--- title: "Type9 — Valve steels" description: "Type9 in ISO: material number 1.4871, also listed as X53CrMnNiN21-9. Category: Valve steels. Designations recorded for this grade: 37." canonical: https://steelequivalents.com/materials/iso/type9 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/iso/type9.md cs: https://steelequivalents.com/cs/materiály/iso/type9.md de: https://steelequivalents.com/de/werkstoffe/iso/type9.md es: https://steelequivalents.com/es/materiales/iso/type9.md fr: https://steelequivalents.com/fr/matériaux/iso/type9.md hu: https://steelequivalents.com/hu/anyagok/iso/type9.md it: https://steelequivalents.com/it/materiali/iso/type9.md nl: https://steelequivalents.com/nl/materialen/iso/type9.md pl: https://steelequivalents.com/pl/materiały/iso/type9.md pt: https://steelequivalents.com/pt/materiais/iso/type9.md ru: https://steelequivalents.com/ru/материалы/iso/type9.md tr: https://steelequivalents.com/tr/malzemeler/iso/type9.md zh: https://steelequivalents.com/zh/材料/iso/type9.md ja: https://steelequivalents.com/ja/材料/iso/type9.md ar: https://steelequivalents.com/ar/المواد/iso/type9.md ko: https://steelequivalents.com/ko/재료/iso/type9.md pt-br: https://steelequivalents.com/pt-br/materiais/iso/type9.md hi: https://steelequivalents.com/hi/सामग्री/iso/type9.md content_hash: sha256:703e936b9fffca195173e3681a2d83a38aa309c44a83148a140b6c6c20e34c95 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/iso/type9 > Canonical URL: https://steelequivalents.com/materials/iso/type9 > 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. ISO · International · 37 designations # Type9 Type9 is a designation in ISO for the material held under material number 1.4871, also listed as X53CrMnNiN21-9. It is a material in the category Valve steels. We list 37 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, BS, AFNOR, UNE, ISO, JIS, GB, GOST, UNI, ČSN, PN, SRPS, MSZ, STAS, BDS and KS. - [*Material no.* **1.4871**](/materials/material-no/1.4871 "Material no.: 1.4871") - [*Category* **Valve steels · 14 grades**](/categories/valve-steels "Category: Valve steels · 14 grades") - *Designations* **37** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=c6d9de76-21b4-43fe-9178-ce2fe15ed0e0&designation=729c3dd9-4520-43e5-a678-276d07bb5652 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/iso/type9.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X53CrMnNiN21-9 This grade’s own name](/materials/din-en/x53crmnnin21-9 "DIN / EN X53CrMnNiN21-9") - [UNS S63008 This grade’s own name](/materials/uns/s63008 "UNS S63008") - [AISI / SAE EV 8 This grade’s own name](/materials/aisi-sae/ev-8 "AISI / SAE EV 8") ## About Valve steels Valve steels are alloy steels developed for valve components exposed to heat, pressure, wear, and corrosive service conditions. They are characterised by combinations of strength, hardness, toughness, and resistance to oxidation or corrosion suited to the operating environment. Typical uses include engine valves and industrial valve parts where reliable performance and dimensional stability are required. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 37 designations · 18 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 - [1.4871 Indicative](/materials/material-no/1.4871 "DIN / EN 1.4871") - [X53CrMnNiN21-9 This grade’s own name](/materials/din-en/x53crmnnin21-9 "DIN / EN X53CrMnNiN21-9") UNS United States · 1 - [S63008 This grade’s own name](/materials/uns/s63008 "UNS S63008") AISI / SAE United States · 3 - [EV 8 This grade’s own name](/materials/aisi-sae/ev-8 "AISI / SAE EV 8") - [EV12 Indicative](/materials/aisi-sae/ev12 "AISI / SAE EV12") - [S63008 Indicative](/materials/uns/s63008 "AISI / SAE S63008") BS United Kingdom · 3 - [349 S 52 Indicative](/materials/bs/349-s-52 "BS 349 S 52") - [349S54 Indicative](/materials/bs/349s54 "BS 349S54") - [X53CrMnNiN21-9 Indicative](/materials/din-en/x53crmnnin21-9 "BS X53CrMnNiN21-9") AFNOR France · 4 - [Z52CMN21.09 Indicative](/materials/afnor/z52cmn21-09 "AFNOR Z52CMN21.09") - [Z53CMN21-09Az Indicative](/materials/afnor/z53cmn21-09az "AFNOR Z53CMN21-09Az") - [Z53CMNS21-09AZ Indicative](/materials/afnor/z53cmns21-09az "AFNOR Z53CMNS21-09AZ") - [Z5CMN21.09 Indicative](/materials/afnor/z5cmn21-09 "AFNOR Z5CMN21.09") UNE Spain · 3 - [F.3217 Indicative](/materials/une/f-3217 "UNE F.3217") - [F.3217-X 53 CrMnln 21-09 Indicative](/materials/une/f-3217-x-53-crmnln-21-09 "UNE F.3217-X 53 CrMnln 21-09") - [X53CrMnNiN21-09 Indicative](/materials/une/x53crmnnin21-09 "UNE X53CrMnNiN21-09") ISO International · 1 - **Type9 Indicative** JIS Japan · 3 - [SUH35 Indicative](/materials/jis/suh35 "JIS SUH35") - [SUH36 Indicative](/materials/jis/suh36 "JIS SUH36") - [SUH661 Indicative](/materials/jis/suh661 "JIS SUH661") GB China · 2 - [5Cr21Mn9Ni4N Indicative](/materials/gb/5cr21mn9ni4n "GB 5Cr21Mn9Ni4N") - [5Cr2Mn9Ni4N Indicative](/materials/gb/5cr2mn9ni4n "GB 5Cr2Mn9Ni4N") GOST Russia / CIS · 6 - [55Ch20G9AN4 Indicative](/materials/gost/55ch20g9an4 "GOST 55Ch20G9AN4") - [55KH20G9AN4 Indicative](/materials/gost/55kh20g9an4 "GOST 55KH20G9AN4") - [55KH20G9АN4 Indicative](/materials/gost/55kh20g9an4 "GOST 55KH20G9АN4") - [55Х20Г9АН4 Indicative](/materials/gost/55kh20g9an4 "GOST 55Х20Г9АН4") - [5Х20Н4АГ9 Indicative](/materials/gost/5kh20n4ag9 "GOST 5Х20Н4АГ9") - [ЭП303 Indicative](/materials/gost/ep303 "GOST ЭП303") UNI Italy · 1 - [X53CrMnNiN21-9 Indicative](/materials/din-en/x53crmnnin21-9 "UNI X53CrMnNiN21-9") ČSN Czechia · 1 - [17465 Indicative](/materials/csn/17465 "ČSN 17465") PN Poland · 1 - [50H21G9N4 Indicative](/materials/pn/50h21g9n4 "PN 50H21G9N4") SRPS Serbia · 1 - [Č.4870 Indicative](/materials/srps/c-4870 "SRPS Č.4870") MSZ Hungary · 1 - [SZ13 Indicative](/materials/msz/sz13 "MSZ SZ13") STAS Romania · 1 - [53NNiMnCr210 Indicative](/materials/stas/53nnimncr210 "STAS 53NNiMnCr210") BDS Bulgaria · 1 - [X53CrMnNiN21-9 Indicative](/materials/din-en/x53crmnnin21-9 "BDS X53CrMnNiN21-9") KS South Korea · 2 - [STR35 Indicative](/materials/ks/str35 "KS STR35") - [STR36 Indicative](/materials/ks/str36 "KS STR36") 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 Mn Ni Iron — the balance, never listed by a standard — 64.8 % Cr — 21 % Mn — 9 % Ni — 3.9 % Traces & impurities · 1.3 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.48–0.58 | | Si | ≤ 0.25 | | Mn | 8–10 — Unusual | | P | 0.045 | | S | 0.03 | | Cr | 20–22 | | Ni | 3.25–4.5 | | N | 0.35–0.5 — Unusual | 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 | 0,48-0,58 | 0.480 | 0.580 | Range | | N | 0,35-0,50 | 0.350 | 0.500 | Range | | Si | ≤0,25 | — | 0.250 | Max | | P | 0,045 | 0.045 | 0.045 | Exact | | S | 0,03 | 0.030 | 0.030 | Exact | | Cr | 20,0-22,0 | 20.000 | 22.000 | Range | | Mn | 8,00-10,0 | 8.000 | 10.000 | Range | | Ni | 3,25-4,50 | 3.250 | 4.500 | 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. ## Properties by condition 2 conditions · 5 values By delivery state**no delivery state stated** source `steeljis` | Delivery state | Rm N/mm² | Re N/mm² | A% | HB | |---|---|---|---|---| | Bars/Rods Precipitation hardening treatment | 880 | 560 | 8 | — | | Precipitation hardening treatment | — | — | — | 302 | By delivery state**Solution annealed** source `steelnumber` | Delivery state | HRC | |---|---| | Solution annealed | 30 | 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. ## 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 / Mn 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. [X53CrMnNiNbN21-9 1.4870 Cr 20,0-22,0 · Mn 8,00-10,0 - ΔCr 0.00 - ΔMn 0.00 - 1 designations](/materials/din-en/x53crmnninbn21-9 "X53CrMnNiNbN21-9")[X50CrMnNiNbN21-9 1.4882 Cr 20,0-22,0 · Mn 8,00-10,0 - ΔCr 0.00 - ΔMn 0.00 - 2 designations](/materials/din-en/x50crmnninbn21-9 "X50CrMnNiNbN21-9")[X55CrMnNiN20-8 1.4875 Cr 19,5-21,5 · Mn 7,00-10,0 - ΔCr 0.50 - ΔMn 0.50 - 6 designations](/materials/din-en/x55crmnnin20-8 "X55CrMnNiN20-8")[X60CrMnMoVNbN21-10 1.4785 Cr 20,0-22,0 · Mn 9,50-11,5 - ΔCr 0.00 - ΔMn 1.50 - 1 designations](/materials/din-en/x60crmnmovnbn21-10 "X60CrMnMoVNbN21-10") ## 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=c6d9de76-21b4-43fe-9178-ce2fe15ed0e0&designation=729c3dd9-4520-43e5-a678-276d07bb5652 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/iso/type9.pdf "Datasheet as PDF")