Provided is a cold work tool material capable of reducing dimensional changes which occur, due to heat treatment, in the longitudinal direction of the material during quenching and tempering. This cold work tool material is drawn through hot working, has an annealed structure including carbides, and is used after being quenched and tempered, wherein, in the annealed structure which is formed in a cross section parallel to a drawing direction due to the hot working of the cold work tool material, the standard deviation in the degree of orientation of carbides Oc, as determined by equation (1) below, is 6.0 or more for carbides having a circle equivalent diameter of 5.0 μm or greater as observed in the annealed structure in the cross section at right angle to a direction perpendicular to the drawing direction. Oc=D×θ . . . (1), where D represents the circle equivalent diameter (μm) of the carbide, and θ represents the angle (rad) between the major axis of an approximate ellipse of the carbide and the drawing direction. A cold work tool using the cold work tool material and a method for manufacturing the same are also provided.

The present invention discloses a swaging die holder for the flexible shaft operations. In the preferred embodiment, the swaging die holder comprises of an elliptical die holder slot, a stress relief slot, a radius curve, a recess and an insert. The die holder slot at top of the die holder allows each die holder to mount to the machine. The insert is adapted through the recess at the bottom of each die holder and designed to produce the different output profiles at the end of the flexible shaft. The insert is made of HSS material with cobalt content to achieve optimal life. The insert is further re-grinded or re-sharpened for same or other profile applications of the flexible shaft.

A heat treatment apparatus for hot stamping includes a frame, and heating units provided to be vertically movable at both upper and lower sides of the frame and configured to heat a cold formed steel plate by electrifying the steel plate. Cooling units are provided to be vertically movable at centers of the upper and lower sides of the frame and are configured to cool the heated steel plate while pressurizing the steel plate from upper and lower sides.

A heat treatment apparatus for hot stamping includes a frame, and heating units provided to be vertically movable at both upper and lower sides of the frame and configured to heat a cold formed steel plate by electrifying the steel plate. Cooling units are provided to be vertically movable at centers of the upper and lower sides of the frame and are configured to cool the heated steel plate while pressurizing the steel plate from upper and lower sides.

A forging device for producing a piston blank has a forging mold that has an essentially cylindrical cavity matching the radial outer surface of the piston blank, a forging base delimiting the cavity, and a central die consisting of a mandrel that has a conically tapering extension which is mounted on the mandrel and the shape of which matches the inner surface of the piston blank. In order to form the radially outer surfaces of the piston slipper walls and a peripheral cooling pocket located radially outside the slipper walls in the piston head, the forging device has two lateral jaws which are mounted in the forging device so as to be movable at an angle to the longitudinal axis of the forging device.

A forging device for producing a piston blank has a forging mold that has an essentially cylindrical cavity matching the radial outer surface of the piston blank, a forging base delimiting the cavity, and a central die consisting of a mandrel that has a conically tapering extension which is mounted on the mandrel and the shape of which matches the inner surface of the piston blank. In order to form the radially outer surfaces of the piston slipper walls and a peripheral cooling pocket located radially outside the slipper walls in the piston head, the forging device has two lateral jaws which are mounted in the forging device so as to be movable at an angle to the longitudinal axis of the forging device.

A ring molded article manufacturing method capable of reliably and efficiently producing a ring molded article in which dead metal regions are reduced, and a ring material used for producing the ring molded article, are provided. The present invention relates to the method for manufacturing a ring molded article having two convex portions which respectively protrude on both sides of the ring molded article in a direction of a center axis thereof and extend in a direction of a circumference of the ring molded article. In the manufacturing method, the ring material is placed inside two molds on which concave portions respectively corresponding to the convex portions are formed, in a condition in which the ring material is supported by a region on an outer peripheral side from an outer peripheral side corner in the concave portion of one of the two molds and a region on an inner peripheral side from an inner peripheral side corner in the concave portion of another of the two molds, the ring material is then forged so as to be pressed by the two molds in a direction of a center axis of the ring material, and the ring molded article is thus produced. In addition, the present invention relates to the ring material used for producing the ring molded article.

A ring molded article manufacturing method capable of reliably and efficiently producing a ring molded article in which dead metal regions are reduced, and a ring material used for producing the ring molded article, are provided. The present invention relates to the method for manufacturing a ring molded article having two convex portions which respectively protrude on both sides of the ring molded article in a direction of a center axis thereof and extend in a direction of a circumference of the ring molded article. In the manufacturing method, the ring material is placed inside two molds on which concave portions respectively corresponding to the convex portions are formed, in a condition in which the ring material is supported by a region on an outer peripheral side from an outer peripheral side corner in the concave portion of one of the two molds and a region on an inner peripheral side from an inner peripheral side corner in the concave portion of another of the two molds, the ring material is then forged so as to be pressed by the two molds in a direction of a center axis of the ring material, and the ring molded article is thus produced. In addition, the present invention relates to the ring material used for producing the ring molded article.

In a center hole forming method, an object to be processed is inserted in a die hole and a shaft is drawn from the object. A load toward a first axial end surface of the object is applied to a second axial end surface of the object without taking out the object from the die hole. A diameter of the first axial end surface is smaller than a diameter of the second axial end surface. A center hole is formed in the first axial end surface by pressing a counter punch against the first axial end surface in a state that the load is applied to the second axial end surface.

A release agent for a hot-forging die, containing micronanobubbles.