--- title: "Č.6451 — Tool steels for hot work" description: "Č.6451 in SRPS: material number 1.2581, also listed as X30WCrV9-3. Category: Tool steels for hot work. Designations recorded for this grade: 33." canonical: https://steelequivalents.com/materials/srps/c-6451 language: en robots: index, follow og_type: website type: material-detail language_alternates: en: https://steelequivalents.com/materials/srps/c-6451.md cs: https://steelequivalents.com/cs/materiály/srps/c-6451.md de: https://steelequivalents.com/de/werkstoffe/srps/c-6451.md es: https://steelequivalents.com/es/materiales/srps/c-6451.md fr: https://steelequivalents.com/fr/matériaux/srps/c-6451.md hu: https://steelequivalents.com/hu/anyagok/srps/c-6451.md it: https://steelequivalents.com/it/materiali/srps/c-6451.md nl: https://steelequivalents.com/nl/materialen/srps/c-6451.md pl: https://steelequivalents.com/pl/materiały/srps/c-6451.md pt: https://steelequivalents.com/pt/materiais/srps/c-6451.md ru: https://steelequivalents.com/ru/материалы/srps/c-6451.md tr: https://steelequivalents.com/tr/malzemeler/srps/c-6451.md zh: https://steelequivalents.com/zh/材料/srps/c-6451.md ja: https://steelequivalents.com/ja/材料/srps/c-6451.md ar: https://steelequivalents.com/ar/المواد/srps/c-6451.md ko: https://steelequivalents.com/ko/재료/srps/c-6451.md pt-br: https://steelequivalents.com/pt-br/materiais/srps/c-6451.md hi: https://steelequivalents.com/hi/सामग्री/srps/c-6451.md content_hash: sha256:c890c3c0309ce72268af6b67525f7aa2afdd9da2d7aacb43a5339b66d96bbb9a 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/srps/c-6451 > Canonical URL: https://steelequivalents.com/materials/srps/c-6451 > 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. SRPS · Serbia · 33 designations # Č.6451 Č.6451 is a designation in SRPS for the material held under material number 1.2581, also listed as X30WCrV9-3. It is a material in the category Tool steels for hot work. We list 33 designations recorded for this grade, in the standards DIN / EN, UNS, AISI / SAE, BS, AFNOR, UNE, ISO, JIS, GB, GOST, UNI, ČSN, STN, SRPS, PN, STAS, BDS, ÖNORM and KS. - [*Material no.* **1.2581**](/materials/material-no/1.2581 "Material no.: 1.2581") - [*Category* **Tool steels for hot work · 37 grades**](/categories/tool-steels-for-hot-work "Category: Tool steels for hot work · 37 grades") - *Designations* **33** [Search](/search "Steel grade search")[Inquiry](/inquiry?material=142fe339-01ab-4534-a559-fe30c3d948f1&designation=fbbbdcf9-278f-407e-9550-abf21617a585 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/srps/c-6451.pdf "Datasheet as PDF") ## If you came for one of these The most-used names for this grade. - [DIN / EN X30WCrV9-3 This grade’s own name](/materials/din-en/x30wcrv9-3 "DIN / EN X30WCrV9-3") - [UNS T20821 This grade’s own name](/materials/uns/t20821 "UNS T20821") - [AISI / SAE H21 This grade’s own name](/materials/aisi-sae/h21 "AISI / SAE H21") ## About Tool steels for hot work Tool steels for hot work are alloy steels designed for tooling that operates in contact with heated metal. They are characterised by hot hardness, wear resistance, toughness and resistance to thermal fatigue, making them suitable for dies, moulds, punches and other forging, extrusion and die-casting tools. This describes the material class as a whole. Always confirm the individual grade against the standard before ordering. ## Also known as 33 designations · 19 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 - [1.2581 Indicative](/materials/material-no/1.2581 "DIN / EN 1.2581") - [X30WCrV9-3 This grade’s own name](/materials/din-en/x30wcrv9-3 "DIN / EN X30WCrV9-3") UNS United States · 1 - [T20821 This grade’s own name](/materials/uns/t20821 "UNS T20821") AISI / SAE United States · 2 - [H21 This grade’s own name](/materials/aisi-sae/h21 "AISI / SAE H21") - [T20821 Indicative](/materials/uns/t20821 "AISI / SAE T20821") BS United Kingdom · 2 - [2581 Indicative](/materials/bs/2581 "BS 2581") - [BH21 Indicative](/materials/bs/bh21 "BS BH21") AFNOR France · 2 - [X30WCrV9 Indicative](/materials/afnor/x30wcrv9 "AFNOR X30WCrV9") - [Z30WCV9 Indicative](/materials/afnor/z30wcv9 "AFNOR Z30WCV9") UNE Spain · 4 - [F.5320 Indicative](/materials/une/f-5320 "UNE F.5320") - [F.5323 Indicative](/materials/une/f-5323 "UNE F.5323") - [WCrV9 Indicative](/materials/une/wcrv9 "UNE WCrV9") - [X30WCrV9 Indicative](/materials/afnor/x30wcrv9 "UNE X30WCrV9") ISO International · 1 - [X30WCrV9-3 Indicative](/materials/din-en/x30wcrv9-3 "ISO X30WCrV9-3") JIS Japan · 1 - [SKD5 Indicative](/materials/jis/skd5 "JIS SKD5") GB China · 2 - [30WCrV9 Indicative](/materials/gb/30wcrv9 "GB 