Camshaft is not equal to camshaft
Camshafts are manufactured in three different procedures. The design used most frequently is a camshaft manufactured from cast iron. The steel camshaft is another popular design. It is used when specific material is required. Here the camshaft is milled from a steel billet and then honed. The third design is known as the assembled camshaft. It is usually manufactured from a cylindrical pipe that the individual cams are pushed onto. The cams are fastened using welding or shrink fitting, for example.
The modular structure and the significantly lower weight of the assembled camshaft in comparison to a cast iron camshaft is a big advantage. The cams arranged on the camshaft actuate the intake and exhaust valves. This converts the rotational movement of the camshafts into a straight-line movement of the valves. Different design variants of cam followers (bucket tappets, finger followers, rocker arms, etc.) are used between the cams and the valves.