Brake rotors are typically made of cast iron. They can also be made from steel, aluminum, or composites. The material that the brake rotor is manufactured with will affect its weight and performance. Aluminum brakes are lightweight and non-corrosive but cost more than other materials. On the other hand, Steel brakes are less expensive but heavier than others. However, Cast iron brakes have a longer lifespan than other materials but weigh the most.