USS Washer Flat Washer Type USS Dimensional Standards ASME B18.22.1 Material Steel Material Grade/Class Grade 2 Finish Zinc Yellow For Screw Size 9/16 in Inside Diameter 0.625 in Outside Diameter 1 1/2 in Maximum Thickness 0.109 in System of Measurement Inch Minimum Thickness 0.109 in Color Yellow Pack Size Bulk Pack Rockwell Hardness RC38 Thickness Tolerance +/-0.023 in Package Quantity 1200