The meaning of the steel grade designation for selected steels

21.06.2023 | Salzgitter Flachstahl GmbH


One of the great advantages of steel as a material is the wealth of different variants with properties specifically adapted and fine tuned to the respective application.
For this purpose, there is a large number of steels with different compositions and properties, especially on the European steel market. In order to classify and designate all these steels, the DIN EN 10020 and DIN EN 10027 are applied. These two European standards contain the definition for the classification of steels (DIN EN 10020) and the designation system (DIN EN 10027). The term "steel" is defined on the basis of individual classes and assigned main quality classes for unalloyed, stainless or other alloyed steels.

There are two different types of designation systems for the concrete identification of steels. These two systems are standardized at a European level and are described in DIN EN 10027.
In order to improve clarity, the designation system in the first part of this standard (DIN EN 10027-1) uses a methodology of short names. In the second part (DIN EN 10027-2), a numbering system is set out for structuring purposes.
In actual practice, the designation of the steel grade by means of the abbreviated name from the first part of DIN EN 10027 has become generally accepted by many of our customers.

Our product range takes this status into account, adopting these abbreviated designations and thereby offering a wide range of steel grades for an extremely wide variety of applications with their special properties.
In the following, the meaning of the short names is explained by way of selected hot-rolled and cold-rolled steels as well as on cold-rolled, surface-treated steels.

The abbreviated names for steels are divided into two main groups according to DIN EN 10027.

Main group 1: According to the intended use and the mechanical or physical properties of the steel

Hot-rolled structural steels according to DIN EN 10025-2
S355 / JR / J0 / J2 / K2 / C / +AR / +N
S: Steel for general steel construction
355: Minimum yield strength at room temperature 355MPa (transverse to rolling direction in widths > 600 mm )
JR: Notched bar impact energy min. 27J at 20°C (longitudinal to rolling direction)
J0: Impact energy min. 27J at 0°C (longitudinal to rolling direction)
J2: Notched bar impact energy min. 27J at -20°C (longitudinal to rolling direction)
K2: Notched bar impact energy min. 40J at -20°C (longitudinal to rolling direction)
C: Suitability for bending, roll forming and cold drawing (recommended smallest inner bending radius depends on the direction)
+AR: As rolled
+N: Normalized or normalizing rolled
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Hot-rolled weather-resistant structural steels according to DIN EN 10025-5
S355 / J0 / J2 / K2 / W / WP / +AR / +N
S: Steel for general steel construction
355: Minimum yield strength at room temperature 355MPa (transverse to rolling direction in widths >600 mm )
J0: Notched bar impact energy min. 27J at 0°C (longitudinal to rolling direction)
J2: Notched bar impact energy min. 27J at -20°C (longitudinal to rolling direction)
K2: Notched bar impact energy min. 40J at -20°C (longitudinal to rolling direction)
W: Weatherproof structural steel
WP: Weatherproof structural steel with added phosphorus
+AR: As rolled
+N: Normalized or normalizing rolled
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Pressure vessel steels according to DIN EN 10028-2
P265 / GH / +N
P: Steel for the production of pressure vessels
265 Minimum yield strength at room temperature 265MPa (transverse to rolling direction).
G: Other characteristic following: here H
H: High temperature application
+N: Normalized or normalizing rolled
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Pressure vessel steels according to DIN EN 10028-3
P355 / N / NH / NL1 / NL2
P: Steel for the production of pressure vessels
355: Minimum yield strength at room temperature 355MPa (transverse to rolling direction).
N: Steel for use at room temperature
NH: Heat resistant steel with specified properties at elevated temperatures.
NL1: Cold toughness steel, impact energy min. 27J at -40°C (transverse to rolling direction)
NL2: Cold toughened special steel, impact energy min. 40J at -40°C (transverse to rolling direction)
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Cold-rolled microalloyed steels according to DIN EN 10268
HC340LA
H: Higher strength steel for cold forming
C: Cold rolled
340: Minimum yield strength at room temperature 340Mpa (transverse to rolling direction).
LA: low alloy/micro alloy
HC220B
H: Higher strength steel for cold forming
C: Cold rolled
220: Minimum yield strength at room temperature 220Mpa (transverse to rolling direction).
B: Bake-hardening (steel with additional hardening after heat treatment)
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Cold-rolled, continuous, hot-dip coated steels according to DIN EN 10346
S250GD / + Z140 / N-M-A-B-C-O-C
S: Steel for general steel construction
250: Minimum yield strength at room temperature 250Mpa (longitudinal to rolling direction)
G: other characteristic following: here D
D: Hot dip coating
Z: Hot dipping with zinc coating
140: Zinc coating on both sides in g/m²
N: Zinc finish: usual spangle
M: Zinc finish: small spangle
A: Surface type: usual surface
B: Surface type: improved surface
C: Surface type: best surface
O: Oiled
C: Chemically passivated
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Cold-rolled, electrolytically galvanized steels according to DIN EN 10152
DC04 / +ZE 75/75 / A-B-P-O-C
D: Steel for cold forming
C: Cold rolled
04: Special deep drawing grade with defined mechanical-technological properties
+ZE: Electrolytic galvanized
75/75: Zinc coating per side 7.5µm
A: Surface type A
B: Surface type B
P: Phosphated
O: Oiled
C: Chemically passivated
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Main group 2: According to the chemical composition of the steel

Pressure vessel steels according to DIN EN 10028-2
16Mo3 Alloyed, heat-resistant stainless steel with specified properties at elevated temperatures
16: Carbon content 0.12 to 0.20% (multiplier for the mean value 100).
3: Molybdenum content 0.25 to 0.35% (multiplier for the mean value 10)
13CrMo4-5 Alloyed, heat-resistant stainless steel with specified properties at elevated temperatures
13: Carbon content. 0.08 to 0.18% (multiplier for mean value 100)
4: Chromium content 0.70 to 1.15% (multiplier for the average value 4)
5: Molybdenum content 0.40 to 0.60% (multiplier for the mean value 10)
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Steels for heat treatment according to DIN EN ISO 683-3
C15 / E / R Unalloyed stainless steel for case hardening
C: Carbon steel
15: Carbon content 0.12 to 0.18% (multiplier for mean value 100)
E: Prescribed maximum sulfur content
R: Prescribed range of sulfur content
20MnCr5 Alloyed stainless steel for case hardening
20: Carbon content 0.17 to 0.22% (multiplier for mean value 100)
Mn: Manganese
Cr: Chrome
5: Manganese content 1.10 to 1.40% (multiplier for the mean value 4)
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If you have any questions concerning the individual designations or our product portfolio, please do not hesitate to contact our Technical Customer Service.