Abstract: A press forming tool is configured to form a press forming part including: a top portion having a convex and concave outer edge part; and a flange portion. The press forming tool includes: an upper die and a lower die; and a lower pad and an upper pad, which sandwich a blank in cooperation with the upper die and the lower die, in which, during an initial stage of forming, the flange portion is formed on the convex outer edge part, and a torsional shape portion having a torsional shape toward the concave outer edge part is formed continuously from the flange portion, and during a late stage of forming, the torsional shape portion is formed into the flange portion, and the flange portion is formed in the concave outer edge part so as to achieve formation of a target shape.

Abstract: A processing unit for processing a workpiece wall of a workpiece with a forward stroke carried out by the processing unit in a forward stroke direction of the processing unit towards the workpiece, and with a backward stroke carried out by the processing unit in a backward stroke direction of the processing unit away from the workpiece, wherein the workpiece and the processing unit move relative to each other along a working axis of the processing unit. A processing machine for processing a workpiece wall of a workpiece contains the processing unit.

Abstract: A first piece (13) includes a first ring portion (13b) and a second ring portion (13c) which are arranged side by side in an axial direction and an inner diameter and an outer diameter of the first ring portion (13b) are respectively larger than an inner diameter and an outer diameter of the second ring portion (13c). A second piece (16) is obtained by pressing the first piece (13) while the first piece (13) is disposed between a first set and a second set.

Abstract: A method for manufacturing a press-formed product includes a blanking step of blanking from a sheet-shaped material into a shape in which an excess material portion is added to the contour outline of a developed shape of the press-formed product, a first pressing step of folding the excess material portion to form straight sides into an intermediate formed product with a bent flange portion, a second pressing step of performing press forming including bulging in which the bulging portion is provided on the intermediate formed product, and a trimming step of trimming the excess material portion. A blank material includes excess material portion to be folded to form straight sides circumscribed around or spaced apart from a contour outline of a developed shape of the press-formed product, and an intermediate formed product includes excess material portion including a bent flange portion folded to form straight sides.

Abstract: An intersecting-axes gear type mechanism includes two gears configured to rotate in mesh with each other. Respective axes of rotation of the two gears being disposed in an intersecting-axes manner, and at least one of the gears has teeth each of which includes a tooth trace extending substantially in a radial direction and a radially inner end face. A chamfered portion is formed on a meeting portion where the radially inner end face and a tooth face of the each of the teeth meet, so as to extend over an overall length of the meeting portion. At least an entirety of an area where the chamfered portion and the radially inner end face meet and an entirety of an area where the chamfered portion and the tooth face meet are each composed of a curved surface in overall length.

Abstract: The present invention provides a method for manufacturing a torsion beam, the method comprising: a planarization step, in which a protruding portion of an upper mold presses the opposite end portions in the width direction of the blank to be plastically deformed to be flat while the opposite end portions in the width direction of the blank are supported by a side cam to face each other; a welding and bonding step for bonding the planarized opposite end portions in the width direction of the blank via welding; and a quenching step for heating the welded and bonded blank within a range of 900 to 970° C. for a retaining time within a range of 1 to 20 minutes and for cooling down the blank in a treatment liquid including at least one of water and oil in a range of 20 to 90° C.

Abstract: Provided is a technology capable of suppressing an edge crack occurring due to stretch flange deformation without being constrained by a target pressed component shape. The technology includes two-stage cutting processing of, when it is estimated that there is concern about risk of occurrence of an edge crack due to stretch flange deformation on an edge of a material (1) to be pressed in press forming, performing twice cutting processing on an edge including at least a site where there is concern about risk of occurrence of the edge crack as pre-processing for press forming in which there is concern about risk of occurrence of the edge crack. In the two-stage cutting processing, cutting to form a partial, beam-shaped overhang portion at a position including a site where there is concern about risk of occurrence of the edge crack is performed in the first cutting and the overhang portion is cut in the second cutting.

