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It has been long known that hold-time during fatigue can cause a significant life debit, but the problem has been mostly dealt with empirical approaches. In this paper, the basic deformation/damage mechanisms are reviewed, and a unified model is presented by considering fatigue crack propagation in coalescence with hold-time induced damage such as wedge cracks or creep cavities. Thus, a nonlinear damage accumulation rate equation for the process is derived. Experimental data from the literature are used to compare with the descriptions of the model.