Gear shafts are used in all manual shift transmissions.  They are produced mainly by the cold forging of case hardening steels.  The extrusion of the steel bars results in a flashless production and thus no material is wasted.  It also guarantees a favorable grain flow.  In subsequent heat treatment operations this leads to less distortion of the shaft and to a higher strength of the finished part.  To optimize the first clamping process, center holes can be introduced on both ends.