Doshi Engineers manufactures Socket Head Cap Screws. Doshi Engineers is an ISO 9001: 2000 certified company that supplies industrial fasteners and engineering components. The Socket Head Cap Screws comes with a hexagonal recessed drive. The most common types in use have a cylindrical head whose diameter is nominally 1.5 times that of the screw shank [major] diameter. The Socket Head Cap Screws are commonly used in assemblies that do not provide sufficient clearance for a conventional wrench or socket.