--- title: "27SiMn — composition, equivalents and standards" description: "27SiMn: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/27simn language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/27simn.md cs: https://steelequivalents.com/cs/materiály/gb/27simn.md de: https://steelequivalents.com/de/werkstoffe/gb/27simn.md es: https://steelequivalents.com/es/materiales/gb/27simn.md fr: https://steelequivalents.com/fr/matériaux/gb/27simn.md hu: https://steelequivalents.com/hu/anyagok/gb/27simn.md it: https://steelequivalents.com/it/materiali/gb/27simn.md nl: https://steelequivalents.com/nl/materialen/gb/27simn.md pl: https://steelequivalents.com/pl/materiały/gb/27simn.md pt: https://steelequivalents.com/pt/materiais/gb/27simn.md ru: https://steelequivalents.com/ru/материалы/gb/27simn.md tr: https://steelequivalents.com/tr/malzemeler/gb/27simn.md zh: https://steelequivalents.com/zh/材料/gb/27simn.md ja: https://steelequivalents.com/ja/材料/gb/27simn.md ar: https://steelequivalents.com/ar/المواد/gb/27simn.md ko: https://steelequivalents.com/ko/재료/gb/27simn.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/27simn.md hi: https://steelequivalents.com/hi/सामग्री/gb/27simn.md content_hash: sha256:a773307c459e9174fb0760f3b7518fd828945009812b12bee32543c00af6a675 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/27simn > Canonical URL: https://steelequivalents.com/materials/gb/27simn > 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 # 27SiMn 27SiMn is a grade designated under GB. Its recorded composition includes C 0.24–0.32%, Si 1.1–1.4%, Cr ≤ 0.3%, Mn 1.1–1.4% and Ni ≤ 0.3%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm 550–800 N/mm², A ≥ 18% and HB 217–255; these figures vary with the delivery condition and dimension. - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=b13c3a64-eadf-4a6f-b198-a9b5eb204801&designation=0baf5b66-9f46-455b-869f-b05d832c9f5a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/27simn.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 — 96.2 % Si — 1.3 % Mn — 1.3 % Cr — 0.3 % Traces & impurities · 1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.24–0.32 | | Si | 1.1–1.4 | | Mn | 1.1–1.4 | | P | ≤ 0.03 | | S | ≤ 0.03 | | Cr | ≤ 0.3 | | 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 | 0.24-0.32 | 0.240 | 0.320 | Range | | Si | 1.1-1.4 | 1.100 | 1.400 | Range | | P | ≤0.03 | — | 0.030 | Max | | S | ≤0.03 | — | 0.030 | Max | | Cr | ≤0.3 | — | 0.300 | Max | | Mn | 1.1-1.4 | 1.100 | 1.400 | 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 834 °C Predicted Ae1 737 °C Predicted Acm 543 °C Predicted Bs 551 °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 5 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 Supply condition - Annealing - Quenching and Tempering d=25 - Annealing and Tempering and Normalizing Supply condition 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/azhlNWIxMTUxNTQ_ "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=b13c3a64-eadf-4a6f-b198-a9b5eb204801&designation=0baf5b66-9f46-455b-869f-b05d832c9f5a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/27simn.pdf "Datasheet as PDF")