6 Struts, plates, tubes and tubing, bars, beams, rods, rails, angle pieces, channels, sections, brackets, joints, junctions, couplers, fasteners, plugs, sockets, collars, studs and clips, socket bases, slab edge brackets, beam clamps, posts, guard rails, barriers, fences and barrier apparatus, mesh panels, all for use in scaffolding, and safety platforms; scaffolding; scaffold towers; scaffold platforms; staging; decking; staircases, stairways, stair treads, steps and ladders; structural parts, components and accessories for all the aforesaid goods; all the aforesaid goods made wholly or principally of common metals or of common metal alloys