Add to ORKGThe increasing demand for the reliability assessment of railways components, especially for high speed trains applications, leads to a new definition of safety factor that can be determined by a “defect tolerant” approach and by the evaluation of “safe life” inspection intervals as a function of materials characteristics, propagation models and NDT inspections. The present paper deals with the definition of inspection intervals of railways axles, considering the special application of a typical alloyed steel grade for high speed trains, hollow axles and a specially developed UT in service inspection device. Initially, the POD curve of an innovative bore probe, developed basing on Lucchini specifications, has been derived by means of dedicat...