METHOD OF PRODUCING SCREW DEVICE, AND SCREW DEVICE

摘要

Provided is a screw device manufacturing method which ensures high productivity and adequate nut strength. The screw shaft manufacturing method of the present invention includes: a groove forming step of forming a loaded ball rolling groove in a flat plate; and a nut forming step of bending the flat plate into a ring to form a nut. As the groove forming step of forming of the loaded ball rolling in the flat plate is followed by the nut forming step of bending the flat plate into a ring, sufficient strength of the nut can be easily achieved. Besides, a high compression stress is left in the loaded ball rolling groove in the inner surface of the nut.