Flat Washer Flat Washer Type Oversized Dimensional Standards ASME B18.21.1 Material Steel Material Grade/Class Grade 2 Finish Black Oxide For Screw Size 1/2 in Inside Diameter 0.563 in Outside Diameter 1 3/8 in Maximum Thickness 0.109 in System of Measurement Inch Minimum Thickness 0.109 in Color Clear Inside Diameter Tolerance 0.557-0.577 Made in North America No Manufacturer Location Globally Sourced Material Quality Standards Not Rated Maximum Temperature 350 Degrees C