Equivalent Grades of Hastelloy C276: The Complete Cross-Reference Guide to UNS N10276

Hastelloy C276 is UNS N10276. Its internationally recognized equivalents are W.Nr. 2.4819 / NiMo16Cr15W (Germany and EN standard), NW 0276 (Japan, JIS), NS334 (China, GB/T 15008), NC17D (France, AFNOR), NCF 276 (South Korea, KS), and NiMo16Cr15W (ISO 6208). All designate the same nickel-molybdenum-chromium-tungsten alloy - provided the certificate of test matches the UNS N10276 chemistry limits.

 

Procurement teams, design engineers, and QA inspectors all eventually face the same question: a drawing says 2.4819, a mill test certificate says NS334, and a vendor quotation says UNS N10276 - are these the same material? In most cases, yes. But treating every so-called equivalent as automatically interchangeable is one of the most common (and expensive) mistakes in nickel alloy sourcing.

This guide gives you the complete cross-reference for Hastelloy C276, explains which designations govern which product forms, and shows you where equivalents stop being interchangeable.

What Are the Official Designations of Hastelloy C276?

Hastelloy C276 has one controlling identity - UNS N10276 - and several trademark and national names that all describe the same alloy. The safest procurement practice is to specify the UNS designation first and treat every other name as an alias.

Hastelloy C276 is the registered trademark of Haynes International. The Unified Numbering System (UNS) designation N10276, established under ASTM E527, is the only designation with a single, globally traceable chemistry definition: approximately 57% nickel (balance), 15.0-17.0% molybdenum, 14.5-16.5% chromium, 3.0-4.5% tungsten, 4.0-7.0% iron, with carbon limited to 0.010% max and silicon to 0.08% max.

The commercial names you may encounter include:

● Hastelloy C276 / C-276 - Haynes International (the trademark most users recognize)

● Nickelvac HC-276 - a legacy Inco/Special Metals trade name

● Nicrofer 4819 hMoW - VDM Metals' trade name for alloy 2.4819

Why does this matter? Because when a dispute arises over material properties, the contract language that prevails is the one tied to a published standard - UNS N10276 together with an ASTM/ASME product specification - not a trademark or a regional nickname. Trademarks identify the producer; designations identify the material.

What Is the Complete Cross-Reference Table for Hastelloy C276 Equivalent Grades?

Hastelloy C276 is listed under more than a dozen national and international standards. The table below is the full cross-reference engineers and buyers actually need, including the governing document for each designation.

 

Note on the German system: 2.4819 is the Werkstoffnummer (material number), while NiMo16Cr15W is the DIN/EN name that encodes the chemistry - roughly, a nickel alloy with 16% molybdenum, 15-16% chromium, and tungsten. Both appear on European certificates; they refer to the same alloy.

Note on China's NS334: this grade is defined in GB/T 15008 with chemistry limits that align with UNS N10276. Chinese mills frequently stamp products dual-designated as NS334 / N10276 / 2.4819. When importing NS334 material into ASME-code work, verify the heat chemistry against the ASTM specification limits, not just the GB designation.

Which ASTM and ASME Standards Apply to Each Hastelloy C276 Product Form?

The equivalent grade tells you what the alloy is; the product-form standard tells you how it must be made and tested. Plate, pipe, tube, bar, forgings, and fittings each have their own ASTM specification - and their ASME SB counterparts govern pressure-code construction.

 

Two supplementary systems complete the picture. Aerospace buyers may see AMS 5530 (plate, sheet, strip) and AMS 5750 (bar, forgings, rings). Oil and gas projects in sour service add NACE MR0175 / ISO 15156 compliance on top of the ASTM product standard. Once equipment falls under ASME pressure-code jurisdiction, the SB editions - not the ASTM originals - are the legally controlling documents.

Are All Equivalent Grades of Hastelloy C276 Truly Interchangeable?

