Is the higher the coefficient of friction of brake pads, the better?

First of all, the answer is in the affirmative: of course not!

Generally speaking, the friction coefficient is a numerical value that represents the amount of friction under the same pressure conditions, the larger the friction coefficient, the greater the friction under the same pressure, and the easier it is to brake the car.

When the vehicle needs emergency braking at high speed, the low friction coefficient makes the braking distance longer under the same pedal force, which is easy to cause accidents; If the coefficient of friction is too high, the tires will lock up, causing the vehicle to slip and pose a serious threat to driving safety.

According to the national standard, the suitable working temperature of brake pads is 100 ~ 350°C. However, when the temperature of many inferior brake pads reaches 250°C, the coefficient of friction will drop sharply, and the brakes may fail.

According to the SAE standard, the manufacturer of the brake pad selects the appropriate coefficient of friction grade, such as the FF friction grade. 

The first letter represents the coefficient of friction at low temperatures, and the second letter represents the coefficient of friction at high temperatures.

At present, the brake pads on the market are generally marked with a friction coefficient between 0.34~0.42. The market generally believes that the higher the coefficient of friction, the safer.

Although a higher coefficient of friction can often provide stronger braking power, it can sometimes be counterproductive, especially when the car brakes urgently at high speeds, a high coefficient of friction may cause the wheels to lock, causing the vehicle to flick and skid, causing safety accidents.

Otherwise, why would the car factory install an ABS system on the car?!

The most important thing for the braking performance of brake pads is not to see how high the friction coefficient of the brake pad is, but to see whether its friction coefficient can be stable under various extreme road conditions such as high speed, high temperature, water, winding road, continuous emergency braking, etc.

Some inferior products can achieve a high coefficient of friction by adding abrasive materials, but the braking force deteriorates rapidly and even loses the braking ability in the above-mentioned emergency situations.

The most basic core function of brake pads is to brake the car, but in addition, our requirements for the performance of noise, dust, wear and tear that may be caused during the braking process are also gradually increasing.

Generally speaking, the friction coefficient of brake pads is too high, which will increase the wear of the brake disc, resulting in damage and dust, and it is often more likely to cause abnormal brake noise. At the same time, an overly sensitive foot feel will also increase the frustration when braking, affecting comfort.

In short, the friction coefficient of the brake pad is based on the actual situation of different vehicles themselves, comprehensive driving speed, torque, inertia, braking distance and comfort and other technical indicators, after the results of multiple verifications such as theory and test tests, in order to maximize the matching of the original car and give full play to the appropriate braking performance of the brake pads.

Careful friends found that the label content on many brake pads has changed from the original "specified friction coefficient" to "set friction coefficient". This is according to the requirements of the new national standard to adjust the content of the label, at the same time, the new national standard on the coefficient of friction test methods and test equipment has also been re-specified.