... Quality system certificate:ISO9001:2008 Type: Sheet-metal Products Speaker cabinet Dongguan Richhong metal Co. Ltd has long history in self ... milling, grinding, chip formatting, rolling, stamping, deep drawing, bending, spot or seam welding, spinning, forging, sand casting, die casting, investment casting ... ; Wire EDM, etc. And we also can offer 4 or 5 axis-CNC center processes. sheet- metal workshop