Grainger.com

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 7/16 in, Outside Diameter Tolerance +/-0.0005 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