High performance feeding lines dedicated exclusively for the automotive sector which increasingly requires the use of high strength steels even over 1200 N/mm2. Designed with a high number of straightening rollers, they allow to eliminate the internal tensions of the material through an adequate plastic deformation, ensuring optimal straightening. They can also be equipped with a cassette change system with different banks of rollers (different diameters, number of rollers and types of coating) to always maintain optimal plasticization values of the fibers according to the different ranges of thicknesses and characteristics of the materials.