--- title: "C40D2 — Quenched and tempered steels" description: "C40D2: 10 equivalent designations across 7 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/din-en/c40d2 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/c40d2.md cs: https://steelequivalents.com/cs/materiály/din-en/c40d2.md de: https://steelequivalents.com/de/werkstoffe/din-en/c40d2.md es: https://steelequivalents.com/es/materiales/din-en/c40d2.md fr: https://steelequivalents.com/fr/matériaux/din-en/c40d2.md hu: https://steelequivalents.com/hu/anyagok/din-en/c40d2.md it: https://steelequivalents.com/it/materiali/din-en/c40d2.md nl: https://steelequivalents.com/nl/materialen/din-en/c40d2.md pl: https://steelequivalents.com/pl/materiały/din-en/c40d2.md pt: https://steelequivalents.com/pt/materiais/din-en/c40d2.md ru: https://steelequivalents.com/ru/материалы/din-en/c40d2.md tr: https://steelequivalents.com/tr/malzemeler/din-en/c40d2.md zh: https://steelequivalents.com/zh/材料/din-en/c40d2.md ja: https://steelequivalents.com/ja/材料/din-en/c40d2.md ar: https://steelequivalents.com/ar/المواد/din-en/c40d2.md ko: https://steelequivalents.com/ko/재료/din-en/c40d2.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/c40d2.md hi: https://steelequivalents.com/hi/सामग्री/din-en/c40d2.md content_hash: sha256:78441057cee3ab7ad58e4b46cb0d74cc976604f6bda9c85bc2ae5a56e0a1ccfc 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/c40d2 > Canonical URL: https://steelequivalents.com/materials/din-en/c40d2 > 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 · 10 designations # C40D2 C40D2 is a material in the category [Quenched and tempered steels](/categories/quenched-and-tempered-steels "Quenched and tempered steels"), held under material number 1.1153. We list 9 designations recorded for this grade, in the standards UNS, AISI / SAE, BS, AFNOR, JIS and GOST. Its recorded composition includes C 0.38–0.42%, Si 0.1–0.3%, Cr ≤ 0.1%, Mn 0.5–0.7% and Cu ≤ 0.15%. Its recorded density is 7.85 g/cm³. - [*Material no.* **1.1153**](/materials/material-no/1.1153 "Material no.: 1.1153") - [*Category* **Quenched and tempered steels · 133 grades**](/categories/quenched-and-tempered-steels "Category: Quenched and tempered steels · 133 grades") - *Designations* **10** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=87126368-54a9-47f5-9915-0dc4e214a0e9&designation=d96e17d7-dcc4-4cd6-ab18-e114d2480e24 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/c40d2.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [UNS G10400 This grade’s own name · 5 grades on that route](/materials/uns/g10400 "UNS G10400") - [AISI / SAE 1040 This grade’s own name · 6 grades on that route](/materials/aisi-sae/1040 "AISI / SAE 1040") ## About Quenched and tempered steels Quenched and tempered steels are heat-treated steels designed to combine high strength with useful toughness and ductility. They are used for heavily loaded components such as shafts, gears, fasteners and structural machine parts where resistance to mechanical stress is required. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 10 designations · 7 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 · 1 - **C40D2 This grade’s own name** UNS United States · 1 - [G10400 This grade’s own name](/materials/uns/g10400 "UNS G10400") AISI / SAE United States · 1 - [1040 This grade’s own name](/materials/aisi-sae/1040 "AISI / SAE 1040") BS United Kingdom · 2 - [060A40 Indicative](/materials/bs/060a40 "BS 060A40") - [080A40 Indicative](/materials/bs/080a40 "BS 080A40") AFNOR France · 2 - [XC 42 Indicative](/materials/afnor/xc42 "AFNOR XC 42") - [XC38H1 Indicative](/materials/afnor/xc38h1 "AFNOR XC38H1") JIS Japan · 1 - [S 40C Indicative](/materials/jis/s40c "JIS S 40C") GOST Russia / CIS · 2 - [40 Indicative](/materials/gb/40 "GOST 40") - [ст.40 Indicative](/materials/gost/st-40 "GOST ст.40") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 11 elements on file · weight % What this alloy is Fe Mn C Si Iron — the balance, never listed by a standard — 98.4 % Mn — 0.6 % C — 0.4 % Si — 0.2 % Traces & impurities · 0.4 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.38–0.42 | | Si | 0.1–0.3 | | Mn | 0.5–0.7 | | P | 0.02 | | S | 0.025 | | Cr | ≤ 0.1 | | Mo | ≤ 0.03 | | Ni | ≤ 0.1 | | Cu | ≤ 0.15 | | Al | ≤ 0.01 | | N | 0.007 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Copper Aluminium 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 | 0,38-0,42 | 0.380 | 0.420 | Range | | N | 0,007 | 0.007 | 0.007 | Exact | | Al | ≤0,01 | — | 0.010 | Max | | Si | 0,10-0,30 | 0.100 | 0.300 | Range | | P | 0,02 | 0.020 | 0.020 | Exact | | S | 0,025 | 0.025 | 0.025 | Exact | | Cr | ≤0,10 | — | 0.100 | Max | | Mn | 0,50-0,70 | 0.500 | 0.700 | Range | | Ni | ≤0,10 | — | 0.100 | Max | | Cu | ≤0,15 | — | 0.150 | Max | | Mo | ≤0,03 | — | 0.030 | 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 computed from composition · °C Predicted Ae3 781 °C Predicted Ae1 721 °C Predicted Acm 575 °C Predicted Bs 582 °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 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. ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.1, 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. [C26D2 1.1139 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.00 - ΔSi 0.00 - 7 designations](/materials/din-en/c26d2 "C26D2")[C32D2 1.1143 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.00 - ΔSi 0.00 - 9 designations](/materials/din-en/c32d2 "C32D2")[C42D2 1.1154 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.00 - ΔSi 0.00 - 5 designations](/materials/din-en/c42d2 "C42D2")[C46D2 1.1162 Mn 0,50-0,70 · Si 0,10-0,30 - ΔMn 0.00 - ΔSi 0.00 - 3 designations](/materials/din-en/c46d2 "C46D2")[C22R 1.1149 Mn 0,40-0,70 · Si ≤0,40 - ΔMn 0.05 - ΔSi 0.00 - 11 designations](/materials/din-en/c22r "C22R")[C22E 1.1151 Mn 0,40-0,70 · Si ≤0,40 - ΔMn 0.05 - ΔSi 0.00 - 27 designations](/materials/din-en/c22e "C22E") ## 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=87126368-54a9-47f5-9915-0dc4e214a0e9&designation=d96e17d7-dcc4-4cd6-ab18-e114d2480e24 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/c40d2.pdf "Datasheet as PDF")