USS Washer Flat Washer Type USS Dimensional Standards ASME B18.22.1 Material Steel Material Grade/Class Grade 8 Finish Zinc Yellow For Screw Size 9/16 in Inside Diameter 0.625 in Outside Diameter 1 1/2 in Maximum Thickness 0.051 in System of Measurement Inch Minimum Thickness 0.08 in Color Yellow Material Quality Standards ASTM F436 Pack Size Small Pack Rockwell Hardness RC38 Package Quantity 25