The thesis refers to the automotive sector and more specifically to car body manufacturing, taking the "Flow Drilling Screw" joining technology as object of analysis. Commonly known by the acronym FDS, it represents a real breakthrough in the creation of multi-material joints, and has had considerable prominance in recent years with the ever-increasing use of aluminum alloys in car design in accordance with the objective of reducing vehicles weight. FDS is born as an evolution of the Flow Drilling technology, in which a hard metal rod with a pointed end is used to obtain a through hole in the workpiece by means of plastic deformation of the material at high temperatures, exploiting the heat of friction that is created during the high speed rod rotation.