Socket set screws are headless and threaded over their entire length. There is a hex or square-shaped socket at the top of the drive in place of a head. Socket set screws come with either cup or knurl cup points shaped to bear on a mating part. The fact that the socket set screw is without head allows it to go in flush. Socket set screws are often found in electronics, in pulleys and shafts, and other places where flush mounting and space are import concerns. They are also used for internal wrenching and where frequent disassembly or adjustment occurs.