SAE Washer Flat Washer Type SAE Dimensional Standards ASME B18.21.1 SAE Material Steel Material Grade/Class Grade 2 Finish Zinc Plated For Screw Size 5/16 in Inside Diameter 0.344 in Outside Diameter 11/16 in Maximum Thickness 0.063 in System of Measurement Inch Minimum Thickness 0.063 in Color Silver Inside Diameter Tolerance 0.339-0.359 Made in North America No Manufacturer Location Globally Sourced Material Quality Standards Not Rated Maximum Temperature 350 Degrees C