Brakes currently include disc brakes, drum brakes and air brakes. Many older cars have front discs and rear drums. Many cars today have disc brakes front and rear. Because disc brakes dissipate heat better than drum brakes, they are less prone to thermal decay under high-speed braking conditions, so their high-speed braking effect is better. However, during low-speed cold braking, the braking effect is not as good as that of drum brakes. The price is more expensive than Gusha. Therefore, many mid- to high-end cars now use full disc brakes, while ordinary cars use front discs and rear drums. Trucks and buses that are relatively low-speed and require large braking force still use drum brakes.

The brake disc of a disc brake is a round disc that rotates when the car is moving. Brake calipers are used to clamp the brake disc between two pieces to generate braking force. Its relatively rotating brake disc is fixed. When you apply the brakes, it clamps the brake disc to slow down or stop the vehicle.

Drum brakes are sealed and shaped like drums. There are many called brake pots in China. It rotates when driving. There are two arc-shaped or semi-circular brake shoes fixed inside the drum brake. When the brakes are applied, the two brake shoes expand outward under the action of the brake wheel cylinder, supporting the brake shoes and rubbing against the inner wall of the brake drum to slow down or stop the vehicle.

Material requirements

The material of the brake disc adopts my country's gray cast iron 250 standard, referred to as HT250, which is equivalent to the American G3000 standard. The requirements for the three main elements of chemical composition are: C: 3.1∽3.4 Si: 1.9∽2.3 Mn: 0.6∽0.9. Mechanical performance requirements: tensile strength>21on/mm2, hardness requirements: between 187∽241.