Flat Washer, Dimensional Standards AMPG 2001 FL.01, Material Steel, Material Grade/Class Case Hardened, Finish Black Oxide, For Screw Size 1/4 in, Inside Diameter 0.281 in, Outside Diameter 2 in, Maximum Thickness 5/64 in, System of Measurement Inch, Minimum Thickness 5/64 in, Color Black, Made in North America Made in North America, Material Quality Standards ASTM A108, Thickness Tolerance +0.005/-0.014 in