Abstract: The fastening metal fitting which allows satisfactory fastening by a hexalobular wrench at the time of assembly and allows loosing or fastening not only by a hexalobular wrench but also by a wide use of wrenches such as a common hexagon wrench at the time of disassembly and repair, which includes the head and the axial portion having the screw portion, in which at the center of the head, the tool insertion hole is formed with the hexagonal socket portion and the circularly-arced notched portions outwardly protruding from the respective corners of the socket portion which are provided at the corners continuously.

Abstract: A grooved nut including a cylindrical shaft portion having a screw hole at the center, a head portion whose outer periphery is polygonal and which is provided at one end portion of the shaft portion, and a peripheral groove provided at a boundary part between the head portion and the shaft portion, in which the peripheral groove is formed by a plasticizing process.

Abstract: A grooved nut including a cylindrical shaft portion having a screw hole at the center, a head portion whose outer periphery is polygonal and which is provided at one end portion of the shaft portion, and a peripheral groove provided at a boundary part between the head portion and the shaft portion, in which the peripheral groove is formed by a plasticizing process.

Abstract: A device for use in a multi-stage former automatically replaces a tool used for successive press work. When the tool is worn or damaged, or when the tool has been used for its estimated life, this condition is detected, whereupon the old tool is automatically removed and replaced by a new one. The device is used in an apparatus wherein a punch is forced against a die by a ram for plastically working a metal by press work, and the device handles the punch mounted on the ram. A punch case or punch holder is utilized to the punch replacing device being assembled therewith.

Abstract: A multi-stage cold forging machine including a parts forming aid unit, which has a number of aid pins corresponding to that of the forging dies, the pins being adapted to retain a forged blank against a knockout pin slidably housed in the dies, and transfer it from the respective stage to the next. The blank is progressively refined as it is transferred from stage to stage. The aid pins are operated in such a manner as to stand out of the way of the hammers moved by a ram.

Abstract: A press assembly by which cut metal workpieces of specified length are formed into blanks of desired shape by punches and dies is provided with a rolling mechanism disposed adjacent to and in line with the press assembly. The blanks formed by the press assembly are fed directly to the rolling mechanism to perform the press work and rolling work continuously.

Abstract: A blind nut is provided for coupling with an object article having a bore, wherein the neck portion of said nut is nested in use. The peripheral side of said bore is immovably attached to a neck portion of said nut by a press deforming means. The blind nut has a particular neck section and there is a tool specifically designed for said section.

Abstract: A tool holder for withdrawably holding a tool inserted therein is provided with an eccentric pressing member which is openly positioned for the insertion of the tool into the holder and bitingly engageable with the tool against the withdrawal of the tool. The eccentric pressing member is biased toward the direction of the bite and has an unlocking lever provided with a power pusher.