The crankshaft is the part to which the connecting rods are connected in the crankcase. The crankshaft converts the alternating motion into a rotating motion, and this is where the flywheel is located. It is usually subject to high stress, so it is mostly made of forged steel. Due to the design of the block, the crankshaft is subjected to a unilateral load (from the combustion chamber), so the shaft may be bent. Crankshafts can be renewed if they are not cracked or too worn. In this case, it can be straightened and / or grinded, which can be used again after work processes.