUPUEUELONUEU DAC UEUATEEDELEGEECEUEEOEROTEOOODETOT EER ET ELE Established 1855 LUUELSAAULAATUAEAEA TNA EADAEA EAE EAEN ETAT UAE TATA ATA EA NA EN EAD ETNA ED EAA AA TATA A TENANT EA ONG AONTA LAAN NATTA EEA NEDA UGANDA AD ENUA NDAD NOAM EGADENEGDEDGGDOUEGEAUAUEOEOAEUEOUOUAOLEUODEAUEDEDEQUALODEOUIDEDEOUUUGUEEUGUALSEUOLAUEDERUEGEEUUE EEE AOUE ROAD EERE EDEN NEAL THE IRON ACE Te eARENEOUAUUGNUAUAeUveeeaeoneeenuaeusnnseeetoveuoeusoeeaeeeestnvensucecennveneznvenveeseuvenvenseesncevsovoeceuvavarawnsonveevaneorevannengnenanannoann TURDULEUUOETETEREDETS OEE ACCT ERD New York, June 10, 1915 | | | TTL Vol. 95: No. 23 Reducing the Cost of Foundry Patterns How Those of Circular Form May Be Quickly and Economically BY D. In executing small orders for castings, it is often found that the intrinsic value of the work produced is comparatively small when considered with regard to their ultimate cost. This is due, in the majority of cases, to the pattern charges, which vary according to the work entailed, being thus proportionately greater than the work produced by their means. When the work in hand is of the “hurry up,” experimental, or “one off” variety these charges appear to be accentuated, even when stock patterns “something like” are altered, or if by means of a skeleton pattern, the objective in hand can be fulfilled. With reference to this latter method of produc- ing castings, relative costs between the pattern shop and foundry have to be carefully considered as an inter-departmental saving in one direction *The author is lecturer-instructor in foundry and pattern- shop practice in the School of Engineering, High Street, Poplar, London, England. The pattern described represents only one aspect of this little known practice and was made by a student in five hours, it being his first work attempt in plaster ae eI PE On Made Using Plaster of Paris and Plastacine in Place of Wood GORDON may be considerably exceeded in another and it may be accepted that a fully formed pattern is, in every respect, the most efficient for casting production. Recognizing this fact, a method is dealt with in this article whereby full patterns of a circular form may quickly, efficiently and economically be produced, using plaster of paris as a substitute for wood. The possibilities of this material as a good substitute for general engineering pattern-making are not fully appreciated or recognized, as its uses in this direction are confined chiefly to pattern work of the sanitary engineering variety; but its easy and quick manipulation should make its uses more extensively applicable, especially for patterns of the “hurry up,” experimental or “one off” variety. Its chief defect as a material for patterns is its liability to fracture, but this disadvantage can in many cases be obviated if precautionary methods are taken in the pattern’s construction, combined with a full recognition of the molding procedure to be adopted for its duplication in metal. Fig. 1 4s ¥ Bhs = 3 i SIr > The Various Stages in Making a Round Pattern by the Use of Plaster of Paris and Plastacine 1277 ere a= 5 Se ae ie ; ‘M78 THE IRON AGE June 10, 915 {fws the plan at thos: . sectional tions wh re } 2vation, contiguo ts Wpugh a-a, the bea y of a bevel surface wiijeel blank, the boa this being age ae This oil ; chésen as an oot” Pe requir: example ex- prevent plaining the plaster procedu re : tor fe nie om Fie =. ry salaey ee hw ne eet ae eae aie aes BE . ing to pro ducin £ has set Fig. 8 (right) is a view of the finished pattern, o being the pins board Su e plaster pat- at those terns of a circular formation as it embodies the main principles involved, which are applicable to many and various types of circular patterns. Upon a making-up board A, Fig. 2, the spindle S is projected, this being done by spigoting one end B of the spindle into the board, and the larger diameter S’ of the spindle forming a bearing, in one direction, upon the board. This larger diam- eter S’ in its length defines the position of a pat- tern-block striking board C Fig. 2. This striking board is cut out to the one sectional profile of the blank, the lower section containing the greater length of boss being the portion cut away. Extend- ing beyond the greater face diameter of the wheel, a further portion X of the board C is cut away having a well defined taper and which, in its length, extends beyond the lower edge of the wheel. The complete section of the wheel is marked upon this board as, at a later stage, the board is cut away to this marking, this being more fully under- stood as the work proceeds. Centrally, the board C is cut out semicircularly, to receive one half of the spindle S and is kept in position with the spindle by means of a block H which is shown in Fig. 3. This block extends from the boss face, where it bears upon the spindle at S’ to the extreme width of the board C at this position and is fixed to the latter by screws. This fixture should allow the striking board to revolve freely, but truly, around the spindle S and although not the most common method for attaching these striking boards, is fre- quently adopted, and is given here as an easy method whereby this practice may be tried. The most common method for fixing these boards for revolving around a fixed center is by means of a pin-plate, a, Fig. 4, and a socket plate b. This latter is fixed into, or upon, a piece of wood, which fulfills the same conditions as the por- tion S’ of the spindle, namely, as the bearing for carrying the striking board centrally. The pin- plate a is let into the striking board, the face of the plate portion being flush with the board surface, and the pin ¢ projects beyond the edge, its center being lineable with the plate face. This pin fits into the socket plate, a center hole in this allowing a free revolving move- ment. Within the striking radius of this board as it is revolved, nails are driven into the making- up board A and allowed or | to project sufficiently to retain, within limits, a tions, its action being a parting one. Over the e bed D, plaster of paris, mixed to the consisten: cream, is poured and the board C revolved swe: the plaster to the conformity of its edge. 1. cilitate the sweeping up of the plaster