--- title: "K91560 — High-temperature steels" description: "K91560 in UNS: material number 1.4903, also listed as X10CrMoVNb9-1. Category: High-temperature steels. Designations recorded for this grade: 13." canonical: https://steelequivalents.com/materials/uns/k91560 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/uns/k91560.md cs: https://steelequivalents.com/cs/materiály/uns/k91560.md de: https://steelequivalents.com/de/werkstoffe/uns/k91560.md es: https://steelequivalents.com/es/materiales/uns/k91560.md fr: https://steelequivalents.com/fr/matériaux/uns/k91560.md hu: https://steelequivalents.com/hu/anyagok/uns/k91560.md it: https://steelequivalents.com/it/materiali/uns/k91560.md nl: https://steelequivalents.com/nl/materialen/uns/k91560.md pl: https://steelequivalents.com/pl/materiały/uns/k91560.md pt: https://steelequivalents.com/pt/materiais/uns/k91560.md ru: https://steelequivalents.com/ru/материалы/uns/k91560.md tr: https://steelequivalents.com/tr/malzemeler/uns/k91560.md zh: https://steelequivalents.com/zh/材料/uns/k91560.md ja: https://steelequivalents.com/ja/材料/uns/k91560.md ar: https://steelequivalents.com/ar/المواد/uns/k91560.md ko: https://steelequivalents.com/ko/재료/uns/k91560.md pt-br: https://steelequivalents.com/pt-br/materiais/uns/k91560.md hi: https://steelequivalents.com/hi/सामग्री/uns/k91560.md content_hash: sha256:653f228fe55882939c83dc386829b4fc590add1980ed7de6931397ba74b2ab70 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/uns/k91560 > Canonical URL: https://steelequivalents.com/materials/uns/k91560 > 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. UNS · United States · 13 designations # K91560 K91560 is a designation in UNS for the material held under material number 1.4903, also listed as X10CrMoVNb9-1. It is a material in the category High-temperature steels. We list 13 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM and PN. - [*Material no.* **1.4903**](/materials/material-no/1.4903 "Material no.: 1.4903") - [*Category* **High-temperature steels · 40 grades**](/categories/high-temperature-steels "Category: High-temperature steels · 40 grades") - *Designations* **13** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=d1ccb659-a7c8-49f7-9d0c-0851c860f0a2&designation=3db7ef36-a8cd-4247-a9a7-f5cb008bfc8f "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/uns/k91560.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X10CrMoVNb9-1 This grade’s own name](/materials/din-en/x10crmovnb9-1 "DIN / EN X10CrMoVNb9-1") - [UNS K90901 This grade’s own name](/materials/uns/k90901 "UNS K90901") - [ASTM A 182 F 9 This grade’s own name · 2 grades on that route](/materials/astm/a-182-f-9 "ASTM A 182 F 9") ## About High-temperature steels High-temperature steels are steels designed to retain useful strength and structural stability during exposure to elevated temperatures. Their alloying systems provide resistance to oxidation, creep and loss of mechanical properties during prolonged heating, making them suitable for furnace components, heat exchangers, boilers and other hot-service equipment. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 13 designations · 5 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 · 2 - [1.4903 Indicative](/materials/material-no/1.4903 "DIN / EN 1.4903") - [X10CrMoVNb9-1 This grade’s own name](/materials/din-en/x10crmovnb9-1 "DIN / EN X10CrMoVNb9-1") UNS United States · 3 - [K90901 This grade’s own name](/materials/uns/k90901 "UNS K90901") - **K91560 This grade’s own name** - [S59180 This grade’s own name](/materials/uns/s59180 "UNS S59180") AISI / SAE United States · 3 - [F91 Indicative](/materials/aisi-sae/f91 "AISI / SAE F91") - [P91 Indicative](/materials/csn/p91 "AISI / SAE P91") - [T91 Indicative](/materials/aisi-sae/t91 "AISI / SAE T91") ASTM United States · 4 - [A 182 F 9 This grade’s own name](/materials/astm/a-182-f-9 "ASTM A 182 F 9") - [A 182 Grade F91 Indicative](/materials/astm/a-182-grade-f91 "ASTM A 182 Grade F91") - [A 234 Grade WP91 Indicative](/materials/astm/a-234-grade-wp91 "ASTM A 234 Grade WP91") - [A 335 Grade P91 Indicative](/materials/astm/a-335-grade-p91 "ASTM A 335 Grade P91") PN Poland · 1 - [X10CrMoVNb91 Indicative](/materials/din-en/x10crmovnb9-1 "PN X10CrMoVNb91") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 13 elements on file · weight % What this alloy is Fe Cr Mo Si Iron — the balance, never listed by a standard — 88.1 % Cr — 8.8 % Mo — 1 % Si — 0.5 % Traces & impurities · 1.7 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.08–0.12 | | Si | ≤ 0.5 | | Mn | 0.3–0.6 | | P | 0.025 | | S | 0.015 | | Cr | 8–9.5 | | Mo | 0.85–1.05 | | Ni | 0.4 | | V | 0.18–0.25 | | Cu | ≤ 0.3 | | Al | ≤ 0.04 | | Nb | 0.06–0.1 | | N | 0.03–0.07 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Nickel Vanadium Copper Aluminium Niobium Nitrogen 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 | 0,08-0,12 | 0.080 | 0.120 | Range | | N | 0,030-0,070 | 0.030 | 0.070 | Range | | Al | ≤0,040 | — | 0.040 | Max | | Si | ≤0,50 | — | 0.500 | Max | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | V | 0,18-0,25 | 0.180 | 0.250 | Range | | Cr | 8,00-9,50 | 8.000 | 9.500 | Range | | Mn | 0,30-0,60 | 0.300 | 0.600 | Range | | Ni | 0,4 | 0.400 | 0.400 | Exact | | Cu | ≤0,30 | — | 0.300 | Max | | Nb | 0,06-0,10 | 0.060 | 0.100 | Range | | Mo | 0,85-1,05 | 0.850 | 1.050 | 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 This grade's composition falls outside the published model's validated range (a low-alloy composition window), so no transformation temperature is predicted here. ## Physical & mechanical properties Density 7,76 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. ## Properties by condition 1 conditions · 5 values By thickness**no delivery state stated** source `steelnumber` | Thickness mm | ReH N/mm² | Rm N/mm² | |---|---|---| | ≤ 60 | 445 | 580 – 760 | | 60 – 150 | — | 550 – 730 | | 60 – 250 | 435 | — | | 150 – 250 | — | 520 – 700 | Every figure holds only for the condition on its own row. Values are never merged across conditions or across sources, never averaged, and never interpolated between two rows. An em dash means no value on file — never zero. Figures are converted to the unit in the column header; the source’s own wording is kept and shown where the two differ. ## 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=d1ccb659-a7c8-49f7-9d0c-0851c860f0a2&designation=3db7ef36-a8cd-4247-a9a7-f5cb008bfc8f "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/uns/k91560.pdf "Datasheet as PDF")