Machine Screw Head Type Hex Material Steel Finish Zinc Plated Drive External Hex Thread Size 1/4 In.-20 Fastener Length 1 in Head Width 0.375 in Head Height 0.19 in Drive Size 3/8 in Dimensional Standards ASME B18.13 Pack Size Small Type Machine Screw Washer Outside Diameter 0.51 in Washer Thickness 0.028 in System of Measurement Inch Thread Type Coarse Package Quantity 25