the stri edge of the board C should be well champered edge thickness not exceeding 1% in. In this re zine plate cut to the required striking edge and tached to a supporting board will be found to give a cleaner surface to the plaster and is preferable ¢ wood as a striking edge. The striking up of the plaster should be done as rapidly as possible ow- ing to the quick setting action of this substance and one method adopted to restrain this quick set- ting is to add a small quantity of lime to the wate: into which the plaster is mixed. The lime als gives additional strength to the material. Fig. 5 gives a plan view of this struck up plaster pattern- block without the spindle S. When this pattern-block, as it is termed, has thoroughly set, the positions of the webs 7, rf, 7, Fig. 1 and the lightening holes d.d.d. are marked out upon its surface, it being then coated over with shellac varnish, this being required to prevent the plaster absorbing the oil which is rubbed over its surface when the varnish has hard set. Referring to oil, it should not be used excessively as it tends to form blowholes and sharp corners tend to lose their definition, a fine film being all that is neces- sary to create a parting between one body of plaster and another. The board C is now re-cut to the other half section profile, Fig. 6, the block H being also cut in proportion as shown. The seating and striking edge X, Fig 2, remain constant, but the board C centrally is *ept to its required hight, which is now to the surface of the shallow boss, by means of a collar G which is made loosely over the spindle 5 and the diameter of this collar is conveniently th« diameter of the print required for the boss core I. To form the holes d. d. d., Fig. 1, plastacine will be found most convenient as, owing to its plasticity, it readily. conforms to and retains a given shape This material is made to the thickness of the whee! plate J, Fig. 1, and of a width sufficient to form from it the holes’ shape. To mark out these shapes the material placed upon the surface of the pattern-block Z at their approximate positions and by means of the strik- ing board the required radii can be obtained. is coke bed D which is In the transverse dir made up around the tion the board, along its spindle and about *%4 to 3 Sosa edge, can be utilized for 1 in. away from the setting out. An easy striking edge of the method for getting plas- board C. The making- tacine to any des red up board A is rubbed . . Method of Kneadi over with oil or tallow the Fig. 11 to Obtain ng Plast Desired Thick thickness is to knead between two wood strips e Between Two Boards ness, A, for Lightening Holes ne 10, 1915 ached to a board, the thickness of these strips ng the required thickness, and their distance rt sufficient to obtain the shape, as shown by ll. A straight-edge, drawn along the strip faces, removes any excess material leaving the red thickness which is easily removed from the rd upon which it has been made up. [he plastacine pieces F, Fig. 6, are attached to pattern block Z by means of nails, and the ut board C is placed into position, the seating ve X taking the bearing of the board outwardly. ster is now poured over the pattern-block and ept to shape in a similar manner to that de- bed for making the block. To give additional ength to this, the plaster pattern, it should be nforced by means of a wire ring bedded into it ring the sweeping up period, but before com- tion. When the plaster has set, a fairly rapid process, plastacine F, Fig. 7, is removed and the mak- up board A, Figs. 2 and 3, well rapped and red, also the pattern block Z is lightly rapped ound its circumference. This rapping and jarr- loosens the pattern P from the block, being en free for removal. The lightening holes d, d, d, 12—A Finished Mold Made from the Plaster Patter! rmed by the plastacine, are cleaned up and tapered, it being readily understood that complete efinition by this material is unnecessary, as paring ols can be easily and quickly applied for finishing irposes. The webs r,r,r, Fig. 1 are of wood and may be xed at their respective positions by means of ews passed through the plaster into them. These s can also be filleted at those positions in con- with the plaster body with leather, wax or aster, leather being the most suitable. A core rint for coring out the boss I is fitted into the col- r G, Fig. 6, which remains in the plaster pattern, e fitment being as shown at e, Fig. 10. The pattern is now body varnished and treated every respect the same as for the more conven- nal wood pattern, being, although still in its een” state, ready for molding, Fig. 8. Owing their fracturing possibilities plaster patterns low sectional thickness are preferably molded on their pattern blocks, and if for example, we ime that the center plate of this wheel is easily ible to fracture when rammed up in the mold, it uld be molded upon its pattern block Z in the lowing manner: The plaster pattern, without the webs r,r,r, is aced into position upon the pattern-block and a olding box placed over the relative position of is box with the pattern being obtained by sup- rting the box by means of blocks L L, Fig. 9. is box is now rammed up after which it, with e pattern P and pattern block Z, is inverted and e pattern block lifted away, leaving the pattern the mold, Fig. 10. Around the periphery of the ittern a mold joint, M, is formed and parted over th parting sand. The webs r,r,r, are next THE IRON AGE 1279 assembled at their respective positions, this being done by means of pins o, Fig. 10, which pass freely, but not loosely, through the webs into the plaster pattern. The top, or cope box, is next placed over and the remaining portion of the pattern rammed up. During this ramming up the pins O are re- moved when the sand, contiguous to the webs r,r,r, has been sufficiently rammed to insure their retaining position. When the top box is lifted away these webs are also lifted with the mold, being afterwards removed as separate units and the necessary fillets cut away by the molder. It of course will be quite obvious that the webs r,r,r, could be fixed to the pattern so that they are not loose pattern pieces, but this would entail cutting away