This roll forming machine is to make the octagonal tube, octagonal tubes are widely used for aluminum roller shutters. According to the difference of shutter size, there are 3 sizes of octagonal tubes:40mm axle, 60mm axle, 70mm axle. Clients can choose suitable tube size to assemble roller shutters to save material cost, size 40mm, 60mm and 70mm make in one machine, can change the size by cassette, it is very easy.