If the brake drum body does not produce hot crack, casting no quality defects, so the general quality of brake drum can be referred to as the "brake do not break" for brake drum is a kind of brittle grey cast iron material and work under the environment of high temperature and high pressure, fatigue crack is from forming on the surface physical properties of cast iron materials, is an irresistible objective laws. With the extension and penetration of cracks in the drum body, the mechanical strength of the drum decreases rapidly, and it is inevitable that the brake will be broken eventually.

Machining spiral groove can change the friction property between the drum hooves from "surface" contact friction to "band" contact friction. Following the lateral movement of the helix and the "continuous" friction displacement "intermittent" friction, the grooved brake drum brings the following benefits in practice:

The characteristics of

1. Grooves can block the free extension of some surface cracks.

2. The groove can resist the swelling and deformation of the drum body, and maintain the original shape of the high temperature state.

3. The groove establishes a heat drain channel for the central part of the drum body.

4. The grooves can overcome the slipping caused by oil and water immersion and prevent the brake failure.

Spiral grooved brake drum can extend the service life of the brake.

Broadband friction and intermittent friction can really control the temperature rise of the drum body, low temperature is very favorable for vehicle braking, which further proves the safety and scientific nature of setting spiral grooves in the brake drum wall.