Mil Spec Washer Flat Washer Type Mil-Spec Dimensional Standards MS15795 Material Stainless Steel Material Grade/Class 18-8 Finish NL-19 For Screw Size 3/8 in Inside Diameter 0.406 in Outside Diameter 13/16 in Maximum Thickness 0.195 in System of Measurement Inch Minimum Thickness 0.17 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B70 Thickness Tolerance +0.051 to 0.080 in Package Quantity 25