Serial number plays an important role in the manufacturing and managing processes to identify the industry products, and automatic recognition of the serial number has become an essential step in modern industries. The limits of manufacture condition in factories and the requirement of real-time operation, however, make the design of a practical automatic serial number recognition system a difficult task. We developed a novel automatic serial number recognition system for railway wheel products, which has been successfully used in real production lines. This system uses visual inspection approaches to automatically recognize the serial numbers in real-time. The flexibility and low cost of the system make it very suitable for the applications described in this paper.