Structural steel

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Structural steels are steels for steel and mechanical engineering . Together with reinforcing steel, structural steels make up over half of global steel production.


The most commonly used types belong to the basic steels category . They are usually low alloyed and only partially heat-treated (if heat treated, then normalized, and normalizing called). This results in moderately good properties (which, however, are sufficient for many applications) at a low price.

The distinction between structural and quality steels is no longer appropriate today due to technical progress, as a distinction is made between the classification according to composition and technical parameters on the one hand and according to purpose on the other. Alloyed stainless steels are also used, for example, as structural steels.

In general, almost all low-carbon steels are structural steels. For the higher-carbon varieties, the limits are fluid and cannot be determined using this rule of thumb. According to the new EN standards, structural steels are all steels that are not used directly as tool steel . Structural steels are weldable and can be annealed to reduce stress. Fine-grain structural steel is particularly suitable for welding and has a higher tensile strength.

Reinforcing steel that is used as reinforcement in reinforced concrete or prestressing steel in prestressed concrete do not count asstructural steelsaccording to the new system.

In the structure of the steels according to EN 10027 they get the prefix symbol S for " S tructural Steel" (steels for steel construction). The following number indicates the yield point (R e ) in N / mm².

Common names are e.g. B.

  • S235JR + AR (new edition EN 10025-2: 2004–10, earlier S235JRG2, even earlier St 37-2, material number 1.0036 to 1.0038, earlier designation according to EU 25-72 also Fe 360 ​​B)
  • S355J2 + N (new edition EN 10025-2: 2004-10, earlier S355J2G3, even earlier St 52-3 N, material number 1.0577 or 1.0570, earlier designation according to EU 25-72 also Fe 510 D1)

The structural steel grades are standardized in EN 10025.

The designations according to DIN 17100 with the prefix “St” (values ​​in brackets above St 37…) are invalid and should no longer be used, but are still widely used in everyday language. The addition after the yield point are additional symbols.


Substance-relevant parameters

Yield point (yield point) 185-355 N / mm²
tensile strenght 340-510 N / mm²
Elongation at break 18-26.1%
Modulus of elasticity 210 GPa
Shear modulus 81000 N / mm²
Emissivity 0.7
Poisson's ratio 0.3

See also

Web links

Wiktionary: structural steel  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Sustainability ( Memento from February 6, 2015 in the Internet Archive )
  2. a b c d Eurocode 3: Steel construction . ( [accessed on May 7, 2020]).