Thick Washer Flat Washer Type Standard Material Brass Material Grade/Class Grade 2 Finish Plain For Screw Size #10 Inside Diameter 0.203 in Outside Diameter 1/2 in Maximum Thickness 0.093 in System of Measurement Inch Minimum Thickness 0.093 in Inside Diameter Tolerance +/-0.010 in Material Quality Standards ASTM B16 Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Resistance Properties Corrosion Resistant Friction Resistant Rust Resistant Rockwell Hardness B50