| 摘要 |
This invention concerns a fastening device which enables two separate members to be fixed together with a relative interval between them and comprises a bolt 1 in which a male screw portion is formed at a front end side of a cylindrical shaft portion 3 thereof and a spacer 10 which has a female screw portion 15 engaging a male screw portion 4 of the bolt 1 and screw-fastens with a screw of the first member 40 side and rotates while receiving a rotation torque from the bolt 1 and moves up to a position in which it comes into a contact with a second member 50. The feature of this invention is that the root diameter of a male screw portion 4 of the bolt 1 is smaller than the diameter of a cylindrical shaft portion 3 while the inside diameter of the female screw portion 15 of the spacer 10 is larger than the diameter of the cylindrical shaft portion 3 of the bolt 1. Consequently, the cylindrical shaft portion 3 of the bolt 1 can be passed through the female screw portion 15 of the spacer 10 even if the diameter of the cylindrical shaft portion 3 of the bolt 1 is not reduced in diameter by cutting processing or the like. Thus, the bolt 1 can be manufactured only by rolling processing, thereby manufacturing cost being reduced.
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