Tool Steel Flat Stock Steel Material Width 2 1/2 in Thickness 1/2 in Fractional Size 1/2 in x 2 1/2 in x 36 in Finish Unfinished Length 36 in Length Tolerance +0.250 to +0.500 in Hardness Scale 220 to 255 BHN Rockwell B97 to 102 Grade D2 Standards ASTM-A681 FED-QQ-T-570 SAE-J-437