the pattern-block to insure a perfect seating for the main body, and in the example in question the most preferable method from a mold ing point of view, would be their working off the pattern as loose pieces, their separate removal being more expeditious than a heavy top lift in the mold. The pattern is next withdrawn from the bottom box, the print e taking the rapping jar necessary for relieving it from the sand, Fig. 12 gives the views of the completed mold. In conclusion, if the pattern should be fractured, its assembly, in two or more pieces, is accurately obtained upon the pattern block so that, fractures notwithstanding, its utility as a pattern for mold- ing purposes is unimpaired. Proper Selection of Employees At the meeting of the Newark Foundrymen’s Asso ciation, Newark, N. J., held June 2, Dr. Henry Satch well, Newark, N. J., talked on “First Aid,” giving practical suggestions for the treatment of injured men. For the reason that nearly every accident is a case for liability against the employer, he emphasized that the greatest economy is by far the proper selection of the employee. In his address he said: “All workmen should be subjected to medical exam- ination, in order that all hidden defects, either physical! or mental, shall be known in advance. Injury by acci- dent to the normal workman is a small factor; by far the greatest loss is from accident to the diseased man. If a sick man is well enough to get work, but is after ward injured, the employer is totally liable; therefore the great importance of selecting labor. It will save more money than all subsequent economies. In foun dries where a great part of the work is heavy, ruptures are the bugbear. Heart disease, weak arterial walls and similar deficiencies incapacitate a man for such labor. “The proper reporting of accidents is a duty that all manufacturers should require. It serves more than one purpose. It gives the employer a chance to check up false claims and to apply the right treatment at the earliest possible moment. Regulations for reporting accidents are almost worthless unless a penalty is attached to the failure to report “It has been found that factories that pay well both in wages and in medical treatment have the least trouble. It has been suggested that if the careful in spection of employees should be carried out, a large class of workmen would be unable to find employment. This would call for a legislative remedy, one that would enable a company to hire a man without being liable for disability caused or contributed to by some existing disease of the man.” Vice-President James Flockhart presided at the business meeting, when Edward Maher’s Sons were elected to membership The Niles-Bement-Pond Company, whose line has been handled on the Pacific coast for some years by Harron, Rickard & McCone, will open a branch office in the Monadnock Building, San Francisco. oes aes 1280 COKING COAL CHAIN STOKER Two Combustion Zones and Inclined Coking Plates to Prevent Clinker Formation Automatic mechanical equipment for the burn- ing of any coal must provide all the features neces- sary to promote progressive combustion in as many stages as that type of coal requires for successful burning. For this reason, all types of stokers have not always been adapted to the burning of all types of coal. Particularly the chain grate stoker, a type desirable for installation at all times because of its low cost of operation anc other natural ad- vantages, has been very successful as applied to the use of free burning, high volatile coals, but has not been suitable for burning low volatile or coking coals. — While the use of the chain grate stoker has developed very rapidly in the Western States, its use in the East has been in- hibited where coking coals so largely pre- dominate. The progressive stages of com- bustion involved in the burning of low volatile coal for which the chain grate stoker has not provided have been the occa- A Chain Grate Stoker sion of several years of experimenting by the Green Engineering Company, Chicago, IIll., as the result of which a modified chain grate stoker, suitable for the burning of coking coal has been developed, this stoker being applicable under this classification to all coals whose volatile constituents fuse at a tem- perature below that of disintegration. Previous to three years ago, the chain grate was considered inapplicable to the coking coals of the Eastern seaboard, and no attempt was made to place the standard chain grate in any locality which involved the use of coking coals. The char- acteristics of this fuel and its action when subjected to heat, it is explained, make it impossible to ignite, coke and consume it uniformly unless it is treated by auxiliary means to an extent which the standard chain grate does not and cannot provide. An in- crease in the draft only serves to accentuate the difficulties which are found to be present in such cases, causing holes to develop in the fuel, per- mitting a marked short-circuiting of the gases through these holes, and seriously diluting the fur- nace gases. Even though the fuel can be success- fully ignited, it has the tendency to draw together into masses or cakes which eventually become solid masses of coke burning only on the surface. These masses of coke will then continue almost indefinitely as such and either form an undesirable accumula- tion at the bridgewall or pass into the ash pit un- consumed. THE IRON Dev eloped for the AGE June 10. - In addition to this unavoidable characteri: this fuel, it forms a practically impervious near the front of the stoker and does not per the passage of air under the influence of the fy draft. It is, therefore, difficult to ignite if turbed, and almost equally difficult to bur even if the ignition is successful and the adequate to furnish oxygen. The Eastern coals do not, as a rule, carry 1 ash, but the intensity of the fire which results froy the combustion of clean coal is such that the as} }+ does contain readily melts in the furnace, and th types of stokers which disturb the general for tion of the fuel bed, produce clinkers by the fus of the ash. There is but one proper method burning bituminous coal, and that is to allow Burning of Coking Coals to remain quiet during the latter stages of combus- tion. Ash is naturally formed first at the grate surface, where the oxygen supply is greatest and where the combustion is, therefore, earliest com- pleted. An inversion of the fuel bed brings this ash layer .