There is no certain relationship between the life of the brake pads and the surface hardness. However, if the surface hardness is high, the actual contact area between the brake pad and the brake disc is small, which often affects the service life. The main factors affecting the service life of brake pads include hardness, strength, and wear properties of friction materials. Under normal circumstances, the service life of the front brake pads is 30,000 km, and the service life of the rear brake pads is 120,000 km.