| 摘要 |
PROBLEM TO BE SOLVED: To provide a bolt having a high guide property which never generates an idle running even when it is inserted to a female screw obliquely. SOLUTION: A constant diameter cylindrical part 8 with the diameter smaller than a bolt shaft 2 is formed, at the front end of the bolt shaft 2, and a perfect screw thread 9 is formed to the constant diameter cylindrical part 8. It is favorable to set the outer diameter d2 of the constant diameter cylindrical part 8 almost same as the minimum value of the inner diameter d3 of a female screw 5. When the bolt is inserted obliquely to the female screw 5, the perfect screw thread 9 of the constant diameter cylindrical part 8 can catch the screw threads 6 of the female screw 5, and the constant diameter cylindrical part 8 can be fitted rightly along the lead by fastening as it is.
|
