A Round Screw Head has a rounded or domed head. The half of the screw that remains visible when screwed into the surface is rounded and domed. Roundhead screws tend to be used less frequently that Flathead screws. This type of screw has a cylindrical shaped head with a hex recess that can be tightened with a socket wrench driver. It is available in a variety of sizes and finishes, and some are designed for outdoor applications. The socket cap head screw is most commonly used in industrial applications.