Abstract: A method of manufacturing a high pressure gas cylinder by deep drawing and ironing a blank of high strength steel, the periphery of the blank being ground prior to cupping.

Abstract: An improved bottom former for a draw and iron can-making apparatus is disclosed. The improved bottom former includes a hydraulically pressurized base-forming die unit. This die unit provides increased pressure and improved results, as compared with conventional bottom formers, especially with regard to large diameter can bodies.

Abstract: A method of drawing metal cups from metal sheets, which includes the steps of separating non-circular blanks of material from a metal sheet and of drawing cups from such blanks. The blanks may be of substantially hexagonal or square shape.

Abstract: Continuous in-line control of work product is provided in draw-redraw processing of flat-rolled sheet metal, coil coated on both its surfaces with organic coating, to finished one-piece can bodies. Drawing of a sheet metal blank is controlled to present flange metal at the open end of the cup-shaped work product which is disposed with its closed end wall in the sheet metal line. The drawn work product is pneumatically controlled to separate the sheet metal line from the can line eliminating random accumulation of work product. Redrawing operations are carried out closed end up to present flange metal which stabilizes in-line movement of work product. Electrostatic lubrication to protect organic coating and facilitate forming is carried out prior to each redrawing operation; in-line movement of work product is controlled during such lubrication.

Abstract: A hydraulic cup holder for use in a draw and iron can making press is disclosed. This cup holder produces increased pressure between the cup being reformed and its holding members, reducing the tendency for wrinkles to occur in reforming the cup into a can body.

Abstract: An apparatus for supporting an elongated ram which is adapted to reciprocate horizontally at a high velocity is provided. The apparatus comprises a slide yoke fixed onto the base of the ram for driving the ram, the slide yoke comprising at least two sets of hydrostatic pressure sliding oil pockets in the longitudinal direction thereof; and a hydrostatic pressure bearing for supporting the ram, the hydrostatic pressure bearing having at least three sets of oil pockets in the longitudinal direction thereof which are spaced with bushings therebetween.

Abstract: The invention herein relates to a method of and apparatus forming a reinforced pressure resistant can end by gripping a central panel of a metallic blank between an axially aligned reform pad and an indent ring, the reform pad being in internal concentric relationship to a draw punch and the indent ring being in internal concentric relationship to a lift ring, the draw punch being movable in a first direction to exert first forces against a peripheral edge portion of the blank in a first direction to form the peripheral edge portion out of the plane of the central panel and shape the blank into a generally flanged cup-shaped configuration defined by the central panel, a radius, a frusto-conical wall and an annular flange, and while the central panel is still gripped, second forces are exerted beyond the first forces and in a second direction opposite the first direction to form at least a part of the metal of the radius, in the absence of restraint or constraint, out of the plane of the central panel and to a

Abstract: An anode cylinder of a magnetron is formed of a rectangular copper plate member. The plate member is curved in a rolling process to be formed into a cylindrical primary workpiece. In a first cold extrusion process, the primary workpiece is forced successively into a first die having an inner diameter shorter than the outer diameter of the primary workpiece and a second die having an inner diameter shorter than that of the first die and arranged in line with the first die. Thus, the primary workpiece is continuously reduced in its outer diameter to be formed into a secondary workpiece. The thickness reduction rate of the primary workpiece used during its passage through each of the first and second dies is limited to 3% or less. The secondary workpiece has its unnecessary portions removed in a cutting process and its seam filled up airtightly in an airtight bonding process.

Abstract: Herein disclosed is a process of manufacturing drawn tubing, in which steps of applying a lubricant to the surface of a bottomed blank fitted on a mandrel, pushing out the mandrel to draw the blank through a die, and pulling in the drawn blank together with the mandrel out of the die are repeated in the recited order. The drawn blank is turned a predetermined angle, e.g., 180 degrees on the axis thereof during each of the repeating steps i.e., during or after the pulling step. As a result, the lubricant can be applied to another portion of the blank surface at a second or subsequent applying step so that the working conditions which might otherwise become different to cause the drawn blank to have a locally irregular or offset thickness can be made uniform in the circumferential direction of the blank.

Abstract: A sheet metal workpiece is formed to have a plurality of relatively large diameter but relatively shallow cup-like depressions in a first draw operation, to have the shapes of the cup-like depressions changed in a subsequent draw operation and to form the base of the central cup-like depression into a secondary cup-like depression in a further draw operation.