Abstract: A method for manufacturing a press-formed article (100) includes a first step for forming a base sheet portion, a first rising portion, and a first strip portion from a sheet-shaped workpiece having a first edge portion and a second edge portion; and a second step for forming a second rising portion by causing a strip-shaped first zone including the second edge portion to be disposed between a first upper die and a first lower die from both sides, causing a second zone adjacent to the first zone to be disposed between a second upper die and a second lower die from both sides, and moving the first upper die and the first lower die relative to the second upper die and the second lower die, wherein, in the second step, a part of the second rising portion which is connected to a vertical ridge line (108) is shear-deformed.

Abstract: The disclosure relates to the technical field of alloys, and in particular to a titanium alloy with a gradient microstructure and a preparation method thereof. Two new gradient microstructures different from the existing microstructure in titanium alloy are designed for the first time by an ingenious three-step heat treatment scheme, specifically, the gradient lamellar microstructure and gradient tri-modal microstructure. Compared with the regular uniform lamellar microstructure, the titanium alloy with gradient lamellar microstructure can achieve the simultaneous improvement of strength and ductility. Compared with the regular bimodal microstructure, the strength of a titanium alloy with a gradient tri-modal microstructure can be increased by about 10%, and the ductility is slightly reduced.

Abstract: A press hardened steel part is provided. The steel of the part has a chemical composition including, in weight: 0.062%?C?0.095%, 1.4%?Mn?1.9%, 0.2%?Si?0.5%, 0.020%?Al?0.070%, 0.02%?Cr?0.1%, wherein: 1.5%?(C+Mn+Si+Cr)?2.7%, 0.040%?Nb?0.060%, 3.4×N?Ti?8×N wherein: 0.044%?(Nb+Ti)?0.090%, 0.0005?B?0.004%, 0.001%?N?0.009%, 0.0005%?S?0.003%, 0.001%?P?0.020%, optionally: 0.0001%?Ca?0.003%, and the remainder being Fe and unavoidable impurities. The microstructure of the part includes, in a majority of the part, in surface fractions: less than 40% of bainite, less than 5% of austenite, less than 5% of ferrite, and a remainder being martensite. The martensite is fresh martensite and self-tempered martensite.

Abstract: To prevent a crack from occurring on a sheared end face due to press forming, a technology is provided for evaluating and predicting a crack limit of the sheared end face of a metal sheet and determining press forming conditions. In a deformation limit evaluation method for, when deforming by press forming a metal sheet subjected to shearing, evaluating a deformation limit of the sheared end face of the metal sheet, the deformation limit is evaluated by an index value obtained from two stress gradients at an evaluation position among stress distributions occurring in the vicinity of the sheared end face of the metal sheet due to the press forming, which gradients are a stress gradient in a sheet thickness direction and a stress gradient in a direction away from the sheared end face.

Abstract: A tool and die set and related method of use of the tool and die set in a press for the compaction of a powder metal into a preform involves an uneven amount of positional deflection of at least two lower or upper tool members. This asymmetrical elastic response under load may help to eliminate cracking of the part after the compressive load is removed.

Abstract: An induction pressing plate type real-time monitoring apparatus, including a fixing portion, an abutting portion, and an inductor. The fixing portion has a hole for fixing and connecting a fastener to an upper or lower platform of a forming device. The abutting portion is connected to the fixing portion, and the abutting portion in at least part of a pressure surface region is configured to press a tested piece to be induced. The inductor is disposed at the abutting portion, and has an induction unit for inducing actual information transmitted to the abutting portion by the direct contact of the tested piece and converting the actual information into measurable data, an output unit for outputting the data, and a power supply unit for providing power to the induction unit and the output unit.

