Hardness ranges for heat treated steel

Heat
Treated
Condition
Q R S T U V W X Z
Tensile
Strength
625-775 n/mm2 700-850 n/mm2 775-925 n/mm2 850-1000 n/mm2 925-1075 n/mm2 1000-1150 n/mm2 1075-1225 n/mm2

1150-1300 n/mm2

1550 n/mm2

Hardness
Brinell
179-229 201-225 223-277 248-302 269-331 293-352 311-375 345-401 444
Reference Table: Steel hardness conversion chart – all values approximate.
Brinell Hardness
HB
Rockwell
HRC
Rockwell
HRB
Vickers
HV
N/mm