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 #12 Inside Diameter 0.25 in Outside Diameter 9/16 in Maximum Thickness 0.065 in System of Measurement Inch Minimum Thickness 0.065 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B70 Thickness Tolerance +0.051 to 0.08 in Package Quantity 100