Inconel 625 Equivalent Grades Explained

What Does "Equivalent Grade" Mean for Inconel 625?

"Inconel 625" is a trade name owned by Special Metals (now part of the Precision Castparts / Berkshire Hathaway group). The same nickel-chromium-molybdenum-niobium alloy is sold, specified and certified under many different names around the world. An equivalent grade is another standard's designation for the same base chemistry and service performance — so a German buyer ordering Werkstoff 2.4856, a Japanese buyer ordering NCF 625, and a U.S. buyer ordering UNS N06625 are all procuring the same material.

The single anchor that ties every table together is the UNS number N06625. UNS (Unified Numbering System) is the universal U.S. identifier printed on mill test reports and certificates of conformance, and virtually every international cross-reference maps its national grade back to N06625. Understanding the mapping lets engineers substitute, source globally and interpret foreign drawings without ambiguity.

For procurement teams this matters in three practical ways. First, global sourcing: a mill in Germany, Japan or China can deliver the same alloy under 2.4856, NCF 625 or NS336, so you are not locked to one geography or one trademark holder. Second, legacy drawings: older plant built to BS, AFNOR or GOST standards can be maintained and upgraded using N06625 stock with documented equivalence. Third, code compliance: most modern projects accept any nationally recognized equivalent provided the mill certificate shows the controlling chemistry and the required tests — which is exactly what the table and the guidance below help you verify.

Key takeaway

"Equivalent" means the same family of alloy — not necessarily a clause-for-clause identical material. Each standard sets its own chemical tolerances, product-form scope and heat-treatment/temper options. The name match gets you 90% of the way; the purchase-order detail closes the last 10% (see How to Read the Table).

Master Cross-Reference Table: Inconel 625 Global Equivalents

The table below is the fastest way to match Inconel 625 across the major standards systems. Bookmark it for procurement, drawing interpretation and quality-welding procedure reviews.

Shared chemistry behind every equivalent

What makes all these designations "the same alloy" is the chemistry they describe. The nominal (typical) composition that underpins N06625, 2.4856, NCF 625, NC 22 DNb, ХН65МВБ, NA 43 and NS336 is:

Note: National designations cover the same nominal chemistry, but exact tolerances and heat-treat conditions differ by document. Confirm against the cited specification before final release.

Important: not every "625-family" name is an equivalent

Some alloys are frequently confused with Inconel 625 but are not equivalents and should not be substituted without re-qualification: Inconel 718 (precipitation-hardened Ni-Fe-Cr-Nb, much higher strength), Hastelloy C276 (lower Nb, optimized for reducing acids), Incoloy 825 (Fe-rich, lower Mo), and Monel 400 (Ni-Cu, no Cr/Mo). These are alternatives selected for different duty — never listed as equivalents of N06625.

UNS N06625 — The Universal Anchor

• UNS N06625

• United States (Unified Numbering System)

The UNS number is the common thread in every cross-reference table and on every ASTM/ASME certificate of conformance.

In the U.S. system, "Inconel 625" as a trade name and "N06625" as a material number are used together. You will see N06625 on:

• Mill test reports (MTRs) and certificates of conformance

• ASTM material specs — B443 (plate/sheet/strip), B444 (seamless pipe/tube), B446 (bar/rod), B564 (forgings), B704/B705 (welded tube/pipe)

• ASME boiler & pressure vessel code — the same specs appear with an "S" prefix (SB-443, SB-444, etc.) in ASME Section II, Part B

• Purchase orders and welding procedure specifications (WPS)

If you only remember one designation from this article, remember N06625. Everything else maps to it.

Europe: EN 2.4856 / NiCr22Mo9Nb

• 2.4856

• European EN / German DIN / Werkstoff

Full designation: NiCr22Mo9Nb per EN 10095 and DIN 17744. Often written as W.Nr. 2.4856.

In Europe the alloy is identified by its material number 2.4856 and its descriptive name NiCr22Mo9Nb, which literally encodes the nominal composition:

• NiCr22 — nickel-chromium base, ~22% Cr

• Mo9 — ~9% molybdenum (the corrosion-resistance workhorse)

• Nb — niobium (columbium) for precipitation strengthening

Within the EU this single number covers plate, sheet, bar, forgings and tube through the EN 10095 family and the DIN 177xx product-specific standards. For a project governed by European codes, specifying "2.4856, EN 10095" is the direct equivalent of "N06625, ASTM B443/B444".

