Self Drilling Tapping Screw Finish Zinc Plated Material Steel Head Type Hex Washer Drive External Hex Screw Size 1/4 in Fastener Length 1 in Drill Point Size 3 Drill Tip Length 25/64 in Maximum Drilling Thickness 0.219 in Head Width 0.375 in Head Height 0.19 in Washer Outside Diameter 0.52 in Drive Size 3/8 in Pack Size Small System of Measurement Inch Maximum Head Width 0.375 in Minimum Head Width 0.367 in Maximum Head Height 0.19 in Minimum Head Height 0.172 in