--- title: "ML25B — composition, equivalents and standards" description: "ML25B: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/ml25b language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/ml25b.md cs: https://steelequivalents.com/cs/materiály/gb/ml25b.md de: https://steelequivalents.com/de/werkstoffe/gb/ml25b.md es: https://steelequivalents.com/es/materiales/gb/ml25b.md fr: https://steelequivalents.com/fr/matériaux/gb/ml25b.md hu: https://steelequivalents.com/hu/anyagok/gb/ml25b.md it: https://steelequivalents.com/it/materiali/gb/ml25b.md nl: https://steelequivalents.com/nl/materialen/gb/ml25b.md pl: https://steelequivalents.com/pl/materiały/gb/ml25b.md pt: https://steelequivalents.com/pt/materiais/gb/ml25b.md ru: https://steelequivalents.com/ru/материалы/gb/ml25b.md tr: https://steelequivalents.com/tr/malzemeler/gb/ml25b.md zh: https://steelequivalents.com/zh/材料/gb/ml25b.md ja: https://steelequivalents.com/ja/材料/gb/ml25b.md ar: https://steelequivalents.com/ar/المواد/gb/ml25b.md ko: https://steelequivalents.com/ko/재료/gb/ml25b.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/ml25b.md hi: https://steelequivalents.com/hi/सामग्री/gb/ml25b.md content_hash: sha256:e2b0308fea8f895d19c945e1cba7875bc903b761aae31a8d5b75fa093fca1ab1 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/gb/ml25b > Canonical URL: https://steelequivalents.com/materials/gb/ml25b > 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 # ML25B ML25B is a grade designated under GB. Its recorded composition includes C 0.23–0.28%, Si 0.1–0.3%, P ≤ 0.025%, S ≤ 0.025% and Mn 0.6–0.9%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm ≤ 520 N/mm². - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=f99f865f-b85f-4138-8f86-d8a1ec26ed48&designation=38f24c98-054d-49a4-80ba-6efb186267b3 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/ml25b.pdf "Datasheet as PDF") ## Chemical composition 7 elements on file · weight % What this alloy is Fe Mn C Si Iron — the balance, never listed by a standard — 98.7 % Mn — 0.8 % C — 0.3 % Si — 0.2 % Traces & impurities · 0.1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.23–0.28 | | Si | 0.1–0.3 | | Mn | 0.6–0.9 | | P | ≤ 0.025 | | S | ≤ 0.025 | | Al | ≥ 0.02 | | B | 0.0008–0.0035 | Carbon Silicon Manganese Phosphorus Sulfur Aluminium Boron 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 | |---|---|---|---|---| | B | 0.0008-0.0035 | 0.001 | 0.004 | Range | | C | 0.23-0.28 | 0.230 | 0.280 | Range | | Al | ≥0.02 | 0.020 | — | Min | | Si | 0.1-0.3 | 0.100 | 0.300 | Range | | P | ≤0.025 | — | 0.025 | Max | | S | ≤0.025 | — | 0.025 | Max | | Mn | 0.6-0.9 | 0.600 | 0.900 | 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 Not enough recorded composition to predict a transformation temperature for this grade — missing: Ni, Cr, Mo. ## Physical & mechanical properties Rm ≤520 N/mm² Max 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=f99f865f-b85f-4138-8f86-d8a1ec26ed48&designation=38f24c98-054d-49a4-80ba-6efb186267b3 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/ml25b.pdf "Datasheet as PDF")