--- title: "309H — Heat resistant steels" description: "309H in AISI / SAE: material number 1.4950, also listed as X6CrNi23-13. Category: Heat resistant steels. Designations recorded for this grade: 32." canonical: https://steelequivalents.com/materials/aisi-sae/309h language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/aisi-sae/309h.md cs: https://steelequivalents.com/cs/materiály/aisi-sae/309h.md de: https://steelequivalents.com/de/werkstoffe/aisi-sae/309h.md es: https://steelequivalents.com/es/materiales/aisi-sae/309h.md fr: https://steelequivalents.com/fr/matériaux/aisi-sae/309h.md hu: https://steelequivalents.com/hu/anyagok/aisi-sae/309h.md it: https://steelequivalents.com/it/materiali/aisi-sae/309h.md nl: https://steelequivalents.com/nl/materialen/aisi-sae/309h.md pl: https://steelequivalents.com/pl/materiały/aisi-sae/309h.md pt: https://steelequivalents.com/pt/materiais/aisi-sae/309h.md ru: https://steelequivalents.com/ru/материалы/aisi-sae/309h.md tr: https://steelequivalents.com/tr/malzemeler/aisi-sae/309h.md zh: https://steelequivalents.com/zh/材料/aisi-sae/309h.md ja: https://steelequivalents.com/ja/材料/aisi-sae/309h.md ar: https://steelequivalents.com/ar/المواد/aisi-sae/309h.md ko: https://steelequivalents.com/ko/재료/aisi-sae/309h.md pt-br: https://steelequivalents.com/pt-br/materiais/aisi-sae/309h.md hi: https://steelequivalents.com/hi/सामग्री/aisi-sae/309h.md content_hash: sha256:daaae60bf190012d26a2db8ce327dc127cb524de3e9762e41678570634cfc8df 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/aisi-sae/309h > Canonical URL: https://steelequivalents.com/materials/aisi-sae/309h > 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. AISI / SAE · United States · 32 designations # 309H 309H is a designation in AISI / SAE for the material held under material number 1.4950, also listed as X6CrNi23-13. It is a material in the category Heat resistant steels. We list 32 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, ASTM, ISO, SAE AMS, JIS and GB. - [*Material no.* **1.4950**](/materials/material-no/1.4950 "Material no.: 1.4950") - [*Category* **Heat resistant steels · 64 grades**](/categories/heat-resistant-steels "Category: Heat resistant steels · 64 grades") - *Designations* **32** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=076e4c7f-3092-4efc-a16b-77a8b3fafc47&designation=eb12c7c8-bf0d-4fe5-ae02-0e5578be1d07 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/aisi-sae/309h.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X6CrNi23-13 This grade’s own name](/materials/din-en/x6crni23-13 "DIN / EN X6CrNi23-13") - [UNS S30908 This grade’s own name · 2 grades on that route](/materials/uns/s30908 "UNS S30908") - [AISI / SAE 309S This grade’s own name · 3 grades on that route](/materials/aisi-sae/309s "AISI / SAE 309S") ## About Heat resistant steels Heat resistant steels are alloyed materials designed to retain useful mechanical properties and resist oxidation or scaling during service at elevated temperatures. They are used for components in furnaces, boilers, heat exchangers and power-generation equipment exposed to hot gases or sustained heat. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 32 designations · 8 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 - [X6CrNi23-13 This grade’s own name](/materials/din-en/x6crni23-13 "DIN / EN X6CrNi23-13") UNS United States · 2 - [S30908 This grade’s own name](/materials/uns/s30908 "UNS S30908") - [S30909 This grade’s own name](/materials/uns/s30909 "UNS S30909") AISI / SAE United States · 3 - [30309S Indicative](/materials/aisi-sae/30309s "AISI / SAE 30309S") - **309H This grade’s own name** - [309S This grade’s own name](/materials/aisi-sae/309s "AISI / SAE 309S") ASTM United States · 19 - [A1012 Indicative](/materials/astm/a1012 "ASTM A1012") - [A213 Indicative](/materials/astm/a213 "ASTM A213") - [A240 Indicative](/materials/astm/a240 "ASTM A240") - [A249 Indicative](/materials/astm/a249 "ASTM A249") - [A276 Indicative](/materials/astm/a276 "ASTM A276") - [A312 Indicative](/materials/astm/a312 "ASTM A312") - [A314 Indicative](/materials/astm/a314 "ASTM A314") - [A358 Indicative](/materials/astm/a358 "ASTM A358") - [A409 Indicative](/materials/astm/a409 "ASTM A409") - [A473 Indicative](/materials/astm/a473 "ASTM A473") - [A478 Indicative](/materials/astm/a478 "ASTM A478") - [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") - [A813 Indicative](/materials/astm/a813 "ASTM A813") - [A814 Indicative](/materials/astm/a814 "ASTM A814") - [A924 Indicative](/materials/astm/a924 "ASTM A924") - [A943 Indicative](/materials/astm/a943 "ASTM A943") ISO International · 1 - [X6CrNi23-14 Indicative](/materials/iso/x6crni23-14 "ISO X6CrNi23-14") SAE AMS United States / Aerospace · 4 - [5523 Indicative](/materials/ams/5523 "SAE AMS 5523") - [5574 Indicative](/materials/ams/5574 "SAE AMS 5574") - [5650 Indicative](/materials/ams/5650 "SAE AMS 5650") - [7490 Indicative](/materials/ams/7490 "SAE AMS 7490") JIS Japan · 1 - [SUS 309S Indicative](/materials/jis/sus309s "JIS SUS 309S") GB China · 1 - [0Cr23Ni13 Indicative](/materials/gb/0cr23ni13 "GB 0Cr23Ni13") Every designation on file is listed — no truncation, no “+ n more”. Each one is itself a route that leads back here. ## Chemical composition 8 elements on file · weight % What this alloy is Fe Cr Ni Mn Iron — the balance, never listed by a standard — 60.6 % Cr — 23 % Ni — 13.5 % Mn — 2 % Traces & impurities · 0.9 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.04–0.08 | | Si | ≤ 0.7 | | Mn | ≤ 2 | | P | 0.035 | | S | 0.015 | | Cr | 22–24 | | Ni | 12–15 | | N | 0.11 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Nickel 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 | 0,04-0,08 | 0.040 | 0.080 | Range | | N | 0,11 | 0.110 | 0.110 | Exact | | Si | ≤0,70 | — | 0.700 | Max | | P | 0,035 | 0.035 | 0.035 | Exact | | S | 0,015 | 0.015 | 0.015 | Exact | | Cr | 22,0-24,0 | 22.000 | 24.000 | Range | | Mn | ≤2,00 | — | 2.000 | Max | | Ni | 12,0-15,0 | 12.000 | 15.000 | 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: 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. [X12CrNi23-13 1.4833 Cr 22,0-24,0 · Ni 12,0-14,0 - ΔCr 0.00 - ΔNi 0.50 - 69 designations](/materials/din-en/x12crni23-13 "X12CrNi23-13")[X12CrNiMoNb20-15 1.4885 Cr 19,0-22,0 · Ni 14,0-16,0 - ΔCr 2.50 - ΔNi 1.50 - 1 designations](/materials/din-en/x12crnimonb20-15 "X12CrNiMoNb20-15")[X7CrNiSiNCe21-11 1.4835 Cr 20,0-22,0 · Ni 10,0-12,0 - ΔCr 2.00 - ΔNi 2.50 - 12 designations](/materials/din-en/x7crnisince21-11 "X7CrNiSiNCe21-11") ## 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=076e4c7f-3092-4efc-a16b-77a8b3fafc47&designation=eb12c7c8-bf0d-4fe5-ae02-0e5578be1d07 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/aisi-sae/309h.pdf "Datasheet as PDF")