The camshaft under cyclical impact load. The contact stress between CAM and lifter is very big, the relative sliding speed is high, so wear more serious on the surface of the CAM work. For this case, the CAM shaft journal and work surfaces should some high dimensional precision, small surface roughness and enough stiffness, also should have a higher wear resistance and good lubrication.
Camshaft are usually made of high-quality carbon steel or alloy steel forgings, alloy cast iron or ductile iron casting is also available. Journal and CAM working surface after heat treatment, polishing.