Abstract: The object of this patent is an advance in the state of the art in the technique of manufacturing rods (2) aimed to be folded for the production of hangers (4) for the civil construction, the reinforced structures in particular, because it prevents the polygons generated in the folding of the hangers (4) form having non-co-planned edges as they are produced, which brings large savings to the process. The formation of hangers (4) with non-co-planned edges brings costs and delays to the civil construction, which are avoided with the use of the rod with octagonal core purpose-built for civil construction, object of this patent. Although the core of the rod with octagonal core purpose-built for civil construction is octagonal, according to the FIG. 8, its specific section is an octagonal structure, formed due to the corrugated material with which the rod (2) is made, according to FIG. 9.