... 3834-3, ISO9001:2008 3.Benz's supplier welding seat base for bus AL-0003Specification:according to drawins and ... . Making process: Stamping, deep drawing, bending, punching, threading, welding , tapping, riveting, grinding Surface treatment: Hot galvanized, polishing, chrome ... bus, train and autobike's spare parts and all products need to technique such as welding, stamping, bending, coating, injection ...