Process Surface coating process where the workpiece through an anode-cathode reaction is coated with a thin decorative layer of hexavalent chrome with a black tone.
Process Polishing process where several workpieces together with an abrasive chips tumbles around so that the surface of the workpieces are smoothed and polished.
Process Mechanical surface cleaning process where the workpiece immersed in water is subjected to a high voltage such that shock waves are formed and clean its surface.