The camshaft undergoes periodic shock loads. The contact stress between the CAM and the tailing column is very large, and the relative sliding speed is very high. In view of this situation, camshaft journal and CAM working surface should have higher dimensional accuracy, smaller surface roughness and enough stiffness, but also should have higher wear resistance and good lubrication.

Camshafts are usually forged from high quality carbon or alloy steel, or can be cast in alloy cast iron or nodular iron. The shaft neck and CAM working surface are polished after heat treatment.

The main body of the camshaft is a cylindrical rod with approximately the same length as the cylinder. It is covered with several cams for driving the valve. Camshaft is supported in the bearing hole of camshaft by camshaft journal, so the number of camshaft journal is an important factor affecting the stiffness of camshaft support. If the camshaft stiffness is insufficient, bending deformation will occur during operation, affecting the timing of valve distribution.

The side of the CAM is shaped like an egg. It is designed to ensure the full intake and exhaust of the cylinder. In addition, considering the durability of the engine and the smoothness of operation, the valve should not generate too much impact due to the acceleration and deceleration process of opening and closing action, otherwise it will cause serious wear of the valve, increase of noise or other serious consequences. Therefore, the CAM and engine power, torque output and running smoothness have a very direct relationship.