This document specifies the characteristics of axles for all heavy rail track gauges. This document applies to heavy rail vehicles and applies, in principle, to other vehicles such as urban rail vehicles. It defines characteristics of forged or rolled solid and hollow axles, made from vacuum-degassed steel grade EA1N1), EA1T1) and EA4T1). For hollow axles, this document applies only to those that are manufactured by machining of a hole in a forged or rolled solid axle. The requirements defined in this document are applicable for cylindrical seats. Most of the requirements are also applicable for axles with conical seats. Specific requirements for conical seats (e.g. geometrical dimensions of the seats& ) are defined in the technical specification. Some characteristics are given as a function of a category 1 or of a category 2. This document is applicable to axles that are designed in accordance with the requirements of EN 13103-1:2017+A1:2022. This document also permits variations of the material characteristics linked to alternative manufacturing processes (e.g. cold rolling, shot blasting, thermal spraying, steel cleanliness, reduction ratio, improved material properties from melting and heat treatment process, etc.).