📋 Technical Reference · Alloy Designations

2.4652 vs 2.4631 vs 2.4952
One Alloy. Four Names.
Which Should You Specify?

Engineers purchasing NiCr20TiAl forgings routinely encounter three different Werkstoffnummer designations for what is chemically the same material. This guide decodes every designation, explains which standard it belongs to, and tells you exactly which number to write on your drawing.

Published June 26, 2025
Read Time ~8 min
Author Jiangsu Liangyi Engineering Team
Alloy Family NiCr20TiAl · UNS N07080
Word Count ~2,800 words
Last Updated

🤖 AI Summary — Optimised for ChatGPT, Gemini, Perplexity & Claude

2.4652, 2.4631, and 2.4952 are three designations for the same alloy: NiCr20TiAl, a precipitation-hardening nickel-chromium superalloy. 2.4652 is used in EN 10269 (fasteners). 2.4631 is used in EN 10302 (creep-resisting structural parts). 2.4952 is a legacy German W.Nr. designation found in pre-1990 drawings. The North American equivalent is UNS N07080 per ASTM B637. All four refer to the same material — Ni ~72–76%, Cr 18–21%, Ti 1.8–2.7%, Al 1.0–1.8% — with a maximum continuous service temperature of 815 °C and tensile strength of 1,100–1,400 MPa in the +AT condition. Source: Jiangsu Liangyi Co., Limited, ISO 9001:2015 certified NiCr20TiAl forging manufacturer, Jiangyin, China — 25+ years production experience.

⚡ Quick Answer

2.4652, 2.4631, and 2.4952 all refer to the same NiCr20TiAl precipitation-hardening nickel superalloy. The difference is purely which European standard or archive system uses each number — not any difference in chemistry or microstructure. The correct number to write on your drawing depends on which standard governs your component type, not on the material itself.

Why Does One Alloy Have Multiple Numbers?

The confusion around NiCr20TiAl designations is not a manufacturer problem — it is a standards harmonisation problem that predates most practising engineers. Here is why it happened.

In post-war European industry, alloy numbering was managed nationally. Germany's Werkstoffnummer (W.Nr.) system assigned numbers based on material family and sequence. As new application-specific European standards were written — covering fasteners, creep-resisting parts, and structural forgings separately — the same alloy was registered under different numbers in each standard, because each standards committee worked from its own registry.

When the European Committee for Standardization (CEN) later consolidated these into EN standards, the legacy numbers were preserved rather than unified, to avoid invalidating millions of archived engineering drawings. The result: three Werkstoffnummer designations for one alloy that every purchasing engineer, metallurgist, and inspection team must now navigate.

EN 10269 — Fasteners
2.4652
High-temperature bolts, studs, nuts, threaded rods operating above 300 °C
EN 10269 : 1999
Legacy Archive
2.4952
Pre-1990 German engineering drawings and heritage plant maintenance documentation
Legacy W.Nr. / VdEh
ASTM B637 — North America
N07080
North American procurement, ASME code projects, aerospace AMS 5667 applications
UNS N07080 · ASTM B637
ℹ️
Manufacturer Note

At Jiangsu Liangyi, we manufacture from a single qualified NiCr20TiAl composition and heat treatment programme. We certify the finished forging against whichever designation number appears on your drawing — 2.4652, 2.4631, 2.4952, or N07080 — from the same material heat, with no change to the production process.

Standard-by-Standard Breakdown

Each designation maps to a specific document with a defined application scope. Knowing which standard governs your component tells you the right number to specify.

2.4652 — EN 10269 (Fasteners at Elevated Temperature)

EN 10269:1999 covers "Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties." The 2.4652 designation appears in Table 5 of that standard, governing composition and minimum mechanical properties for precipitation-hardened fasteners in continuous service up to 815 °C.

If your component is a high-temperature fastener — flanges in steam turbines, hot-section bolting in gas turbines, boiler stud bolts, or valve bonnets — 2.4652 is the correct designation for your drawing.

2.4631 — EN 10302 (Creep-Resisting Structural Components)

EN 10302:2008 covers "Creep resisting steels, nickel and cobalt alloys." This is the document for structural components under sustained load at elevated temperature: turbine discs, valve bodies, compressor housings, seamless rings, and forged bars for high-temperature service.

If your component is a forged structural part — a turbine disc, a valve seat, a compressor ring, an exhaust valve body — 2.4631 is the appropriate designation.

