Crank Pin and Crank Shaft - Part of combustion engine:
Crank Pin: Crank pin is region on crank shaft on which big end of connecting rod is attached. These pins are eccentrically located with respect to axis of crank shaft. The eccentricity is called as throw of the crank.
Crank Shaft: It is a rotating member which receives the power transmitted by piston connecting rod assembly via crank. It is made of forged alloy steel or carbon steel.
Crank Web or counter weights: It is given in the crank shaft to counter act the tendency of bending of the crank shaft because of centrifugal action.