Flat Washer Flat Washer Type USS Dimensional Standards ASME B18.21.1 USS Material Stainless Steel Material Grade/Class 18-8 Finish Plain For Screw Size 1/4 in Inside Diameter 0.313 in Outside Diameter 47/64 in Maximum Thickness 0.08 in System of Measurement Inch Minimum Thickness 0.051 in Color Silver Inside Diameter Tolerance +0.015 in -0.005 in Made in North America No Manufacturer Location Globally Sourced Maximum Temperature 302 Degrees F Minimum Temperature -58 Degrees F