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Introduction to the Euronorm Standard Designation System

Abstract

This article examines the European Norm (EN) standard designation system, established to create a unified language for steel specification across Europe. Since 1988, these mandatory standards have gradually replaced national systems in 18 Western European countries. The article details the structure and implementation of EN standards, their relationship with international standards through ISO, and their comprehensive coverage of steel products. Special attention is given to the coding system and classification methods used for different steel types and applications.

Introduction to European Standards

The standardization of steel products emerged from the need to establish clear communication between producers and customers. While individual countries developed their own standards throughout the 20th century, the formation of the European Economic Community (EEC) necessitated a unified approach through European Norms (EN).

Standard Definition and Authority

A standard is officially defined 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." The European Committee for Standardization (CEN) serves as the European Union's officially recognized standards body.

Implementation and Scope

Despite the mandatory nature of EN standards since 1988, traditional national systems (DIN, BS, AFNOR, UNI) remain present in technical documentation. EN standards encompass:

Delivery conditions
Quality specifications
Dimensional requirements
Product testing protocols
Chemical composition determinations

Figure 1: The Code designation according to chemical composition

Standard Classification System

EN standards utilize a systematic coding approach. For example: EN 10 025 S355 indicates:

Norm number
Fe symbol
Minimum guaranteed tensile strength (N/mm²)

Table 1. Classification of steels by 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

Steel Grade Examples

German specifications illustrate the system's application: DIN 40NiCrMo66 (1.6565): Ni-Cr-Mo steel with specific composition ranges DIN 17200 1.1149: Non-resulfurized carbon steel with defined elements.

Figure 2: The EN Code designation system

International Recognition

The close relationship between CEN and the International Standards Organization (ISO) has facilitated the adoption of EN standards globally. This cooperation enables rapid conversion of EN standards to ISO standards, expanding their international application.