6 Transportable buildings of metal; small items of metal hardware, namely fittings of metal, handles of metal for waste containers, bolts, rollers and runners of metal for waste containers, hinges of metal, locks of metal, other than electric; pipes and tubes of metal; bars of metal, namely, common metals in bar form, metal latch bars, metal bars for metal railings; building materials of metal, namely tubbings, girders, joists, bindings, fittings for buildings, building boards, coverings, sheets, plates, roofings, refractory construction materials, framework for buildings, stands, gratings, hooks, posts, tile flooring, duckboards, manhole covers, building panels, props, partitions, linings for building, for building waste collecting systems for receiving or housing waste, collecting or depot containers of bins for the collection, composting, reception, recycling of waste and valuable substances; containers, barrels, and boxes of metal, particularly for domestic and industrial and commercial and public and office use, particularly waste containers and skips, depot containers, for temporarily storing, composting, reception, recycling of waste and valuable substances, whether or not on wheels, for indoor and outdoor use; metal bins and metal containers for the use in the collection of waste and valuable substances for commercial use; all of the aforementioned for use with underground or semi-underground containers, systems or container banks