--- title: "WR40B — Weathering steels" description: "WR40B in BS: material number 1.8958, also listed as S235J0W. It is a material in the category Weathering steels. Designations recorded for this grade: 5." canonical: https://steelequivalents.com/materials/bs/wr40b language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/bs/wr40b.md cs: https://steelequivalents.com/cs/materiály/bs/wr40b.md de: https://steelequivalents.com/de/werkstoffe/bs/wr40b.md es: https://steelequivalents.com/es/materiales/bs/wr40b.md fr: https://steelequivalents.com/fr/matériaux/bs/wr40b.md hu: https://steelequivalents.com/hu/anyagok/bs/wr40b.md it: https://steelequivalents.com/it/materiali/bs/wr40b.md nl: https://steelequivalents.com/nl/materialen/bs/wr40b.md pl: https://steelequivalents.com/pl/materiały/bs/wr40b.md pt: https://steelequivalents.com/pt/materiais/bs/wr40b.md ru: https://steelequivalents.com/ru/материалы/bs/wr40b.md tr: https://steelequivalents.com/tr/malzemeler/bs/wr40b.md zh: https://steelequivalents.com/zh/材料/bs/wr40b.md ja: https://steelequivalents.com/ja/材料/bs/wr40b.md ar: https://steelequivalents.com/ar/المواد/bs/wr40b.md ko: https://steelequivalents.com/ko/재료/bs/wr40b.md pt-br: https://steelequivalents.com/pt-br/materiais/bs/wr40b.md hi: https://steelequivalents.com/hi/सामग्री/bs/wr40b.md content_hash: sha256:e2dbc816d18e432bf499361a281f5b0a7350a2352dd0594d8b9f31e7a421fa0c 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/bs/wr40b > Canonical URL: https://steelequivalents.com/materials/bs/wr40b > 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. BS · United Kingdom · 5 designations # WR40B WR40B is a designation in BS for the material held under material number 1.8958, also listed as S235J0W. It is a material in the category Weathering steels. We list 5 designations recorded for this grade, in the standards DIN / EN, BS, AFNOR and UNI. - [*Material no.* **1.8958**](/materials/material-no/1.8958 "Material no.: 1.8958") - [*Category* **Weathering steels · 27 grades**](/categories/weathering-steels "Category: Weathering steels · 27 grades") - *Designations* **5** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=119bd01e-dab1-464d-9e7c-66eb1ce8a6f0&designation=6f9a53aa-7116-4b8d-ace8-7149c30d93ca "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/bs/wr40b.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN S235J0W This grade’s own name](/materials/din-en/s235j0w "DIN / EN S235J0W") ## About Weathering steels Weathering steels are structural steels designed to develop a protective patina when exposed to the atmosphere. This characteristic helps limit further corrosion and makes them suitable for bridges, building facades, rail vehicles and other outdoor structures where reduced coating maintenance is desirable. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 5 designations · 4 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 - [Fe360CKI Indicative](/materials/din-en/fe360cki "DIN / EN Fe360CKI") - [S235J0W This grade’s own name](/materials/din-en/s235j0w "DIN / EN S235J0W") BS United Kingdom · 1 - **WR40B Indicative** AFNOR France · 1 - [E24W3 Indicative](/materials/afnor/e24w3 "AFNOR E24W3") UNI Italy · 1 - [Fe360CK1 Indicative](/materials/uni/fe360ck1 "UNI Fe360CK1") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 9 elements on file · weight % What this alloy is Fe Ni Cr Si Iron — the balance, never listed by a standard — 97.3 % Ni — 0.7 % Cr — 0.6 % Si — 0.4 % Traces & impurities · 1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.13 | | Si | ≤ 0.4 | | Mn | 0.2–0.6 | | P | 0.035 | | S | 0.035 | | Cr | 0.4–0.8 | | Ni | 0.65 | | Cu | 0.25–0.55 | | N | 0.009 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel Copper 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 | ≤0,13 | — | 0.130 | Max | | N | 0,009 | 0.009 | 0.009 | Exact | | Si | ≤0,40 | — | 0.400 | Max | | P | 0,035 | 0.035 | 0.035 | Exact | | S | 0,035 | 0.035 | 0.035 | Exact | | Cr | 0,40-0,80 | 0.400 | 0.800 | Range | | Mn | 0,20-0,60 | 0.200 | 0.600 | Range | | Ni | (0,65) | 0.650 | 0.650 | Exact | | Cu | 0,25-0,55 | 0.250 | 0.550 | Range | 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: Mo. ## Physical & mechanical properties Density 7,85 g/cm³ Exact 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 1 conditions · 16 values By thickness**no delivery state stated** source `steelnumber` | Thickness mm | ReH N/mm² | Rm N/mm² | A80% | A% | |---|---|---|---|---| | 1.5 – 2 | — | — | 19 | — | | 2 – 2.5 | — | — | 20 | — | | 2.5 – 3 | — | — | 21 | — | | ≤ 3 | — | 360 – 510 | — | — | | 3 – 100 | — | 360 – 510 | — | — | | 3 – 40 | — | — | — | 26 | | ≤ 16 | 235 | — | — | — | | 16 – 40 | 225 | — | — | — | | 40 – 63 | 215 | — | — | 25 | | 63 – 80 | 215 | — | — | — | | 63 – 100 | — | — | — | 24 | | 80 – 100 | 215 | — | — | — | | 100 – 150 | 195 | 350 – 500 | — | 22 | 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 1.8, a shared category, and a published range for Ni / Cr 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. [A709-50W 1.8959 Ni (0,65) · Cr 0,40-0,80 - ΔNi 0.00 - ΔCr 0.00 - 23 designations](/materials/din-en/a709-50w "A709-50W")[Fe360DKI 1.8961 Ni (0,65) · Cr 0,40-0,80 - ΔNi 0.00 - ΔCr 0.00 - 6 designations](/materials/din-en/fe360dki "Fe360DKI")[A600C 1.8963 Ni 0,65 · Cr 0,40-0,80 - ΔNi 0.00 - ΔCr 0.00 - 29 designations](/materials/din-en/a600c "A600C")[S355J2W 1.8965 Ni (0,65) · Cr 0,40-0,80 - ΔNi 0.00 - ΔCr 0.00 - 8 designations](/materials/din-en/s355j2w "S355J2W")[S355K2W(+N) 1.8966 Ni 0,65 · Cr 0,40-0,80 - ΔNi 0.00 - ΔCr 0.00 - 5 designations](/materials/din-en/s355k2w-n "S355K2W(+N)")[S355K2W 1.8967 Ni (0,65) · Cr 0,40-0,80 - ΔNi 0.00 - ΔCr 0.00 - 3 designations](/materials/din-en/s355k2w "S355K2W") ## 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=119bd01e-dab1-464d-9e7c-66eb1ce8a6f0&designation=6f9a53aa-7116-4b8d-ace8-7149c30d93ca "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/bs/wr40b.pdf "Datasheet as PDF")