Washer Flat Washer Type Standard Dimensional Standards TCMA Material Steel Material Grade/Class Not Graded Finish Black Oxide For Screw Size 1/4 in Inside Diameter 0.281 in Outside Diameter 5/8 in Maximum Thickness 0.204 in System of Measurement Inch Minimum Thickness 0.172 in Color Black Maximum Temperature 400 Degrees F Thickness Tolerance +/-1/64 in Package Quantity 25