METAL BUILDING MATERIALS, NAMELY, OVERHEAD BEAMS AND METAL RAILWAY TRACK PARTS, NAMELY, OVERHEAD TROLLEY TRACKS AND RAILS ALONG WHICH OVERHEAD TROLLEYS RUN; NON-ELECTRIC CABLES AND WIRES OF COMMON METAL USED AS COMPONENTS IN AN OVERHEAD TROLLEY, SUCH TROLLEY BRINGING PRESSURIZED AIR AND ELECTRIC ENERGY TO A MOVEABLE UNIT RUNNING ALONG A RAIL; PIPES AND TUBES OF METAL, NAMELY, PIPES AND FITTINGS THEREFORE, AND TUBES AND FITTINGS THEREFORE FOR USE IN AN OVERHEAD TROLLEY; PIPES AND TUBES OF META...