6 [ Structural steel, stainless steel, tool steel and aluminum for use in construction, namely, sheets, plates, angles, bars, channels, I-beams, and tubes; metal materials for use in metals service center operations, namely, steel in the form of coils, sheets, plates, and I-beams; materials of metal for railway and railway bridge construction, namely, metal railway crossovers, metallic materials for railway tracks, and metal railroad ties; steel in form of sheets, plates, rods, bars, foils and coils; unwrought steel; nuclear grade steel construction materials, namely, fasteners, pipes, plates, bars, tubing, structural shapes, sheets, pipe hangers and supports ]