Abstract: A forming machine (10) is provided for forming a finished part (12) from a flat blank (14). Draw stations (18-24) are provided to initially form the intermediate part. Each draw station includes a punch (44, 62, 66, 70') and a draw die (48, 64, 68, 72). Each punch defines a shoulder along its length to create a first step (60) in the side walls (26) of the intermediate part. In a subsequent draw stage, a draw punch (70') forms a second shoulder along its length to create a second step (100) in the side walls (26) of the intermediate part. A draw shoulder (61) on the draw punch (71') mates with the step (60) to maintain the concentric shape thereof. In the subsequent necking and final form stages (30, 32, 34) the punch employed also has a shoulder to permit variation of the force applied to the intermediate part between the step and bottom portion.

Abstract: An ironing apparatus for forming a cup-like metallic article such as an one-piece metallic can body is provided. The apparatus comprises a punch provided on a tip of a ram adapted to reciprocate in the horizontal direction and a plurality of ring dies cooperating with the punch. In the apparatus, the punch reciprocates such that the center of the end face thereof moves along a locus curved downwardly with the gravity, and the die is disposed to be slightly inclined with respect to a vertical plane such that the axis of the die extends substantially in the tangential direction of the locus at the location of the die.

Abstract: A forming machine (10) is provided for forming a finished part (12) from a flat blank (14). Draw stations (18-24) are provided to initially form the intermediate part. Each draw station includes a punch (44, 62, 66, 70) and a draw die (48, 64, 68, 72). Each punch defines a shoulder along its length to create a step (60) in the side walls (26) of the intermediate part. In the subsequent necking and final form stages (30, 32, 34) the punch employed also has a shoulder to permit variation of the force applied to the intermediate part between the step and bottom portion.

Abstract: A tool pack assembly for the drawing and ironing of containers wherein the ironing and guiding dies are movably mounted for automatic centering thereof to regain axial realignment thereof with the axis of the provided punch should such disc shift from alignment. The assembly includes a redraw dye or ring to receive the blanked container and associated support and ram with the ironing dies being spaced therefrom for ironing of the container as the same is driven therepast by movement of the ram. Ironing dies are mounted for radial floatation within a housing, and biasing means are spaced peripherally thereabout to bring the ironing dies and guides into axial relationship with the ram. The assembly further includes a stripper die assembly for removal of the finally formed container which die is similarly radially floatable and similarly biased to bring the die into axial relationship with the container and container driving punch.

Abstract: An air transfer system for a shell press is provided which air conveys a blanked and formed shell from a blanking and forming die station in the shell press to a curling die station in the same shell press. The air transfer system further provides for the blanked and formed part to be air conveyed within the curling die, and after the shell is curled within the die, provides for the curled shell to be air ejected from the curling die for subsequent fluid conveyance therefrom. A guide track extending between the die stations is just slightly wider than the diameter of the shell being conveyed and the fluid conveyance is provided by a hollow tube disposed in the upwardly facing surface of the guide track. A shell is air conveyed within the curling die station when an opening in a sleeve member, which is disposed about the curling die station and connected to a reciprocating blanking slide, becomes aligned with the guide track upon downward motion of the blanking slide.

Abstract: The present invention provides a novel process for forming a cell can or container, for a cylindrical battery having longitudinally extending internally projecting ribs which are formed along the internal surface of the battery cell. These ribs provide increased physical and electrical contact between the cell and the electrode material disposed therein. Also disclosed herein is the product formed by this process.

Abstract: An apparatus and method for the high-speed production of seamless metal container bodies is disclosed utilizing a reciprocating ram which forces a relatively shallow metal cup through a die assembly to iron the sidewall of said cup to form an elongated ironed container body, the ram is supported and critically-aligned by at least two stationary guide means along its length and a slide blank means rigidly secured to its rearward end, the slide block means having opposed hydrostatic pressure pads to provide constant critical alignment of the rear end of the ram and prevent misalignment of the ram relative to the die assembly to avoid producing container bodies of overly-inconsistent length.

Abstract: A process for forming an improved deep drawn and ironed metal shell for use as a pressure vessel having selectively controlled wall thicknesses to impart additional strength to predetermined portions of the improved metal shell. A stepped mandrel is utilized in conjunction with at least one ironing die to fabricate the improved metal shell.

