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. Stainless Steel material. Grade 18-8 has the same design advantages as a low carbon bolt, however can be used in environments that require greater atmospheric corrosion resistance. Nylon patch acts as a thread locker.