Japan: JIS NCF 625

• NCF 625

• Japanese Industrial Standards (JIS)

Covered by JIS G 4901 (plate/sheet), G 4902 (bar), G 4904 (tube), G 4926 (forgings).

Japanese equipment — common in power generation, chemical plants and marine systems — specifies the alloy as NCF 625. The "NCF" prefix denotes nickel-chromium-iron corrosion-resistant alloys in the JIS G 49xx series, and NCF 625 is fully chemically equivalent to UNS N06625. When working with Japanese EPCs or drawings, match NCF 625 to N06625 directly; the mechanical and corrosion properties are the same family.

France: AFNOR NC 22 DNb

• NC 22 DNb

• French AFNOR

French national designation; now aligned with the European EN 10095 as NF EN 10095.

The French NC 22 DNb designation follows the AFNOR "NC" (nickel-chromium) naming convention. With France adopting the harmonized European standards, NC 22 DNb is functionally the French expression of 2.4856 / N06625. Older French drawings and supplier stocks may still carry the NC 22 DNb label — treat it as equivalent to N06625.

United Kingdom: BS NA 43

• NA 43

• British Standards (legacy)

Legacy BS 3072 (plate), BS 3074 (tube), BS 3076 (bar) designations; now superseded by the EN system.

British drawings and refurbishment projects on older plant may reference NA 43 (part of the former "NA" nickel-alloy series). The UK has largely migrated to the European EN/2.4856 designations, but NA 43 remains the recognizable UK equivalent of N06625 for legacy equipment, spares and maintenance specifications.

Russia / CIS: GOST ХН65МВБ (EP814)

• ХН65МВБ

• Russian GOST

Covered by GOST 5632 (corrosion-resistant steels and alloys) and GOST 22442; also referenced as EP814 / EP814A.

The Russian equivalent is commonly cited as ХН65МВБ (transliterated KhN65MVB), with the marke "EP814" used for the wrought/forged quality. The GOST chemistry is intentionally close to N06625, but Russian standards allow slightly different tolerance bands, so for critical service a side-by-side composition check against the actual MTR is recommended. When sourcing from CIS supply or matching Russian-designed equipment, map ХН65МВБ to N06625 and verify elemental limits before acceptance.

China: GB/T NS336

• NS336

• Chinese GB/T

Modern Chinese designation per GB/T 15007 (grade list) and GB/T 15008–15014 (product-form specs).

Chinese chemical, nuclear and marine projects specify the alloy as NS336, a "corrosion-resistant alloy" grade in the GB/T 15007 system. Legacy drawings may use the older descriptive name 0Cr20Ni65Mo3Nb2. NS336 is the direct Chinese equivalent of UNS N06625 and is produced to the full range of product-form standards (plate, sheet, bar, tube, forgings, wire). For Chinese-sourced equipment, NS336 ↔ N06625 is the correct mapping.

International: ISO NiCr22Mo9Nb

The International Organization for Standardization lists the alloy as NiCr22Mo9Nb (and references N06625 in compositional documents such as ISO/TR 15510). The relevant ISO product specifications are:

• ISO 6208 — plate, sheet and strip

• ISO 9723 — bar

• ISO 9724 — wire

• ISO 9725 — forgings

ISO designations are most often encountered in multinational tender documents and where no single national code governs the project (e.g., offshore or EPC work spanning several jurisdictions).

Aerospace: AMS Specifications

For aerospace, gas-turbine and engine applications, the Society of Automotive Engineers (SAE) publishes tighter AMS controls on top of the ASTM/ASME material specs. The principal AMS documents for this alloy are:

Aerospace buyers specify both the AMS number (for procurement control and traceability) and the underlying UNS N06625. The matching filler metal is ERNiCrMo-3 (solid wire) / ENiCrMo-3 (covered electrode) per AWS A5.14 / A5.11 — note that the filler metal is a separate designation, not an "equivalent base grade."

How to Read an Equivalent-Grades Table Correctly

A name match is a strong starting point, but three details separate a safe substitution from a costly mistake:

1. Product-form coverage

Not every national standard covers every shape. A designation valid for plate may not carry the same dimensional or test requirements for seamless pipe. Always confirm the standard cited actually covers your product form (see the "Product Forms Covered" column in the master table).

