What causes wheel screws to rust?

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Reasons for wheel rust: the original screws are cast in cast iron, although the outer layer has a layer of paint to protect, but with the increase in working time, part of the paint will be worn out and decolourised, and then in the event of water pouring, it will rust. Wheel bolts are high-strength bolts connecting the wheels of vehicles, and the connection position is the hub unit bearing of the wheels, which is generally used in mini-vehicles with 10.9 grade, and large and medium-sized vehicles use 12.9 grade.

Wheel screws are classified as follows:

1. Cast iron casting screws, the material is cast iron, most of the original automotive wheel screws are this, with a long time will rust, the colour is relatively single, but the cost is low;

2. Cast iron forging screws, material cast iron, in addition to the colour to do more than casting rich, other than with casting about the same, and rust is also serious over casting;

3. Aluminium alloy forging screws, the material is generally 7075 aluminium, a small number of high-grade automotive original wheel screws with this process, colour variety, lighter than the weight of the cast iron screws, strength is also higher than the casting;

4. Titanium alloy screws, the material is generally CT4, this screw is expensive, but the performance is indeed much higher than the former 3. Although the first 3 kinds of screws in terms of use is also enough, but for a better pursuit, install a set of titanium alloy, is also very beautiful.