Flat Washer Flat Washer Type Oversized Material Stainless Steel Material Grade/Class 18-8 Finish Plain For Screw Size #12 Inside Diameter 0.25 in Outside Diameter 1/2 in Maximum Thickness 0.057 in System of Measurement Inch Minimum Thickness 0.043 in Color Silver 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