Flat Washer Flat Washer Type Standard Dimensional Standards ASTM F844 Material Stainless Steel Material Grade/Class 18-8 Finish NL-19 For Screw Size 3/8 in Inside Diameter 0.391 in Outside Diameter 7/8 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 +/-0.005 in Package Quantity 100