| 摘要 |
PROBLEM TO BE SOLVED: To increase the working degree in a method and an apparatus for manufacturing a bolt having a flat plate-like seat plate at the other end of a shaft having threads formed at one side. SOLUTION: The apparatus for manufacturing the bolt comprises the flat plate-like seat plate provided at the other end of the shaft 3 having the threads formed at the one side. The apparatus further comprises a die 11 for heading which is energized by a coiled spring 19 to compress the other end of the shaft 3 made of a metal to thickly form the other end. The other end is formed further in the flat plate-like state and the threads 2 are formed at the one end of the shaft 3. Since the die is buffered by the spring 19 at the time of compressing, a plastically working speed can be decelerated so that a craze or the like is hardly brought about with the result that the plastically forming degree can be increased. The other end of the shaft 3 is cold-forged, and hence even when a facility such as a heating furnace or the like is not necessary to hot work, the working degree can be increased.
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