6 Common metals and their alloys; transportable buildings of metal; materials of metal for railway tracks; non-electric cables and wires of common metal; ironmongery and small items of metal hardware, namely, elbow joints for pipes, crossovers for pipes, pipe couplings, pipe tees, pipe reducers, plugs, pipe adaptors, flanged pipe joints, pipe joints, pipe valve connectors; pipes and tubes of metal; safes; hardware of common metal, namely, elbow joints for pipes, crossovers for pipes, pipe couplings, pipe tees, pipe reducers, plugs, pipe adaptors, flanged pipe joints, pipe joints, pipe valve connectors; grease nipples; water-pipe valves of metal; drain traps [valves] of metal; alloys of common metal; common metals, unwrought or semi-wrought; water pipes of metal; water-pipe valves of metal; soldering wire of metal; rods of metal for welding, valves, of metal, other than parts of machines; wire of common metal; ring-shaped fittings of metal; nuts of metal; elbows of metal for pipes; pipe muffs of metal; chains of metal; couplings of metal for chains