6 Prefabricated elements of metal for building, namely, structural steel space frame, structural profiles, brackets, straps, rails, window reveals, window sills, columns, beams, wall and ceiling panels, roof trusses, roof lugs being supports, crane lugs being supports, bracing, bracing lugs being supports, ceiling support rails, structural window surrounds, joining inserts being supports, joining inserts being guides; pre-fabricated metal buildings