USS Washer Flat Washer Type USS Dimensional Standards ASME B18.22.1 Material Steel Material Grade/Class Class 10.9 Finish Zinc Yellow For Screw Size 3/8 in Inside Diameter 0.438 in Outside Diameter 1 in Maximum Thickness 0.083 in System of Measurement Inch Minimum Thickness 0.083 in Color Yellow Inside Diameter Tolerance 0.433-0.453 Made in North America No Manufacturer Location Globally Sourced Material Quality Standards ASTM A-325 Maximum Temperature 350 Degrees C