Steel designation / Normative correspondences

New designation systems have been elaborated at the European level and formed the subject of European Standards approved at the end of 1991 and published as French Standards. This is on one hand a designation system based on names and described in NF EN 10027-1 and CR 10260. These steel names consist of alphanumerical characters. This standard defines two main groups of steels : - steel designated on the basis of their use and their mechanical and physical properties, e. g, S420ML designates a structural steel (S) with a minimum specified yield strength of 420 MPa (420), thermo-mechanically rolled (M) and with impact minimal values specified at + 20 °C and - 50 °C (L) ; - steels designated on the basis of their chemical composition, e. g, X2CrNi18-9 designates a stainless steel whose average contents in carbon, nickel and chromium are about 0,02 %, 18 % and 9 %, respectively. On the other hand, a numerical designation system was agreed. It is described in NF EN 10027-2. The steel numbers consist of one « 1 » followed by a point and 4 figures. As an example, the steel numbers of the above-mentioned steels are respectively 1.8836 and 1.4307. The steel numbers are given by the European Registering Office the responsibility of which was given to VDEh in Düsseldorf ; proposals should be made by ECISS Technical Committees for steels defined in European Standards or by the national standardisation bodies in the case of steels only defined by national standards. The documentation booklet FD A 35-610 allows to establish the link between the applicable European designations (steel names and numbers) and the steels names previously used in some European countries. It also gives informations on designations of equivalent steels grades manufactured in the United States of America and Japan. The correspondence table available on OTUA (Office Technique pour l’Utilisation de l’Acier, Technical office for the steel use) web site (www.otua.asso.fr ) gives a correspondence with the valid designations from a lot of steel names and numbers.