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.
Material Coverage
The standards encompass diverse steel products:
- Hot and cold rolled carbon steels
- Alloy steels
- Plates, sheets, and strips
- Spring steels
- Heat treatable steels
- Stainless and heat-resisting steels
- Electrical steels
Click on the below links to see lists of Euronorm standards covering the following material categories:
Structural and Constructional Steels: Part One
Structural and Constructional Steels: Part Two
Stainless Steels / Welding & Filler Materials
Electrical Steels / Coated Steels / Castings / Forgings
Introduction to Aluminium EN Materials
Aerospace Aluminium
Wrought, Castings, Ingots and Remelting
Copper Materials