PURPOSE: To facilitate manufacture of a bolt having a cam where a cam plate whose center position is displaced from the center line of this bolt is arranged in a boundary part between a head part of the bolt and a shaft part.

CONSTITUTION: A cam plate 27 is manufactured separately from a bolt 24, and a recessed part 34 which is equal to a head part shape of the bolt 24 and is slightly larger than a head part 25 of the bolt 24, is formed in a part of a bolt 24 inserting hole 33 on one surface of this cam plate 27. When a shaft part 26 of the bolt 24 is inserted in the hole 33 of the cam plate 27, the head part of the bolt 24 is forcibly inserted in the recessed part 34, and is formed integrally, so that a bolt 23 having a cam is obtained.