This work contains results of investigations on short crack threshold stress intensities and defect tolerance of SAE 52100 bearing steel. An analytical model for short crack propagation prediction is developed. This model is based on elastic-plastic fracture mechanias approach and the effective stress intensity (and closure) concept. The threshold effective stress intensity values are compared with those from the only existing, Newman’s, analytical model. These values have been used to make defect tolerance and crack propagation modes predictions based on the Tanaka resistance curve approach.