Common metal, namely, metal rings, tubes, pipes, ducts of metal, elbows for pipes, feeding pieces, breeches pipes, T-pieces, connection pieces, pipe junctions, pipe flanges, adapter pieces, threaded pipes, clips for pipes, pipe muffs, nuts, shell coupling pieces, tie plates, valves other than for parts of machines; parts of the aforementioned goods of metal; reinforcing metal sleeves for pressure pipes; fittings of metal for pipes and ducts for gases, liquids and solids in particulate form