Inserts are used in structural assemblies, such as forgings, castings and machined components where repeated bolt assembly and removal could jeopardize the integrity of tapped threads in a less durable parent material. These inserts act as a hardened thread liner to prevent wear and protect expensive housings, cases, or gearboxes from thread damage. Inserts are also often used to repair damaged threads in housings, and deliver performance and durability superior to original stock designs.