4140 Alloy Steel Plate Material Alloy Steel Material Grade 4140 Heat Treatable Yes Mechanical Finish Mill Precision Ground Overall Length 12 in Overall Width 12 in Thickness 0.625 in Thickness Tolerance +/-0.002 in Yield Strength 127 000 psi Fabrication Cold Finished Rockwell Hardness C26 to C32 Machinability Not Rated Tensile Strength 148 000 psi Length Tolerance +/-0.002 in Width Tolerance +/-0.002 in Standards DFARS Compliant Includes Material Certificate Yes