Rolled tubular centralizer

A method of forming a centralizer where a flat plate is created into a tubular where the flat plate is typically rolled so that two sides of the plate contact one another and are then linked, typically by welding. Openings are then created in the tubular such that there are no corners or other points that stress cracks may originate. Once the openings are created the remaining material between adjacent openings forms ribs. The openings created in the tubular are generally aligned with the long axis of the tubular. The material at the upper and lower end of the flat plate where openings were not created serve as circumferential collars. The ribs may be radially outwardly expanded in order to provide adequate stand-off. In many instances the ribs will also be hardened by heat treating or other hardening processes.