2. Temper / heat-treatment condition

Inconel 625 is supplied in Grade 1 (solution-annealed) or Grade 2 (annealed + aged, higher strength). An equivalent grade table tells you the chemistry matches; it does not tell you which temper was ordered. A Russian or Chinese equivalent can be delivered in either condition, so the temper must be stated explicitly on the PO.

3. Chemical tolerance bands

National standards set their own acceptable ranges for each element. The differences are usually small, but for sour-service (NACE MR0175), nuclear or aerospace work, the controlling elemental limits are defined by the governing code, not by the name equivalence. Read the actual MTR against the relevant specification.

4. Certification and traceability

Equivalence is only as good as the paper behind it. Require a mill test report (EN 10204 3.1, or 3.2 with surveyor attestation for critical service) that states the actual heat chemistry, mechanical results and the issuing standard. A supplier saying "this is 625 equivalent" without a conformance certificate is not a qualified substitute — the certificate is what lets an inspector, insurer and end-user accept the material across borders.

5. Dual certification

Many mills now ship material dual-certified — e.g., marked both N06625 (ASTM) and 2.4856 (EN), or both N06625 and NS336. Dual certification is the simplest way to satisfy multinational EPC requirements and to keep one stock code serving every project. When available, specify dual certification on the PO to eliminate future interpretation questions.

Frequently Asked Questions

What is the UNS number for Inconel 625?

The Unified Numbering System (UNS) designation for Inconel 625 is N06625. UNS is the universal U.S. identifier used on mill test reports, purchase orders and certificates of conformance. In most international cross-reference tables, N06625 is the anchor grade that every other national designation (2.4856, NCF 625, NC22DNb, etc.) is mapped against.

What is the European (EN/DIN) equivalent of Inconel 625?

The European equivalent is material number 2.4856 with the designation NiCr22Mo9Nb under EN 10095 and DIN 17744. In German supply it is commonly written as Werkstoff Nr. 2.4856 or simply W.Nr. 2.4856. The "NiCr22Mo9Nb" name describes the nominal composition: ~22% nickel-chromium, ~9% molybdenum, niobium-stabilized.

Is Inconel 625 the same as NiCr22Mo9Nb / 2.4856?

They are metallurgically the same nickel-chromium-molybdenum-niobium alloy and are used interchangeably in procurement, but they are not legally identical in every respect. Each standard sets its own chemical tolerances, product-form coverage and temper options (e.g., Grade 1 solution-annealed vs Grade 2 aged). Always confirm that the specific standard, grade and product form on your purchase order match the service requirement — do not assume a name match alone is sufficient.

What is the Japanese (JIS) equivalent of Inconel 625?

The Japanese Industrial Standards (JIS) designation is NCF 625, covered by JIS G 4901/4902/4904/4926 for various product forms (plate/sheet, bar, tube, forgings). NCF 625 is fully equivalent to UNS N06625 and is the grade specified for Japanese-built chemical, power and marine equipment.

What are the AMS (aerospace) specifications for Inconel 625?

The main Society of Automotive Engineers (AMS) aerospace specifications are AMS 5599 (sheet, strip and plate), AMS 5666 (bar, forging and ring), AMS 5581 (seamless tube) and AMS 5837 (welding wire, matching ERNiCrMo-3). These are tighter, procurement-control specifications used by aerospace and engine manufacturers in addition to the ASTM/ASME material specs.

What is the Chinese equivalent of Inconel 625?

The Chinese GB/T designation is NS336 (corrosion-resistant alloy grade), with product-form standards GB/T 15008–15014. An older descriptive name, 0Cr20Ni65Mo3Nb2, is sometimes seen in legacy drawings. NS336 is the modern equivalent of UNS N06625 used in Chinese chemical, nuclear and marine projects.

Continue the Inconel 625 Series

• Ultimate Guide to Inconel 625

• Inconel 625 Chemical Composition

• Inconel 625 Mechanical Properties

• Inconel 625 Corrosion Resistance

• ASTM Standards for Inconel 625

JN Alloy supplies Inconel 625 across all product forms — pipe, tube, plate, sheet, bar, forgings, flanges and fittings — with full EN 10204 3.1 certification and global-grade cross-referencing support. Tell us your standard and temper; we'll match it.

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