Track rollers are with strict quality-control and processed by advanced machine. Moreover, the track rollers are dealt with middle-frequency quench and protecting air of carbon dioxide, assuring that the qualified hardness and reach the machine request. Thirdly, track rollers are assembled by advanced processing to make the parts more stable and reach the pressure request. Fourthly, track rollers finally will be dealt with the pressure test and travel test in order to reduce the defect of operation.