Abstract: During the hot ring rolling process, it is the prerequisite to manufacture a qualified ring product that the ring products’ dimensions meet the tolerance requirements. The interrelationships and influence rules between ring blank’s weight error and ring product’s geometrical dimensions during hot ring rolling are analyzed. A dimensional tolerance control method and mathematical model are proposed, that is, the ring blank’s weight error and the dimensional tolerance of the ring’s inner and outer diameter are set to the constrain parameters, the ring’s wall thickness is taken as the control parameter, thus the ring product with qualified dimension can be rolled. Based on this method, three series of hot ring rolling experiments are conducted on the HRM160 NC hot ring rolling mill which is developed by Wuhan University of Technology. The results show that the values of ring’s geometrical dimensions calculated by the mathematical model are in good agreement with the experiments’ data. The research conclusions have practical significance for manufacturing the high quality ring products

Key words: hot ring rolling;dimensional precision;tolerance allocation;measurement and control