... 7.4KN/T max thick of board 2+2 Rivetless riveting machine joint two layers of several layers of metal board by punch ... steel plate, stainless plate, zinc and aluminum etc. 1.Good quality after process and metal flown line are naturally, the pieces ... plating or painting in surfaceTo the metals material request not high, the copper , aluminums, steel, zinc are all unlimited Rivetless riveting machine