METHOD OF FORM ROLLING WITH VARIABLE LEAD

摘要

PROBLEM TO BE SOLVED: To provide a method of form rolling which can apply form rolling on an outer circumference of a hollow tube and also change lead angle and/or depth of thread in process. SOLUTION: When applying form rolling on the outer circumference of the hollow material 13 using a round die 12a with a single rolling tooth 3, movement of the hollow material 13 in its axial direction is kept free, while the material 13 moves reciprocally by rotating the die 12a in normal and reverse directions.