Stainless steel socket cap screw has a plain finish and a flat head with an internal hex drive. Type 316 stainless steel is the preferred material used in the marine enviroment and boating industry due to its resistance to pitting corrosion. 316 stainless steel has high resistance to corrosion from sea sealt water and industrial chemicals. The flat head is cone shaped for use in countersunk holes and has a flat top that fits flush with the mated surface. The internal hex drive, also known as a hex-socket drive, has a hexagonal slot that requires an Allen key driver, also known as a hex key or Allen wrench. Socket cap screws are threaded fasteners that have a cap head with an internal socket drive for installing in areas with limited side clearance. These screws are available with a variety of head shapes, which determine how the screw interacts with the mating surface, and drive styles, which determine the type of tool required to install the screw.