--- title: "AE255D — Unalloyed structural steels" description: "AE255D in NBN: material number 1.0144, also listed as St 44-3 N. Category: Unalloyed structural steels. Designations recorded for this grade: 64." canonical: https://steelequivalents.com/materials/nbn/ae255d language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/nbn/ae255d.md cs: https://steelequivalents.com/cs/materiály/nbn/ae255d.md de: https://steelequivalents.com/de/werkstoffe/nbn/ae255d.md es: https://steelequivalents.com/es/materiales/nbn/ae255d.md fr: https://steelequivalents.com/fr/matériaux/nbn/ae255d.md hu: https://steelequivalents.com/hu/anyagok/nbn/ae255d.md it: https://steelequivalents.com/it/materiali/nbn/ae255d.md nl: https://steelequivalents.com/nl/materialen/nbn/ae255d.md pl: https://steelequivalents.com/pl/materiały/nbn/ae255d.md pt: https://steelequivalents.com/pt/materiais/nbn/ae255d.md ru: https://steelequivalents.com/ru/материалы/nbn/ae255d.md tr: https://steelequivalents.com/tr/malzemeler/nbn/ae255d.md zh: https://steelequivalents.com/zh/材料/nbn/ae255d.md ja: https://steelequivalents.com/ja/材料/nbn/ae255d.md ar: https://steelequivalents.com/ar/المواد/nbn/ae255d.md ko: https://steelequivalents.com/ko/재료/nbn/ae255d.md pt-br: https://steelequivalents.com/pt-br/materiais/nbn/ae255d.md hi: https://steelequivalents.com/hi/सामग्री/nbn/ae255d.md content_hash: sha256:34ea5c8616599509f1a27d93c5d3281fab607b0418ec48be5f655087b30a6cc0 generated: 2026-09-24 --- > **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/nbn/ae255d > Canonical URL: https://steelequivalents.com/materials/nbn/ae255d > 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. NBN · Belgium · 64 designations # AE255D AE255D is a designation in NBN for the material held under material number 1.0144, also listed as St 44-3 N. It is a material in the category Unalloyed structural steels. We list 64 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, BS, AFNOR, UNE, ISO, NS, JIS, NP, GB, GOST, UNI, SS, ČSN, SRPS, PN, STAS, BDS, ÖNORM, NBN, SFS and KS. - [*Material no.* **1.0144**](/materials/material-no/1.0144 "Material no.: 1.0144") - [*Category* **Unalloyed structural steels · 452 grades**](/categories/unalloyed-structural-steels "Category: Unalloyed structural steels · 452 grades") - *Designations* **64** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=84170605-5b2c-4e3d-b96a-a29c715059df&designation=6d4a26a7-3f2c-4153-8805-ecb3a2332fa4 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/nbn/ae255d.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN S275J2 This grade’s own name · 2 grades on that route](/materials/din-en/s275j2 "DIN / EN S275J2") - [UNS K02601 This grade’s own name · 9 grades on that route](/materials/uns/k02601 "UNS K02601") - [KS SM400A This grade’s own name](/materials/ks/sm400a "KS SM400A") ## About Unalloyed structural steels Unalloyed structural steels include all low-carbon steels in which the iron companions do not exceed specified minimum values. The yield strength, formability and weldability are the decisive factors for their use. They are soft, pliable, tough and stretchy, but cannot be hardened by heat treatment. