The camshaft is subjected to periodic impact loads. The contact stress between the CAM and tappet is very large, and the relative sliding speed is also very high, so the wear of the CAM working surface is more serious. In this case, camshaft journal and CAM working surface should have high dimensional accuracy, small surface roughness and enough stiffness, but also should have high wear resistance and good lubrication.Camshafts are usually forged by high quality carbon steel or alloy steel, but can also be cast by alloy or ductile iron. The working surface of the journal and CAM is polished after heat treatment.
