If you must choose between fasteners and pins for locating parts, which is the typical choice?

• A. Fasteners
• B. Pins
• C. Welds
• D. Adhesives

Answer: (B)

Pins are the typical choice for locating parts because they provide a precise, repeatable reference that aligns components consistently from one assembly to the next. A locating pin fits into a corresponding hole or bushing and, when the workpiece is seated against a shoulder or reference face, establishes a fixed datum. This setup minimizes movement during clamping and makes reassembly fast and accurate, which is essential in fixtures and jigs.

Fasteners, by contrast, are meant to hold parts together, not to control their exact position. Threads and tightening variation can introduce play, distortion, or misalignment, making them less reliable for repeatable locating. Welds and adhesives create permanent bonds, so they don’t allow easy repositioning or repeatable re-location.

So, for establishing a repeatable position between parts, locating pins are the best fit.