The material of the wheel is divided into iron wheel hub and steel wheel hub, which are more used in trucks or buses. Moreover, aluminum wheels commonly used in cars are now divided into two kinds: forging and casting in aluminum wheels. The strength of forging wheels is many times that of casting wheels. The exaggeration is that they can be driven directly on the rails. Forging and casting can only be distinguished by the use of instruments to see the molecular structure, or is to do destructive tests.
[VIP第7年] 指数:7
