What Are Brake Rotors and their Function?

by | Brakes

To stop your automobile in an emergency, you need a braking system you can rely on. Modern cars effectively slow down and stop moving vehicles by combining several parts, mainly at high speed.

The brake rotor is a crucial part of any braking system. Let’s go further into the nature of rotors, their functions, and the many options available for replacement.

Rotors, Summed Up

Auto brake rotors are discs of metal, usually a circular shape, that are attached to the wheels. To stop the vehicle, brake rotors are mounted on all four wheels. The rotors’ principal function is to reduce the rotational speed of the wheels by applying friction.

When the brake pads in your vehicle are compressed by the callipers, the rotors in your brakes spin. Wheel rotation and vehicle speed are reduced when friction is generated between the pads and the rotors.

The Function of Rotors

The rotors on your brakes work in tandem with the rest of your braking system to bring your car to a halt. Aside from progressive slowing brought on by interaction with the air and the road itself, your car wouldn’t be able to stop or decelerate following acceleration without brake rotors properly.

Your car is equipped with brake pads to prevent the wheels from spinning. The pads that are pressed against are called rotors. They last long since iron is often used to make them. Brake rotors are built to last, but they need to be serviced and replaced occasionally.

How do rotors for brakes work?

When you press the brake pedal, the rotors within your brakes immediately get to work. The brake pads squeeze the rotors when the pedal is depressed. Remember that your automobile has one rotor per wheel. Each wheel slows down at the same rate when you use the brakes.

The wheels of your vehicle will gradually slow down when the brake pads provide friction to the brake rotors. Frictional heating is produced naturally as wheels slow down.

So that they can withstand this heat, brake rotors are made of steel. Ribs or gaps are often seen in brake rotors to aid in the effective dissipation of heat during braking. Different types of brake rotors may be identified by the ribs included in their construction.

When you release the foot brake, the brake pads quit contacting the rotors, restoring unrestricted wheel movement.

Disc and Rotor Brake Systems

The rotors that stop your car might be of various varieties. It’s essential to know about these brake rotors to find and buy the right ones for your vehicle when it’s time to replace them.

As far as I’m aware, four kinds of brake rotors exist. You can either take apart your brake system to check it yourself or call the company that made your car to find out what rotors it uses.

Let’s look at the four most common varieties of brake rotors.

Blank & Smooth

The most frequent rotor type for passenger cars, like ordinary sedans, is blank and smooth. The cost and simplicity of blank rotors make them a popular choice.

However, certain manufacturers may use reclaimed steel to make blank rotors. Therefore, the performance and longevity of specific blank and smooth rotors are inferior to those of other rotor types.

OEM rotors, which the vehicle’s original manufacturer makes, tend to last longer because their interior fins are thicker and more effectively cool the brake pads during usage.


Holes are drilled in a spiral pattern on the surface of a drilled rotor. The perforations help disperse heat and let debris like dust and water run down the rotor’s surface where they won’t clog anything or cause any damage to the brakes.

It is common for drivers in rainy areas to favour drilled rotors because they improve stopping performance. Drilled rotors, however, wear out more quickly at high temperatures and are thus seldom used in racing cars.


Instead of having holes on the outside of the rotor, slotted rotors have narrow slots cut into the metal. Heavy-duty trucks and SUVs often employ slotted rotors because of their increased stopping force. Those who carry big weights often also like slotted rotors.

The gaps in the rotors allow more air to flow between the rotor surfaces and the brake pads. Better cooling, heat dissipation, and debris clearance are the results of the rotors. However, slotted rotors wear brake pads out faster than other rotors and don’t last as long.

Drilled & Slotted

Drilled and slotted rotors use the aforementioned thermal transfer and debris removal strategies. They have slots and drilled holes in a spiral pattern around the brake rotor’s circumference.

Brake rotors of this kind are often seen in high-performance automobiles. For instance, consider sports automobiles. Extremely high performance from these cars is only possible with state-of-the-art cooling and heat dispersion systems. In addition, frequent brake rotor replacement is not out of the question financially for sports cars and their drivers.

Replacing Brake Rotors

It would be best if you periodically changed up your rotors. Since every braking causes gradual wear on the rotors’ steel surfaces and the brake pads, rotor replacement is always required. When these parts wear out, your brakes will become less sensitive and reliable, putting you and other drivers in harm’s way.

Checking the brake rotors should be a yearly tradition. Or you may check the brake rotors every so often on your own. When your rotors’ performance starts to decline, you’ll probably notice that your braking isn’t as quick and responsive as it used to be.

To save money, you may conduct the upkeep yourself by purchasing rotors and installing/repairing them, but this requires expertise.


It would be impossible to stop your automobile without brake rotors and the rest of the braking system. Keep an eye on how they’re functioning and the responsiveness of your braking action, so you know when to replace them. When purchasing new rotors for your car, don’t hesitate to consult a technician about which kind would work best for your vehicle and driving style.