Tool Steel Square Bar, Material Tool Steel, Material Grade D2, Thickness 0.625 in, Thickness Tolerance +/-0.001 in, Overall Length 36 in, Overall Width 5/8 in, Heat Treatable Heat Treatable, Heat Treatment Air-Hardened, Mechanical Finish Mill, Yield Strength 68,000 psi, Tensile Strength 110,000 psi, Brinell Hardness 220 BHN, Rockwell Hardness 97 HRB, Standards ASTM A681, SAE J437, Includes Material Certificate Material Certificate with Lot Number, Length Tolerance +0.125 in/0 in, Shape Square