Thread inserts, we also call it threaded bushing , it is made of smooth-faced and cold-rolled stainless steel wire with high strength, high precision . Mainly used to enhance and protect internal threads of low strength material. The principle is the elastic connection between the screw and the matrix thread, eliminate the thread manufacturing error and improve the connection strength. Thread inserts is divided into two types that are common type and screw lock type, locking ring is to add a coil or a few rings on the basis of the common type, and to fasten the assembly screws.Thread inserts embedded in aluminum, magnesium alloy, cast iron, glass fiber reinforced plastic, plastic and other low strength engineering materials, which can form high-precision internal thread with high connection strength, seismic resistance, impact resistance and wear resistance, and can spread stress protection for matrix thread, greatly prolong the service period of the substrate.