Thread Cutting Screw Finish Zinc Plated Material Steel Head Style Hex Washer Drive Slotted Thread Size 1/4 In.-20 Fastener Length 1/2 in Head Type Hex Washer Head and Washer Height 0.19 in Dimensional Standards ASME B18.6.3 Maximum Head Width 0.477 in Minimum Head Width 0.442 in Maximum Head Height 0.19 in Minimum Head Height 0.172 in System of Measurement Inch Head Height 0.19 in Head Width 0.477 in Package Quantity 50