--- title: "A213 T9 — Hydrogen resistant steels" description: "A213 T9 in ASTM: material number 1.7386, also listed as X11CrMo9-1. Category: Hydrogen resistant steels. Designations recorded for this grade: 17." canonical: https://steelequivalents.com/materials/astm/a213-t9 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/astm/a213-t9.md cs: https://steelequivalents.com/cs/materiály/astm/a213-t9.md de: https://steelequivalents.com/de/werkstoffe/astm/a213-t9.md es: https://steelequivalents.com/es/materiales/astm/a213-t9.md fr: https://steelequivalents.com/fr/matériaux/astm/a213-t9.md hu: https://steelequivalents.com/hu/anyagok/astm/a213-t9.md it: https://steelequivalents.com/it/materiali/astm/a213-t9.md nl: https://steelequivalents.com/nl/materialen/astm/a213-t9.md pl: https://steelequivalents.com/pl/materiały/astm/a213-t9.md pt: https://steelequivalents.com/pt/materiais/astm/a213-t9.md ru: https://steelequivalents.com/ru/материалы/astm/a213-t9.md tr: https://steelequivalents.com/tr/malzemeler/astm/a213-t9.md zh: https://steelequivalents.com/zh/材料/astm/a213-t9.md ja: https://steelequivalents.com/ja/材料/astm/a213-t9.md ar: https://steelequivalents.com/ar/المواد/astm/a213-t9.md ko: https://steelequivalents.com/ko/재료/astm/a213-t9.md pt-br: https://steelequivalents.com/pt-br/materiais/astm/a213-t9.md hi: https://steelequivalents.com/hi/सामग्री/astm/a213-t9.md content_hash: sha256:45581ccf02b4b5f73a2a9667ab046515ec45061af3b023a23e69e15332a22f12 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/astm/a213-t9 > Canonical URL: https://steelequivalents.com/materials/astm/a213-t9 > 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. ASTM · United States · 17 designations # A213 T9 A213 T9 is a designation in ASTM for the material held under material number 1.7386, also listed as X11CrMo9-1. It is a material in the category Hydrogen resistant steels. We list 17 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM, JIS, GOST and ČSN. - [*Material no.* **1.7386**](/materials/material-no/1.7386 "Material no.: 1.7386") - [*Category* **Hydrogen resistant steels · 8 grades**](/categories/hydrogen-resistant-steels "Category: Hydrogen resistant steels · 8 grades") - *Designations* **17** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=6c72c884-812d-4377-937e-a380760e8719&designation=db9a1b2e-609c-45fe-9107-6a5b9af1cf94 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/astm/a213-t9.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X11CrMo9-1 This grade’s own name](/materials/din-en/x11crmo9-1 "DIN / EN X11CrMo9-1") - [UNS K90941 This grade’s own name](/materials/uns/k90941 "UNS K90941") - [AISI / SAE 503 This grade’s own name](/materials/aisi-sae/503 "AISI / SAE 503") - [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 Hydrogen resistant steels Hydrogen resistant steels are steels designed to withstand hydrogen-related damage, including hydrogen embrittlement and hydrogen attack. They are used for pressure vessels, piping and process equipment exposed to hydrogen-containing environments, where resistance to hydrogen ingress and loss of toughness is important. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 17 designations · 7 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 - [X11CrMo9-1 This grade’s own name](/materials/din-en/x11crmo9-1 "DIN / EN X11CrMo9-1") - [X12CrMo9-1 This grade’s own name Withdrawn](/materials/din-en/x12crmo9-1 "DIN / EN X12CrMo9-1") UNS United States · 3 - [K90941 This grade’s own name](/materials/uns/k90941 "UNS K90941") - [S50400 This grade’s own name](/materials/uns/s50400 "UNS S50400") - [S50488 This grade’s own name](/materials/uns/s50488 "UNS S50488") AISI / SAE United States · 2 - [503 This grade’s own name](/materials/aisi-sae/503 "AISI / SAE 503") - [504 Indicative](/materials/aisi-sae/504 "AISI / SAE 504") ASTM United States · 4 - [A 182 F 9 This grade’s own name](/materials/astm/a-182-f-9 "ASTM A 182 F 9") - **A213 T9 Indicative** - [A335 P9 Indicative](/materials/astm/a335-p9 "ASTM A335 P9") - [A387 Grade 9 Indicative](/materials/astm/a387-grade-9 "ASTM A387 Grade 9") JIS Japan · 3 - [STBA26 Indicative](/materials/jis/stba26 "JIS STBA26") - [STFA26 Indicative](/materials/jis/stfa26 "JIS STFA26") - [STPA26 Indicative](/materials/jis/stpa26 "JIS STPA26") GOST Russia / CIS · 2 - [13Ch9M Indicative](/materials/gost/13ch9m "GOST 13Ch9M") - [13Х9М Indicative](/materials/gost/13kh9m "GOST 13Х9М") ČSN Czechia · 1 - [17116 Indicative](/materials/csn/17116 "ČSN 17116") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 9 elements on file · weight % What this alloy is Fe Cr Mo Si Iron — the balance, never listed by a standard — 88.4 % Cr — 9 % Mo — 1 % Si — 0.6 % Traces & impurities · 0.9 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.08–0.15 | | Si | 0.25–1 | | Mn | 0.3–0.6 | | P | 0.025 | | S | 0.02 | | Cr | 8–10 | | Mo | 0.9–1.1 | | Cu | ≤ 0.3 | | Al | ≤ 0.04 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Molybdenum Copper Aluminium 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 | 0,08-0,15 | 0.080 | 0.150 | Range | | Al | ≤0,040 | — | 0.040 | Max | | Si | 0,25-1,00 | 0.250 | 1.000 | Range | | P | 0,025 | 0.025 | 0.025 | Exact | | S | 0,02 | 0.020 | 0.020 | Exact | | Cr | 8,00-10,0 | 8.000 | 10.000 | Range | | Mn | 0,30-0,60 | 0.300 | 0.600 | Range | | Cu | ≤0,30 | — | 0.300 | Max | | Mo | 0,90-1,10 | 0.900 | 1.100 | 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 Not enough recorded composition to predict a transformation temperature for this grade — missing: Ni. ## 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=6c72c884-812d-4377-937e-a380760e8719&designation=db9a1b2e-609c-45fe-9107-6a5b9af1cf94 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/astm/a213-t9.pdf "Datasheet as PDF")