Flat Washer Flat Washer Type Standard Dimensional Standards ASME B18.22.1 Material Stainless Steel Material Grade/Class 316 Finish NL-19 For Screw Size 1 in Inside Diameter 1.063 in Outside Diameter 2 1/2 in Maximum Thickness 0.12 in System of Measurement Inch Minimum Thickness 0.12 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B80 Thickness Tolerance +/-0.010 in Package Quantity 10