Thread Forming Screw, Finish Black Oxide, Material Steel, Head Style Round, Drive Star, Thread Size 1/4 In.-20, Fastener Length 1 27/32 in, Head Type Flat, Head and Washer Height 0.153 in, Drive Size T27, Maximum Head Width 15/32 in, Minimum Head Width Not Applicable, Maximum Head Height 5/32 in, Minimum Head Height Not Applicable, System of Measurement Inch, For Use in Systems Drilled or Punched Holes in Ductile Metal and Punch Extruded Metal, Head Height 0.153 in, Head Width 0.469 in