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: An elongated continuous steel round bar is cut to a specified length, and the cut piece is pressed by forging machine to form a workpiece including an annular portion and a smaller annular portion concentrically integrally projecting therefrom. An outer ring and an inner ring are simultaneously produced from the workpiece by an apparatus comprising an inner ring die and an outer ring die mounted on a stationary base, and an inner ring punch and outer ring punch opposing the dies and mounted on a movable ram. The inner and outer ring punches simultaneously punch out the inner and outer rings from the workpiece fitted to the inner and outer dies. In relation to this operation, a cam operates to depress a rolling member disposed in the rear of hollow portion of the inner ring die, whereby the foremost of like finished inner rings each pushed into the hollow portion of the inner ring die at every stroke of the ram is allowed to drop through the die assembly and is thereby automatically withdrawn.