Cast iron flywheel is also known as cassette sprockets, flying wheel, Freewheel.

The cast iron flywheel is usually made of gray cast iron HT250 (ASTM NO.35, GG25, ISO250) and ductile iron QT500-7 (ASTM NO.70-50-05, GGG50, ISO500-7), QT450-10 (ASTM NO.65-45) -12, GGG40, ISO450-10). Flywheels made of No. 45 steel are also used internationally

Our foundry manufactures many types of flywheels. In the other words, flywheel is one of the main products of our foundry. Because of its large demand and strict requirements, flywheel is generally produced on automatic molding lines. Furthermore, the flywheel must use very high-quality cast iron materials to achieve good durability and precision.


iron casting flywheelcast iron flywheel


The flywheel is a disc-shaped part with a large moment of inertia. Its function is like an energy storage. For a four-stroke engine, work is done once every four piston strokes. That means, only the power stroke does work, and the exhaust, intake, and compression strokes consume work. Therefore, the torque output by the crankshaft changes periodically, and the crankshaft speed is also unstable. In order to improve this situation, we need to install a flywheel at the rear end of the crankshaft.

The function of the flywheel

1) Install a clutch on the flywheel to connect the engine with the automobile transmission system.

2) In order to facilitate the starting of the engine, a ring gear which is connected with the starter is installed.

3) In order to overcome the resistance of other strokes, the flywheel stores part of the energy of the engine’s work stroke, so that the crankshaft can rotate evenly.

flywheel cast iron flywheel