CR20 .023 THICK COIL STEEL 3

[fox9719]

Under hardness on the metallurgical test report is says 99 RB. Is RB the Rockwell B scale? And is this considered full hard?

 

[TVP]

Yes, this is indicating Rockwell B scale. The official designation is HRB according to ASTM and ISO standards, but it is often written as Rb, RB, H_RB. And yes, this meets the requirements for steel strip that has been cold rolled to the full hard temper according to SAE J2392. For thickness < 0.6 mm, the minimum hardness should be 90 HR15T minimum, which is just a lighter load version of HRB, with 90 HRB = 89.9 HR15T.