Steel pipes; pipework of metal; drain pipes of metal; penstock pipes of metal; clips of metal for cables and pipes; casings of metal for oilwells; framework of metal for building; telegraph posts of metal; metal guard rails; scaffolding of metal; water-pipes of metal; gutter pipes of metal; drains of metal for use in the construction of basement waterproofing systems; metal sewage pipe; underdrainage pipes of metal; ventilating ducts of metal.