Abstract: In a redrawing-ironing apparatus provided with a punch fixed on a ram, a die means including a redrawing die and ironing dies, an annular piston for fastening the die means, a cup retained pad adapted to push the inner periphery of the bottom of a drawn cup placed on the redrawing die, and pins fixed on the annular piston and extending axially, the free end surface of the pin is engaged with the flange of the cup retainer pad at the end of the redrawing. As a result, the earing portions of the drawn cup can be prevented from being thinned and broken into fragments at the redrawing.

Abstract: A system for forming unitary containers from flat metal stock includes a unique arrangement of both previously known and newly discovered apparatus, including means for blanking and cupping the flat metal stock into individual cups; means for drawing and redrawing the cups and bottom profiling them in one machine; and additional means for trimming, flanging, and beading the containers thus drawn. The system and method include, among other things, the utilization of apparatus which permits drawing, redrawing, and bottom profiling to take place in one press. This is accomplished by carrying draw, redraw, and bottom profile tooling in a single press and by inserting the cups in the press for the draw operation and them removing them and reinserting them for the redraw and bottom profile operations.

Abstract: A cup feeding mechanism for a bodymaker includes a guide chute defining a vertical path with a stop located at the lower end of the path defining a transfer area. The stop has a specifically configured area for receiving each cup and defining a fixed position for the cup in the transfer area. A drive member is reciprocated transversely of the path and picks up cups from the transfer area and positively drives them into alignment with a ram that extends perpendicular to the axis of the path so that the cups are maintained in accurate alignment with the ram prior to being transferred through the bodymaker.

Abstract: An apparatus and method for the high speed production of seamless metal container bodies is disclosed utilizing a reciprocating ram which forces a relatively shallow metal cup through a die assembly to iron the sidewall of said cup to form an elongated ironed container body, the ram is supported and critically aligned by at least two stationary points and also at its rearward end by a slideable ram block assembly to which the ram is rigidly secured, the critical alignment of the rear end of the ram prevents misalignment of the ram relative to the die assembly to avoid producing container bodies of overly inconsistent length.

Abstract: A forming machine (10) is provided for forming a finished part (12) from a flat blank (14). Draw stations (18-24) are provided to initially form the intermediate part. Each draw station includes a punch (44, 62, 66, 70') and a draw die (48, 64, 68, 72). Each punch defines a shoulder along its length to create a first step (60) in the side walls (26) of the intermediate part. In a subsequent draw stage, a draw punch (70') forms a second shoulder along its length to create a second step (100) in the side walls (26) of the intermediate part. A draw shoulder (61) on the draw punch (71') mates with the step (60) to maintain the concentric shape thereof. In the subsequent necking and final form stages (30, 32, 34) the punch employed also has a shoulder to permit variation of the force applied to the intermediate part between the step and bottom portion.

Abstract: A method and apparatus for making a necked container are disclosed wherein a sheet material is formed into a generally cylindrical tubular member and the adjacent longitudinally extending edges of the sheet are butt welded. The welded tubular member is progressively necked-in over a dome-shaped surface of a single mandrel provided within the welded tubular member. The free end of the necked end portion of the tubular member is trimmed and curled to form a necked container body.

Abstract: An aluminum alloy food can body and a method of forming the same whereby an uncoated high strength aluminum alloy sheet stock is blanked and drawn into a sized cup and redrawn by one or more redraws to form the sized can body. The end wall of the can body is formed into a pressure resistant profile, the side wall adjacent the open end is trimmed and outwardly flanged, a plurality of annular beads is formed in a central portion of the side wall, and at least the interior of the can body is coated with a material compatible with the food product to be packaged in the can. An end portion of the can side wall is ironed to reduce its thickness during at least one of the redraw operations.

Abstract: A forming machine (10) is provided for forming a finished part (12) from a flat blank (14). Draw stations (18-24) are provided to initially form the intermediate part. Each draw station includes a punch (44, 62, 66, 70) and a draw die (48, 64, 68, 72). Each punch defines a shoulder along its length to create a step (60) in the side walls (26) of the intermediate part. In the subsequent necking and final form stages (30, 32, 34) the punch employed also has a shoulder to permit variation of the force applied to the intermediate part between the step and bottom portion.

