--- title: "S255N — Fine-grain structural steels" description: "S255N: 18 equivalent designations across 6 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/din-en/s255n language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/s255n.md cs: https://steelequivalents.com/cs/materiály/din-en/s255n.md de: https://steelequivalents.com/de/werkstoffe/din-en/s255n.md es: https://steelequivalents.com/es/materiales/din-en/s255n.md fr: https://steelequivalents.com/fr/matériaux/din-en/s255n.md hu: https://steelequivalents.com/hu/anyagok/din-en/s255n.md it: https://steelequivalents.com/it/materiali/din-en/s255n.md nl: https://steelequivalents.com/nl/materialen/din-en/s255n.md pl: https://steelequivalents.com/pl/materiały/din-en/s255n.md pt: https://steelequivalents.com/pt/materiais/din-en/s255n.md ru: https://steelequivalents.com/ru/материалы/din-en/s255n.md tr: https://steelequivalents.com/tr/malzemeler/din-en/s255n.md zh: https://steelequivalents.com/zh/材料/din-en/s255n.md ja: https://steelequivalents.com/ja/材料/din-en/s255n.md ar: https://steelequivalents.com/ar/المواد/din-en/s255n.md ko: https://steelequivalents.com/ko/재료/din-en/s255n.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/s255n.md hi: https://steelequivalents.com/hi/सामग्री/din-en/s255n.md content_hash: sha256:53cc2bd6b4014ed6a12b3e911aece47b369c683b339c2c03d4edeeda8039e7e8 generated: 2026-09-22 --- > **Machine-readable Markdown rendering.** This is a Markdown representation of a web page, > served for AI agents and crawlers as a token-efficient alternative to the full HTML. > Full interactive HTML version: https://steelequivalents.com/materials/din-en/s255n > Canonical URL: https://steelequivalents.com/materials/din-en/s255n > Available languages: en, cs, de, es, fr, hu, it, nl, pl, pt, ru, tr, zh, ja, ar, ko, pt-br, hi > Change detection: `content_hash` is the SHA-256 of this document's Markdown body — everything > below this block, whitespace-trimmed, excluding the front-matter. Compare it to detect a real > content change; `generated` moves on every render and is not a change signal. DIN / EN · Europe · 18 designations # S255N S255N is a material in the category [Fine-grain structural steels](/categories/fine-grain-structural-steels "Fine-grain structural steels"), held under material number 1.0461. We list 17 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ISO, JIS and GOST. Its recorded composition includes C ≤ 0.18%, Si ≤ 0.4%, Cr ≤ 0.3%, Mn 0.5–1.3% and Ni ≤ 0.3%. Recorded mechanical properties include Rm 390–570 N/mm², Re 245–255 N/mm² and A5 23–24%; these figures vary with the delivery condition and dimension. Its recorded density is 7.85 g/cm³. Its weldability is recorded as good. - [*Material no.* **1.0461**](/materials/material-no/1.0461 "Material no.: 1.0461") - [*Category* **Fine-grain structural steels · 50 grades**](/categories/fine-grain-structural-steels "Category: Fine-grain structural steels · 50 grades") - *Designations* **18** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=05163c5b-34ed-4cb5-8b5f-585ea2b761a0&designation=c66f5447-a7d2-4d77-8da6-1f2b568ec98d "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/s255n.