To facilitate the search and the choice, the catalog of DC electric motors is divided into sub-categories, identified by the external diameter of the stator. In each sub-category there is then a further classification based on other technical characteristics: standard or enhanced version, possible presence of the Hall sensor. An automatic assembly process has been designed for each DC electric motor that allows variations in the shaft output, wiring and flanges, always guaranteeing high standards of reliability and competitiveness.