A composite constituted of a steel sheet taken in a sandwich between two aluminum (Al) sheets is produced by cold roll bonding. A good adherence between Al and steel sheets, ensuring a good mechanical resistance, is obtained with a specific process. A previous work of the authors has shown that optimal condition between adherence and magnetic shielding effectiveness (SEH) is obtained with a 230 µm composite produced with an initial thickness of Al and steel sheets respectively of 250 and 100 µm. In this paper, the 230 µm Al/Steel/Al composite is used in three applications modelized by 2D numerical simulations. To facilitate calculations, a homogenization method is applied to the composite. Studied applications are a cylindrical box containing a coil, a square box under an external magnetic field and a high voltage cable. In each application, SEH is calculated at low frequency (1 Hz-100 kHz) and different materials (Al/Steel/Al, Al, steel, and copper) are compared. It is observed that, in each application, the composite is more advantageous at equal mass and especially at frequencies higher than around 5-10 kHz.