Surface treatment, working, coating, finishing and processing of objects of metal and not of metal, in particular furniture hinges; mechanical and chemical conversion of metallic surfaces, in particular light metals, and non-metallic surfaces, namely, surfaces of steel, aluminum and copper alloys, plastics and ceramics; galvanizing; galvanising of metal; galvanization services; staining; zinc plating; anodising and enamelling of metallic and non-metallic objects; electroplating of metallic an...