Fender Washer Flat Washer Type Oversized Material Stainless Steel Material Grade/Class 316 Finish Plain For Screw Size 5/16 in Inside Diameter 0.344 in Outside Diameter 2 in Maximum Thickness 0.073 in System of Measurement Inch Minimum Thickness 0.053 in Inside Diameter Tolerance +/-0.010 in Material Quality Standards ASTM A276 Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Resistance Properties Corrosion Resistant Saltwater Resistant Solvent Resistant