AbstractThe change in geometry of surface cracks during alternating tension and bending is calculated using the stress intensity factors of Newman and Raju and of the ASME Boiler and Pressure Vessel Code. It is assumed that the crack extends at the deepest point and at the surface according to the stress intensity factors at these points. Calculations were performed with local K‐values and with K‐values obtained by a weighted averaging along the crack front. The obtained results were compared with results from the literat