Abstract: The drift method can effectively increase the fatigue strength of the link plates of roller chains.Tests and analyses show that for the 1(1/2")roller chains, the reasonable parameters used in drifting should make the hoop plastic strain ε_θ of the hole rand of the outer link plate to be 1.73%.The endurance limit of the high strength link plates of 1(1/2")oil field roller chains manufactured in China using the above parameters has reached 31% of the rated breaking load of the roller chains.