Flat Washer Flat Washer Type Oversized Dimensional Standards ASME B18.22.1 Material Steel Material Grade/Class Class 8.8 Finish Black Oxide For Screw Size #4 Inside Diameter 0.125 in Outside Diameter 5/16 in Maximum Thickness 0.078 in System of Measurement Inch Minimum Thickness 0.078 in Color Clear Inside Diameter Tolerance 0.12-0.133 Made in North America No Manufacturer Location Globally Sourced Material Quality Standards ASTM A-325 Maximum Temperature 350 Degrees C