Steel inserts used in low strength materials such as aluminum, magnesium, can avoid damage to the wires and achieve good connection performance, connection to improve the strength and improve the connection condition. Used for parts that require frequent removal, it can significantly improve the life and wear of screws. Due to a certain elasticity, thread insert can even distribute the load on each thread, eliminate pitching and tooth deviation between screw hole and screw, and absorb vibration, thereby increasing the screw connection and resistance tofatigue. It can prevent screws from bulking, especially used for products requiring high coefficient of assurance. Easy to maintain, install a damage wire insert it into a screw hole, then the screw hole can be used as normal, to avoid rough loss.