Abstract: A reduced ring groove rivet at least includes a pin having a head and a body connected to the head; a plurality of sets of ring grooves are equidistantly arranged on the body, and each of the sets of ring grooves includes a first ring groove and a second ring groove adjacent to the first ring groove, wherein the first ring groove has a first groove bottom and a first groove peak adjacent to the first groove bottom, and the second ring groove has a second groove bottom and a second groove peak adjacent to the second groove bottom; a diameter of the second groove bottom is smaller than a diameter of the first groove bottom, or a diameter of the second groove peak is smaller than that of the first groove peak, so that any of the plurality of sets of ring grooves can be breaking part during operation.

Abstract: A method for manufacturing a pressed component including an elongated top plate, a wall having one end connected to a short direction end portion of the top plate, that curves with a convex shape bowing toward an opposite side to the top plate as viewed from an upper side of the top plate, and that includes a sharp curve portion, and a flange that is connected to another end of the wall, and that extends in a plate thickness direction of the wall toward the opposite side to the top plate side. The manufacturing method includes pressing to form an intermediate formed component including a preliminary flange and pressing to deform the preliminary flange to form the preliminary flange into the flange.

Abstract: A sealing plate including an explosion-proof valve whose opening pressure can be set easily, and whose groove will not be not ruptured by a repeated stress before reaching an opening pressure. The explosion-proof valve including a thin plate portion thinner than a plate; a valve portion formed by partially projecting the thin plate portion in a thickness direction to enhance a bending rigidity; and a groove drawn as a boundary between the valve portion and the thin plate portion to serves as a score line. A rupturable portion that is ruptured after the groove is ruptured is formed between a straight line and a folding line. The valve portion is bent along the folding line to open the explosion-proof valve when the rupturable portion is ruptured after the groove is ruptured.

Abstract: The present disclosure discloses an apparatus and a method for forming a large-scale thin-walled ring shell by hot-press bending with internal gas pressure. The method comprises: welding a first head and a second head to the pipe; arranging a first electrode and a second electrode at the two ends of the pipe; charging compressed gas to the heated sealed pipe assembly; placing the sealed pipe assembly between the convex part of the first die and the concave part of the second die, controlling the temperatures of the first and second dies to perform press bending; increasing the gas pressure in the bent sealed pipe assembly, to attach the bent sealed pipe assembly to the die cavity profile; discharging the compressed gas, cutting the first head, second head and extra material to obtain a formed ring shell segment; welding formed ring shell segments to obtain a large-scale thin-walled ring shell.

Abstract: A system and method for forming an integral flange in an end portion of a composite laminate structure, such as an aerospace or other vehicle structure. First and second tool components cooperate to support the structure during a layup process, with the second tool component imparting an initial angle to the end portion. A third tool component includes a male radius positioned at an apex of the initial angle. A heater heats a succession of localized areas along the end portion to lower a viscosity of the resin. A roller applies pressure to the succession of localized areas after each is heated so as to push them around and against the third tool component to form a flange angle and the integral flange. The heater and the roller may make multiple passes along the end portion, with the roller angle increasing with each pass until the flange angle is achieved.

Abstract: A lower die has a first lower-die edge extending along the outline shape of a sheet material, and a plurality of second lower-die edges disposed vertically below the first lower-die edge and each extending in a direction traversing an offcut of a sheet base material that is left behind after the sheet material is punched out. An upper die has a first upper-die edge which extends along the first lower-die edge and between which and the first lower-die edge the sheet base material is shorn to punch out the sheet material, and a plurality of second upper-die edges which is provided so as to be protrusible to vertically below the second lower-die edges and between which and the second lower-die edges the offcut is shorn and divided.

Abstract: A method of manufacturing a separator includes subjecting a metal thin sheet material to be transported to stepwise forming working at an identical location by a plurality of press machines having different working shapes and arranged sequentially from an upstream side to a downstream side in a transport direction of the metal thin sheet material to form a flow passage groove. The thin sheet material is subjected to annealing treatment in at least one space of spaces between the press machines arranged adjacent to each other in the transport direction of the thin sheet material.

