'Machine Screw w/Captive Washer, Head Type Hex, Steel, Length 1/2", Drive Type Hex, Finish Zinc, Thread Size 10-32, Driver Size 5/16", Head Dia. 0.312", Head Height 0.120", Washer Type External Tooth, Washer Material C1050-C1065 Steel, Washer O.D. 0.381", Washer Thickness 0.025", Meets/Exceeds ANSI/ASME B18.13, Package Quantity 100'