--- title: "20CrMnSi — composition, equivalents and standards" description: "20CrMnSi: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/20crmnsi language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/20crmnsi.md cs: https://steelequivalents.com/cs/materiály/gb/20crmnsi.md de: https://steelequivalents.com/de/werkstoffe/gb/20crmnsi.md es: https://steelequivalents.com/es/materiales/gb/20crmnsi.md fr: https://steelequivalents.com/fr/matériaux/gb/20crmnsi.md hu: https://steelequivalents.com/hu/anyagok/gb/20crmnsi.md it: https://steelequivalents.com/it/materiali/gb/20crmnsi.md nl: https://steelequivalents.com/nl/materialen/gb/20crmnsi.md pl: https://steelequivalents.com/pl/materiały/gb/20crmnsi.md pt: https://steelequivalents.com/pt/materiais/gb/20crmnsi.md ru: https://steelequivalents.com/ru/материалы/gb/20crmnsi.md tr: https://steelequivalents.com/tr/malzemeler/gb/20crmnsi.md zh: https://steelequivalents.com/zh/材料/gb/20crmnsi.md ja: https://steelequivalents.com/ja/材料/gb/20crmnsi.md ar: https://steelequivalents.com/ar/المواد/gb/20crmnsi.md ko: https://steelequivalents.com/ko/재료/gb/20crmnsi.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/20crmnsi.md hi: https://steelequivalents.com/hi/सामग्री/gb/20crmnsi.md content_hash: sha256:7f1afba8fb36a222304902f807daa2f52ca57c0e093d843cb9c2a3b413e44989 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/gb/20crmnsi > Canonical URL: https://steelequivalents.com/materials/gb/20crmnsi > 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 # 20CrMnSi 20CrMnSi is a grade designated under GB. Its recorded composition includes C 0.17–0.23%, Si 0.9–1.2%, Cr 0.8–1.1%, Mn 0.8–1.1% and Ni ≤ 0.3%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm 450–700 N/mm², A ≥ 21% and HB 207–255; these figures vary with the delivery condition and dimension. - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=a5a83aa7-5699-48d8-9516-7508140cdb1e&designation=c0b4a3f3-9029-4dc4-b5ef-3c5ecfe16d7b "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/20crmnsi.pdf "Datasheet as PDF") ## Chemical composition 9 elements on file · weight % What this alloy is Fe Si Mn Cr Iron — the balance, never listed by a standard — 96.1 % Si — 1.1 % Mn — 1 % Cr — 1 % 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 | 0.9–1.2 | | Mn | 0.8–1.1 | | P | ≤ 0.03 | | S | ≤ 0.03 | | Cr | 0.8–1.1 | | Mo | ≤ 0.1 | | Ni | ≤ 0.3 | | Cu | ≤ 0.3 | 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 | 0.9-1.2 | 0.900 | 1.200 | Range | | P | ≤0.03 | — | 0.030 | Max | | S | ≤0.03 | — | 0.030 | Max | | Cr | 0.8-1.1 | 0.800 | 1.100 | Range | | Mn | 0.8-1.1 | 0.800 | 1.100 | Range | | Ni | ≤0.3 | — | 0.300 | Max | | Cu | ≤0.3 | — | 0.300 | Max | | Mo | ≤0.1 | — | 0.100 | 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 844 °C Predicted Ae1 756 °C Predicted Acm 503 °C Predicted Bs 539 °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. ## Properties by condition 0 conditions · 0 values 6 further values are held for this grade under a condition the source did not name — a bound with no quantity attached. They are withheld rather than shown against a guessed condition. ## Heat treatment **GJB 1220** In this order d=25 1. Quenching 880 °C Cooling Oil 2. Tempering 480 °C Cooling Water or Oil Supply condition - Annealing - Quenching and Tempering d=25 - Annealing and Tempering and Normalizing Supply condition - Annealing or Tempering Steel product Conditions the standard permits on delivery. No temperature or medium is published for these, so no order and no alternation is implied. Source: [www.caishuku.com](https://www.caishuku.com/detail/azhlNWIxMjUxNTg_ "Source: www.caishuku.com") ## 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=a5a83aa7-5699-48d8-9516-7508140cdb1e&designation=c0b4a3f3-9029-4dc4-b5ef-3c5ecfe16d7b "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/20crmnsi.pdf "Datasheet as PDF")