This heat treatment is most often applied on carburizing steels and cold working steels and it is performed at negative temperatures (between -80ºC and -196ºC) between hardening and tempering.

Hardness improvement could achieve +2 to +6 HRC points, depending on treated steels.

Ensures greater dimensional stability of the parts during service (forming tools), higher wear resistance (hardening or carburizing steels) or higher toughness (cutting steels and hot forming).

With Sub Zero heat treatment a greater durability of the components of moulds tools or machine components is ensured.