Arbor Spacer, Inside Diameter 0.375 in, Outside Diameter 0.625 in, Inside Diameter Tolerance +0.011/-0.000 in, Outside Diameter Tolerance +/-0.002 in, Thickness 0.012 in, Thickness Tolerance +/-0.0008 in, Keyway Width 1/8 in, Keyway Depth 3/64 in, Round Shim Type Arbor Spacer, Material Steel, Finish Plain, Temper Full Hard, Material Grade/Class Ungraded, Rockwell Hardness B90, Tensile Strength 80,000 psi, Manufacturer Location Made in USA*, Package Quantity 10