Why is there rust on the wheel hubs of my newly bought car?

[DiConnor]

Wheel hub screws are made using a process where cast iron is chrome-plated on the surface. Repeatedly removing the screws or using poor-quality tools during removal can damage the chrome-plated layer on the screws. Once the chrome layer is damaged, the cast iron underneath will rust. Wheel hubs come in various types based on diameter, width, manufacturing method, and material. In the market, wheel hubs can be categorized into two main types based on material: 1. Steel wheel hubs: The main advantages are simple manufacturing process, relatively low cost, and strong resistance to metal fatigue. However, the disadvantages are also obvious, such as heavy weight, high inertial resistance, poor heat dissipation, etc. 2. Alloy wheel hubs: Their advantages include lightweight, high manufacturing precision, great strength, low inertial resistance, strong heat dissipation capability, and good visual effects, etc. The disadvantages are complex manufacturing process and high cost.