The EN standard gives the chemical composition and mechanical properties of stainless steels.

Stainless steels are particularly resistant to chemically aggressive substances. They contain at least 10, 5% Cr and no more than 1, 2%C.  In accordance with their essential use characteristics, they are further subdivide into:

• Corrosion-resistant steels:
  material numbers 1.40xx to 1.46xx
• Heat-resistant steels:
  material numbers 1.47xx to 1.48xx
• Creep-resistant steels:
  material numbers 1.49xx

Stainless steels can also be classified in accordance with their microstructure into:

• Ferritic steels:
  good suitability for welding, creep-resistant, special magnetic properties, poor suitability for machining by cutting, suitable for cold forming, not resistant to intercrystalline corrosion, E=220 000 N/mm²
• Martensitic steels:
  hardenable, good suitability for machining by cutting, high strength, magnetic, weldable under certain conditons, E=216 000 N/mm²
• Precipitation hardening steels:
  hardenable by precipitation hardening, suitability for machining by cutting dependent on hardness, magnetic, E=200 000 N/mm²
• Austenitic steels:
  good suitability for welding, good suitability for cold forming, difficult to machine by cutting, non-magnetic, E=200 000 N/mm²
• Austenitic-ferritic steels (duplex steels):
  resistant to stress corrosion cracking, high erosion resistance and high fatigue strength, E=200 000 N/mm²