D2 Tool Steel Rod Material Tool Steel Material Grade D2 Overall Length 12 in Heat Treatable Yes Heat Treatment Air Hardened Mechanical Finish Mill Outside Diameter 5/8 in Outside Diameter Tolerance +.01/+.032 Yield Strength 50 000 psi Fabrication Hot Rolled Rockwell Hardness C60 to C62 Brinell Hardness 217 to 255 Tensile Strength Not Rated Machinability 27 Percent Length Tolerance +/-1.00 in Includes Material Certificate Yes Standards ASTM A681 DIN 1.2379 SAE J437 SAE J438