HWASHI Stainless Steel Sink Welding Machine for Wide Applications The seam (roll) welding special machine is the evolution of spot welder. It uses the roller electrode to replace the cylindrical electrode of spot welding and as the welding work piece moves between the rolling plates, the seal welding will generate weld nuggets which will overlap with each other so as to achieve welding effect. We adopts the AC converter type seam welding system with easy operation and stable