Miniaturised Tensile Test (MTT) were applied to obtain the local mechanical properties of the material in real parts with an insufficient amount of material available for conventional testing. This test made it possible to determine the mechanical properties – yield strength, ultimate tensile strength, uniform elongation, total plastic elongation, and reduction of the cross-sectional area – of both parts with and without cracks from three different areas of the packaging product. The results allowed Aludium to redesign its thermomechanical production process in order to prevent the occurrence of cracks in the closure parts during the forming processes.