O1 Tool Steel Rod Material Tool Steel Material Grade O1 Overall Length 36 in Heat Treatable Yes Heat Treatment Oil Hardened Mechanical Finish Precision Ground Outside Diameter 1/2 in Outside Diameter Tolerance +/-0.001 in Yield Strength 55 000 psi Fabrication Hot Rolled Rockwell Hardness B100 Brinell Hardness 241 Tensile Strength 95 000 psi Machinability 90 Percent Length Tolerance +1/8 in/-0 in Includes Material Certificate Yes