5/16-18 x 5/8" Socket Cap Screw - Steel - Black Oxide - UNC - Pkg of 100 - USA - Holo-Krome 72122

Socket Head Cap screws are ideal for precision work with close tolerances and applications needing a well tooled appearance. Socket Head Cap screws supply greater tensile strength than equivalent Hex Head Caps screws, while requiring less surface area to counterbore. Thermal Black Oxide finish features a standard heat treatment finish which includes light drying oil; Chemical Black Oxide is a chemical treatment plus rust resistant with no drying oil.