Brake rotor thickness serves an important role in driving safety; thin rotors may increase the risk of brakes cracking and fading, ultimately causing braking failure. The acceptable and recommended amount of brake rotor thickness varies among different automobile types and makes, but all maintain a certain level of rotor thickness, which increases vehicle stability, stopping time and structural integrity. Brake rotors must maintain a certain level of thickness to absorb heat and allow heat dissipation; unable to perform this function, thin rotors may cause extensive damage and present a driving risk.
Brake rotors come from manufacturers with adequate thickness, as deemed appropriate for various makes and models. Rotors, like other car parts, wear over time, requiring replacement. Usually, rotors reaching a worn thickness of 0.3 to 0.6 millimeters require discarding. In addition to maintaining vehicle safety and stability, keeping brake rotors from wearing or replacing them when worn extends the longevity of other car parts, including the brake pads. Typically, people rotate or replace their brake rotors when bringing cars in for routine brake alignments. At a brake change, mechanics might lathe brakes, smoothing them to ensure even wear and optimal performance.
Brake rotor wear varies among drivers; sometimes, brake rotors do not need lathing at each brake change if they keep smooth surfaces. Brake rotors with rough patches or showing signs of damage, such as warping, may need replacement.