Tool steels - Classification and evolution

To enable the tool for which it is intended to meet the specifications imposed on it (shaping with or without chip removal), the steel selected must ensure that hardness, toughness and surface finish are maintained at the temperature reached by the active part of the tool during operation. This working temperature is therefore the decisive criterion on which the classification of tool steels is based:

• tool steels for cold working, for service temperatures below 200°C ;

• Alloyed hot-work tool steels for service temperatures above 250°C ;

• high-speed steels, for any steel that retains acceptable levels of hardness up to 600°C.

Improving the properties of steels in these different classes is still the subject of research and development work exploring various avenues:

• modification of the chemical composition of steels and development of new metallurgies;

• production methods (powder metallurgy, coatings, etc.).

This document is part of a series devoted to tool steels:

• Tool steels – Chemical composition and structure [M 4 585] ;

• Tool steels – Elaboration and transformation [M 4 586] ;

• Tool steels – Processing [M 4 587] ;

• Tool steels – Standard numerical data [M 4 590] ;

• Tool steels – Non-standardized numerical data