Automotive brake discs, also known as brake discs, are a key component on a car that is fixed to the hub or axle head that rotates with the wheels and is the part that rotates with the wheels. The function of the brake disc is to cooperate with the brake pads in the brake caliper to create friction in the car's braking system, thus helping the car to slow down or stop. When the driver presses the brake pedal, the brake fluid in the master cylinder is pushed to the cylinders, and the pistons in the cylinders then push the brake pads outward, causing them to rub against the brake discs to achieve the braking effect.

The design and material selection of the brake disc are critical to its performance. Common brake disc materials include cast iron (grey cast iron or ductile iron) and carbon fiber ceramic. Cast iron brake discs are widely used due to their good thermal conductivity, wear resistance and relatively low cost. Carbon-ceramic brake discs are lighter and more resistant to high temperatures, and are often used in high-performance cars or racing cars to provide better braking performance and longer service life.

Brake discs experience extreme conditions such as high temperatures, friction and wear during operation, so they need to be inspected and maintained regularly. The degree of wear of the brake disc can be checked by measuring its thickness or by using a depth gauge. If the brake disc is worn below the specified limit value, or if there are cracks, deformations and other problems, it needs to be replaced in time to avoid a decrease in braking performance or a safety accident.

In general, automotive brake discs are an indispensable part of the automotive braking system, and their performance directly affects the driving safety of the car and the driving experience of the driver. Therefore, sufficient attention should be paid to the maintenance and replacement of brake discs.