Crankshaft is a kind of shafts which transforms the linear movement with the assistance of rod arm to periodical rotation movement and carries it over clutch and flywheel. Crankshaft transforms the opposite movement of cylinders to rotation movement in an axis. It gives movement to vehicle by changing linear movement to circular movement with the assistance of flywheel and cam shaft in a pistonic engines with the assistance of rod arm. It consists of main bearing, axle arm, balance weights,flange etc.