Abstract: To obtain fatigue design data under different reliabilities for grade B cast wheel steel for railway vehicles,a Goodman-Smith diagram of the steel was obtained using probabilistic mechanical properties,fatigue limits,and the data available in S-N curves of the steel covering mid-and-long fatigue lives.The fatigue lives were measured by the running distance of the wheel.The effects of average stresses on fatigue properties were considered in terms of Goodman modification,and the fatigue strength was evaluated with the probabilistic fatigue S-N curves covering the mid-and-short and long lives.The coordinates of octagon vertices of the diagram were determined on an entire probabilistic space.