ISO 5954:2014 applies to cold-reduced carbon steel sheet and corresponding hardness requirements. It is suitable for applications where the surface is of prime importance.
The following are common hardness ranges (see 6.6): CRH-50: Rockwell B 50 to 70, CRH-60: Rockwell B 60 to 80, CRH-70: Rockwell B 70 to 90, CRH-NN: Any Rockwell B range of 20 points up to and including HRB 90 maximum (designated minimum of specified range will be shown).