Recently Atzori et al. [
] analysed the sensitivity to defects and to standard notches in axial fatigue of metallic materials commonly adopted in manufacturing engineering components and structures, like steels and aluminium alloys. As a result of the proposed approach, the effect of any kind of geometrical discontinuity on the fatigue limit can be treated, such as small defects, cracks, sharp notches or crack-like notches and standard rounded notches characterised by an arbitrary notch tip radius and notch opening angle. Two material parameters are needed, i.e. the material fatigue limit and the threshold value of the Stress Intensity Factor.