In contrast to case hardening, hardening and tempering is a hardening process that permeates the entire component. Steels which are hardened and tempered have a higher set content of carbon and alloy and therefore ideally harden all the way to the core.

The hardening process includes heating to what is known as the austenitizing temperature, followed by quenching according to the component requirements. The austenitizing temperatures range between 800 °C and 1,000 °C depending on the composition of the steel. Following hardening, the material being treated is adapted to the desired surface hardness in a subsequent, second heat treatment at a maximum of 350 °C. This is referred to as tempering or relaxing.

Steels with a low to moderate alloy content of up to 5% can be hardened in RENK’s hardening shop.