Depending on the purpose of threaded inserts, they are available in various materials. For plastic inserts, threaded inserts are available in plastic. Thermal insertion or ultrasonic welding machines may be used to insert them into the plastic materials. For wooden materials, there are wooden inserts available; there are threaded inserts available in metal for metallic products. Metal threaded inserts are threaded inserts for composites typically used for all plumbing works, unless the bathroom accessories are plastic. In such a case, plastic threaded inserts are used.