30WCrV9") - [3Cr2W8V Indicative](/materials/gb/3cr2w8v "GB 3Cr2W8V") GOST Russia / CIS · 2 - [3KH2V8F Indicative](/materials/gost/3kh2v8f "GOST 3KH2V8F") - [3Х2В8Ф Indicative](/materials/gost/3kh2v8f "GOST 3Х2В8Ф") UNI Italy · 2 - [X28W09KU Indicative](/materials/uni/x28w09ku "UNI X28W09KU") - [X30WCrV9-3KU Indicative](/materials/uni/x30wcrv9-3ku "UNI X30WCrV9-3KU") ČSN Czechia · 2 - [19721 Indicative](/materials/csn/19721 "ČSN 19721") - [19830 Indicative](/materials/csn/19830 "ČSN 19830") STN Slovakia · 1 - [19 721 Indicative](/materials/csn/19721 "STN 19 721") SRPS Serbia · 1 - **Č.6451 Indicative** PN Poland · 2 - [WWV Indicative](/materials/pn/wwv "PN WWV") - [WWW Indicative](/materials/pn/www "PN WWW") STAS Romania · 1 - [30VCrW85 Indicative](/materials/stas/30vcrw85 "STAS 30VCrW85") BDS Bulgaria · 2 - [3Ch2B8F Indicative](/materials/bds/3ch2b8f "BDS 3Ch2B8F") - [X30WCrV9-3 Indicative](/materials/din-en/x30wcrv9-3 "BDS X30WCrV9-3") ÖNORM Austria · 2 - [BOHLERW100 Indicative](/materials/onorm/bohlerw100 "ÖNORM BOHLERW100") - [W100 Indicative](/materials/onorm/w100 "ÖNORM W100") KS South Korea · 1 - [STD5 Indicative](/materials/ks/std5 "KS STD5") 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 W Cr V Iron — the balance, never listed by a standard — 86.9 % W — 9 % Cr — 2.9 % V — 0.4 % Traces & impurities · 0.9 % Logarithmic scale, 0.01 % to 100 % — every value here compares directly, decade by decade. | Element | % by weight | |---|---| | C | 0.25–0.35 | | Si | 0.1–0.4 | | Mn | 0.15–0.45 | | P | 0.03 | | S | 0.02 | | Cr | 2.5–3.2 | | V | 0.3–0.5 | | W | 8.5–9.5 | Carbon Silicon Manganese Phosphorus Sulfur Chromium Vanadium Tungsten 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 | 0,25-0,35 | 0.250 | 0.350 | Range | | Si | 0,10-0,40 | 0.100 | 0.400 | Range | | P | 0,03 | 0.030 | 0.030 | Exact | | S | 0,02 | 0.020 | 0.020 | Exact | | V | 0,30-0,50 | 0.300 | 0.500 | Range | | Cr | 2,50-3,20 | 2.500 | 3.200 | Range | | Mn | 0,15-0,45 | 0.150 | 0.450 | Range | | W | 8,50-9,50 | 8.500 | 9.500 | 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: Ni, Mo. ## Physical & mechanical properties Density 7,85 g/cm³ Exact Transformation point Ac1 800 °C Exact Transformation point Ac3 850 °C Exact · Ac3(Acm) Transformation point Ar3 750 °C Exact · Ar3(Arcm) Transformation point Ar1 690 °C Exact Weldability not suitable for welding As published: is not used. Flake sensitivity susceptible As published: predisposed Temper brittleness susceptible As published: predisposed 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 5 conditions · 27 values By delivery state**no delivery state stated** source `steeljis` | Delivery state | HB | HRC | |---|---|---| | Annealed | 241 | — | | Quenched and tempered | — | 48 | By delivery state**Soft annealed** source `steelnumber` | Delivery state | HB | |---|---| | Soft annealed | 241 | By heat-treated condition**no delivery state stated** source `splav` | Heat-treated condition | Rm N/mm² | Re N/mm² | A5% | Z% | KCU kJ/m² | |---|---|---|---|---|---| | Steel | 1530 | 1390 | 12 | 36 | 200 | By delivery state**no delivery state stated** source `splav` | Delivery state | HB | |---|---| | (annealing) | 241 | At temperature**no delivery state stated** source `splav` | Temperature °C | Elastic modulus GPa | Thermal conductivity W/(m·K) | Electrical resistivity nΩ·m | |---|---|---|---| | 20 | 224 | — | — | | 100 | 218 | 25 | 250 | | 200 | 211 | 27 | 200 | | 300 | 204 | 29 | 170 | | 400 | 196 | 40 | 140 | | 500 | 187 | 46 | 120 | | 600 | 177 | 50 | — | 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. ## Heat treatment **GB /T 1299-2025** Single operation Test specimen - Quenching 1070–1125 °C Cooling Oil Supply condition - Quenching Test specimen - Annealing Supply condition Conditions the standard permits on delivery. No temperature or medium is published for these, so no order and no alternation is implied. Source: [www.caishuku.com](https://www.caishuku.com/detail/azhlNWIxMzUyNDI_ "Source: www.caishuku.com") ## Similar grades — and why Selection rule, stated so you can disagree with it: same number class 1.2, a shared category, and a published range for W / Cr 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. [X30WCrCoV9-3 1.2662 W 8,00-9,00 · Cr 2,20-2,50 - ΔW 0.50 - ΔCr 0.50 - 3 designations](/materials/din-en/x30wcrcov9-3 "X30WCrCoV9-3") ## 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=142fe339-01ab-4534-a559-fe30c3d948f1&designation=fbbbdcf9-278f-407e-9550-abf21617a585 "Inquiry")[**Datasheet as PDF** Print-ready A4 document **Generating …** **Download started** **Try again**](/materials/srps/c-6451.pdf "Datasheet as PDF")