~ the surface with the incandescent car- bon below, and a fluxing of the ash is inevitable. There is no getting away from the fact that this action is objectionable to an extreme degree, it be- ing the primary cause of both the hvick and metal deterioration in the furnace and stoker which in- verts or mixes the fuel. The L type chain grate stoker of the Green Engineering Company provides for two distinct zones in the combustion process; the first being for the distillation and ignition of the combustible volatiles and the second for the combustion of fixed carbon. The inclined coking plates, over which the fuel flows in its descent from the hopper to the chain grate surface are agitated to a sufficient ex- tent so that the fuel particles are in constant mo- tion relative to one another, and the binding sub- stance which exudes from the particles of coal is not permitted to set so as to cement such particles together. The length of the incline and the extent of its agitation are relied upon to provide for the complete distillation of the combustible volatiles which precludes further caking of the fuel and produces a resultant fuel bed in the form of uni- form coke of a comparatively small size. The frag- e 10, 1915 tary and porous nature of such a fuel bed in permits the carrying of unusually thick fires the almost complete extraction of the oxygen | the entering air. Many recent installations of this type of stoker e been made. One of these is at the plant of Duquesne Light, Heat & Power Company, Pitts- gh, Pa. This consists of 20 stokers of 822 hp. fitted to Sterling boilers having a furnace ith of 15 ft. The stokers are 14 ft. wide, 12 ft. r and have a grate area of 160 sq. ft. Natural ift is used for light loads and forced draft when demand on the boilers increases. Each of the lers is equipped for individual coal weighing ind has flow heaters and double draft gauges in the ash pit, furnace and uptake. The characteristic perating feature of these stokers is the simplicity f adjustments to meet varying loads. Increased load is met simply by opening the damper to ob- tain more draft and increasing the stoker feed to tain more coal. These adjustments are simple ind one fireman can handle six to eight stokers. \s the front portion of the fuel bed is raised to ake an angle with the rear section, the ignition is intense and the capacity limit of the stokers is simply the limit of the draft to burn the fuel. Ratings in excess of 200 per cent. are reached in daily practice. Double-Lever Machine for Bending Bars For making a right and a left hand bend with- out resetting the bending device or removing the stock, the Wallace Supplies Mfg. Company, 412 Orleans street, Chicago, Ill., has developed a double- lever bar bending machine. It is also possible to make obtuse-angle bends with the machine. An- other feature is the use of hand screws for clamp- ing the stock after it is placed in position, an ar- rangement which is relied upon to prevent any slippage. The machine practically embraces what might be termed a right hand and a left hand bending machine mounted on a long base with means for adjustment so that any distance between the bends above 4 in. can be secured. The machine is designed to be mounted on a work bench to which it is secured by lag screws or machine bolts. Angle iron is employed for the supporting rails which an be made of any desired length to cover the range of work that is to be done. The bedplates are of cast iron and the dies are of tool steel, ma- chinery steel being employed for the other parts. A sample bend is shown and in addition to the regular dies for bending round, square or flat bars, it is possible to fit the machine with dies for bend- ing flat stock edgewise, for bending angle iron and dies which have the corners rounded off so that the bends may be without a sharp corner at the point of bending and of practically any desired radius. \ouble-Lever Machine for Making U Bends in Flat Bar Stock THE IRON AGE 1281 Vertical Milling Machine for Shrapnel A special high-speed vertical-spindle milling machine or tool suitable for high-speed drilling has been developed by the George Gorton Machine Company, Racine, Wis. It was designed especially to meet the requirements of a firm having a con- tract for milling the powder groove in the timing disks used on shrapnel shells. The table has a special fixture with a quick-clamping device for holding the disk and for locating the dimensions A High-Speed Vertical-Spindle Milling Machine Used in Cor nection with the Manufacture of Shrapnel for Milling the Powder Groove in the Timing Disks outside of the groove. The capacity of the machine is approximately 1200 disks per 10-hr. day with an inexperienced operator. The machine is equipped with ball bearings throughout and the spindle is driven by a belt 1 in. wide provided with an adjustment on the small countershaft at the rear for keeping the tension at the proper degree. The spindle is of hardened and ground tool steel and has a movement of 2 in. for doing this special work. A foot treadle is em- ployed to move the spindle, but by sliding the pinion of this mechanism out of mesh with the rack hand control of the spindle travel is secured. The table, which has an oil groove surrounding it, is 8 in. square and has a vertical adjustment of 4 in. The maximum distance between the cutter point and the top of the table is 8 in. Motor drive can be employed if desired, the motor being placed on the machine underneath the shelf as illustrated. The net weight of the machine is 650 lb. The Leece-Neville Company, Cleveland, Ohio, maker of automobile lighting and starting outfits, has pur- chased the old plant of the Parish & Bingham Com- pany on Hamilton avenue, into which it will move shortly from its present quarters in the Whitney Power Block. It has secured a two-story building having 110,000 sq. ft. of floor space. Modern Merchant Rolling Mills* A Historical! How