Flat Washer Flat Washer Type Standard Dimensional Standards ASME B18.22.1 Material Stainless Steel Material Grade/Class 18-8 Finish NL-19 For Screw Size 3/8 in Inside Diameter 0.438 in Outside Diameter 1 in Maximum Thickness 0.08 in System of Measurement Inch Minimum Thickness 0.051 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B70 Thickness Tolerance +0.064 to 0.104 in Package Quantity 25