Flat Washer Flat Washer Type Standard Dimensional Standards ANSI B18.22.1 Material Stainless Steel Material Grade/Class 18-8 Finish NL-19 For Screw Size 1/4 in Inside Diameter 0.281 in Outside Diameter 5/8 in Maximum Thickness 0.05 in System of Measurement Inch Minimum Thickness 0.05 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B70 Thickness Tolerance +/-0.010 in Package Quantity 100