Specialization Has Presentation of Their Effected Development— Economies—The Mechanical Cooling Bed—Some Recent Improvements BY JEROME A well-known writer has recently stated that the rolling mill is the key to all industrial development that it is perhaps the greatest mechanical factor in the civilization of the present day. The most important and the most interesting of all rolling mills is the so- called merchant mill. In fact the history of all mills for rolling metal shapes other than flats commences with and is embraced in the subject of merchant mills. The first mill with grooved rolls, designed by Henry Cort, in Fontley, England, was what we to-day would call a merchant mill. For some years after the inven- tion of the Cort mill there were no specialty mills, and all rolling mills produced a variety of sections and ma- ; Fig. 1 A Type of Notched Bed of Moderate Length in a Merchant R. GEORGE mills which rolled certain simple sections for stoc retailed them out later cut to length as ordered. word is not entirely appropriate as applied to pres: day mills rolling a variety of section and always t der. In this country, however, a merchant mill is mill which produces regularly more than one shape, a the word “merchant” is so used by the writer. In } land a merchant mill is known as a rod mill. In country many merchant mills are called bar mills. The writer has in mind a plant in the Middle W where there are two rolling mills side by side. One has a 10-in. train of rolls and the other a 14-in. tra The former is called a merchant mill and the latter ; Rolling Mill, the Roll Train in the Background Being Searcely Visible terials commensurate with the strength of the roll trains and the demands of the trade. Rails, wire rods, beams, hoops, skelp and many other sections now produced on specialty mills were first de- veloped and rolled on merchant mills, and as a rule the merchant mill is still turning out large quantities of all the above-mentioned shapes in addition to a multitude of other old and new forms: WHAT IS A MERCHANT MILL It is perhaps natural that a general-purpose mill should be rather loosely named. The use of the word “merchant” undoubtedly was first applied to those *A paper presented at the eighth general meet'ng of the American Iron and_ Steel Institute in New York, May 28, 1915. The author is chief engineer, Morgan Construc- - a a ee 3 tion Company, Worcester, Fig. 2—The Rack Notch of Mass Surfaces at 90 Deg. a Merchant Mill bar mill. At another works not far from the border of this State (New York) there is a 10-in. mill which is known throughout the works and on the company books “The Steel Mill.” All of these mills with different local names roll the same shapes, but different sizes and weights, depending upon the strength of the rolls. The present normal annual production of the princi pal rolled-steel products in the United States is shown 1 the table. Thirty-two per cent. of all the steel rolled in thé United States is the product of merchant mills, and thi: proportion would probably hold throughout the world. With wider and larger a markets many shapes now \ecgaaiaaal / § rolled on merchant mills & ® ( will undoubtedly be pro- duced on mills especial!) — aostnpaeiisnajaiall laid down for the purpose; but it is probable that th It Presents Two . . merchant mill will neve! Opposed to Gravity 1282 10, 1915 THE IRON AGE 1283 SS eS =a —-eeseiennindtiianinieametaeieeatteasinaenighbaiatie ings en aloe de nrecernanieneneinneatinennenimensntangnimennnanaitindiapeniaan deem eminmaninemaemmmnmemainngs me + a} MAT 1c eaaviiitr , nTélwuolus FYWANACES ee rt I = fasso | +S Coooo a iy = - + r = = + e = y R aN ™ a ny ~ — oF a ~ ~Y¥ —)\ THis . ‘ 18) ew eel : , o) an ih, Y ‘ 3 ‘ ! Hh! OUS GAS PRODUCERS : > ae a SS N AT “ = ROA A ee ee ee : Fig ; A Merchant Rolling M h ¢ Composite plar four retain its relative importance as a large pro- ognition of the economic benefits of highly developed and continue its important duty of working up specialized rolling mills If we are to have an ope! ess for special mills. market and at the same time continue to pay higher wages than our competitors we must pursue this policy : even more vigorously in the future. This does not mear howing the Normal Annual Production of the Principa ' ¢ : . : , ; Rolled Steel Products in the United States however, that we can afford to neglect the merchar Gross tons mill in the slightest degree, because, as stated above, it Rolled on specialty mills 344 millio: a aa ae 2 os 1 Rolled on specialty mills 3 = millior is the main root of the rolling-mill busines Rolled on specialty mills 3 million The use of rounds chiefly for bolts and rivets ha er ....+.+Rolled on specialty mills 244 million wrN : ‘tint Gas . See ; s : | shapes ........ Rolled on specialty mills 2% million creased to such an extent that for some years past a itdetuakakan Rolled on specialty mills 1 million number of rolling mills have been employed almost ex eous eee . Rolled on specialty mills 1 millior er ar ‘ fy ‘ t mill products...... s (iegdteeektonves § million clusively in the production of round sections The wri er suggests it would be proper and beneficial to give uj 41% B. Ss eee ge in Se eree - the name “merchant” as applied to these mills and cal them round mills. There is always a benefit in under The United States for some years has held a leading standing and expressing clearly what we are really do sition in the steel business, and in the writer’s opin- ing. this has been due in large measure to the early rec- Steel bars for reinforcing concrete, used extensively abroad for years and now increasing in use in this cour LITLE try at the rate of about 16 per cent. per annum, consti th ita: wTmuous FURNACE 2 nh Fon SOPt Baers i = <2 f | t . @ 4 a . aa | ike sadilaIS Fevine HEAR - . a <> ‘ 1 \ ~ > aij» ' 7 ' ' ' ; ; <> ’ ; 7 ” i! | U k : a 5 r r 4 4 u " a ‘ ih AN - | | 4 te ; ods ——— —_—_- — <=> cop <p <p | ' ? _ ' Power Onven 1 _ Fmcrion Roi. ‘ mumeeuunaeis aitgiinatinaneparistiiingansinmmcest | > -ef> et ep " : | \ , : a : 5 : > } p~— ’ a aa caieaieiaa 2 Lemp <Q. <ap <cUp SA j ; ~ in Pi an A = 3 1,104 ‘ ip [ep aiitp ri iandgann ste — J > SS A Lp ) ; rat F 2 ae x gg SE 2 <p <p SS SB ae aR ; ELEVATION Contir Billets ‘—A Merchant Rolling Mill with Edwards Sem is Finishing Trains with a Furnace for 30-Ft i Fig. 5.