THREAD FORMING DIE AND METHOD

摘要

A die for roll forming threads on a cylindrical blank includes a planar die body having a longitudinally elongate working face of sufficient length for the blank to make multiple revolutions across the face. A plurality of thread forming elements on the face. The thread forming elements are spaced apart longitudinally of the die working face an ever increasing distance, based on the actual rolling diameter of the blank with the spacing between the thread forming elements at the start end equal to the diameter of the blank and the spacing between the thread forming elements at the finish end equal to eighty-five percent of the final diameter of the thread formed on the blank. The thread forming elements on the working face of the die are equally spaced apart in a direction perpendicular to the longitudinal extent of the working face.