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN StE 255 This grade’s own name · 2 grades on that route](/materials/din-en/ste255 "DIN / EN StE 255") - [UNS K01800 This grade’s own name · 7 grades on that route](/materials/uns/k01800 "UNS K01800") ## About Fine-grain structural steels Fine-grain structural steel is a name for structural steels whose properties are particularly suitable for welding. They have a higher yield strength than comparable steels. Due to the negative influence of carbon on the weldability of a material, the maximum carbon content in fine-grained structural steels is less than 0.2%. These properties are achieved in steelmaking by the addition of oxygen and nitrogen-binding elements. The fine grain in the metallurgical structure is achieved by alloying elements whose nitrides and carbides only dissolve at higher temperatures. With the same composition, they are stronger and tougher than coarse-grained steels. Fine-grained structural steels are used above all in reinforced concrete structures such as bridges, in the construction of cranes, hydraulic cylinders or other welded structures due to their special welding suitability and in the offshore area. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 18 designations · 6 standards · nothing hidden This grade’s own name recorded in our sources as this grade’s own designation under that standard. Indicative taken from a published cross-reference table; a close match, not a guarantee of interchangeability. Verify against the mill certificate before ordering. Withdrawn designation no longer current — a separate column from the two above, so a name can be same grade and withdrawn at once. DIN / EN Europe · 2 - **S255N This grade’s own name** - [StE 255 This grade’s own name](/materials/din-en/ste255 "DIN / EN StE 255") UNS United States · 2 - [K01800 This grade’s own name](/materials/uns/k01800 "UNS K01800") - [K02202 This grade’s own name](/materials/uns/k02202 "UNS K02202") AISI / SAE United States · 4 - [GradeB Indicative](/materials/aisi-sae/gradeb "AISI / SAE GradeB") - [K02101 Indicative](/materials/uns/k02101 "AISI / SAE K02101") - [K02102 Indicative](/materials/aisi-sae/k02102 "AISI / SAE K02102") - [K02301 Indicative](/materials/uns/k02301 "AISI / SAE K02301") ISO International · 4 - [E235-C Indicative](/materials/iso/e235c "ISO E235-C") - [E235-D Indicative](/materials/iso/e235-d "ISO E235-D") - [Fe360-C Indicative](/materials/iso/fe360c "ISO Fe360-C") - [Fe360-D Indicative](/materials/uni/fe360d "ISO Fe360-D") JIS Japan · 4 - [SM400B Indicative](/materials/ks/sm400b "JIS SM400B") - [SM400C Indicative](/materials/ks/sm400c "JIS SM400C") - [SM41B Indicative](/materials/jis/sm41b "JIS SM41B") - [SM41C Indicative](/materials/jis/sm41c "JIS SM41C") GOST Russia / CIS · 2 - [St3Gsp Indicative](/materials/gost/st3gsp "GOST St3Gsp") - [Ст3Гсп Indicative](/materials/gost/st3gsp "GOST Ст3Гсп") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 12 elements on file · weight % What this alloy is Fe Mn Si Cr Iron — the balance, never listed by a standard — 97.5 % Mn — 0.9 % Si — 0.4 % Cr — 0.3 % Traces & impurities · 0.9 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.18 | | Si | ≤ 0.4 | | Mn | 0.5–1.3 | | P | 0.035 | | S | 0.03 | | Cr | ≤ 0.3 | | Mo | ≤ 0.08 | | Ni | ≤ 0.3 | | Cu | ≤ 0.2 | | Al | ≥ 0.02 | | Nb | ≤ 0.03 | | N | 0.02 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Copper Aluminium Niobium Nitrogen 0.01 % 0.1 % 1 % 10 % 100 % The scale is logarithmic, not the element’s raw share of the alloy — the only honest way to fit 0.01 % and 100 % in one picture, and it means every value here can be compared with every other. | Element | As published source text, verbatim | Min% by weight | Max% by weight | Bound | |---|---|---|---|---| | C | ≤0,18 | — | 0.180 | Max | | N | 0,02 | 0.020 | 0.020 | Exact | | Al | ≥0,020 | 0.020 | — | Min | | Si | ≤0,40 | — | 0.400 | Max | | P | 0,035 | 0.035 | 0.035 | Exact | | S | 0,03 | 0.030 | 0.030 | Exact | | Cr | ≤0,30 | — | 0.300 | Max | | Mn | 0,50-1,30 | 0.500 | 1.300 | Range | | Ni | ≤0,30 | — | 0.300 | Max | | Cu | ≤0,20 | — | 0.200 | Max | | Nb | ≤0,03 | — | 