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 64 designations · 23 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 · 9 - [1.0144 Indicative](/materials/material-no/1.0144 "DIN / EN 1.0144") - [A633Gr.A Indicative](/materials/din-en/a633gr-a "DIN / EN A633Gr.A") - [Fe430D1 Indicative](/materials/din-en/fe430d1 "DIN / EN Fe430D1") - [S275J2 This grade’s own name](/materials/din-en/s275j2 "DIN / EN S275J2") - [S275J2(+N) Indicative](/materials/din-en/s275j2-n "DIN / EN S275J2(+N)") - [S275J2G3 Indicative](/materials/bs/s275j2g3 "DIN / EN S275J2G3") - [S275J2G3C This grade’s own name](/materials/din-en/s275j2g3c "DIN / EN S275J2G3C") - [St 44-3 N This grade’s own name](/materials/din-en/st-44-3-n "DIN / EN St 44-3 N") - [St.44.2 Indicative](/materials/din-en/st-44-2 "DIN / EN St.44.2") UNS United States · 3 - [K02601 This grade’s own name](/materials/uns/k02601 "UNS K02601") - [K02702 This grade’s own name](/materials/uns/k02702 "UNS K02702") - [K03000 This grade’s own name](/materials/uns/k03000 "UNS K03000") AISI / SAE United States · 7 - [A572 Indicative](/materials/astm/a572 "AISI / SAE A572") - [A573 Indicative](/materials/aisi-sae/a573 "AISI / SAE A573") - [A573-81 Indicative](/materials/aisi-sae/a573-81 "AISI / SAE A573-81") - [A573Gr.70 Indicative](/materials/aisi-sae/a573gr-70 "AISI / SAE A573Gr.70") - [A611Gr.D Indicative](/materials/aisi-sae/a611gr-d "AISI / SAE A611Gr.D") - [A633Gr.A Indicative](/materials/din-en/a633gr-a "AISI / SAE A633Gr.A") - [K03000 Indicative](/materials/uns/k03000 "AISI / SAE K03000") BS United Kingdom · 6 - [4360 43 C Indicative](/materials/bs/4360-43c "BS 4360 43 C") - [43C Indicative](/materials/bs/43c "BS 43C") - [43D Indicative](/materials/bs/43d "BS 43D") - [Fe430D1FF Indicative](/materials/bs/fe430d1ff "BS Fe430D1FF") - [S275J2G3 Indicative](/materials/bs/s275j2g3 "BS S275J2G3") - [S275N Indicative](/materials/din-en/s275n "BS S275N") AFNOR France · 2 - [E28-3 Indicative](/materials/afnor/e28-3 "AFNOR E28-3") - [E28-4 Indicative](/materials/afnor/e28-4 "AFNOR E28-4") UNE Spain · 2 - [AE275D Indicative](/materials/une/ae275d "UNE AE275D") - [Fe430D1FF Indicative](/materials/bs/fe430d1ff "UNE Fe430D1FF") ISO International · 3 - [E275-A Indicative](/materials/is/e275-a "ISO E275-A") - [Fe430-A Indicative](/materials/iso/fe430-a "ISO Fe430-A") - [Fe430D Indicative](/materials/uni/fe430d "ISO Fe430D") NS Norway · 1 - [NS12-143 Indicative](/materials/ns/ns12143 "NS NS12-143") JIS Japan · 3 - [SM400A Indicative](/materials/ks/sm400a "JIS SM400A") - [SM400B Indicative](/materials/ks/sm400b "JIS SM400B") - [SM400C Indicative](/materials/ks/sm400c "JIS SM400C") NP Portugal · 1 - [Fe430-D Indicative](/materials/uni/fe430d "NP Fe430-D") GB China · 1 - [Q255 Indicative](/materials/gb/q255 "GB Q255") GOST Russia / CIS · 3 - [St4kp Indicative](/materials/gost/st4kp "GOST St4kp") - [St4ps Indicative](/materials/gost/st4ps "GOST St4ps") - [Ст4кп Indicative](/materials/gost/st4kp "GOST Ст4кп") UNI Italy · 4 - [Fe430B Indicative](/materials/iso/fe430b "UNI Fe430B") - [Fe430C(FN) Indicative](/materials/uni/fe430c-fn "UNI Fe430C(FN)") - [Fe430D Indicative](/materials/uni/fe430d "UNI Fe430D") - [Fe430D(FF) Indicative](/materials/uni/fe430d-ff "UNI Fe430D(FF)") SS Sweden · 4 - [1411 Indicative](/materials/gost/1411 "SS 1411") - [1412 Indicative](/materials/gost/1412 "SS 1412") - [1414 Indicative](/materials/ss/1414 "SS 1414") - [1414-00 Indicative](/materials/ss/1414-00 "SS 1414-00") ČSN