--- title: "ML45CrMo — composition, equivalents and standards" description: "ML45CrMo is a designation in GB for the grade also listed as 4145. We list 3 designations recorded for this grade, in the standards ASTM, JIS and GB." canonical: https://steelequivalents.com/materials/gb/ml45crmo language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/gb/ml45crmo.md cs: https://steelequivalents.com/cs/materiály/gb/ml45crmo.md de: https://steelequivalents.com/de/werkstoffe/gb/ml45crmo.md es: https://steelequivalents.com/es/materiales/gb/ml45crmo.md fr: https://steelequivalents.com/fr/matériaux/gb/ml45crmo.md hu: https://steelequivalents.com/hu/anyagok/gb/ml45crmo.md it: https://steelequivalents.com/it/materiali/gb/ml45crmo.md nl: https://steelequivalents.com/nl/materialen/gb/ml45crmo.md pl: https://steelequivalents.com/pl/materiały/gb/ml45crmo.md pt: https://steelequivalents.com/pt/materiais/gb/ml45crmo.md ru: https://steelequivalents.com/ru/материалы/gb/ml45crmo.md tr: https://steelequivalents.com/tr/malzemeler/gb/ml45crmo.md zh: https://steelequivalents.com/zh/材料/gb/ml45crmo.md ja: https://steelequivalents.com/ja/材料/gb/ml45crmo.md ar: https://steelequivalents.com/ar/المواد/gb/ml45crmo.md ko: https://steelequivalents.com/ko/재료/gb/ml45crmo.md pt-br: https://steelequivalents.com/pt-br/materiais/gb/ml45crmo.md hi: https://steelequivalents.com/hi/सामग्री/gb/ml45crmo.md content_hash: sha256:44b0682f6d7d8b88cd0860ce6080f7e149e40102779883738d8ccdce6d0764d8 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/ml45crmo > Canonical URL: https://steelequivalents.com/materials/gb/ml45crmo > 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 · 3 designations # ML45CrMo ML45CrMo is a designation in GB for the grade also listed as 4145. We list 3 designations recorded for this grade, in the standards ASTM, JIS and GB. - *Designations* **3** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=1cdb8707-dda1-4548-b037-b6ffbeed4386&designation=72a0f8d8-2d73-4b44-9162-ca4282ecf6b9 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/ml45crmo.pdf "Datasheet as PDF") ## Also known as 3 designations · 3 standards · nothing hidden This grade’s own name recorded in our sources as this grade’s own designation under that standard. Indicative taken from a published cross-reference table; a close match, not a guarantee of interchangeability. Verify against the mill certificate before ordering. Withdrawn designation no longer current — a separate column from the two above, so a name can be same grade and withdrawn at once. ASTM United States · 1 - [4145 Indicative](/materials/aisi-sae/4145 "ASTM 4145") JIS Japan · 1 - [SCM445 Indicative](/materials/jis/scm445 "JIS SCM445") GB China · 1 - **ML45CrMo This grade’s own name** Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 7 elements on file · weight % What this alloy is Fe Cr Mn C Iron — the balance, never listed by a standard — 97.3 % Cr — 1.1 % Mn — 0.8 % C — 0.5 % Traces & impurities · 0.5 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.43–0.48 | | Si | 0.1–0.3 | | Mn | 0.6–0.9 | | P | ≤ 0.025 | | S | ≤ 0.025 | | Cr | 0.9–1.2 | | Mo | 0.15–0.3 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum 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 | 0.43-0.48 | 0.430 | 0.480 | Range | | Si | 0.1-0.3 | 0.100 | 0.300 | Range | | P | ≤0.025 | — | 0.025 | Max | | S | ≤0.025 | — | 0.025 | Max | | Cr | 0.9-1.2 | 0.900 | 1.200 | Range | | Mn | 0.6-0.9 | 0.600 | 0.900 | Range | | Mo | 0.15-0.3 | 0.150 | 0.300 | 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. ## 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. ## 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=1cdb8707-dda1-4548-b037-b6ffbeed4386&designation=72a0f8d8-2d73-4b44-9162-ca4282ecf6b9 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/gb/ml45crmo.pdf "Datasheet as PDF")