To obtain a male screw which can improve detaching workability by preventing only a screw part from being left when a tightening torque is applied excessively.
A first tool-engaging part 16 is provided in the upper end part 12A of the screw part 12 of the male screw 10 and a mounting means 18 is provided on the first tool-engaging part 16. On the upper part of the mounting means 18, a second tool-engaging part 20 is formed and on the top surface 20A of the second tool-engaging part 20, a crisscross recessed part 22 is formed. Furthermore, the male screw 10 is structured with a first resin 24 and a second resin 26 different from each other. A tightening torque causing the deformation of the second tool-engaging part 20 at the time of tightening the second tool-engaging part 20 by a fastening tool is made smaller than a tightening torque causing the break of a boundary part of a flange part 14 with the first tool-engaging part 16 provided thereon and an upper end part 12A of the screw part 12.
Kato Kazunori
Hiroshi Fukuda