Abstract: Apparatus for removing a drawn container from a draw horn which is carried by the inner slide of a double acting press includes a stripper assembly also carried by the inner slide and capable of controlled axial movement relatively of the draw horn. The draw horn and draw riser have coaxial, centrally disposed bores within which is received an elongate shaft of the stripper assembly. The distal end of the shaft carries a stripper pad while the proximal end is adjustably connected to a pivoting linkage mounted on the inner slide and normally pivoted under pressure by a pneumatically actuated piston so as to maintain the stripper assembly in retracted condition, the pad then forming the bottom of the horn.

Abstract: A metal container comprising a seamless body and an end wall integral therewith and having on at least its interior surface a protective coating which is the reaction product of a citric acid ester utilized as a lubricant in forming the container and an after-applied synthetic resin.

Abstract: A method and apparatus for forming nestable two-piece containers includes forming a cup from a metal blank; redrawing the cup thus formed to approximately one-half its final height while imparting a tapered sidewall thereto by use of a tapered die center; redrawing the container thus formed to its full height while continuing the taper by use of a second tapered die center while simultaneously profiling the bottom of the container thus drawn. The apparatus includes at least two redraw stations, each including a tapered redraw die center and corresponding die. The second of said stations also includes bottom profiling tooling.

Abstract: An apparatus for drawing and ironing a cup with a peripheral flange from relatively thin material into an elongated container also having a flange by moving a die and punch relative to one another and draw clamping and centering sleeve coaxial therewith and thereafter applying a bottom forming member axially relative to the die against the punch to profile shape said container bottom without the benefit of coolant flooding of said material during drawing and ironing, the improvement comprising; a die of a predetermined shape and size carried in the apparatus, a punch of a predetermined shape and size for cooperating with said die and each having surfaces which define a clearance therebetween during forming of said material; separate passages through said die means and said punch means to permit flow of coolant; valving in line with die and punch passages for independent control of the coolant flow from a supply means to said die and punch to permit regulation of the operating temperature of said die means wit

Abstract: In a drawing device for presses with a mechanically driven drawing ram (24) and with a sheet metal holder (5) exerting its holding force, acting on the metal sheet (27) and counteracting the drawing direction, by way of a pressure plate (7) by means of a die cushion piston (10), supporting the pressure plate and being under the effect of a pressure medium, in a fixed die cushion cylinder (12), the objective consists in avoiding, or at least reducing, the noise-generating impact shock upon impingement of the drawing ram (24) on the sheet metal holder (5) with the metal sheet (27) lying thereon.

Abstract: A strong, seamless one-piece metal bottle of substantially uniform wall thickness for containing and dispensing gas under pressure is produced from a flat metal piece by a series of deep-drawing operations to provide an elongated cylindrical shell having an open end mouth and a slight flange thereabout. A dimple is formed in its bottom end wall. The flange and an adjacent cylindrical open end mouth portion of the shell is then severed from the main body, and the wall thickness of the new open end mouth portion is tapered from the cylindrical side wall of the shell towards its mouth edge. Thereafter, the tapered open mouth end portion is turned or swaged inwardly into a somewhat blunt, rounded-in nose portion of a substantially uniform thickness that substantially corresponds in the thickness to the side and bottom walls of the formed metal bottle and that has an open end of reduced size suitable for mounting a nipple, ferrule or valve fitting therein.

Abstract: This disclosure relates to a product, the process for making same from precoated metal and the tool used for making the product. The product is a concurrently drawn and ironed sanitary food can wherein the side wall thickness of the container is relatively uniform and approximately 0.001" thinner than the thickness of the starting material. The process is a concurrent multiple drawing and ironing operation wherein the diameter and the wall thickness are reduced in each of a plurality of operations. Finally, the tools used for each drawing and ironing operation have particular configurations designed to permit this concurrent forming of both the diameter and the side wall thickness.

Abstract: A system for forming unitary containers from flat metal stock includes a unique arrangement of both previously known and newly discovered apparatus, including means for blanking and cupping the flat metal stock into individual cups; means for drawing and redrawing the cups and bottom profiling them in one machine; and additional means for trimming, flanging, and beading the containers thus drawn. The system and method include, among other things, the utilization of apparatus which permits drawing, redrawing, and bottom profiling to take place in one press. This is accomplished by carrying draw, redraw, and bottom profile tooling in a single press and by inserting the cups in the press for the draw operation and then removing them and reinserting them for the redraw and bottom profile operations.

