Light metals and their alloys, especially aluminum alloys because of their good strength/weight ratio, have been used in the automotive and aerospace industries to reduce the amount of fuel required and consequently the amount of energy, in a worldwide effort to save energy resources. As mentioned above, among the alloys, the aluminum-silicon binary (Al Si) stands out, as it is used in the construction of mechanical parts of automobiles and the aeronautical industry in the structure of airplane wings. In the automotive industry, components made from the Al-Si alloy need to be machined for their final application and, therefore, this implies in-depth knowledge of the machinability of such alloys, to estimate the machining parameters that require less energy expenditure and provide better surface finish of the part with less tool wear. The present study determined the dependence of the solidification parameters and alloy composition on the machinability of the material, as well as specified parameters for measuring the machining temperature during necking tests.