Socket Head Cap Screw Head Type Standard System of Measurement Inch Drive Type Socket Drive Size 1/4 in Material Alloy Steel Finish Black Oxide Thread Size 5/16 In.-18 Minimum Thread Length 3/4 in Fastener Length 3/4 in Head Height 0.312 in Head Diameter 0.469 in Pack Size Small Pack Thread Style Fully Threaded Special Features Not Applicable Countersink Angle Not Applicable Dimensional Standards ASME B18.3 Flange Diameter Not Applicable Flange Thickness Not Applicable