—A Merchant Rolling Mill for Heavy Sections. Finish ing Train Equipped Throughout with Automatic Repeaters i . a oe 1284 THE IRON AGE z i Pit H V H He ——- A ‘ Conhing $4 me 0s eee ? Bed i419 Plan No. 1—Finishing in : Light |! sses pat) Tit A iif : Cpahing ‘ ' ! : 4 + tis—~ ML “TIT ee ' a Plan No. 2—Finishing in iy Eight Passes ne ' Coating ' 4-4-4 ——-44— | % , Bed ph He Finishing in Six Passes a Vial ah amt Leth nn EE Aah \ 8 Voang ll T y spt hates at ota } + : + + if : $2 er Seer > 34 [A 2 \ . ( ip } Beal Finishing in Eight Passes, Y Double Strand =,-2 ~~ + oe peg |g Tht | ISI, 4 | - ath Z 4 f —< ; $ § { ¥ ‘ Caokh ng . pid 1 | O41 TLL —-HH— H+ ileal <v4 - - Bed ~“ b Finishing in Ten Passes i Fig. 6—Units of a Merchant Rolling Miil with Spare Finishing Trains and Arrangement for Rolling Two Strands of Small Size Bars June 10, (915 tute a rolled product not requiri usual accuracy of section and sho rolled at extremely low cost on mills. The pressing demand for great curacy of section and temper ma very desirable to segregate the diff classes of work in order, first, that accurate rolling may be assured, second, that the general cost of r may be kept down. Just at the pr time there is a marked increase i; demand of users of merchant bar sections rolled more accurately to with better surfaces, and particularly j; straighter lengths, and this improve: in quality and additional expense to th mill is not accompanied by any co: sponding tendency to higher prices. All the present mechanical means ji: sight for improving the quality of mer- chant bars along the above lines involv the use of special auxiliary equipment, which, if installed, should be kept in con- stant use; and this is a further reasor for classifying and segregating merchant- mill work as fast as permissible. Ordinarily, when a special mill is laid down for the purpose of operating exclu- sively on a product previously rolled on a general merchant mill the investment per ton of product is cut from 33% to 50 per cent., and the cost of labor is reduced from 50 to 65 per cent. Notable exam- ples are to be found in comparatively re- cent installations for rolling angles and skelp. Largely on account of favorable labor conditions in Europe very few specialty mills have been laid down there, although Germany recently made a_ beginning along this line by contracting for a few mills of American make. Extraordinary development in highly organized mills in Germany can be looked for upon the res- toration of normal business conditions. ECONOMIES THROUGH SPECIALIZATION The writer hopes he has been able to point out that along the line of special- ization economies may be accomplished that do not lie within the province of the rolling-mill engineer. This is a question of general policy, to be determined by the management. Another important point in the hands of the operating department is the systematic scheduling of rolling orders. Up to within a comparatively short time much of the dissatisfaction in- cident to the merchant-mill business re- sulted from a lack of understanding of the operating difficulties with which these mills have had to contend. The satisfac- tion of the operator and the customer is dependent upon the infrequency of roll changing, and the importance of this can hardly be exaggerated. A rolling cycle covering the full range of sections in three or four weeks seems to give the best satisfaction all around. An ordinary rail mill rolling rails from 25 to 100 lb. per yd. covers a range of weights of only 1 to 4, whereas the most favored merchant mill covers 4 range of weights of 1 to 10, the ordinary mill a range of 1 to 20, and many mer- chant mills a range of weights of 1 to 60. If, in addition to meeting these extreme conditions, a roller is asked to roll rounds, squares, nut iron, ovals, flats, angles, rails, beams, channels and a multitude of other shapes, and change without notice from one section to another to suit the demands of the sales department and the June 10, 1915 mer the result is sure to be dissatisfaction all , the line. or almost a century the merchant mill retained its nal simplicity and the minor changes and improve- ts adopted were confined almost wholly to the roll Billets were charged, drawn and fed to the mill hand. The finished product was rolled in short ths so that it could be manipulated on the cooling by hand. the past 20 years all this has changed, and the roll trains of modern mills are almost lost in the mass of mechanical equipment designed to convey the metal to and from the rolls. The cost of a modern notched cooling bed =+4+ a —$Hit+ PLAN 4 Merchant Rolling Mill with Arrangement for Jo Double Strand ne equals or exceeds the former cost of an entire , and the mechanical problems involved are extreme- y difficult. Fig. 1 is a photograph of one type of tched bed of moderate length with the roll train in background scarcely visible. THE MECHANICAL COOLING BED The writer does not believe it proper to go exten- ely into the many intricate details of modern mer- hant mills, but brief reference to the mechanical bed should be of interest. The principal feature lies in the rack notch, which presents two surfaces at 90 degrees ypposed to gravity, as shown by Fig. 2. The beds con- sist of live roll conveyors for receiving the stock as de- ered from the mill at a speed in some cases up to bout 25 ft. per second, and with less than 1 second earance between bars; means for accurately stopping the stock without injury, and transferring it to the cool- ng racks; notched racks close enough together to sup- port the lightest material rolled, and so designed that the stock is automatically advanced across the bed; a eceiving and assembling table at the end of the racks with means for transferring the assembled bars to the front shear table. All the various operations are per- med by electric power. Notwithstanding the fact that these machines are constantly subjected to scale and varying degrees of heat they have been developed to such a point of mechanical perfection that the cost of operation and mainte- nance is practically