Abstract: A method of adjusting a stamping die is provided. The method includes providing a two-sided stamping die configured to form parts from sheet metal blanks according to a desired geometry upon closing the die, adjusting the desired geometry of the part, and repeatedly depositing layer upon layer of material onto a first side of the die in a stacked configuration to modify the geometry of the first side of the die such that the die forms parts from sheet metal blanks according to the adjusted desired geometry.

Abstract: A press forming method for forming a press-formed product having no flange portion from a blank by performing a crash forming process while using a die and a punch, the press-formed product including at least a top portion and a side wall portion continued from the top portion via a connecting portion and being structured so that either all or a part of the side wall portion curves toward an outside of the press-formed product to form a convex shape in a planar view, the press forming method including forming the side wall portion while keeping a tip end portion of the blank in continuous contact with a side wall forming portion of the die and causing the die to impose no restraint on any part other than the tip end portion of the blank.

Abstract: Provided is a forging method capable of preventing a vibration state from being disturbed during forming. The present invention relates to a forging method in which, when a forging material W1 in a forming hole 12 of a die body 11 is plastically worked by driving a punch 2 into a forming hole 12 of the die body, ultrasonic vibrations are applied to the die body 11. The contact state of the forging material W1 with respect to a forming hole inner peripheral surface during the plastic working of the forging material W1 is classified into an insufficient contact state, a sufficient contact state, and a full contact state in order from the forming start time. An application of ultrasonic vibrations is started after shifting from the insufficient contact state to the sufficient contact state.

Abstract: The present invention relates to a methods and systems for monitoring and/or characterizing multi-component tablets and for monitoring punch and die surfaces and, more particularly, to methods and systems for in-die and out-of-die monitoring and/or characterizing multi-component tablets based on acoustic and vibrational spectroscopy and for detecting and monitoring stiction and tooling material modifications on punch and die surfaces during compaction based on acoustic/ultrasonic waves.

Abstract: A rotatable forming apparatus and a method for modifying a shape of a container. The rotatable forming apparatus includes a frame and a forming turret assembly. The forming turret assembly includes a drive shaft, a fixed turret portion, a turret starwheel, an axially moveable turret portion and forming ram assemblies. The forming ram assemblies extend around and connect to the axially movable turret portion. Each of the forming ram assemblies includes cam followers, a forming die, a knockout tooling device and a drive cylinder. The cam followers are configured to follow the cam as the forming ram assemblies rotate around the stationary cam. The forming die is operatively connected to the cam followers such that the forming die moves in the vertical direction while following the cam. The drive cylinder causes axial movement of the knockout tooling device and is configured to operate independently of the forming die.

Abstract: In a method for producing a component by hot forming of a pre-product made of steel, the pre-product is heated to forming temperature and subsequently formed. The product is heated to a temperature below the AC1-transformation temperature and undergoes a strength increase prior to the heating by cold forming.

Abstract: In a step of forming a fixing groove for a wheel disk (20), an inner circumferential end of a first hub hole peripheral portion (41) is squeezed by a protruding portion (D21) of a back die (D2) and a dent portion (D31) of a front die (D3). In this manner, a fixing groove (50) is formed in a back surface of the first hub hole peripheral portion (41). Along with this, an excess material is pushed into the dent portion (D31) so that a protrusion (51) is formed on a front surface of the first hub hole peripheral portion (41). Thus, without requiring a step of cutting the excess material, the fixing groove (50) can be formed in a back surface of a hub hole peripheral portion (30).

Abstract: A forging apparatus and method is disclosed in which a die has two separate cavities, each having a first cavity portion and a second cavity portion. A billet of material is received in a first cavity portion and struck by a striking portion of an extrusion punch so as to be forced into the corresponding second cavity portion to form a shaped component. The billet of material can be placed into either of the two cavities for extrusion. This may increase the number of extrusion operations that can be performed by a single die.

