The trailer axles are used to support all or part of the load of a trailer, transmit various external forces and reaction forces and ensure the normal running of the trailer. The axle mainly contains a beam assembly, a brake assembly and a wheel hub assembly.

The axle is widely applied to skeletal trailers, lowbed trailers, flatbed trailers, dump trailers, car transport trailers, oil tank trailers, van trailers, full trailers, logging transport trailers, agricultrucal vehicles, etc. Classification of axles included German series semi trailer axles, American series semi trailer axles, spoke series semi trailer axles, disc-brake series semi trailer axles, low bed series semi trailer axles, agricultural series trailer axles, Brazilian trailer axles, Henred Fruedauf trailer axles, and York trailer axles, etc.