negli- THE IRON AGE 1285 several feet. The movement of the ends of the long bars as they travel first in one direction and then in an- other is surprisingly rapid. ECONOMIES THROUGH IMPROVED MACHINERY Although the modern merchant mill represents a large investment of capital the cost per ton of product is no greater than the cost of the lowest type of hand mill laid down under equal conditions. The writer’s ex perience has been that all kinds of merchant mills cost from $5 to $6.50 per ton of product per annum, this in vestment covering everything necessary to equip and start the mill excepting the land. Aside from some sacrifice in flexibility the modern vy merchant mill is a great im ' provement over the mills in use ; os ee 20 years ago. In the space of a time mentioned the tons produced per man has been in- creased 400 to 500 per cent., and all the work made in- finitely easier and safer. The loss in crops and shorts has been reduced 75 per cent. The cost of heating has been reduced 50 per cent., and the total cost of putting billets into finish bars has been reduced on the average from 50 per cent. to 60 per cent. The above-mentioned ecoonmies have been accomplished in the face of new and more exacting requirements as to accuracy of gauge, straightness and temper. The ring and limit gauge and the autocratic inspector were little known in the merchant mills of 20 years ago. The United States can claim all the credit for the entire development of merchant mills during the last 20 or 25 years. Whether or not we can retain our leader- ship in this work will depend almost entirely upon the restoration of favorable business conditions under which funds will again be available for expansion and devel- opment. Concerning the technical development of the mer- chant mill volumes could be written if one ventured into the field of details. The writer will, however, endeavor to present in brief outline the most important steps re- lating to changes in arrangement of rolls and the in- troduction of important auxiliary equipment. For many years all merchant bars were rolled on the simplest possible form of mill, namely, the two-high train. The bars were given gible. It will be of inter- --}--—_——_~, org bt a reduction by passing be- est to learn that one dou- } 7 tween the rolls and re- ble bed installed in a 10-in. Nes ach : , turned over the top roll merchant mill, and reduced ——}— — 0 — for the next succeeding to the smallest practicable Shag a 2 pass. The length finished imber of parts, contained o o_) Was usually about 16 to 20 all 96,225 pieces exclu- ¢ 8} it. Only the simplest sive of the motor parts. fig. S—A Merchant Rolling Mill with Supplemental Sizing forms of guides were Certain types of mer- Train used. Then, as now, the chant mills producing a imited range of flats, large rounds, etc., do not have ind do not require the notched type of bed; but practi- y all modern merchant mills are now equipped with me form of mechanical cooling bed. The large ton- ge and superior quality of material, as well as the w cost of production which obtains in modern mer- int mills, could not be approached, particularly in ill mills, without the long mechanical bed with hed racks. \ most fascinating feature of these long beds, which made at present in lengths up to 500 ft., is present- in the opportunity to observe the peculiar effect of ecular changes incident to the cooling of the hot After the bars reach the bed they first contract, expand several inches, and then finally contract most common sections rolled were rounds, and these were made quite true and accurate by first rolling a round bar slightly above the desired area and then passing it through a final finishing groove several times, the roller holding the bar with tongs and turning it 45 to 90 deg. between each pass until the desired roundness was obtained. ECONOMIES THROUGH MORE EFFICIENT OPERATION The three-high train was designed to avoid the idle pass over the top roll, and soon replaced the two-high mills and brought about a considerable economy of la- bor. The number of stands of rolls was increased with the object of enlarging the size of billets and decreas- ing the number of passes per stand. Since the tonnage was still limited by the time re- = Mo ee i — 1286 quired to pass the bar several times through the single finishing groove, it was necessary to progress that some means be found to make a round in one pass in the finishing groove. It was finally discovered that if an oval section of certain proportions was held up by metal guides on the receiving side of the finishing rolls good commercial rounds could be made in one pass. This really great discovery introduced the “guide” mill of today. The finishing of long lengths commenced at this point of development. In order to get more tonnage on the smaller mills it was necessary to run the rolls at a greater speed, and the speed was gradually increased up to the point where trouble was experienced in the roughing end of the train because of the rolls not “taking” the billet. To overcome this trouble the first roughing roll was set up independently of the finishing train and run at a lower speed. The next step forward in the production of light sections came from a new method of working the bars in the finishing train. The early method was to allow the bar to run out on the floor and pick up the last end and enter it into the next pass. It was found that a man could catch the first end in a pair of tongs and turn it back into the next pass, forming a loop which overfed onto the floor. As it was easier to turn in the bar from one roll to another than into another pass in the same roll, the alternate two-high mill came into use at this stage. The alternate two-high mill later reached its greatest point of usefulness in the Garrett type of rod mills. Overfeed in the loop was slightly reduced by stepping up the roll diameters as the section was reduced. A condition was soon brought about where the pro- duction was again limited by the hand-fed roughing train. Up to this time no mechanical appliance of any nature excepting the hook and tongs had been em- ployed about the roughing or finishing trains. About this time the steel