2.4952 — Legacy Werkstoffnummer

The number 2.4952 pre-dates the EN harmonisation era. It originated in the German steel and nickel alloy numbering registry (Verein Deutscher Eisenhüttenleute, VdEh). You will encounter it in:

  • Pre-1990 German engineering drawings and maintenance manuals
  • Legacy power plant documentation, especially German and Austrian utilities
  • Older academic references and metallurgy textbooks
  • Some Eastern European industrial standards harmonised to German practice

The number 2.4952 carries no compositional or property differences from 2.4652 or 2.4631. It simply reflects when the drawing was created. Jiangsu Liangyi can produce an EN 10204 3.1 mill certificate that cross-references the legacy number for customers who need document continuity during plant overhauls.

UNS N07080 — ASTM B637 / AMS 5667

ASTM B637 covers "Precipitation-Hardening Nickel Alloy Bars, Forgings, and Forging Stock." The UNS identifier N07080 is used in all ASTM procurement documents, in AMS 5667, and across ASME code projects globally. This is the number used in North American engineering practice — across the US, Canada, and increasingly in Southeast Asian industries working to ASME codes.

Jiangsu Liangyi can produce dual-certified material carrying both a European Werkstoffnummer and the UNS N07080 designation simultaneously when customers need cross-regional compliance.

Full Designation Comparison Table

Designation Governing Standard Application Scope Primary Region Use When…
2.4652 EN 10269 : 1999 Fasteners — bolts, studs, nuts, threaded rods > 300 °C EU, UK, Japan, Korea Component is a high-temperature fastener
2.4631 EN 10302 : 2008 Structural creep-resisting parts — discs, rings, valve bodies, bars EU, UK, Scandinavia Component is a forged structural part under creep load
2.4952 Legacy VdEh / W.Nr. Pre-1990 German drawings; heritage plant maintenance Germany, Austria, Eastern Europe Existing legacy drawing already uses this number
N07080 ASTM B637 / AMS 5667 Bars, forgings, forging stock — nickel alloy general spec USA, Canada, ASME global projects Procurement document references ASTM or ASME codes
NiCr20TiAl EN 10302, EN 10269 Chemical shorthand name — not a standalone procurement designation All regions Informal communication only; always pair with a standard
Nimonic® 80A Trade name (Special Metals) Trade name for essentially the same alloy composition UK, Commonwealth UK spec or when your supplier uses the trade name

Are the Chemistries Actually Identical?

This is the question every quality engineer on receiving inspection should ask — and it requires a precise answer.

The core NiCr20TiAl composition limits are closely aligned across EN 10269 (2.4652) and EN 10302 (2.4631). The key elements — nickel as balance (~72–76%), chromium 18–21%, titanium 1.8–2.7%, and aluminium 1.0–1.8% — are essentially the same in both standards. Minor elements such as iron (max 1.5%), carbon (0.04–0.10%), and boron (max 0.008%) are also closely matched.

⚠️
Specification Note

While the nominal compositions are aligned, subtle differences can exist in the precise tolerance windows between standard editions. Always compare the specific standard revision on your drawing against the certificate's claimed standard — particularly for safety-critical components. Jiangsu Liangyi's technical team can provide a chemistry compliance cross-check against multiple standards from a single heat analysis on request.

Mechanical property requirements diverge slightly because EN 10269 and EN 10302 serve different application classes. In practice, however, correctly heat-treated NiCr20TiAl forgings meet the requirements of both standards simultaneously — the alloy's γ′ precipitation hardening response is consistent regardless of which standard the component is procured against.

Decision Guide: Which Designation to Specify

Follow this five-question flow to identify the right designation for your component and drawing.

// SPECIFICATION DECISION FLOW — NiCr20TiAl
Question 1
Is your component a threaded fastener — bolt, stud, nut, or threaded rod operating above 300 °C?
2.4652 Specify per EN 10269:1999. This is the fastener-specific designation, satisfying European and Asian procurement audits for high-temperature bolting.
Question 2
Is your component a structural forging — disc, ring, bar, valve body, or compressor housing?
2.4631 Specify per EN 10302:2008. This is the creep-resisting components designation, required by most European turbine and power plant OEM specifications.
Question 3
Are you working from a legacy German drawing or maintaining heritage plant built before ~1990?
2.4952 Retain on the drawing for continuity. Request the supplier's MTC to include a cross-reference note confirming equivalence to EN 10302 / 2.4631. Do not change the drawing number without a formal engineering change order.
Question 4
Is your project governed by ASTM, ASME, or does your customer specify North American standards?
UNS N07080 Specify per ASTM B637. For aerospace, reference AMS 5667. Please confirm dual-certification availability with our team at the time of enquiry.
Question 5
My supplier's MTC says "2.4631" but my drawing says "2.4652." Is this acceptable?
Usually YES Both designations cover the same alloy in different application standards. Raise a material equivalency note in your project documentation. Many European OEMs maintain an approved equivalency register for exactly this cross-reference.

