The crankshaft is the rotating part of machines and engines that transmits, through other rotary parts firmly connected to it, torques forces which act in normal levels compared to the rotation axis. In the vehicles the crankshaft, the camshaft and the driveshaft are very important. The crankshaft (also called crank and gooseneck) has the task of converting the up and down movement of the pistons into a rotary motion with the aid of the connecting rods. The crankshaft infact consists of one or more cranks (depending on the number of cylinders) on which pins (buttons) move the connecting rods small heads, connected to the other side to the pistons. The two pins at the edges od the crankshaft rest on conrod bearings. The crankshaft has counterweights on the cranks arms that allow dynamic balancing, thus voiding the vibration in any point of its axis. The crankshaft may be in one piece or compounds (this is the case of large crankshafts for diesel engines).