Definition of a Disc Brake Rotor

Let’s first start by supplying a definition for a disc rotor. The disc brake is a device for slowing or stopping the rotation of a wheel. A brake disc, or rotor, usually made of cast iron, is connected to the wheel or the axle. To stop the wheel, friction material in the form of brake pads (mounted in a device called a brake caliper) is forced mechanically, hydraulically or pneumatically against both sides of the disc. Friction causes the disc and attached wheel to slow or stop.

The better a disc rotor dissipates heat, the more effectively it can stop a vehicle.