The paper deals with the characterization and modelling of the mechanical stress dependency of magnetic losses along two orthogonal directions in non-oriented electrical steels. Significant anisotropy effects are highlighted. Using the three-term loss-separation approach, the different loss components are computed at each stress level for a wide range of frequency. Stress dependence of the core losses can be described in terms of the hysteresis and excess loss components, classical losses being assumed to be constant as a function of stress. Variations of the model coefficients with stress along the two principal directions are discussed. Such a model can be used for computing the losses in finite element analysis of rotating electrical machines or T-joint of transformers.