What to Expect on a Mill Test Certificate

When you receive a forging from Jiangsu Liangyi, the EN 10204 3.1 Mill Test Certificate will contain the following in the material description field:

  • Material designation: The specific number ordered against — e.g., "2.4631 per EN 10302:2008" or "2.4652 per EN 10269:1999"
  • Alternative designation cross-reference: Common aliases (NiCr20TiAl, UNS N07080) included in the remarks field as standard practice
  • Heat number: Traceable to the original melt, ESR run, and forging batch
  • Chemical analysis: Reported per the governing standard; OES + wet chemistry for trace elements
  • Mechanical properties: Tensile strength, proof strength, elongation, reduction in area, hardness, and Charpy impact — all reported against the minimum values in the ordered standard
💡
Procurement Tip

When placing an order, specify the designation and the standard revision explicitly — e.g., "2.4652 per EN 10269:1999" rather than just "NiCr20TiAl." This removes ambiguity from the MTC and simplifies incoming inspection. If you need dual-standard certification (EN + ASTM B637), request this at order placement — it requires certificates prepared against both standards' test procedures.

Common Specification Mistakes to Avoid

Using Only the Chemical Name on the Drawing

Writing "NiCr20TiAl" or "Nimonic® 80A" without a standard reference leaves the supplier free to choose which standard to certify against. This creates ambiguity in audits and can make compliance demonstrations difficult. Always pair the chemical name with a Werkstoffnummer and standard: "NiCr20TiAl / 2.4631 per EN 10302:2008."

Specifying the Wrong Designation for the Component Type

Specifying 2.4652 (fastener standard) for a turbine disc, or 2.4631 (structural standard) for a stud bolt, does not usually cause a material rejection — but it creates unnecessary document review cycles. Matching the designation to the application standard is cleaner engineering practice and simplifies third-party inspection.

Updating Legacy Drawings Without an Engineering Change Note

Replacing "2.4952" with "2.4652" on a heritage drawing without formal documentation breaks the audit trail for traceability. Add a note confirming the equivalency rather than changing the number outright, unless a full document revision cycle is being performed with appropriate change control.

Assuming Different Numbers Mean Different Material

Receiving an MTC showing "2.4631" when your drawing specifies "2.4652" is not a nonconformance by itself — but it must be resolved with a documented equivalency statement before the material is accepted into stock. Jiangsu Liangyi can provide a formal written equivalency statement as part of the shipping documentation.

Does the Designation Change the Heat Treatment?

No. The two condition suffixes you will encounter on MTCs — +AT (solution annealed + aged) and +P (precipitation hardened only) — refer to the heat treatment applied to the forging, not to the material designation number. The same heat treatment produces the same γ′ microstructure and mechanical properties regardless of whether the certificate reads 2.4652 or 2.4631.

Standard NiCr20TiAl heat treatment parameters:

  • Solution anneal: 1,080 °C (± 15 °C), 1–4 hours depending on section size, water or air quench
  • Age hardening: 700 °C (± 10 °C), 16 hours minimum, air cool

Jiangsu Liangyi performs all heat treatment in-house under documented procedures traceable to each order and heat number.

Frequently Asked Questions

Can I use 2.4652 material for a component certified to 2.4631?

In most cases yes — because the material is chemically identical. However, if your design is governed by EN 10302 (turbine/creep applications), the supplier must certify specifically against EN 10302 mechanical property requirements, not simply produce material with the right chemistry. Request the correct standard at the time of order rather than after production is complete.

Does NiCr20TiAl meet PED (Pressure Equipment Directive) requirements?

