USS Washer Flat Washer Type USS Dimensional Standards ASME B18.22.1 Type A Wide USS Standard Material Steel Material Grade/Class Grade 8 Finish Zinc Yellow For Screw Size 1/4 in Inside Diameter 0.313 in Outside Diameter 3/4 in Maximum Thickness 0.065 in System of Measurement Inch Minimum Thickness 0.065 in Color Yellow Material Quality Standards ASTM F436 Pack Size Small Pack Rockwell Hardness 38HRC Thickness Tolerance +0.015/-0.014 in Package Quantity 100