PURPOSE: To prevent an implanting member from turning by driving away a caulking allowance to the corners of a square hole, by boring concentrically a round hole and a square hole to form a caulking hole in a sheet material and caulking the clearance between the caulking hole and a circular caulking allowance, which is formed at a part of the implanting member and is inserted into the bored round hole.

CONSTITUTION: A sheet material 7 is punched by a general-purpose punching die by overlapping a round hole 8 and a square hole 9 to form a caulking hole of specific shape in it. Further, a caulking allowance 12 with a diam. of the degree capable of being fitted to the round hole 8 of sheet material 7, is formed at one end of an implanting member 11, and a screwed hole 13 is also provided to the other end. Then the caulking allowance 12 of member 11 in the hole 6, is deformed and bulged to the outer periphery and is driven away to each corner to tightly stick to the sheet material 7, thereby preventing the member 11 from turning with respect to the material 7 as well as preventing it from slipping off.