Czechia · 3 - [11 448 Indicative](/materials/csn/11448 "ČSN 11 448") - [11423 Indicative](/materials/csn/11423 "ČSN 11423") - [11428 Indicative](/materials/csn/11428 "ČSN 11428") SRPS Serbia · 1 - [Č.0452 Indicative](/materials/srps/c-0452 "SRPS Č.0452") PN Poland · 2 - [St4SW Indicative](/materials/pn/st4sw "PN St4SW") - [St4SX Indicative](/materials/pn/st4sx "PN St4SX") STAS Romania · 1 - [OL42.1 Indicative](/materials/stas/ol42-1 "STAS OL42.1") BDS Bulgaria · 2 - [BSt4kp Indicative](/materials/bds/bst4kp "BDS BSt4kp") - [WSt4kp Indicative](/materials/bds/wst4kp "BDS WSt4kp") ÖNORM Austria · 1 - [St430D Indicative](/materials/onorm/st430d "ÖNORM St430D") NBN Belgium · 2 - **AE255D Indicative** - [FE430D1FF Indicative](/materials/bs/fe430d1ff "NBN FE430D1FF") SFS Finland · 1 - [Fe44D Indicative](/materials/sfs/fe44d "SFS Fe44D") KS South Korea · 2 - [SM400A This grade’s own name](/materials/ks/sm400a "KS SM400A") - [SM400C This grade’s own name](/materials/ks/sm400c "KS SM400C") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 4 elements on file · weight % What this alloy is Fe Mn C P Iron — the balance, never listed by a standard — 98.3 % Mn — 1.5 % C — 0.2 % P — 0 % Traces & impurities · 0 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.18 | | Mn | ≤ 1.5 | | P | 0.035 | | S | 0.035 | Carbon Manganese Phosphorus Sulfur 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 | | P | 0,035 | 0.035 | 0.035 | Exact | | S | 0,035 | 0.035 | 0.035 | Exact | | Mn | ≤1,50 | — | 1.500 | Max | 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 Not enough recorded composition to predict a transformation temperature for this grade — missing: Si, Ni, Cr, Mo. ## Physical & mechanical properties Density 7,85 g/cm³ Exact Weldability weldable with restrictions As published: limited weldability. 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 5 conditions · 32 values By thickness**Flat and long products** source `steelnumber` | Thickness mm | ReH N/mm² | Rm N/mm² | |---|---|---| | ≤ 3 | — | 430 – 580 | | 3 – 100 | — | 410 – 560 | | ≤ 16 | 275 | — | | 16 – 40 | 265 | — | | 40 – 63 | 255 | — | | 63 – 80 | 245 | — | | 80 – 100 | 235 | — | | 100 – 150 | 225 | 400 – 540 | | 150 – 250 | — | 380 – 540 | | 150 – 200 | 215 | — | | 200 – 250 | 205 | — | By thickness**no delivery state stated** source `steelnumber` | Thickness mm | A80% · Lo = 80 mm | A% · Lo = 5,65 √So | |---|---|---| | ≤ 1 | 15 | — | | 1 – 1.5 | 16 | — | | 1.5 – 2 | 17 | — | | 2 – 2.5 | 18 | — | | 2.5 – 3 | 19 | — | | 3 – 40 | — | 23 | | 40 – 63 | — | 22 | | 63 – 100 | — | 21 | | 100 – 150 | — | 19 | | 150 – 250 | — | 18 | By delivery state**no delivery state stated** source `splav` | Delivery state | Rm N/mm² | Re N/mm² | A5% | |---|---|---|---| | Pipe, GOST 10705-80 | 412 | 245 | 21 | | Rolled stock, GOST 535-2005 | 400 – 510 | 225 – 255 | 22 – 25 | By delivery state**no delivery state stated** source `steeljis` | Delivery state | Rm N/mm² | Re N/mm² | A% | |---|---|---|---| | Hot-rolled | 400 – 510 | 195 – 245 | 18 – 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. ## 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=84170605-5b2c-4e3d-b96a-a29c715059df&designation=6d4a26a7-3f2c-4153-8805-ecb3a2332fa4 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/nbn/ae255d.pdf "Datasheet as PDF")