Principle of Self-piercing:    The end of rivet open a horn shape under the action of concave die and riveting pin at base layer to locking it with top layer. Generally the thicker layer at base and same thickness have no limited, ductile material at base layer. Metal material at base layer if joint metal with non-metal material. ► No need to drilling holes,no wast and no iron crap occured. ► Self-piercing processing allowed Non-metallic sandwich material. ► No thermal stress concentraition and no damage to the surface coating. ► High dynamic strength and far superior to the traditional welding. ► Forming by special die with stamping and processed quality is stable. ► By check the riveting point geometry size can judging teh riveting quality. ► No damage to plating or coating and no need after painting or plating. ► Application:Automotive metal sheet components. ► Computer chassis,home appliances metal sheet etc. ► Elevator's metal sheet and other commercial facilities. ► Busway's industrial engineering applications. ► Other metal sheet connect occasion.