--- title: "U71Mn — composition, equivalents and standards" description: "U71Mn: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/u71mn language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/u71mn.md cs: https://steelequivalents.com/cs/materiály/gb/u71mn.md de: https://steelequivalents.com/de/werkstoffe/gb/u71mn.md es: https://steelequivalents.com/es/materiales/gb/u71mn.md fr: https://steelequivalents.com/fr/matériaux/gb/u71mn.md hu: https://steelequivalents.com/hu/anyagok/gb/u71mn.md it: https://steelequivalents.com/it/materiali/gb/u71mn.md nl: https://steelequivalents.com/nl/materialen/gb/u71mn.md pl: https://steelequivalents.com/pl/materiały/gb/u71mn.md pt: https://steelequivalents.com/pt/materiais/gb/u71mn.md ru: https://steelequivalents.com/ru/материалы/gb/u71mn.md tr: https://steelequivalents.com/tr/malzemeler/gb/u71mn.md zh: https://steelequivalents.com/zh/材料/gb/u71mn.md ja: https://steelequivalents.com/ja/材料/gb/u71mn.md ar: https://steelequivalents.com/ar/المواد/gb/u71mn.md ko: https://steelequivalents.com/ko/재료/gb/u71mn.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/u71mn.md hi: https://steelequivalents.com/hi/सामग्री/gb/u71mn.md content_hash: sha256:41e877cf2b59d25d31d79215d06d93bbd4be7d78e831ad1b7d238cffc24987e8 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/u71mn > Canonical URL: https://steelequivalents.com/materials/gb/u71mn > 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 # U71Mn U71Mn is a grade designated under GB. Its recorded composition includes C 0.6–0.8%, Si 0.15–0.58%, Cr ≤ 0.15%, Mn 0.7–1.2% and Cu ≤ 0.15%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm ≥ 880 N/mm², A ≥ 10% and HB 260–300. - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=3e9b789a-3c08-41e3-82e0-185336e85162&designation=e972a876-cdfa-48ee-b4ca-15ecbf0a29d1 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/u71mn.pdf "Datasheet as PDF") ## Chemical composition 15 elements on file · weight % What this alloy is Fe Mn C Si Iron — the balance, never listed by a standard — 97.4 % Mn — 1 % C — 0.7 % Si — 0.4 % Traces & impurities · 0.6 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.6–0.8 | | Si | 0.15–0.58 | | Mn | 0.7–1.2 | | P | ≤ 0.025 | | S | ≤ 0.025 | | Cr | ≤ 0.15 | | Mo | ≤ 0.02 | | Ni | ≤ 0.1 | | V | ≤ 0.03 | | Cu | ≤ 0.15 | | Al | ≤ 0.004 | | Ti | ≤ 0.025 | | Nb | ≤ 0.01 | | Sn | ≤ 0.03 | | Sb | ≤ 0.02 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Vanadium Copper Aluminium Titanium Niobium Tin Antimony 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 | 0.6-0.8 | 0.600 | 0.800 | Range | | Al | ≤0.004 | — | 0.004 | Max | | Si | 0.15-0.58 | 0.150 | 0.580 | Range | | P | ≤0.025 | — | 0.025 | Max | | S | ≤0.025 | — | 0.025 | Max | | Ti | ≤0.025 | — | 0.025 | Max | | V | ≤0.03 | — | 0.030 | Max | | Cr | ≤0.15 | — | 0.150 | Max | | Mn | 0.7-1.2 | 0.700 | 1.200 | Range | | Ni | ≤0.1 | — | 0.100 | Max | | Cu | ≤0.15 | — | 0.150 | Max | | Nb | ≤0.01 | — | 0.010 | Max | | Mo | ≤0.02 | — | 0.020 | Max | | Sn | ≤0.03 | — | 0.030 | Max | | Sb | ≤0.02 | — | 0.020 | 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 This grade's composition falls outside the published model's validated range (a low-alloy composition window), so no transformation temperature is predicted here. ## 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 3 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. ## 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=3e9b789a-3c08-41e3-82e0-185336e85162&designation=e972a876-cdfa-48ee-b4ca-15ecbf0a29d1 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/u71mn.pdf "Datasheet as PDF")