Abstract: An apparatus is provided for manufacturing a cylindrical member utilizing a pair of dies each of which has a semi-cylindrical recess formed therein and which are adapted to be brought into abutment against each other to form a material disposed within the recesses into a cylindrical form. The abutting surfaces of the pair of dies are offset from a plane which includes the axis of a cylindrical member to be formed within the recesses of the dies and which is perpendicular to the direction of movement of one or both of the dies. In this manner, the formation of a bulge or flash on the outer periphery of the cylindrical member can be prevented which may be formed if the abutting surfaces lie in said plane.

Abstract: A strip material is subjected to an end bending step, and subsequently the bent ends of the strip material, namely, those portions of the strip material which are located adjacent to its abutting ends, are pre-coined to increase the accuracy in the region of the abutting ends, followed by a conventional U-bending and a final coining step, thereby producing a cylindrical material. The use of the pre-coining step for the abutting ends improves the circularity of the cylindrical member.