--- title: "G18Mo5 — Heat-resistant structural steels" description: "G18Mo5: 1 equivalent designations across 1 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/din-en/g18mo5 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/g18mo5.md cs: https://steelequivalents.com/cs/materiály/din-en/g18mo5.md de: https://steelequivalents.com/de/werkstoffe/din-en/g18mo5.md es: https://steelequivalents.com/es/materiales/din-en/g18mo5.md fr: https://steelequivalents.com/fr/matériaux/din-en/g18mo5.md hu: https://steelequivalents.com/hu/anyagok/din-en/g18mo5.md it: https://steelequivalents.com/it/materiali/din-en/g18mo5.md nl: https://steelequivalents.com/nl/materialen/din-en/g18mo5.md pl: https://steelequivalents.com/pl/materiały/din-en/g18mo5.md pt: https://steelequivalents.com/pt/materiais/din-en/g18mo5.md ru: https://steelequivalents.com/ru/материалы/din-en/g18mo5.md tr: https://steelequivalents.com/tr/malzemeler/din-en/g18mo5.md zh: https://steelequivalents.com/zh/材料/din-en/g18mo5.md ja: https://steelequivalents.com/ja/材料/din-en/g18mo5.md ar: https://steelequivalents.com/ar/المواد/din-en/g18mo5.md ko: https://steelequivalents.com/ko/재료/din-en/g18mo5.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/g18mo5.md hi: https://steelequivalents.com/hi/सामग्री/din-en/g18mo5.md content_hash: sha256:271c952c367a85d05713685d24655a08d286e0d3121b2e6250e494848aeb30ff 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/din-en/g18mo5 > Canonical URL: https://steelequivalents.com/materials/din-en/g18mo5 > 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. DIN / EN · Europe · 1 designation # G18Mo5 G18Mo5 is a material in the category [Heat-resistant structural steels](/categories/heat-resistant-structural-steels "Heat-resistant structural steels"), held under material number 1.5422. Its recorded composition includes C 0.15–0.2%, Si ≤ 0.6%, Mn 0.8–1.2%, Ni 0.4% and Mo 0.45–0.65%. No cross-standard equivalents are recorded for this grade yet. Its recorded density is 7.85 g/cm³. - [*Material no.* **1.5422**](/materials/material-no/1.5422 "Material no.: 1.5422") - [*Category* **Heat-resistant structural steels · 62 grades**](/categories/heat-resistant-structural-steels "Category: Heat-resistant structural steels · 62 grades") - *Designations* **1** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=7c5f6568-7376-4e3d-be11-328ffaab6112&designation=99400687-e308-4c19-a921-e5cc6b15c84c "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/g18mo5.pdf "Datasheet as PDF") ## About Heat-resistant structural steels Heat-resistant structural steels are structural steels designed to retain useful strength and dimensional stability at elevated temperatures. They are used for load-bearing components in hot-service equipment where mechanical performance must be maintained during heating. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Chemical composition 10 elements on file · weight % What this alloy is Fe Mn Si Mo Iron — the balance, never listed by a standard — 96.6 % Mn — 1 % Si — 0.6 % Mo — 0.6 % Traces & impurities · 1.3 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.15–0.2 | | Si | ≤ 0.6 | | Mn | 0.8–1.2 | | P | 0.02 | | S | 0.02 | | Cr | ≤ 0.3 | | Mo | 0.45–0.65 | | Ni | 0.4 | | V | ≤ 0.05 | | Cu | ≤ 0.3 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Vanadium 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 | 0,15-0,20 | 0.150 | 0.200 | Range | | Si | ≤0,60 | — | 0.600 | Max | | P | 0,02 | 0.020 | 0.020 | Exact | | S | 0,02 | 0.020 | 0.020 | Exact | | V | ≤0,05 | — | 0.050 | Max | | Cr | ≤0,30 | — | 0.300 | Max | | Mn | 0,80-1,20 | 0.800 | 1.200 | Range | | Ni | 0,4 | 0.400 | 0.400 | Exact | | Cu | ≤0,30 | — | 0.300 | Max | | Mo | 0,45-0,65 | 0.450 | 0.650 | 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 computed from composition · °C Predicted Ae3 821 °C Predicted Ae1 721 °C Predicted Acm 441 °C Predicted Bs 541 °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 Density 7,85 g/cm³ Exact 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. ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.5, a shared category, and a published range for Mn / Mo that overlaps this grade’s. These are neighbours in composition space — they are not equivalents, and none is claimed to be interchangeable with this grade. [11MnMo4-5 1.5425 Mn 0,85-1,15 · Mo 0,48-0,62 - ΔMn 0.00 - ΔMo 0.00 - 5 designations](/materials/din-en/11mnmo4-5 "11MnMo4-5")[10MnMo4-5 1.5424 Mn 0,95-1,25 · Mo 0,48-0,62 - ΔMn 0.10 - ΔMo 0.00 - 1 designations](/materials/din-en/10mnmo4-5 "10MnMo4-5")[15MnMoV4-5 1.5402 Mn 0,90-1,40 · Mo 0,40-0,60 - ΔMn 0.15 - ΔMo 0.05 - 1 designations](/materials/din-en/15mnmov4-5 "15MnMoV4-5")[20MnMo3-5 1.5421 Mn 0,70-1,00 · Mo 0,40-0,60 - ΔMn 0.15 - ΔMo 0.05 - 3 designations](/materials/din-en/20mnmo3-5 "20MnMo3-5")[18MnMo4-5 1.5414 Mn 0,90-1,50 · Mo 0,45-0,60 - ΔMn 0.20 - ΔMo 0.03 - 4 designations](/materials/din-en/18mnmo4-5 "18MnMo4-5")[10MnMoCrV4-7 1.5407 Mn 0,70-1,10 · Mo 0,50-1,00 - ΔMn 0.10 - ΔMo 0.20 - 1 designations](/materials/din-en/10mnmocrv4-7 "10MnMoCrV4-7") ## 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=7c5f6568-7376-4e3d-be11-328ffaab6112&designation=99400687-e308-4c19-a921-e5cc6b15c84c "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/g18mo5.pdf "Datasheet as PDF")