Studs & Nuts: ​A bolt with threads on both ends designed to be screwed permanently into a fixed part at one end and to receive a nut on the other. A bolt is a threaded fastener mated with a nut. A screw has either pre-formed or self-made external threads. A stud is an externally threaded headless fastener. One end mate with a tapped component and the other with a standard nut.