Automatic equipment for double bell-shaping of stainless steel tubes for chimneys, diameters between 80 mm and 400 mm, thickness 0,4-0,6 mm. The machine is equipped with two units for bell-shaping on an automatic line for chimneys production. On every station there’s a hydraulic expansion system with 3 inner sectors and 12 outer sectors, shaped and interchangeable for different diameters. One station is dedicated to male shaping, while the other is dedicated to female shaping.