Socket Flat Head Screw, Head Type Flat, System of Measurement Inch, Drive Type Socket, Drive Size 5/16 in, Material Steel, Finish Black Oxide, Thread Size 1/2 In.-13, Minimum Thread Length 2 1/4 in, Fastener Length 2 1/4 in, Head Height 0.251 in, Head Diameter 0.938 in, Pack Size Small Pack, Thread Style Fully Threaded, Special Features Not Applicable, Countersink Angle 82 Degrees , Dimensional Standards ASME B18.3, Flange Diameter Not Applicable, Flange Thickness Not Applicable