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 1/2 in Inside Diameter 0.563 in Outside Diameter 1 1/4 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 B70 Thickness Tolerance +/-0.005 in Package Quantity 100