Abstract: A mold for molding a case of a mobile device includes a first, second, third, fourth and fifth main body, connection slide blocks, and first and second abutment slide blocks. The connection slide blocks and the second abutment slide blocks are inlaid in first and second slide channels of the first and second main bodies. The first abutment slide blocks are inlaid in channels of the connection slide blocks. The third, fourth and fifth main bodies are horizontally movable relative to the first and second main bodies. The first and second main bodies, the connection slide blocks and the first and second abutment slide blocks together define a male mold section and the third, fourth and fifth main bodies together define a female mold section. A metal thin sheet is placed on the male mold section and pressurized and molded by the female mold section to form the case.

Abstract: An apparatus for forming an article by forging. The apparatus has at least one die having a die cavity to receive material, said material being at least partially molten, and at least one punch to slidably engage the die cavity and to exert a forming pressure on material disposed in the cavity. There is also at least one pin for forming an article feature. The pin is to slidably engage the die and to contact the material, the pin being further to recede upon exertion of the forming pressure and to exert a feature forming pressure when receded and thereby form the article having the article feature when the material solidifies under the forming pressure.

Abstract: A surgical implant component comprising an implant component body manufactured from an alloy comprising from about 23 to about 33 wt % Cr, from about 8 to about 20 wt % Mo, from about 0.05 to about 1.5 wt % Si, from about 0.35 to about 3.5 wt % C, from about 40 to about 60 wt % Co, and incidental impurities. The implant component alloy has an atomic % ratio of (Cr+Mo+Nb)/Co of at least 0.59, a matrix metallurgical microstructure comprising between about 45% and about 85% by volume face-centered cubic structure, and between about 15% and about 55% by volume hexagonal close-packed structure; and a Rockwell C hardness of greater than 35. A method for manufacturing a surgical implant component body for a surgical implant by a manufacturing method selected from the group consisting of casting, forging, and powder metallurgy pressing-plus-sintering from an alloy.

Abstract: A device and a method of using the device for construction of baffles that may be used in suppressors or solvent traps for firearms out of metal cups sold as engine block freeze plugs. The device has a bottom die, a top die and an alignment cylinder. The metal cup is transformed into a baffle by placing the metal cup on the bottom die, placing the bottom die inside the alignment cylinder, placing the top die inside the alignment cylinder, and applying compressive forces to the bottom die and top die. A hole may be drilled in the center of the baffle by placing a drill bit into a top die center hole completely penetrating through the top die and coaxial thereto, and drilling through the baffle, the drill bit passing into a bottom die center hole penetrating at least partially into the bottom die and coaxial thereto.

Abstract: Provided is a mold steel for plastic injection that is excellent in fatigue strength and tensile strength and available for long term use, where the mold steel includes: 0.15 to 0.40 wt. % of carbon (C), 0.15 to 0.50 wt. % of silicon (Si), 0.70 to 1.50 wt. % of manganese (Mn), 0.50 to 1.20 wt. % of nickel (Ni), 1.50 to 2.50 wt. % of chrome (Cr), 0.25 to 0.70 wt. % of molybdenum (Mo), 0.20 wt. % or less of vanadium (V), 0.010 wt. % or less of boron (B), and a trace of iron (Fe) and a plurality of impurities.

Abstract: [Problem] To present a manufacturing apparatus of a plate-like tooth profile member capable of forging and forming in one process by using a closed type die, being hardly accompanied by burrs due to plastic changes in the circumferential direction and in the axial direction of the material of the plate-like tooth profile member.

Abstract: A method of manufacturing a valve for an internal combustion engine, comprises: (i) a primary step of forging a bulging portion at one end of a rod material to form a generally disk-shape valve head of the valve having a tapered periphery; (ii) an thickness adjustment step of machining an excessively thick portion of the valve head; and (iii) a secondary step of forging a peripheral region of the valve head to create radial slip deformations therein to form a valve face of the valve head. In the step of thickness adjustment, only the front end of the disk-shape valve head is machined without harming dense grain flow lines induced in the tapered face (16a) in the primary forging while advantageously saving the valve material and reducing thickness adjustment time. In the secondary forging, the hardness of the valve face is further enhanced.

