Metal building materials, namely, steel, stainless steel, unwrought or semi-wrought brass, aluminum and its alloys, stamped metal sheets, folded metal sheets; mechanical fastening elements made entirely or principally made of metal; metal or principally made of metal fastener connection elements, namely bolts, screws, nuts, rivets, rivet nuts, anchor nuts, inserts; anchor bolts made of metal; metal or principally made of metal dowels, connecting dowels and hardware metal pins; metal or princi...