Tempering is a crucial heat treatment process used to improve the toughness and reduce the brittleness of hardened steel. After the steel undergoes the initial hardening process, it becomes very hard but also brittle. Tempering involves heating the steel to a temperature below its critical transformation point and holding it at that temperature for a specific duration.

This controlled heating allows some of the excess hardness to be reduced and relieves internal stresses that may have accumulated during the hardening process. As a result, the tempered steel becomes tougher, more ductile, and better able to withstand impact and load-bearing applications. The specific tempering temperature and duration depend on the desired mechanical properties for the final application.