Abstract: A floor support for a grain bin floor made from a sheet of galvanized steel having a top surface, a bottom surface and flat ends. The floor support has a plurality of flanges and notches disposed within the top surface and a plurality of openings disposed through the sheet of galvanized steel. Positioned between each opening is a first bend. Positioned on either side of selected first bends is a second bend thereby forming a z-shaped floor support.

Abstract: A method for manufacturing a toothed part from a cylindrical blank using a forming die. When forming a toothed portion on a radially outer section of the blank by applying a load in the axial direction of the blank to a radially center section of the blank while constraining a portion of an outer circumferential surface of the blank such that a constituent material of the blank flows radially outward, the constituent material of the blank at an intermediate section between the center section and the outer section flows in the axial direction toward a depressed portion of the forming die to form a projection portion. When the load is at maximum, a space is provided between the toothed portion and the forming die, and a space is provided between the projection portion and the forming die.

Abstract: A method of manufacturing an automobile door hinge includes hot forging a round steel bar to form a forged workpiece including a mounting portion, an arm portion, and a column portion, and forming a shaft hole by punching the column portion by using a special die and a punch. The die has a gap formed therein so that, during punching, a slug is not generated and the column portion expands outward when the punch is pressed from a punching start point to a predetermined dimension, and a slug is generated and discharged when the punch is pressed from the predetermined dimension to a punching end point.

Abstract: A method forms a steel sheet having a tensile strength of 440 MPa or more into a press-formed part including a flange portion and other portions by press forming. The method includes: heating the steel sheet to a temperature of 400° C. to 700° C.; and press-forming the heated steel sheet by crash forming to obtain a press-formed part such that an average temperature difference among a flange portion and other portions of the press-formed part immediately after the formation is kept within 100° C. Geometric changes such as springback that occur in a panel can thus be suppressed, dimensional accuracy of the panel can be enhanced accordingly, and the desired mechanical properties can easily be obtained in the press-formed part.

Abstract: A top cap is provided for a bicycle handlebar stem. The top cap includes a cap body, which has a lower portion forming a fitting cylinder of a reduced diameter and a radially expanding circumferential shoulder atop the fitting cylinder. A barrel extends from a bottom of the fitting cylinder. The barrel forms a downward-facing hollow blind hole. The cap body forms a bolt head hole extending therethrough and coaxial with and communicating the blind hole. The barrel forms slits, which define a tightening section.

Abstract: The present invention relates to a method of forging turbine blade, which comprises forging a plurality of turbine blades as an integrally connected body in a longitudinal direction, and then separating the integrally connected body into said respective turbine blades. According to the method of the invention, a yield of material can be improved as compared with the conventional art and the number of processes for forging work can be reduced. In addition, the turbine blades cab be forged into a favorable shape without occurring cracks. Further, it is possible to effectively reduce the cost for the die required for the forging work.

Abstract: A wheel bearing apparatus has an outer member, an inner member and double row rolling elements freely rollably contained between double row inner raceway surfaces and outer raceway surfaces of the inner member and the outer member. A plurality of bolt insertion bores, that fastening bolts pass through to fasten to the knuckle, are formed on the body mounting flange at plurality of positions circumferentially along the body mounting flange. The outer member is previously formed by hot forging. A seating surface for the fastening bolts is formed on an outboard-side surface of the body mounting flange by cold forging.

Abstract: A high strength and high toughness magnesium alloy, characterized in that it is a plastically worked product produced by a method comprising preparing a magnesium cast product containing a atomic % of Zn, b atomic % in total of at least one element selected from the group consisting of Dy, Ho and Er, a and b satisfying the following formulae (1) to (3), and the balance amount of Mg, subjecting the magnesium alloy cast product to a plastic working to form a plastically worked product, and it has a hcp structure magnesium phase and a long period stacking structure phase at an ordinary temperature; 0.2?a?5.0??(1) 0.2?b?5.0??(2) 0.5a?0.

