Hardened Martensite steel strips are obtained as shown in the typical I-t diagram, by quenching the steel to the Ms point. The steel must be held at this temperature long enough for the center of the Steel to cool to the same temperature, but not so long as to form Bainite.

This martensitic structure

has extremely high hardness and lack of ductility until it is tempered to convert it into a ductile material with a high elasticity limit and the hardness required.