Socket Head Cap Screw, System of Measurement Inch, Cylindrical, Basic Material Steel, Material Grade Alloy Steel, 5/16 In. -18, Length 2 1/4 in, Fastener Finish Black Oxide, Fastener Thread Type UNC (Coarse), Drive Type Hex Socket, Drive Size 1/4 in, Thread Style Partially Threaded, Thread Direction Right Hand, Min. Thread Length 1 3/8 in, Thread Length 1 3/8 in, Head Height 0.312 - 0.306, Thread Dia. 5/16 in, Package Quantity 100