Abstract: An apparatus for forging may include a moveable first tooling member configured to form a workpiece upon impact with the workpiece, a moveable second tooling member configured to form the workpiece upon impact with the workpiece, wherein the first tooling member and the second tooling member are each moveable relative to one another, and wherein a net momentum of a simultaneous impact with the workpiece by the first tooling member and the second tooling member is approximately zero.

Abstract: A forging process is conducted in a temperature range of 350-600° C. on at least a portion that is required to have a fatigue strength in an intermediate forged product having a ferrite and pearlite texture obtained by conducting a hot forging on a steel in which N is not greater than an amount at which N is unavoidably dissolved as a solid, thereby improving strength of the portion that is required to have a fatigue strength. With this, there is provided a forged product having a good strength and a low price.

Abstract: The present disclosure is directed towards a method of creating, in a foundry, a preform to the desired shape and size, in transferring this preform from the foundry to a tunnel oven, then preheating it to a temperature of around 500° C., transferring the preheated foundry preform into a die forge with a substantially smaller size and shape, and performing the die punching operation at a pressure of between 600 and 700 MPA, before the transfer of the preheated foundry preform to the forge die, the forge die and the means of positioning the preform, consisting of pins, are put through a powder-spraying operation on the entire inner surface of the forge die which is liable to receive the preheated foundry preform and the pins.

Abstract: An electromechanical actuator housing assembly comprising a reinforcement ring is disclosed herein. The design of the electromechanical actuator housing assembly may be directed to improving load measurement accuracy. The design of the electromechanical actuator housing assembly may be directed to reducing housing deflections. A method of manufacture of an EMA housing assembly is also disclosed herein. This method may include an electromechanical actuator housing assembly having a reinforcement ring.

Abstract: Provided is a hot upset forging method enabling high shape precision to be obtained. The hot upset forging method includes inserting a workpiece (1), with a bottom face diameter d and a height h satisfying h/d>3, into an insertion hole provided passing through a mold (2) of a height H disposed on an anvil (4), and increasing the diameter of the workpiece (1) while decreasing the height of the workpiece (1) to form a forged material. The mold satisfies the following relationships (1) to (3). (1) A shape of the insertion hole and the cross-sectional shape of the workpiece are substantially similar shapes. (2) The height h of the workpiece (1)?the height H of the mold (2). (3) A largest diameter dl of the workpiece 1, and the maximum inner diameter D of the insertion hole, in the height range of the workpiece (1), satisfy dl<D<dl×1.5.

Abstract: The present invention provides a golf club improved in ball hitting sound and ball hitting feeling and its manufacturing method. First, low-carbon steel is subjected to press processing of hot forging to form portions of irregularity on the face on a side of a hitting surface. Then, when there are projecting portions in the portions of irregularity, only the projecting portions are subjected to press processing of cold forging to crush the projecting portions to be flat. Then, the surface is slightly smoothed by machining to be flat and crystal grains at the portions of irregularity and the area therearound are pressed to be fined, thereby enhancing the hardness and forming fiber flows parallel to the hitting surface. A part of the hardened face becomes harder than the hardness of a base material before press processing by 10% or more within a range of 1 mm in a depth.

Abstract: This invention relates to a method for manufacturing a damping shaft sleeve that includes: forging a base material into a billet that includes a cylindrical body having two opposite ends and an annular flange formed on one of the opposite ends; forging a shaft hole in the cylindrical body; inverting the base material and forming two annular grooves that are respectively indented from two opposite surfaces of the annular flange; forging the billet to form the annular flange into a bottom wall and a side wall, the bottom wall cooperating with the side wall to form an asymmetrical and helical groove; and forging the shaft hole to pass through the cylindrical body of the billet.