Thick Washer Flat Washer Type Standard Material Stainless Steel Material Grade/Class 18-8 Finish Plain For Screw Size #4 Inside Diameter 0.125 in Outside Diameter 5/16 in Maximum Thickness 0.078 in System of Measurement Inch Minimum Thickness 0.078 in Inside Diameter Tolerance +/-0.010 in Material Quality Standards ASTM A582 Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Resistance Properties Chemical Resistant Corrosion Resistant Rockwell Hardness B83