6 Building materials (of metal), in particular for drainage installations in building construction, in particular prefabricated components (of metal) for the construction of installations, for collecting and draining water, surface water, waste water and other liquids (as far as included in Class 006), in particular metal drainage channels, inflow basins and tanks, intermediate containers, catch basins, gutter basins, silt chambers, prefabricated inspection chambers, covers, cover grates and grids, cover plates, manhole covers with and without perforations, shaped parts of metal for the aforementioned goods for building drainage