Abstract: Drawn and ironed can bodies are formed from cold rolled steel sheet having a thin coating of a nickel-zinc alloy electroplated thereon by drawing the coated steel into a cup and ironing the sidewall of the cup on a mandrel by passing it through a toolpack comprising a plurality of ironing rings each including a generally conical lead-in surface having an angle relative to the axis of the mandrel within the range of 6.degree. to 81/2.degree. and a substantially cylindrical land extending no more than about 0.025 inches in the axial direction of the toolpack through the rings. The diameter of the land on successive ironing rings is progressively smaller in the direction of movement of the can through the toolpack, with the diameter of the final ironing ring being such as to reduce the sidewall of the cup to about one half its original thickness. The length of the land of the final ironing ring may be less than that of the previous ironing rings and preferably is within the range of 0.003 to 0.007 inches.

Abstract: An integrated system and apparatus for completely forming the body of a two-piece can in one press, including performing the operations of cupping, drawing, redrawing, bottom profiling, and trimming. The system includes the concept of performing all of the operations required to form the body of a two-piece can in one press and includes feeding the precoated stock material, either in the form of sheet or coil, through a lubricator and into a feeding apparatus which, in turn, selectively feeds sufficient quantities of the stock material into a press. The press carries the double die necessary to perform the typical blanking and cupping operation and passes the cups out of the press in two lanes onto cup conveyors which feed them back into the press whereupon the draw-redraw dies on both sides of the cup die perform the additional steps of first redraw, second redraw, bottom profile, and trimming. The formed containers are then conveyed to secondary processing stations such as beaders, testers, or palletizers.

Abstract: A drawing and ironing assembly including a punch movable along a path having a plurality of spaced ironing die assemblies with the last of the ironing die assemblies having twin spaced lands, the diameter of the second twin land is slightly greater than the diameter of the first land to produce a very small amount of ironing.

Abstract: A process for forming hollow bodies of metal materials, particularly of aluminum alloys, based on a suitable combination of mechanical operations comprising deep drawing, stretching, tapering and tool machining, whereby it is possible to obtain essentially cylindrical one-piece metal bodies with a concave dished bottom and a dome-shaped head provided with a beaded opening. The unitary bodies are characterized in that the cylinder walls are very thin, highly strain-hardened and endowed with high mechanical properties, permitting a remarkable reduction in the metal material amount used in the aforesaid enbloc bodies, destined for being used chiefly as pressure containers, for example for aerosol.

Abstract: In manufacture of a can body by drawing a cup from a blank and subsequently redrawing the cup, one or more redrawing steps are performed by pulling the sidewall of the cup (2) by means of a punch (12) through an S-shaped path (30,24,31), whereby the wall is bent first in one direction and then in the other, to reduce its diameter, which is then reduced further in a convergent portion (20) of the die (10). The bending induces back tensions which stretch the metal and reduce its wall thickness.

Abstract: An improved method and apparatus for deep drawing metal containers is disclosed in which flat sheet metal blanks are initially drawn into shallow cups having an open top, a substantially flat bottom wall, a substantially cylindrical sidewall and a curved transition section joining the bottom wall and sidewall. A redraw sleeve adapted to fit into and support the cups has a first annular clamping surface on its free end contoured and arranged to engage the transition section and the adjacent annular peripheral portion of the bottom wall of a cup. An annular redraw die is supported for movement from a retracted position spaced from the redraw sleeve to a clamping position cooperating with the redraw sleeve to clamp and hold the cups during redrawing. The redraw die has a second clamping surface contoured to engage the outer surface of the transition section and the adjacent annular peripheral portion of the bottom wall of a cup supported on the redraw sleeve.

Abstract: This disclosure relates to a product, the process for making same from precoated metal and the tool used for making the product. The product is a concurrently drawn and ironed sanitary food can wherein the side wall thickness of the container is relatively uniform and approximately 0.001" thinner than the thickness of the starting material. The process is a concurrent multiple drawing and ironing operation wherein the diameter and the wall thickness are reduced in each of a plurality of operations. Finally, the tools used for each drawing and ironing operation have particular configurations designed to permit this concurrent forming of both the diameter and the side wall thickness.

