| 摘要 |
The objective is to prevent the loosening of a structure with which a member 80 to be fastened and a base material 90 are fastened through a male screw body 10 and a washer 50. A screw-body-side seat part 22 is formed on the male screw body 10, and a first receiving part 60 and second receiving part 70 are formed on the washer side. A member-side seat part 82 is formed on the member 80 to be fastened. The first receiving part 60 and the screw-body-side seat part 22 have sawtooth-shaped recesses and protrusions. When an attempt is made to rotate the male screw body 10 in the direction of loosening, the recesses and protrusions engage one another, thereby preventing rotation. A recessed housing part of the member-side seat part 82 and the outer wall of the second receiving part 70 of the washer 50 have an eccentric circular shape. When an attempt is made to rotate the washer 50 in the direction of loosening, the eccentric circular shapes engage one another, thereby preventing rotation. |
