USS Washer, Flat Washer Type USS, Dimensional Standards ASME B18.21.1, Material Steel, Material Grade/Class Grade 2, Finish Hot Dipped Galvanized, For Screw Size 1/2 in, Inside Diameter 0.563 in, Outside Diameter 1 3/8 in, Maximum Thickness 0.109 in, System of Measurement Inch, Minimum Thickness 0.109 in, Color Silver, Inside Diameter Tolerance 0.557-0.577, Made in North America No, Manufacturer Location Globally Sourced, Material Quality Standards Not Rated, Maximum Temperature 350 Degrees C WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov - Nickel (Metallic)