A.Rockwell scale B in used for hard metals
B.Rockwell scale C is used for hard metals
C.Rockwell scale C is used for soft metals
D.Rockwell scale A is used for hard metals
A.Rockwell scale B in used for hard metals
B.Rockwell scale C is used for hard metals
C.Rockwell scale C is used for soft metals
D.Rockwell scale A is used for hard metals