--- title: "S145 — Special steels for aviation and aerospace" description: "S145 in BS: material number 1.4546, also listed as X5CrNiNb18-10. It is a material in the category Special steels for aviation and aerospace." canonical: https://steelequivalents.com/materials/bs/s145 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/bs/s145.md cs: https://steelequivalents.com/cs/materiály/bs/s145.md de: https://steelequivalents.com/de/werkstoffe/bs/s145.md es: https://steelequivalents.com/es/materiales/bs/s145.md fr: https://steelequivalents.com/fr/matériaux/bs/s145.md hu: https://steelequivalents.com/hu/anyagok/bs/s145.md it: https://steelequivalents.com/it/materiali/bs/s145.md nl: https://steelequivalents.com/nl/materialen/bs/s145.md pl: https://steelequivalents.com/pl/materiały/bs/s145.md pt: https://steelequivalents.com/pt/materiais/bs/s145.md ru: https://steelequivalents.com/ru/материалы/bs/s145.md tr: https://steelequivalents.com/tr/malzemeler/bs/s145.md zh: https://steelequivalents.com/zh/材料/bs/s145.md ja: https://steelequivalents.com/ja/材料/bs/s145.md ar: https://steelequivalents.com/ar/المواد/bs/s145.md ko: https://steelequivalents.com/ko/재료/bs/s145.md pt-br: https://steelequivalents.com/pt-br/materiais/bs/s145.md hi: https://steelequivalents.com/hi/सामग्री/bs/s145.md content_hash: sha256:1c0f26acb0e648a2900e1c1a2635af831578db85200bfb8e0e773fbc33769b88 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/bs/s145 > Canonical URL: https://steelequivalents.com/materials/bs/s145 > 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. BS · United Kingdom · 70 designations # S145 S145 is a designation in BS for the material held under material number 1.4546, also listed as X5CrNiNb18-10. It is a material in the category Special steels for aviation and aerospace. We list 70 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM, BS and SAE AMS. - [*Material no.* **1.4546**](/materials/material-no/1.4546 "Material no.: 1.4546") - [*Category* **Special steels for aviation and aerospace · 39 grades**](/categories/special-steels-for-aviation-and-aerospace "Category: Special steels for aviation and aerospace · 39 grades") - *Designations* **70** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=00eb1d6b-8bb4-4a92-81de-b1b031c067cf&designation=2a048c0c-0ddb-4477-9426-ad9e7596989a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/bs/s145.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X5CrNiNb18-10 This grade’s own name](/materials/din-en/x5crninb18-10 "DIN / EN X5CrNiNb18-10") - [UNS S34700 This grade’s own name · 3 grades on that route](/materials/uns/s34700 "UNS S34700") - [AISI / SAE 347 This grade’s own name · 4 grades on that route](/materials/aisi-sae/347 "AISI / SAE 347") ## About Special steels for aviation and aerospace Special steels for aviation and aerospace are engineered steels designed to provide controlled mechanical properties and reliable performance in demanding service. Their alloying and heat-treatment capabilities support components that require a combination of strength, toughness and fatigue resistance, including aircraft structures and engine parts. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 70 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 - [X5CrNiNb18-10 This grade’s own name](/materials/din-en/x5crninb18-10 "DIN / EN X5CrNiNb18-10") UNS United States · 3 - [S34700 This grade’s own name](/materials/uns/s34700 "UNS S34700") - [S34800 This grade’s own name](/materials/uns/s34800 "UNS S34800") - [S34809 This grade’s own name](/materials/uns/s34809 "UNS S34809") AISI / SAE United States · 6 - [30347 Indicative](/materials/aisi-sae/30347 "AISI / SAE 30347") - [30348 Indicative](/materials/aisi-sae/30348 "AISI / SAE 30348") - [347 This grade’s own name](/materials/aisi-sae/347 "AISI / SAE 347") - [348 This grade’s own name](/materials/aisi-sae/348 "AISI / SAE 348") - [348H This grade’s own name](/materials/aisi-sae/348h "AISI / SAE 348H") - [S34800 Indicative](/materials/uns/s34800 "AISI / SAE S34800") ASTM United States · 38 - [A1012 Indicative](/materials/astm/a1012 "ASTM A1012") - [A1049 Indicative](/materials/astm/a1049 "ASTM A1049") - [A182 Indicative](/materials/aisi-sae/a182 "ASTM A182") - [A193 Indicative](/materials/astm/a193 "ASTM A193") - [A194 Indicative](/materials/astm/a194 "ASTM A194") - [A213 Indicative](/materials/astm/a213 "ASTM A213") - [A240 Indicative](/materials/astm/a240 "ASTM A240") - [A249 Indicative](/materials/astm/a249 "ASTM A249") - [A264 Indicative](/materials/astm/a264 "ASTM A264") - [A269 Indicative](/materials/astm/a269 "ASTM A269") - [A276 Indicative](/materials/astm/a276 "ASTM A276") - [A312 Indicative](/materials/astm/a312 "ASTM A312") - [A313 Indicative](/materials/astm/a313 "ASTM A313") - [A314 Indicative](/materials/astm/a314 "ASTM A314") - [A320 Indicative](/materials/nbn/a320 "ASTM A320") - [A336 Indicative](/materials/astm/a336 "ASTM A336") - [A358 Indicative](/materials/astm/a358 "ASTM A358") - [A376 Indicative](/materials/astm/a376 "ASTM A376") - [A403 Indicative](/materials/astm/a403 "ASTM A403") - [A409 Indicative](/materials/astm/a409 "ASTM A409") - [A430 Indicative](/materials/astm/a430 "ASTM A430") - [A473 Indicative](/materials/astm/a473 "ASTM A473") - [A479 Indicative](/materials/astm/a479 "ASTM A479") - [A511 Indicative](/materials/astm/a511 "ASTM A511") - [A554 Indicative](/materials/astm/a554 "ASTM A554") - [A580 Indicative](/materials/astm/a580 "ASTM A580") - [A632 Indicative](/materials/astm/a632 "ASTM A632") - [A774 Indicative](/materials/astm/a774 "ASTM A774") - [A778 Indicative](/materials/astm/a778 "ASTM A778") - [A813 Indicative](/materials/astm/a813 "ASTM A813") - [A814 Indicative](/materials/astm/a814 "ASTM A814") - [A943 Indicative](/materials/astm/a943 "ASTM A943") - [A965 Indicative](/materials/astm/a965 "ASTM A965") - [F2281 Indicative](/materials/astm/f2281 "ASTM F2281") - [F593 Indicative](/materials/astm/f593 "ASTM F593") - [F594 Indicative](/materials/astm/f594 "ASTM F594") - [F738 Indicative](/materials/astm/f738 "ASTM F738") - [F836 Indicative](/materials/astm/f836 "ASTM F836") BS United Kingdom · 10 - [2 S.130 Indicative](/materials/bs/2s130 "BS 2 S.130") - [2 S.143 Indicative](/materials/bs/2-s-143 "BS 2 S.143") - [3 S.144 Indicative](/materials/bs/3-s-144 "BS 3 S.144") - [347S17 Indicative](/materials/bs/347s17 "BS 347S17") - [3S.145 Indicative](/materials/bs/3s-145 "BS 3S.145") - [S.525 Indicative](/materials/bs/s-525 "BS S.525") - [S143 Indicative](/materials/bs/s143 "BS S143") - [S144 Indicative](/materials/bs/s144 "BS S144") - **S145 Indicative** - [S527 Indicative](/materials/bs/s527 "BS S527") SAE AMS United States / Aerospace · 12 - [5362 Indicative](/materials/ams/5362 "SAE AMS 5362") - [5512 Indicative](/materials/ams/5512 "SAE AMS 5512") - [5556 Indicative](/materials/ams/5556 "SAE AMS 5556") - [5558 Indicative](/materials/ams/5558 "SAE AMS 5558") - [5571 Indicative](/materials/ams/5571 "SAE AMS 5571") - [5575 Indicative](/materials/ams/5575 "SAE AMS 5575") - [5646 Indicative](/materials/ams/5646 "SAE AMS 5646") - [5654 Indicative](/materials/ams/5654 "SAE AMS 5654") - [5674 Indicative](/materials/ams/5674 "SAE AMS 5674") - [5790 Indicative](/materials/ams/5790 "SAE AMS 5790") - [5897 Indicative](/materials/ams/5897 "SAE AMS 5897") - [7490 Indicative](/materials/ams/7490 "SAE AMS 7490") 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 — 18 % Ni — 10.3 % Mn — 2 % Traces & impurities · 1.2 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | ≤ 0.08 | | Si | ≤ 1 | | Mn | ≤ 2 | | P | 0.045 | | S | 0.03 | | Cr | 17–19 | | Ni | 9–11.5 | 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 | ≤0,08 | — | 0.080 | Max | | Si | ≤1,00 | — | 1.000 | Max | | P | 0,045 | 0.045 | 0.045 | Exact | | S | 0,03 | 0.030 | 0.030 | Exact | | Cr | 17,0-19,0 | 17.000 | 19.000 | Range | | Mn | ≤2,00 | — | 2.000 | Max | | Ni | 9,00-11,5 | 9.000 | 11.500 | Range | - ≥(10xC)≤1,00 - ≥(10xC)≤1,00 - ≥(10xC)≤1,00 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. [S30347 1.4544 Cr 17,0-19,0 · Ni 9,00-11,5 - ΔCr 0.00 - ΔNi 0.00 - 69 designations](/materials/uns/s30347 "S30347")[S30400 1.4314 Cr 17,0-19,0 · Ni 8,50-10,5 - ΔCr 0.00 - ΔNi 0.75 - 86 designations](/materials/uns/s30400 "S30400")[S30100 1.4324 Cr 16,0-18,0 · Ni 7,00-9,00 - ΔCr 1.00 - ΔNi 2.25 - 52 designations](/materials/uns/s30100 "S30100") ## 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=00eb1d6b-8bb4-4a92-81de-b1b031c067cf&designation=2a048c0c-0ddb-4477-9426-ad9e7596989a "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/bs/s145.pdf "Datasheet as PDF")