business in this country experienced a severe and prolonged depression combined with labor troubles, and this led to the installation of a continuous roughing train in the hope of eliminating the trouble- some and expensive crew gf roughers on the hand mill. This is shown in Fig. 3. Notwithstanding prejudice and some bad details of construction, the continuous roughing train proved a commercial success for general merchant mill work. Continuous roughing trains were soon added to many existing merchant mills and to the Garrett wire rod mills. The usual number of men, known as roughers, em- ployed about a stand of hand roughing rolls amounted to 12 in 24 hours, and in 1900, working under 140 card Amalgamated scale, the men averaged to earn $3.60 for eight hours on the smallest tonnage mills. The continuous mill displaced nine of these men and in most cases increased the output of the mill 50 per cent. At about this period the continuous heating furnace was improved at the delivery end by the gravity end discharge, and this type of furnace came into general and permanent use for all kinds of merchant work. The notched mechanical cooling bed of greatly in- creased length was introduced about the same time as the continuous roughing train, and the length of finished bars increased from three to four times. It was a simple matter to speed up a continuous roughing train to overfeed the finishing pass, and so the output of the mill was again limited at the finishing train. Some considerable improvement in tonnage and yield was in sight, providing bars could be finished in longer lengths and the cooling bed no longer presented any obstacles. The problem of further improvement, therefore, resolved itself into a question of uniform heat treatment throughout the length of the finished bars. This was partially solved by an arrangement of rolls in the finishing train as shown in Fig. 4. The principal feature of this arrangement is that the peripheral speed of each roll is enough less than the speed of the one following to hold back the metal so that much of it lies in the furnace instead of upon the mill floor. The problem was completely solved by the use of 30-ft. small billets heated in a furnace placed close by THE IRON AGE June 10, 915 and immediately in front of the first stand . With this arrangement of furnace and finishin; the time of exposure from furnace to finishing substantially the same for both ends of the bar | less of the length finished. The short distance }. furnace and mill was made possible by the us flying shear. The novel arrangement of roll and housings retained all the advantages of the ali two-high construction and none of its inherent d- vantages. Mills of this type produce regularly 100 tons per month, and on a good day’s run will tury oy: 750 gross tons of %-in. rounds. Another type of mill for heavier sections is in Fig. 5. This mill is used for producing sectio. stiff to be turned in by hand and is entirely auto: in operation. Note the entire absence of roller and mechanical transfers. The first successful em, ment of mechanical repeaters on both sides of a mer. chant mill train was made in a mill of this type. One of these mills produces more than 150,000 tons of | per year. For rolling heavier merchant sections there are several types of improved mills, notably the three-high mill with traveling roller tables, and the Slick er country mill with stationary roller tables. These mills permit of the maximum flexibility and produce larg tonnages. The tendency of the times, however, is t revert to the two-high construction of the original Cort mill for all kinds of rolling, on account of its simplicity and great stiffness. SOME RECENT IMPROVEMENTS From the beginning two fundamental difficulties have obtained in all general merchant mills, due to the wide range of sections required to be rolled on a given mill, and the problem for the future to solve is the elimination of these difficulties, which are as follows: Lost time during roll changes. Extreme variation in output from light to heavy sections. Spare finishing trains seem to be the remedy for the first. Speed changes can be employed to only a limited extent to correct the second trouble, and therefore it seems necessary to increase or decrease the number of strands rolled in inverse proportion to the weight of bar to be rolled. For 8-in., 9-in. and 10-in. mill work the arrangement of rolls shown in Figs. 6 and 7 seems to offer a simple selution of both of these difficulties. Improvement in mill construction, together with the perfection of the art of roll design and guide design, has made possible the production of sections of almost unbelievable accuracy; but the insistent demand of many buyers of steel for extreme exactness of round sections has made it necessary to provide means for rolling hot rounds with almost the accuracy of cold drawn bars. To meet this new requirement of the steel trade a special mill has been evolved with which the genera! trade may not be familiar, although it has been in suc- cessful operation for some months. This new mill, curiously enough, works upon the same principle as employed in the original merchant mill for securing an accurate and true round, but, of course, without revert- ing to hand labor. Two pairs of rolls set at 90 deg. to each other are mounted so close together in a common housing that the leading pair performs the function of the man with the tongs on the old two-high hand mill. As in the old-time mill, a round bar slightly larger in area than the finished bar is first made in the regular way and then passed through the sizing mill, which is located between the regular finishing train and the cooling bed shown in Fig. 8. The usual best rolling practice of plus or minus about seven-one-thousandths of an inch in diameter has by this machine been re- duced 50 per cent. The Berlin Machine Works, operating a plant at Beloit, Wis., and a branch in Canada, has refused shrap- nel orders which would have taken two years to fill. A report has been current that it had booked large orders but the president of the company says that he does no favor such business. 10, 1915 H. nmer Drill Bit Sharpening Machine e Sullivan Machinery Compa