Flat Washer Type B Flat Washer Type Standard Dimensional Standards ASME B18.22.1 Material Stainless Steel Material Grade/Class 18-8 Finish Plain For Screw Size 5/16 in Inside Diameter 0.344 in Outside Diameter 7/8 in Maximum Thickness 0.071 in System of Measurement Inch Minimum Thickness 0.056 in Color Silver Inside Diameter Tolerance +/-0.010 in Material Quality Standards ASTM A582 Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack