A thread insert is a fastener element that is inserted into an object to add a threaded hole. Externally threaded inserts have threads on the outside and inside of the insert. The insert is threaded into a pre-tapped hole or some inserts tap their own threads in a drilled or molded hole.
How to Install Threaded Inserts
By Ilya Leybovich
Threaded inserts are fastener-related devices constructed of metal or plastic materials. They are generally used to provide thread tracks for screws or bolts. These inserts can allow a fastener to form a more secure attachment to soft or pliable surfaces that would otherwise reject fastening, repair a damaged thread track, or install threads into a workpiece without relying on a more elaborate production process. Threaded inserts are usually placed inside an existing hole or slot, and they feature an external design that allows them to be lodged securely, along with a cylindrical inner cavity lined with threads.
Photo: manchesterguitartech.co.uk
Fastener inserts can be made from a wide range of materials, including metals such as brass and steel, and plastics such as PVC. Likewise, they are available in a variety of design types depending on their application. Molded inserts are used in plastic fabrication cavities, while key-lock inserts are employed for repairing stripped thread holes. Threaded brass inserts are most often used for fastening plastic materials, although they can also be applied to wood and other surfaces as well. Installing these inserts is usually a multistage process, and can sometimes require special equipment or techniques to accomplish.