Insert Injection moulding

Insert injection moulding is to add metal parts into plastic parts before injection, so  to combine the features of both metal and plastic. In most common cases, it is to insert copper/stainless steel threads or threaded rods into plastic parts, as plastic threads are ease to damages and non-repeatable.  Also it is often very costly or even impossible to make thread out of plastic directly. These metal threads or rods are designed particularly to fit the insert injection process and grab plastic firmly. In some other cases, metal might play the main function role, with plastic for better touch feeling and handy shapes.

Insert injection parts may have increased cost due to 1> cost of inserts, 2> insert cost by hands,3> extended injection time.