Flat Washer Flat Washer Type Standard Dimensional Standards ASTM F844 Material Stainless Steel Material Grade/Class 316 Finish NL-19 For Screw Size 5/8 in Inside Diameter 0.531 in Outside Diameter 1 1/2 in Maximum Thickness 0.78 in System of Measurement Inch Minimum Thickness 0.78 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B80 Thickness Tolerance +/-0.010 in Package Quantity 10