Fastener is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints that can be dismantled without damaging the joining components.

Threaded insert, also known as a threaded bushing, is a fastener element that is inserted into an object to add a threaded hole. They may be used to mold thread into a plastic work piece or place a thread on a material too thin to accept it.