Patent ID: 9511414
Filing Date: 2016-12-06
CPC Classification: B21H

Claim Text:
1. A die for roll forming threads on a cylindrical blank, comprising, a generally planar die body having a longitudinally elongate working face extending from a start end of said die to a finish end of said die, said working face having a plurality of spaced apart thread forming elements extending across said entire working face spaced apart longitudinally of said die working face an ever increasing distance from the start end to the finish end measured along an axis “Y”, in a pattern that extends across the entire longitudinal extent of the working face of said die wherein said thread forming elements on said working face of said die are spaced apart along said axis “Y” a distance equal to the transverse rolling pitch (P R =πd b−R ) wherein πd b−R at said start end is equal to the diameter of the blank and πd b−R at said finish end is equal to eighty-five percent of the final outer diameter of the thread formed on the blank.