Iron alloy that can be forged without aftertreatment, the limit of forgeability being about 2.0% carbon. In the iron-carbon phase diagram, for example, all alloys up to approx. 2.0% C to be referred as steels (Fig. 1). All cast iron alloys as well as malleable cast iron and chilled cast iron have higher carbon contents.

According to the European standard DIN EN 10 027, the steels can be identified either by short names (DIN EN 10 027 part 1) or by material numbers (DIN EN 10 027 part 2).

Important selected types of steel include:

Austenitic steel
Stainless steel
High-alloy steel
Heat-resistant  steel
Cold work steel
Low-temperature steel
Corrosion resistant steel
Austenitic manganese steel
Low-alloy steel
Hot-forming steel
Tool steel

Additional references:
Cast steel


  • Fig. 1: “Steel area” in the Iron-carbon phase diagram, source: der