| 摘要 |
PROBLEM TO BE SOLVED: To easily separate a synthetic resin head from a metallic thread part at the time of disposal or the like by providing the head with a hole, forming a press-in part to the hole, at the thread part, and carving serration in the press-in part. SOLUTION: A head 2 is made of a syntehtic resin and provided with a large diameter hole 2a and a small diameter hole 2b in the communicating state at the center. The hole 2b is formed in tapered shape with the thread part press-in side diameter slightly larger than the opposite side diameter. The thread part 3 is formed by carving a thread 3a in a round iron bar and serration 3c is carved with a flange 3b placed between. The thickness of the head 2 is to be slightly longer than the press-in part length of the thread part 3. The head 2 is fixed to insert the thread part 3 from the hole 2a side, and large force is applied to press in the thread part 3 to form a bolt. At the time of disposal, the head 2 is gripped to put a bar from the outside of the hole 2b, and external force is applied with a hammer or the like to detach the thread part 3 from the head 2.
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