This European Standard specifies the characteristics of railway wheels for all track gauges. This standard can also apply to light rail and tramway applications. Five steel grades, ER6, ER7, ER8, ERS8 and ER9 are defined in this standard. NOTE ERS8 has been integrated in this standard as an optimization of steel grades ER8 and ER9 in the context of RCF, and by taking into account European service experience e.g. BS 5892-3 in the UK. Certain characteristics are defined according to a category 1 or a category 2. Category 1 is generally chosen when the operation train speed is higher than 200 km/h. Vehicles running at speeds lower than or equal to 200 km/h generally use wheels of category 2. These categories can sometimes be subdivided, depending upon the characteristics. This standard is applicable to solid forged and rolled wheels which are made from vacuum degassed steel and have a chilled rim. They are to have already been used in commercial conditions on a European network in a significant quantity, or to have satisfied a technical approval procedure according to EN 13979-1 for their design. Annex A describes the assessment process for acceptance of new materials not cited in this standard. The standard defines the wheel product requirements; the technical approval procedure is not within the scope of this standard. NOTE Rim-chilled describes heat treatment of the rim, the aim of which is to harden the rim and to create compressive residual stresses in the rim.