METHOD FOR FORMING ROLLING TAPER SCREW TO METAL PIPE

摘要

PROBLEM TO BE SOLVED: To safely manufacture a taper screw of a shape as designed.SOLUTION: A process of forming a rolling taper screw is the process of forming a rolling taper screw 33 at an end part of a metal pipe 30 with a rolling roller 10 and makes the metal pipe 30 and the rolling roller 10 relatively move. The rolling roller 10 has a plurality of threads aligned at a predetermined pitch. In the process of forming the rolling taper screw 33, the metal pipe 30 and the rolling roller 10 relatively move in the pipe axial direction Y of the metal pipe 30 as it keeps a contact with the rolling roller 10 under relative rotation as viewed from the metal pipe 30. This process is characterized in that a movement distance of the rolling roller 10 in the pipe axial direction Y as viewed from the metal pipe 30 while the rolling roller 10 turns around the metal pipe 30 is smaller than the pitch of the threads of the rolling roller 10.