Fender Washer Flat Washer Type Oversized Dimensional Standards ASTM F844 Material Stainless Steel Material Grade/Class 316 Finish NL-19 For Screw Size 5/16 in Inside Diameter 0.344 in Outside Diameter 1 1/2 in Maximum Thickness 0.062 in System of Measurement Inch Minimum Thickness 0.062 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B80 Thickness Tolerance +/-0.010 in Package Quantity 10