6 Common metals and their alloys; building materials of metal, namely, sheet piling structures, quay walls; semi-finished steel products, namely, ingots, beam blanks, iron slabs, billets; goods made from steel, namely, beams, girders, piles, sheet piles, special profiles, tubes, strip, sheets and plates of metal; steel grades offering better resistance to corrosion in seawater, namely, corrosion resistant steel