Patent ID: 6598453
Filing Date: 2003-07-29
Classification: B21H

Abstract:
A tooth rolling flat die for forming a tooth, of the type including a spline tooth and a gear tooth, on a periphery of a cylindrical workpiece, said die having teeth sections on one working surface thereof, with the teeth sections comprising, in series, a leading teeth section wherein heights of the tops of the teeth are gradually increasing from a front edge to a rear edge of the die until a full height thereof is reached, a finishing teeth section in which each of the teeth has the full height, and a roll-off teeth section in which heights of the teeth are rapidly decreasing;wherein a first substantially quarter length portion of the leading teeth section has a first surface roughness Rz of maximum height ranging from 20 to 35 &mgr;m, and a second substantially quarter length portion of the leading teeth section has a second surface roughness Rz of maximum height ranging from 5 to 20 &mgr;m, so that roughness heights differ between the first and second quarter length portions.