Patent ID: 7866198

Claim:
A method for forming a stepped shaft, the method comprising: providing a billet of a predetermined mass; heating the billet; cross-wedge rolling the billet to form an intermediate workpiece about a shaft axis having a first cylindrical portion and a second cylindrical portion that are axially spaced apart along the shaft axis by a neck that is smaller in diameter than the first and second cylindrical portions, the first and second cylindrical portions having first and second exterior surfaces, respectively, that are disposed concentrically about the shaft axis; and performing at least one upset forging operation on the end of the intermediate workpiece to enlarge the first cylindrical portion such that in at least one location its diameter is larger than a diameter of any other portion of the stepped shaft and larger than a diameter of the billet, wherein the second cylindrical portion is substantially unchanged by the at least one upset forging operation, wherein the at least one location is cylindrically shaped and wherein the diameter of the at least one location and the second exterior surface are disposed concentrically about the shaft axis, and wherein a plurality of teeth are formed around a circumference of the first cylindrical portion during the at least one upset forging operation.