"According to the big level, the wheel hub is divided into two grades, one is cast and the other is forged. Forged wheel hub is better than cast wheel hub. Moreover, forged wheel hub is the highest grade wheel hub. Generally, the wheel hub of ordinary cars is cast and the wheel hub of high-end cars and sports cars is forged. If subdivided, the wheel hub process can be divided into four grades, because For casting, it can be divided into three grades. "