Patent ID: 9289828
Filing Date: 2016-03-22
CPC Classification: B23B,B23P,C21D,C23C,F16C,F16H,Y10T

Claim Text:
1. A ball screw comprising: a nut formed with a helical ball rolling groove on its inner circumference; a screw shaft formed with a helical ball rolling groove on its outer circumference, said shaft inserted into the nut; a number of balls rollably contained within a ball rolling passage formed by oppositely arranged helical ball rolling grooves of the nut and the screw shaft, respectively; and the nut is made of case hardened steel, and that the ball rolling groove, a shoulder and a transition portion continuous with the ball rolling groove and shoulder, are cut by a single universal turning tool with a cutting edge so that the ball rolling groove shoulder and transition portion has a continuous point-cut surface, the universal turning tool cutting edge has a nose radius (R