Automobile halfshafts are usually made of the following materials:

1. Steel: The main material of automobile semi-axle is steel, usually made of high-quality alloy steel or carbon steel. This material has the characteristics of high strength, wear resistance, corrosion resistance, etc., and can withstand the torsion and impact force when the vehicle is running, and ensure the normal operation of the transmission system.

2. Aluminum alloy: Some high-performance cars or racing cars may use aluminum alloy to make axle shafts, so as to reduce the overall weight of the vehicle and improve the handling performance and acceleration performance of the vehicle. Aluminum alloy half shaft has high strength and rigidity, and good thermal conductivity.

3. Carbon fiber composite materials: In some high-end cars or racing cars, carbon fiber composite materials may also be used to manufacture half shafts. Carbon fiber has extremely high strength and stiffness, and at the same time, it has the characteristics of lightweight, which can improve the performance of vehicles.

To sum up, automobile axle shafts are usually made of steel, aluminum alloy or carbon fiber composite materials. Semi-axles made of different materials are suitable for different types of vehicles and use environments. Choosing the appropriate materials can improve the performance and reliability of vehicles. When purchasing and replacing the axle shaft, it is suggested to choose the appropriate material according to the vehicle model, purpose and performance requirements to ensure the quality and reliability of the axle shaft.