A method and a plant for manufacturing fasteners, in particular screws, along an automated production line; the method comprising the following steps: feeding the raw material made of titanium; heating the raw material to a predefined temperature; cutting one or more pieces of a predefined length, in succession, from the heated raw material; deforming plastically each piece by means of one or more finishing stations, so as to obtain a fastener; heating, during the deforming step, the material that passes through each workstation to a predefined temperature; wherein the material manipulated along the production line during the feeding, heating, and deforming steps is automatically transported along the production line.

A forging and pressing production systems enables at least one material to be formed by hot melt and forging and pressing by itself without human operation, thereby completing the mass production of the material. Operating factors such as the pressure, temperature and mold required for formation are taken into account, and the identification requirements for the material are reduced, thereby realizing large-scale production.

A forging and pressing production systems enables at least one material to be formed by hot melt and forging and pressing by itself without human operation, thereby completing the mass production of the material. Operating factors such as the pressure, temperature and mold required for formation are taken into account, and the identification requirements for the material are reduced, thereby realizing large-scale production.

Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing, excellent delayed fracture resistance, and high tensile shear stress after resistance spot welding by properly adjusting its chemical composition and its microstructure such that at least 20 Nb-based precipitates having a grain size of less than 0.10 μm are present on average per 100 μm.sup.2 of a cross section parallel to a thickness direction of the member, a prior austenite average grain size is 8 μm or less, an average aspect ratio of prior austenite grains is 2.5 or less, and a volume fraction of martensite is 90% or more, and such that a standard deviation of Vickers hardness measured every 200 μm on a surface of the member is 40 or less.

Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing, excellent delayed fracture resistance, and high tensile shear stress after resistance spot welding by properly adjusting its chemical composition and its microstructure such that at least 20 Nb-based precipitates having a grain size of less than 0.10 μm are present on average per 100 μm.sup.2 of a cross section parallel to a thickness direction of the member, a prior austenite average grain size is 8 μm or less, an average aspect ratio of prior austenite grains is 2.5 or less, and a volume fraction of martensite is 90% or more, and such that a standard deviation of Vickers hardness measured every 200 μm on a surface of the member is 40 or less.

A forging apparatus and a forged product manufacturing method aim to prevent decrease in the temperature of a forging space and the temperature of a forging material, efficiently maintain the uniformity of the temperatures of upper and lower dies, and improve forging efficiency. In the forging apparatus and the forged product manufacturing method according to the present invention, the upper and lower dies are heated by a heating mechanism in a housing in which a charging port of an integrally formed housing body is closed by a door, the upper and lower dies are moved relatively in a facing direction of the upper and lower dies, the heating mechanism is moved relatively in the facing direction with respect to at least one of the relatively moving upper and lower dies, and whereby the forging material is forged between the upper and lower dies. Furthermore, the forged product manufacturing method is used to manufacture a forged product from the forging material.

A forging apparatus and a forged product manufacturing method aim to prevent decrease in the temperature of a forging space and the temperature of a forging material, efficiently maintain the uniformity of the temperatures of upper and lower dies, and improve forging efficiency. In the forging apparatus and the forged product manufacturing method according to the present invention, the upper and lower dies are heated by a heating mechanism in a housing in which a charging port of an integrally formed housing body is closed by a door, the upper and lower dies are moved relatively in a facing direction of the upper and lower dies, the heating mechanism is moved relatively in the facing direction with respect to at least one of the relatively moving upper and lower dies, and whereby the forging material is forged between the upper and lower dies. Furthermore, the forged product manufacturing method is used to manufacture a forged product from the forging material.

An insert including a taper is covered with a molten metal. A metal molded product with the insert joined thereto is generated by semi-cooling the molten metal to a press-fitting temperature which is higher than a recrystallization temperature of the molten metal and lower than a melting point of the molten metal. A fitting hole which is filled with the insert is formed in the metal molded product. The taper is fitted into the fitting hole. An undercut is not formed in front of a tip of the taper. The insert is press-fitted into the fitting hole while pressing and extending the fitting hole with the taper in a thinning direction of the taper at a press-fitting temperature. The metal molded product is further cooled with the press-fitting maintained.

An insert including a taper is covered with a molten metal. A metal molded product with the insert joined thereto is generated by semi-cooling the molten metal to a press-fitting temperature which is higher than a recrystallization temperature of the molten metal and lower than a melting point of the molten metal. A fitting hole which is filled with the insert is formed in the metal molded product. The taper is fitted into the fitting hole. An undercut is not formed in front of a tip of the taper. The insert is press-fitted into the fitting hole while pressing and extending the fitting hole with the taper in a thinning direction of the taper at a press-fitting temperature. The metal molded product is further cooled with the press-fitting maintained.

A multistage press for the bulk deformation of a piece of wire includes a wire feed with associated apparatus for cutting to length, and a transfer device—having grippers—for receiving a piece of wire that has been cut to length and transferring the latter to subsequent forming stages, there being arranged, on that side of the cutting-to-length apparatus opposite from the wire feed, a device for partially heating a length of wire. A method produces a formed part with a multistage press of this type.