... , stamping, deep drawing, bending, spot or seam welding, spinning, forging, sand casting, die casting, investment casting, etc. 3. Surface treatment: Polishing, zinc plating, nickel ... , PVC powder coating, dichromate plating, decrement plating, etc. 4. Machinery and equipments: CNC machining center; CNC lathe; Normal lathe; CNC milling ...