US Patent 7765846 Method of producing a hollow shaft

A method of producing a hollow shaft having first and second profilings provided for torque transmission at respective ends thereof, wherein a shaft section between the ends has a smaller diameter than at least one of the profilings, and the hollow shaft is assembled from hollow shaft and sleeve components joined via a torque-transmitting slip joint, in which the shaft and sleeve components are each formed from cut blanks by cupping, perforating. cold extrusion and turning steps, and the respective components are assembled to each other.