Steel in sheet form, steel pipes, steel tubes, steel plates, steel in bar and/or billet form, steel blooms, slabs of alloy steel, and steel rails; steel pipes and tubes for pipelines; nonferrous common metals and their alloys; nonferrous metals and their alloys, all being unwrought or semiwrought; building and construction materials of metal, namely, metal door frames, steel frames for building, metal window frames, metal greenhouse frames, metal ceiling panels, metal roofing panels, wall pan...