Flat Washer Flat Washer Type Standard Dimensional Standards ASME B18.22.1 Material Steel Material Grade/Class Grade 2 Finish Zinc Plated For Screw Size #0 Inside Diameter 0.068 in Outside Diameter 1/4 in Maximum Thickness 0.028 in System of Measurement Inch Minimum Thickness 0.022 in Color Silver Inside Diameter Tolerance +/-0.010 in Outside Diameter Tolerance +/-0.010 in Pack Size Small Pack Rockwell Hardness B55 Thickness Tolerance -0.014 in/ +0.005 in Package Quantity 50