| 摘要 |
PROBLEM TO BE SOLVED: To provide a rolling method by which elongation of a life of a movable round die having thread ridges on an outer peripheral surface can be achieved.SOLUTION: A rolling method in which a rolling apparatus, which comprises a pair of rotatable round dies having thread ridges 22 on an outer peripheral surface thereof and in which one of the pair of round dies is variable in a position for a work-piece, is used, the rotatable round die is pushed onto the work-piece while rotating by the rolling device, whereby rolling of the work-piece is performed. In the movable round die, a curvature radius of an apex 23X of a part 22X of the thread ridges is relatively larger than a curvature radius of an apex 23X of other parts 22Y of thread ridges, and the part 22X of the thread ridges of which the apex has a relatively larger curvature radius is firstly brought into contact with the work-piece 30.SELECTED DRAWING: Figure 2 |
