SAE Washer Flat Washer Type SAE Dimensional Standards ASME B18.21.1 SAE Material Steel Material Grade/Class Grade 2 Finish Black Oxide For Screw Size 1/4 in Inside Diameter 0.281 in Outside Diameter 5/8 in Maximum Thickness 0.065 in System of Measurement Inch Minimum Thickness 0.065 in Color Clear Inside Diameter Tolerance 0.276-0.296 Made in North America No Manufacturer Location Globally Sourced Material Quality Standards Not Rated Maximum Temperature 350 Degrees C