building materials and tools made of metal, namely, standard panels, normal wedges, normal corner pieces, strengthened panels, strengthened wedges, slabs/panels, special panels, standard and special foundation arch centering centerings, head centerings, hollow centerings, treatment centerings, special centerings, caps straight caps, curved caps, taps for continuous walls, special curved arch centerings, screws, plates, beams, joists, layout patterns, locking spacers, locks for spacers, screw ...