--- title: "A 105 — Heat-resistant structural steels" description: "A 105: 2 equivalent designations across 2 standards, with the recorded chemical composition shown next to the source text." canonical: https://steelequivalents.com/materials/din-en/a105 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/din-en/a105.md cs: https://steelequivalents.com/cs/materiály/din-en/a105.md de: https://steelequivalents.com/de/werkstoffe/din-en/a105.md es: https://steelequivalents.com/es/materiales/din-en/a105.md fr: https://steelequivalents.com/fr/matériaux/din-en/a105.md hu: https://steelequivalents.com/hu/anyagok/din-en/a105.md it: https://steelequivalents.com/it/materiali/din-en/a105.md nl: https://steelequivalents.com/nl/materialen/din-en/a105.md pl: https://steelequivalents.com/pl/materiały/din-en/a105.md pt: https://steelequivalents.com/pt/materiais/din-en/a105.md ru: https://steelequivalents.com/ru/материалы/din-en/a105.md tr: https://steelequivalents.com/tr/malzemeler/din-en/a105.md zh: https://steelequivalents.com/zh/材料/din-en/a105.md ja: https://steelequivalents.com/ja/材料/din-en/a105.md ar: https://steelequivalents.com/ar/المواد/din-en/a105.md ko: https://steelequivalents.com/ko/재료/din-en/a105.md pt-br: https://steelequivalents.com/pt-br/materiais/din-en/a105.md hi: https://steelequivalents.com/hi/सामग्री/din-en/a105.md content_hash: sha256:a51057767ce713d69b03748887418e081515bda28ad8fdea848b070fde99e2c0 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/din-en/a105 > Canonical URL: https://steelequivalents.com/materials/din-en/a105 > 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 · 2 designations # A 105 A 105 is a material in the category [Heat-resistant structural steels](/categories/heat-resistant-structural-steels "Heat-resistant structural steels"), held under material number 1.9443. Its recorded composition includes C ≤ 0.35%, Si 0.1–0.35%, Mn 0.6–1.05%, Ni 0.4% and Cu ≤ 0.4%. We list one designation recorded for this grade, in the standard UNS. Its recorded density is 7.85 g/cm³. - [*Material no.* **1.9443**](/materials/material-no/1.9443 "Material no.: 1.9443") - [*Category* **Heat-resistant structural steels · 62 grades**](/categories/heat-resistant-structural-steels "Category: Heat-resistant structural steels · 62 grades") - *Designations* **2** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=9825c1e5-08a4-4a2d-b7f2-4baf02697520&designation=120643de-d5d5-45d3-827b-9e78ac0c27cf "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/a105.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. ## Also known as 2 designations · 2 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. DIN / EN Europe · 1 - **A 105 Indicative** UNS United States · 1 - [K03504 Indicative](/materials/uns/k03504 "UNS K03504") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 11 elements on file · weight % What this alloy is Fe Mn Ni Cu Iron — the balance, never listed by a standard — 97.2 % Mn — 0.8 % Ni — 0.4 % Cu — 0.4 % Traces & impurities · 1.2 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.35 | | Si | 0.1–0.35 | | Mn | 0.6–1.05 | | P | 0.035 | | S | 0.04 | | Cr | ≤ 0.3 | | Mo | ≤ 0.12 | | Ni | 0.4 | | V | ≤ 0.08 | | Cu | ≤ 0.4 — Unusual | | Nb | ≤ 0.02 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Vanadium Copper Niobium 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 | ≤0,35 | — | 0.350 | Max | | Si | 0,10-0,35 | 0.100 | 0.350 | Range | | P | 0,035 | 0.035 | 0.035 | Exact | | S | 0,04 | 0.040 | 0.040 | Exact | | V | ≤0,08 | — | 0.080 | Max | | Cr | ≤0,30 | — | 0.300 | Max | | Mn | 0,60-1,05 | 0.600 | 1.050 | Range | | Ni | 0,4 | 0.400 | 0.400 | Exact | | Cu | ≤0,40 | — | 0.400 | Max | | Nb | ≤0,02 | — | 0.020 | Max | | Mo | ≤0,12 | — | 0.120 | Max | - (Cu+Ni+Cr+Mo+V)≤1,00; (Cr+Mo)≤0,32 - (Cu+Ni+Cr+Mo+V)≤1,00; (Cr+Mo)≤0,32 - (Cu+Ni+Cr+Mo+V)≤1,00; (Cr+Mo)≤0,32 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 785 °C Predicted Ae1 717 °C Predicted Acm 543 °C Predicted Bs 559 °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. ## 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=9825c1e5-08a4-4a2d-b7f2-4baf02697520&designation=120643de-d5d5-45d3-827b-9e78ac0c27cf "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/din-en/a105.pdf "Datasheet as PDF")