Typically, perpendicular features like thrust walls on crankshafts and camshafts have been finished by either turning or plunge grinding. Both approaches have their drawbacks.
Taking a thin turning cut on these hard features often results in problematic "bird's nest" chips, leading to frequent tool changes and a consequent loss of productivity. Costs associated with poor tool life also are experienced, and quality suffers as well, especially in the areas of surface finish and geometry. In addition, the fillet rolling operation--performed on crankshafts after the turning process to place in relief the corner formed by the pin and the thrust face--can distort precisely machined side walls, leading to a loss of perpendicularity.