PURPOSE: To provide an engaging mechanical element capable of simply fitting the engaging mechanical element to a fitting member, and of easy fitting by using a fitting member difficult to form a female screw, and the joining method for the engaging mechanical element.

CONSTITUTION: In the end part of a spring-like engaging body 2 having screw parts 4 and 5 in the inside or in the inside and outside, the interval of adjoining wire rods 2a is joined to the engaging hole 9 of a fitting member 8 to fix the engaging body 2 by nipping the wire rods 2a. Consequently the fitting work for an engaging mechanic element can be simply made by single finger motion, moreover, an engaging body can be surely fixed even in a thin plate where a female screw for engaging can not be formed, or in a member having a weak female screw.