An equipment for the thermal treatment of metals comprising: - A bell provided with a receiving cavity into which to be able to position one or more than one metal pieces to be thermally treated; - Heating means to raise the internal temperature of the receiving cavity to a pre-established value and; - An assembly of thermal exchange (100; 200; 300) to lower the temperature reached in the receiving cavity in such a way as to operate the pre-established thermal treatment on the pieces and wherein - said assembly of thermal exchange (100; 200; 300) is arranged externally to the bell in such a way as to allow a reduction of the overall dimensions of the said bell and forms a closed circulation path for a cooling fluid, the said closed circulation path comprising a thermal exchanger (30, 60; 230, 260" 260"; 330, 360" 360'') integrated along the path and into which the cooling fluid directly circulates in such a way that when the cooling fluid is injected into the cavity, the cooling fluid circulates along the said closed circulation from the receiving cavity to the thermal exchanger to lower its temperature, to be then thrust again into the bell in such a way as to be able to operate the lowering of temperature on the internally arranged pieces - said closed circulation path further includes an impeller to force the circulation of the cooling fluid along the said circulation - said closed circulation path is formed by a feed pipe connected to the receiving cavity and through which the cooling fluid injected in the receiving cavity is sucked, by a return pipe through which the cooling fluid circulated into the receiving cavity is injected again, and the thermal exchanger (30, 60; 230, 260', 260''; 330, 360', 360'') with the impeller interposed between the feed pipe and the return pipe and characterized in that said thermal exchanger (30, 60) comprises a coil pipe connected by an end to the feed pipe and by the other end to the impeller, and a forced aeration system arranged with respect to the coil in such a way as to be able to throw a cooling air flow against the coil, thus operating the lowering of the cooling fluid circulating into the coil. - A bell provided with a receiving cavity into which to be able to position one or more than one metal pieces to be thermally treated; - Heating means to raise the internal temperature of the receiving cavity to a pre-established value and; - An assembly of thermal exchange (100; 200; 300) to lower the temperature reached in the receiving cavity in such a way as to operate the pre-established thermal treatment on the pieces and wherein - said assembly of thermal exchange (100; 200; 300) is arranged externally to the bell in such a way as to allow a reduction of the overall dimensions of the said bell and forms a closed circulation path for a cooling fluid, the said closed circulation path comprising a thermal exchanger (30, 60; 230, 260" 260"; 330, 360" 360'') integrated along the path and into which the cooling fluid directly circulates in such a way that when the cooling fluid is injected into the cavity, the cooling fluid circulates along the said closed circulation from the receiving cavity to the thermal exchanger to lower its temperature, to be then thrust again into the bell in such a way as to be able to operate the lowering of temperature on the internally arranged pieces - said closed circulation path further includes an impeller to force the circulation of the cooling fluid along the said circulation - said closed circulation path is formed by a feed pipe connected to the receiving cavity and through which the cooling fluid injected in the receiving cavity is sucked, by a return pipe through which the cooling fluid circulated into the receiving cavity is injected again, and the thermal exchanger (30, 60; 230, 260', 260''; 330, 360', 360'') with the impeller interposed between the feed pipe and the return pipe