Abstract: An improved sheet steel suitable for the production of containers and the like has a thin composite coating of nickel and zinc plated on both sides thereof. The steel substrate may be flat rolled blackplate and the composite nickel-zinc coating may be plated thereon by drawing a running length or strip of the steel through a nickel electroplating bath to which has been added the necessary concentration of zinc, and electrodepositing the two coating metals simultaneously and in the desired proportions. The coated steel sheet is particularly useful in forming drawn and ironed cans although it may be used for other purposes.

Abstract: An inverted press for producing multiple drawn metal containers combines in one press the functions of cupping and drawing presses. The press includes a blanking and cupping station and several drawing and redrawing stations, disposed one adjacent the other and rendered serially operative by a vertically reciprocable slide assembly. At each stage of operation the material, semifinished article or finished article is under complete control. A method for producing a drawn container by multiple forming and reforming of a drawn article, is also provided.

Abstract: A method and apparatus for forming a cylindrical wall-ironed sleeve having a bottom and a radially inwardly enlarged wall thickness at an end remote from said bottom with there being an internally tapered transition region between a normal wall thickness and the enlarged wall thickness, said method including the forming of the sleeve on a mandrel with said enlarged wall thickness being interlocked with said mandrel; the step of introducing a fluid under pressure through the mandrel between the mandrel and the sleeve at the transition region of the sleeve to momentarily radially enlarge the end of the sleeve remote from the bottom and release the inter-lock between the sleeve and the mandrel.

Abstract: An inverted press for producing multiple drawn metal containers combines in one press the functions of cupping and drawing presses. The press includes a blanking and cupping station and several drawing and redrawing stations, disposed one adjacent the other and rendered serially operative by a vertically reciprocable slide assembly. At each stage of operation the material, semifinished article or finished article is under complete control. A method for producing a drawn container by multiple forming and reforming of a drawn article, is also provided.

Abstract: An apparatus for forming an inward dome in the bottom wall of a metal can body having a beveled peripheral edge bordering the bottom wall. The apparatus includes a housing which supports a convex die member adapted to engage the bottom wall of the can body to form the dome. A pressure ring is disposed radially outward of the die member and is mounted for sliding movement with respect to the die member. The pressure ring is provided with a beveled surface which is adapted to be engaged by the beveled edge of the can body to prevent deformation of the bevelled edge as the dome is formed in the bottom wall. The pressure ring is connected to an air spring which provides uniform resistance to movement of the ring relative to the die member. In addition, the housing and die member are connected through a second air spring to a fixed support and after the dome has been formed, continued axial movement of the can body will result in compression of the second air spring to insure full formation of the dome.

Abstract: Apparatus and method for discharging flanged cups in a controlled oriented fashion from a blanking and forming press. The formed cup is raised to a position slightly higher than the upper face of the drawing die, and moved in a straight line by means of a high pressure air pulse to the inlet of a conduit-like discharge chute. The formed cups are moved through the discharge chute by air pressure issuing from angled slots in the walls of the chute. The invention is particularly advantageous for use with blanking and forming presses simultaneously producing a plurality of formed cups in order to discharge the formed cups separately from each station in an orientation substantially the same as that in which the cup was formed. The invention eliminates damage to the formed cup caused by random bulk handling in conventional discharge equipment.

Abstract: Improved ironing material and structure for drawing and ironing can bodies from lightweight flat rolled sheet metal while facilitating stripping from the ironing mandrel and providing desired flanging metal are disclosed. The exterior surface of the mandrel is provided with a uniform-taper transition zone contiguous to the trim height for a can body being formed such that sidewall metal thickness increases uniformly above the main body portion of the can body and expires along the tapered surface of the transition zone. The tapered surface extends beyond formed can body height so that stripping means approach the open end of an ironed can body along a portion of the mandrel having a smaller diameter than the interior diameter of the mandrel mounted can body.

Abstract: A metal forming tool useful to form internal and external impressions of various configurations upon two piece can bodies of round, oval, triangular, rectangular or irregular and unsymmetrical cross-section.

Abstract: The method of drawing uniformly heavy walled parts in a multiple plunger machine without any intermediate anneals and a machine for carrying out the method. The method comprises a number of press operations which convert a flat blank to a final desired drawn configuration, the relatively uniform wall thickness being maintained throughout the operation by the mouth configuration of each die and by means of supplemental sleeves that assist the punches in extending the drawn shells into the dies with no stretch to the metal or thinning of walls. Work hardening due to stretch or tensile load is minimized allowing more deformation without anneals.