An insert nut,or knock in nut,provides a strong,permanent threaded socket for a wooden work piece,similar to a wall anchor.The insert nuts we manufactuer ensure strong resistance against vibration and pull-out,providing a powerful internal fixing where there is no access to the nut after the bolt is inserted.And the standard inserts are usually made from zinc alloy,galvanized finished.Also,OEM is welcomed to In-saiL.