A medium carbon steel used for heat treating (quenching and tempering). Although it has only a fair response to conventional quenching, it is widely used where requirements are not too stringent. 1045 is also used extensively in induction hardening applications.

This is not normally considered a screw machine and is only fair for brazing and welding. However, it can be forged satisfactorily and is the most common shafting steel in the medium carbon range.

Turned, ground, & polished.