Abstract: A structural product comprising: one or more layers of a component lightened by the presence of cavities and made of steel manufactured article with multiple-cells configuration, that can be obtained from the integration of hermetically sealed tube-like units; a layer of other materials that embeds the lightened component so as to obtain a modular unit with a rectangular section; and an outer coating layer. Inside the cavities is present a compressed gas mainly helium, and/or vacuum.