Also known as tap-end studs, inch setup studs have Class 5 friction-fit threads on one end to resist loosening and Class 2A standard threads on the other end for attaching a nut. Metric setup studs have Class SK6 friction-fit threads on one end to resist loosening and Class 6g standard threads on the other end for attaching a nut. They are ideal for machining applications where vibration can loosen clamps. They withstand sideways forces better than fully threaded studs because they have an unthreaded middle that is stronger than the threaded ends. The unthreaded middle also makes more contact with unthreaded holes, creating better alignment than a fully threaded stud. Remove studs with pliers to reuse them.