A threaded insert is a threaded metal cylinder that is inserted into an existing hole to provide a threaded pathway for a fastener such as a screw or bolt. Also known as threaded bushings, threaded inserts are used to repair damaged threads and improve the thread strength of the parent material. Threaded inserts are used in metal, plastic and wood and typically require special tools for installation.
Threaded inserts are fabricated in two primary ways. In the wire forming method threaded inserts are made by tightly winding wire to form a coil. The wire coil mimics threads and results in a cost effective and reliable threaded insert. Wire formed threaded inserts are often referred to as Helicoil inserts. The other method of manufacturing inserts is by machining solid metal bars. Threaded inserts made in this way are known as solid inserts and have a higher pull-out and torque-out strength than wire formed threaded inserts.