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Introduction to the Euronorm Standard Designation System

The creation of the EEC (European Economic Community) has made it necessary to establish common standards named "European Norms" (EN), therefore standardizing the common language across Europe. Since 1988 a new series of 'mandatory' European standards (EN) has been created, to replace national standards, such as BS, DIN, SS and NF, throughout 18 countries of Western Europe.

The main reason for Steel standardization is to ensure a common language between producers and customers of steel products. Since the beginning of the 20^th century, countries have developed their own standards defining and classifying steel products. The creation of the EEC (European Economic Community) has made it necessary to establish common standards named "European Norms" (EN), therefore standardizing the common language across Europe. The official definition of a Standard is recorded as :

‘a document, established by consensus and approved by a recognized body, that provides, for common and repeated use, rules, guidelines or characteristics for activities of their results, aimed at the achievement of the optimum degree of order in given context’

Steel standards are used worldwide in many projects to determine steel type, strength, and properties. The European Committee for Standardization (CEN) is officially recognized as a European standards body by the European Union.

Since 1988 a new series of 'mandatory' European standards (EN) has been created, to replace national standards, such as BS, DIN, SS and NF, throughout 18 countries of Western Europe. Although it is accepted and effectively used in all European countries, “obsolete” national systems, such as the German DIN, British BS, French AFNOR and Italian UNI can steel often be found in many documents.

Another key fact is that European standards are commonly becoming international standards. Due to the close relationship between The CEN and the International Standards Organization (ISO), CEN standards are being fast-tracked as ISO standards and increasingly used worldwide. Included in the EN standards are the details concerning the delivery conditions, quality, dimensions and definitions of all products, raw materials, and processes of the iron and steel industry. Furthermore, the standards include product-specific test standards (as long as they are not excluded because of specific agreements with other standardization committees), and information for the determination of the chemical composition of iron and steel.

The EN standards cover a wide range of materials including hot and cold rolled carbon and alloy steels, plates, sheets and strips, spring steels, heat treatable steels, castings, stainless and heat resisting steels, electrical steels etc.

The EN is concerned with the standardization of the manufacture, chemical composition and mechanical characteristics of steel products. In the below tables you can find some examples of standards according to the different types of steels available.

German steel standards and specifications are represented by the letters EN or DIN and followed by an alphanumeric or a numeric code. Examples:

DIN 40NiCrMo66 or 1.6565 is a Ni-Cr-Mo steel that contains 0.35-0.45%C, 0.9-1.4%Cr, 0.5-0.7%Mn, 0.2-0.3%Mo, 1.4-1.7%Ni, 0.035%S;

DIN 17200 1.1149 or DIN 17200 Cm22 is a non-resulfurized carbon steel containing 0.17-0.245C, 0.3-0.6%Mn, 0.02-0.035% S and 0.4% max Si.

Below you can find further information about EN codes according to their chemical composition:

Figure 1: The Code designation according to chemical composition

Also within the EN code, is the specific information regarding the steel quality and is categorized as follows:

Example: EN 10 025 S355

The Norm number.
The Fe symbol.
The minimum guaranteed tensile strength expressed in N/mm².

Some of the Classification of steels in accordance with their designated use are shown in table 1.

Table 1: The Classification of steels in accordance with their designated use

Designation	Meaning	Examples
S	Steels for structural steel engineering	S235JR; S355J0
P	Steels for pressure vessel construction	P265GH; P355M
L	Steels for pipeline construction	L360A; L360QB
E	Engineering steels	E295; E360
B	Reinforcing steels	B500A; B500B
Y	Prestressing steels	Y1770C; Y1230H
R	Steel for rails	R350GHT
H	Cold rolled flat rolled steels with higher-strength drawing quality	H400LA
D	Flat products made of soft steels for cold reforming	DC04; DD14