Tool Steel Rectangular Bar, Material Tool Steel, Material Grade D2, Thickness 0.5 in, Thickness Tolerance +0.015 in, Overall Length 18 in, Overall Width 4 in, Heat Treatable Heat Treatable, Heat Treatment Air-Hardened, Mechanical Finish Precision Ground, 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/+0.25 in