0.030 | Max | | Mo | ≤0,08 | — | 0.080 | Max | - (Nb+Ti+V) ≤ 0,05; (Cr+Cu+Mo)≤0,45 - (Nb+Ti+V) ≤ 0,05; (Cr+Cu+Mo)≤0,45 - (Nb+Ti+V) ≤ 0,05; (Cr+Cu+Mo)≤0,45 The published column is the source string byte-for-byte, decimal comma and all; Min and Max are the parsed bounds. Elements not listed have no value on file — they are omitted, never inferred. ## Predicted transformation temperatures computed from composition · °C Predicted Ae3 816 °C Predicted Ae1 716 °C Predicted Acm 418 °C Predicted Bs 563 °C These four temperatures are a CALCULATION from this grade's own composition, using the published Li, Niebuhr, Meekisho & Atteridge (1998) model — never a measurement, and computed from the UPPER BOUND of each element's specified range, not a mid-range figure. Where this grade also has a measured transformation point (Ac1, Ac3, Ar1, Ar3) on file, it is shown separately, in Physical & mechanical properties, and is never replaced by the predicted figures here — Ae (predicted, equilibrium) and Ac/Ar (measured, on heating or cooling) are different physical quantities and can differ by tens of degrees; a mismatch between the two is not an error in either. ## Physical & mechanical properties Density 7,85 g/cm³ Exact Weldability readily weldable As published: without limitations. An absent property means we hold no value for it — it is left out rather than estimated, interpolated from a neighbouring grade, or filled from a handbook. It does not mean the property is undefined for the material. ## Properties by condition 2 conditions · 7 values By delivery state**no delivery state stated** source `splav` | Delivery state | Rm N/mm² | Re N/mm² | A5% | |---|---|---|---| | Rolled stock, GOST 535-2005 | 390 – 570 | 245 | 24 | | Sheet trick, GOST 14637-89 | 390 – 570 | 245 – 255 | 23 – 24 | At temperature**no delivery state stated** source `splav` | Temperature °C | Density g/cm³ | |---|---| | 20 | 7.85 | Every figure holds only for the condition on its own row. Values are never merged across conditions or across sources, never averaged, and never interpolated between two rows. An em dash means no value on file — never zero. Figures are converted to the unit in the column header; the source’s own wording is kept and shown where the two differ. ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.0, a shared category, and a published range for Mn / Si that overlaps this grade’s. These are neighbours in composition space — they are not equivalents, and none is claimed to be interchangeable with this grade. [P245GH 1.0352 Mn 0,50-1,30 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.00 - 3 designations](/materials/din-en/p245gh "P245GH")[P255NH 1.0462 Mn 0,50-1,30 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.00 - 4 designations](/materials/din-en/p255nh "P255NH")[P255NL 1.0463 Mn 0,50-1,30 · Si ≤0,40 - ΔMn 0.00 - ΔSi 0.00 - 6 designations](/materials/din-en/p255nl "P255NL")[1.0486 1.0490 Mn 0,50-1,50 · Si ≤0,40 - ΔMn 0.10 - ΔSi 0.00 - 12 designations](/materials/material-no/1.0486 "1.0486")[S275NL 1.0491 Mn 0,50-1,50 · Si ≤0,40 - ΔMn 0.10 - ΔSi 0.00 - 10 designations](/materials/din-en/s275nl "S275NL")[A662Gr.A 1.0488 Mn 0,60-1,50 · Si ≤0,40 - ΔMn 0.15 - ΔSi 0.00 - 18 designations](/materials/din-en/a662gr-a "A662Gr.A") ## Looking for this grade under another name? Search the catalogue by designation, material number or composition — every name on this page is itself a way in. [Search](/search "Steel grade search")[Inquiry](/inquiry?material=05163c5b-34ed-4cb5-8b5f-585ea2b761a0&designation=c66f5447-a7d2-4d77-8da6-1f2b568ec98d "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/s255n.pdf "Datasheet as PDF")