Brembo brake disc They are almost always attached to the brake hub. During braking, the brake pads press on the disc brake and reduce the rotational speed of the disc and thus the entire vehicle. Brake discs are usually made of cast iron or even steel alloys. Just like the brake pads, the brake disc also wears out. However, slower than the pads. With frequently repeated braking operations, the brake discs heat up very strongly and must therefore withstand the highest demands. To withstand extreme loads, there are also discs made of carbon and ceramic. To achieve increased heat resistance, brake discs are sometimes heat-treated. After production, the discs are heated and cooled down again. Furthermore, there are ventilated brake discs. A better braking effect in wet conditions is achieved by perforated or slotted brake discs, because they transport the water standing on the brake disc faster and more effectively through their recesses. Another advantage is that dirt, such as brake dust, disappears more quickly from the brake disc.