--- title: "1.4551 — Stainless steels" description: "1.4551 is the material number of the grade also listed as X5CrNiNb19-9. Category: Stainless steels. Designations recorded for this grade: 10." canonical: https://steelequivalents.com/materials/material-no/1.4551 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/material-no/1.4551.md cs: https://steelequivalents.com/cs/materiály/číslo-materiálu/1.4551.md de: https://steelequivalents.com/de/werkstoffe/werkstoff-nr/1.4551.md es: https://steelequivalents.com/es/materiales/número-de-material/1.4551.md fr: https://steelequivalents.com/fr/matériaux/numéro-de-matériau/1.4551.md hu: https://steelequivalents.com/hu/anyagok/anyagszám/1.4551.md it: https://steelequivalents.com/it/materiali/numero-materiale/1.4551.md nl: https://steelequivalents.com/nl/materialen/materiaalnummer/1.4551.md pl: https://steelequivalents.com/pl/materiały/numer-materiału/1.4551.md pt: https://steelequivalents.com/pt/materiais/número-do-material/1.4551.md ru: https://steelequivalents.com/ru/материалы/номер-материала/1.4551.md tr: https://steelequivalents.com/tr/malzemeler/malzeme-numarası/1.4551.md zh: https://steelequivalents.com/zh/材料/材料编号/1.4551.md ja: https://steelequivalents.com/ja/材料/材料番号/1.4551.md ar: https://steelequivalents.com/ar/المواد/رقم-المادة/1.4551.md ko: https://steelequivalents.com/ko/재료/재료번호/1.4551.md pt-br: https://steelequivalents.com/pt-br/materiais/número-do-material/1.4551.md hi: https://steelequivalents.com/hi/सामग्री/सामग्री-संख्या/1.4551.md content_hash: sha256:099b17341429fe060ed1d9d063cf79230cbcda78e6065016e4b66d65fded8f70 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/material-no/1.4551 > Canonical URL: https://steelequivalents.com/materials/material-no/1.4551 > 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. Material number · Europe · 10 designations # 1.4551 1.4551 is the material number of the grade also listed as X5CrNiNb19-9. It is a material in the category Stainless steels. We list 10 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, AFNOR, JIS and ČSN. - ***Material no.* **1.4551**** - [*Category* **Stainless steels · 468 grades**](/categories/stainless-steels "Category: Stainless steels · 468 grades") - *Designations* **10** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=f35266e2-b9e7-433d-907e-c16d37935df1 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/material-no/1.4551.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X5CrNiNb19-9 This grade’s own name](/materials/din-en/x5crninb19-9 "DIN / EN X5CrNiNb19-9") - [UNS S34780 This grade’s own name](/materials/uns/s34780 "UNS S34780") ## About Stainless steels Stainless steels are corrosion-resistant alloy steels whose chromium content promotes a protective passive surface film. They are used for equipment, structures and components exposed to moisture, chemicals or hygienic service, with different alloy compositions selected for corrosion resistance, strength, formability or weldability. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 10 designations · 6 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 - [X5CrNiNb19-9 This grade’s own name](/materials/din-en/x5crninb19-9 "DIN / EN X5CrNiNb19-9") UNS United States · 3 - [S34780 This grade’s own name](/materials/uns/s34780 "UNS S34780") - [S34781 This grade’s own name](/materials/uns/s34781 "UNS S34781") - [S34788 This grade’s own name](/materials/uns/s34788 "UNS S34788") AISI / SAE United States · 3 - [S347780 Indicative](/materials/aisi-sae/s347780 "AISI / SAE S347780") - [S34781 Indicative](/materials/uns/s34781 "AISI / SAE S34781") - [S34788 Indicative](/materials/uns/s34788 "AISI / SAE S34788") AFNOR France · 1 - [Z6CNNb20-10 Indicative](/materials/afnor/z6cnnb20-10 "AFNOR Z6CNNb20-10") JIS Japan · 1 - [SUS Y 347 Indicative](/materials/jis/susy347 "JIS SUS Y 347") ČSN Czechia · 1 - [S 07 Cr20Ni10Nb1 Indicative](/materials/csn/s-07-cr20ni10nb1 "ČSN S 07 Cr20Ni10Nb1") 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 Ni Mn Iron — the balance, never listed by a standard — 68.6 % Cr — 19 % Ni — 9 % Mn — 1.9 % Traces & impurities · 1.5 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.06 | | Si | ≤ 1.4 | | Mn | ≤ 1.9 | | P | 0.025 | | S | 0.015 | | Cr | 18.2–19.8 | | Ni | 8.2–9.8 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel 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 | ≤0,06 | — | 0.060 | Max | | Si | ≤1,40 | — | 1.400 | Max | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Cr | 18,2-19,8 | 18.200 | 19.800 | Range | | Mn | ≤1,90 | — | 1.900 | Max | | Ni | 8,20-9,80 | 8.200 | 9.800 | Range | - ≥(12xC)≤1,15 - ≥(12xC)≤1,15 - ≥(12xC)≤1,15 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 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 1.4, a shared category, and a published range for Cr / Ni 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. [X5CrNiN19-9 1.4315 Cr 18,0-20,0 · Ni 8,00-11,0 - ΔCr 0.00 - ΔNi 0.50 - 26 designations](/materials/din-en/x5crnin19-9 "X5CrNiN19-9")[1.4301 1.4301 Cr 17,5-19,5 · Ni 8,00-10,5 - ΔCr 0.50 - ΔNi 0.25 - 170 designations](/materials/material-no/1.4301 "1.4301")[1.4307 1.4307 Cr 17,5-19,5 · Ni 8,00-10,5 - ΔCr 0.50 - ΔNi 0.25 - 88 designations](/materials/material-no/1.4307 "1.4307")[X 12 CrNi 18 8 1.4300 Cr 17,0-19,0 · Ni 8,00-10,0 - ΔCr 1.00 - ΔNi 0.00 - 76 designations](/materials/din-en/x-12-crni-18-8 "X 12 CrNi 18 8")[1.4305 1.4305 Cr 17,0-19,0 · Ni 8,00-10,0 - ΔCr 1.00 - ΔNi 0.00 - 77 designations](/materials/material-no/1.4305 "1.4305")[X9CrNi18-9 1.4325 Cr 17,0-19,0 · Ni 8,00-10,0 - ΔCr 1.00 - ΔNi 0.00 - 51 designations](/materials/din-en/x9crni18-9 "X9CrNi18-9") ## 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=f35266e2-b9e7-433d-907e-c16d37935df1 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/material-no/1.4551.pdf "Datasheet as PDF")