What is a wheel hub in a car?

The wheel hub is a cylindrical metal support component inside the inner contour of a car tyre, connected to the axle at its centre. As the core component of the wheel, its functions include supporting the tyre, transmitting driving force and braking force, and directly affecting driving safety, handling stability, and comfort. For materials, steel wheel hubs have low cost and strong fatigue resistance but are heavy and have poor heat dissipation. Aluminum alloy wheel hubs, on the other hand, are more lightweight, which can reduce engine load, improve heat dissipation efficiency, and enhance high-speed driving stability, making them predominantly used in mid-to-high-end models. The structure of a wheel hub consists of the rim (the part where the tyre is installed), the wheel centre (the part connected to the axle), and the spokes (the supporting structure connecting the two). Manufacturing processes include gravity casting (low cost but prone to air bubbles), forging (high strength but costly), and low-pressure precision casting (balancing performance and cost). When purchasing, parameters such as the ET value (mounting surface offset) and J value (rim width) should be considered to ensure compatibility with the vehicle. With technological advancements, wheel hubs made of new materials such as carbon fibre are increasingly being adopted in high-performance models, though aluminum alloy remains the market mainstream due to its lightweight properties, which offer significant advantages in improving fuel efficiency and driving experience.