--- title: "20CrNiMoA — composition, equivalents and standards" description: "20CrNiMoA: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/20crnimoa language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/20crnimoa.md cs: https://steelequivalents.com/cs/materiály/gb/20crnimoa.md de: https://steelequivalents.com/de/werkstoffe/gb/20crnimoa.md es: https://steelequivalents.com/es/materiales/gb/20crnimoa.md fr: https://steelequivalents.com/fr/matériaux/gb/20crnimoa.md hu: https://steelequivalents.com/hu/anyagok/gb/20crnimoa.md it: https://steelequivalents.com/it/materiali/gb/20crnimoa.md nl: https://steelequivalents.com/nl/materialen/gb/20crnimoa.md pl: https://steelequivalents.com/pl/materiały/gb/20crnimoa.md pt: https://steelequivalents.com/pt/materiais/gb/20crnimoa.md ru: https://steelequivalents.com/ru/материалы/gb/20crnimoa.md tr: https://steelequivalents.com/tr/malzemeler/gb/20crnimoa.md zh: https://steelequivalents.com/zh/材料/gb/20crnimoa.md ja: https://steelequivalents.com/ja/材料/gb/20crnimoa.md ar: https://steelequivalents.com/ar/المواد/gb/20crnimoa.md ko: https://steelequivalents.com/ko/재료/gb/20crnimoa.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/20crnimoa.md hi: https://steelequivalents.com/hi/सामग्री/gb/20crnimoa.md content_hash: sha256:f2208329b2731d279b7cac19c063a4c9a1757f68b3c92aa713617cfe51233ec3 generated: 2026-09-23 --- > **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/gb/20crnimoa > Canonical URL: https://steelequivalents.com/materials/gb/20crnimoa > 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. GB · China · 1 designation # 20CrNiMoA 20CrNiMoA is a grade designated under GB. Its recorded composition includes C 0.17–0.23%, Si 0.17–0.37%, Cr 0.4–0.7%, Mn 0.6–0.95% and Ni 0.35–0.75%. No cross-standard equivalents are recorded for this grade yet. - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=a1376a03-47a1-4ff9-8800-b0980da650d0&designation=73899deb-1c87-43b4-b1b0-6115e1e92500 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/20crnimoa.pdf "Datasheet as PDF") ## Chemical composition 9 elements on file · weight % What this alloy is Fe Mn Cr Ni Iron — the balance, never listed by a standard — 97.1 % Mn — 0.8 % Cr — 0.6 % Ni — 0.6 % Traces & impurities · 1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.17–0.23 | | Si | 0.17–0.37 | | Mn | 0.6–0.95 | | P | ≤ 0.025 | | S | ≤ 0.025 | | Cr | 0.4–0.7 | | Mo | 0.2–0.3 | | Ni | 0.35–0.75 | | Cu | ≤ 0.25 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Copper 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 | 0.17-0.23 | 0.170 | 0.230 | Range | | Si | 0.17-0.37 | 0.170 | 0.370 | Range | | P | ≤0.025 | — | 0.025 | Max | | S | ≤0.025 | — | 0.025 | Max | | Cr | 0.4-0.7 | 0.400 | 0.700 | Range | | Mn | 0.6-0.95 | 0.600 | 0.950 | Range | | Ni | 0.35-0.75 | 0.350 | 0.750 | Range | | Cu | ≤0.25 | — | 0.250 | Max | | Mo | 0.2-0.3 | 0.200 | 0.300 | 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 computed from composition · °C Predicted Ae3 802 °C Predicted Ae1 723 °C Predicted Acm 470 °C Predicted Bs 543 °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 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. ## 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=a1376a03-47a1-4ff9-8800-b0980da650d0&designation=73899deb-1c87-43b4-b1b0-6115e1e92500 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/20crnimoa.pdf "Datasheet as PDF")