USS Washer, Flat Washer Type USS, Dimensional Standards ASME B18.22.1, Material Steel, Material Grade/Class Through Hardened, Finish Zinc Yellow, For Screw Size 1/4 in, Inside Diameter 0.313 in, Outside Diameter 3/4 in, Maximum Thickness 9/64 in, System of Measurement Inch, Minimum Thickness 3/16 in, Color Yellow, Material Quality Standards ASTM F436, Pack Size Small Pack, Rockwell Hardness RC38, Package Quantity 100