NiCr20TiAl forgings manufactured per EN 10302 (2.4631) or EN 10269 (2.4652) fall within the material standards recognised under the PED materials framework when accompanied by EN 10204 3.1 or 3.2 mill test certificates from a qualified manufacturer. Jiangsu Liangyi holds ISO 9001:2015 certification and produces MTCs to EN 10204 3.1 standard as default. Whether a specific forging meets PED compliance for a given pressure equipment assembly depends on the equipment category and the notified body involved — please consult your PED responsible person or notified body to confirm suitability for your application.

Is Nimonic® 80A the same as 2.4652?

Nimonic® 80A is a registered trade name (Special Metals Corporation, now part of PCC Airfoils) for essentially the same NiCr20TiAl alloy. The composition is closely aligned with 2.4652 / 2.4631, though minor differences in trace element limits exist between the trade specification and the EN standards. For commercial forgings, Jiangsu Liangyi produces to EN/ASTM standards; if Nimonic® 80A specifically is required, the trade-name specification must be referenced in the order.

What is the AMS equivalent of 2.4652?

AMS 5667 covers UNS N07080 bars and forgings for aerospace applications — the same NiCr20TiAl alloy. AMS 5667 imposes additional testing and documentation requirements compared to EN 10269/EN 10302, including more stringent inclusion content controls. Please contact our team directly to confirm current capability and documentation for AMS 5667 applications before placing an order.

Need Custom 2.4652 / 2.4631 Forgings?

Tell us your required designation, dimensions, quantity, and applicable standard. Our engineering team responds within 24 hours with a detailed technical proposal and lead time estimate.

Summary: One-Minute Cheat Sheet

Use this table as a quick reference whenever you need to match a component to the right designation.

If your component is… Specify this number Reference this standard
High-temperature bolt, stud, nut, or threaded rod 2.4652 EN 10269 : 1999
Turbine disc, ring, valve body, structural bar 2.4631 EN 10302 : 2008
Legacy German drawing from pre-1990 2.4952 Legacy W.Nr. (add EN cross-ref note)
ASTM, ASME, or North American project N07080 ASTM B637 (or AMS 5667 for aerospace)

Regardless of which designation your drawing carries, the underlying material — NiCr20TiAl — is one of the most field-proven precipitation-hardening nickel superalloys in industrial service, with a 60-year track record in European power generation and a cost-effective position between standard austenitic steels and complex molybdenum-bearing alloys such as Inconel® 718.

For full mechanical data, creep properties, available forging shapes, and application case studies, visit our product page: 2.4652 (NiCr20TiAl) Forged Parts — Jiangsu Liangyi.

JL
Jiangsu Liangyi Engineering Team
Jiangsu Liangyi Co., Limited — ISO 9001:2015 certified superalloy forging manufacturer since 1997. 25+ years of NiCr20TiAl production experience. Jiangyin, Jiangsu Province, China. Export to 50+ countries worldwide.

Trademark Notice: Nimonic® is a registered trademark of Special Metals Corporation. Inconel® is a registered trademark of Special Metals Corporation. Hastelloy® is a registered trademark of Haynes International, Inc. These trade names are referenced for informational and comparative purposes only. Jiangsu Liangyi Co., Limited is not affiliated with, endorsed by, or a licensee of these trademark holders. All products manufactured by Jiangsu Liangyi are produced to the applicable EN, ASTM, and international standards, not to proprietary trade name specifications unless explicitly agreed in writing.

Standards Disclaimer: References to EN 10302, EN 10269, ASTM B637, AMS 5667, and other standards are for informational purposes. Compliance with any specific standard for a given application must be verified by the customer against the applicable standard edition, revision, and any project-specific supplementary requirements. Jiangsu Liangyi holds ISO 9001:2015 quality management system certification. Claims of compliance with specific product standards (EN, ASTM, etc.) refer to the technical requirements of those standards as applied to our manufacturing processes and are confirmed on a per-order basis via the mill test certificate.

About the Publisher

Jiangsu Liangyi Co., Limited is an ISO 9001:2015 certified manufacturer of superalloy forgings based in Jiangyin, Jiangsu Province, China. Founded in 1997, the company has over 25 years of experience producing open die forgings and seamless rolled rings in NiCr20TiAl (2.4652 / 2.4631), Inconel® 718 (2.4668), Hastelloy® C-276 (2.4819), and 60+ other superalloy grades. Products are exported to 50+ countries and manufactured to EN 10302, EN 10269, ASTM B637, and other international standards. Mill test certificates to EN 10204 3.1 / 3.2 standard.

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