--- title: "55Si2MnB — composition, equivalents and standards" description: "55Si2MnB: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/gb/55si2mnb language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/55si2mnb.md cs: https://steelequivalents.com/cs/materiály/gb/55si2mnb.md de: https://steelequivalents.com/de/werkstoffe/gb/55si2mnb.md es: https://steelequivalents.com/es/materiales/gb/55si2mnb.md fr: https://steelequivalents.com/fr/matériaux/gb/55si2mnb.md hu: https://steelequivalents.com/hu/anyagok/gb/55si2mnb.md it: https://steelequivalents.com/it/materiali/gb/55si2mnb.md nl: https://steelequivalents.com/nl/materialen/gb/55si2mnb.md pl: https://steelequivalents.com/pl/materiały/gb/55si2mnb.md pt: https://steelequivalents.com/pt/materiais/gb/55si2mnb.md ru: https://steelequivalents.com/ru/материалы/gb/55si2mnb.md tr: https://steelequivalents.com/tr/malzemeler/gb/55si2mnb.md zh: https://steelequivalents.com/zh/材料/gb/55si2mnb.md ja: https://steelequivalents.com/ja/材料/gb/55si2mnb.md ar: https://steelequivalents.com/ar/المواد/gb/55si2mnb.md ko: https://steelequivalents.com/ko/재료/gb/55si2mnb.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/55si2mnb.md hi: https://steelequivalents.com/hi/सामग्री/gb/55si2mnb.md content_hash: sha256:5361736addd51f7a940c84c439bd287d2ff06521f1aa7c24c88469eab4bf7569 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/55si2mnb > Canonical URL: https://steelequivalents.com/materials/gb/55si2mnb > 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 # 55Si2MnB 55Si2MnB is a grade designated under GB. Its recorded composition includes C 0.52–0.6%, Si 1.5–2%, Cr ≤ 0.35%, Mn 0.6–0.9% and Ni ≤ 0.35%. No cross-standard equivalents are recorded for this grade yet. Recorded mechanical properties include Rm ≥ 1274 N/mm², Re ≥ 1176 N/mm², A ≥ 6% and HB 321. - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=d63ea469-fe1f-4d01-90bf-8983804c96c7&designation=3fe8f67a-e275-40ee-a696-c2208ba465d4 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/55si2mnb.pdf "Datasheet as PDF") ## Chemical composition 9 elements on file · weight % What this alloy is Fe Si Mn C Iron — the balance, never listed by a standard — 95.9 % Si — 1.8 % Mn — 0.8 % C — 0.6 % Traces & impurities · 1 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.52–0.6 | | Si | 1.5–2 | | Mn | 0.6–0.9 | | P | ≤ 0.035 | | S | ≤ 0.035 | | Cr | ≤ 0.35 | | Ni | ≤ 0.35 | | Cu | ≤ 0.25 | | B | 0.0005–0.004 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel Copper 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 | 0.0005-0.004 | 0.001 | 0.004 | Range | | C | 0.52-0.6 | 0.520 | 0.600 | Range | | Si | 1.5-2 | 1.500 | 2.000 | Range | | P | ≤0.035 | — | 0.035 | Max | | S | ≤0.035 | — | 0.035 | Max | | Cr | ≤0.35 | — | 0.350 | Max | | Mn | 0.6-0.9 | 0.600 | 0.900 | Range | | Ni | ≤0.35 | — | 0.350 | Max | | Cu | ≤0.25 | — | 0.250 | 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 Not enough recorded composition to predict a transformation temperature for this grade — missing: Mo. ## 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 - Quenching and Tempering Wire and As-rolled 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/azhlNWIxODUyNA__ "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=d63ea469-fe1f-4d01-90bf-8983804c96c7&designation=3fe8f67a-e275-40ee-a696-c2208ba465d4 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/55si2mnb.pdf "Datasheet as PDF")