No - equivalent does not mean identical. National grades are nearly always within a few hundredths of a percent of the UNS chemistry, but tolerance ranges, testing scope, and heat-treatment wording can differ between standards. For code work, always specify UNS N10276 plus the ASTM product standard and demand a full heat-by-heat certificate.

Three real differences deserve attention:

● Chemistry tolerance windows. GB/T 15008's NS334 and EN 10095's NiMo16Cr15W publish their own min/max ranges for Mo, Cr, W, and Fe. An NS334 heat is 'equivalent' only if its actual ladle analysis falls inside the ASTM B-series limits as well. For 95% of heats it does - but 'almost always' is not a specification.

● Scope and testing differences. DIN 17750-17752 and JIS H4551 define their own mechanical test frequencies, grain-size requirements, and finish requirements. A product certified only to a national standard may not satisfy every ASTM clause without additional testing.

● Code jurisdiction. ASME Section VIII vessels and B31.3 piping require material in the ASME Code material database. Equivalent national grades without an ASME allowance cannot simply be substituted in code-stamped equipment, regardless of chemistry.

The engineering rule is simple: equivalents are for identification and cross-checking, not for silent substitution. If a vendor offers 2.4819 material against an N10276 requirement, accept it only with a mill test certificate showing the full heat chemistry and the applicable dual certification.

Which Alloys Are Often Confused With C276 but Are NOT Equivalent?

Hastelloy C22, C-4, C-2000, Alloy 59, and B-2 belong to the same C-family of nickel alloys but have distinctly different chemistries and corrosion profiles. They are alternatives to consider, not equivalents to substitute.

 

The consequences of confusing these grades are not academic. Substituting B-2 where C276 was specified removes the chromium that protects against oxidizing media; substituting C22 where C276 was specified reduces resistance to reducing acids such as concentrated hydrochloric acid. Each C-family alloy was engineered for a specific corrosion envelope. Use the comparison articles in this series - C276 vs Inconel 625, C276 vs Alloy 20, C276 vs Incoloy 825 - for head-to-head data.

How Should You Write Hastelloy C276 Into Drawings and Procurement Documents?

Specify the material by UNS designation, product form, ASTM/ASME standard, and condition - never by trade name alone. A complete call-out eliminates substitution risk before it reaches the shop floor.

A fully traceable specification reads like this:

"Plate, UNS N10276 (Hastelloy C276), per ASTM B575 / ASME SB-575, solution annealed 1095-1170 C, rapid cool, with EN 10204 3.1 mill test certificate."

Checklist for the material line on your requisition:

● UNS designation: N10276 - state it explicitly; 'Hastelloy' alone does not exclude C22 or C-4.

● Product standard: B575 / B619 / B622 / B626 / B574 / B564 / B366 to match the form.

● Condition: solution annealed - C276 is always supplied annealed for corrosion service.

● Certificate: EN 10204 3.1 minimum; 3.2 with third-party witness for code-stamped work.

● Welding consumables: ERNiCrMo-4 wire / ENiCrMo-4 electrodes per AWS A5.14/A5.11.

● Secondary references: 2.4819, NS334, or NW 0276 may be noted in parentheses for supplier convenience - but the UNS line controls.

How Do You Verify That Delivered Material Is Genuine Hastelloy C276?

Verification rests on three pillars: a full chemical analysis on the mill test certificate, positive material identification (PMI) on the delivered product, and mechanical/corrosion testing against the ASTM product standard. Paper, instrument, and mechanicals must all agree.

A practical receiving-inspection sequence:

● 1. Check the certificate: heat number, full ladle chemistry against ASTM limits, solution-anneal temperature, and mechanical results (typical: tensile 690 MPa min, yield 283 MPa min, elongation 40% min).

● 2. Match heat numbers: the number on the certificate must appear stamped or stenciled on the actual product.

● 3. Run PMI: portable XRF confirms the Mo/Cr/W fingerprint and screens out look-alike alloys such as C22 or 316L. For full accuracy on carbon, use optical emission spectrometry (OES) per ASTM E304/E305 methods.

● 4. Add corrosion testing for critical service: ASTM G28 Method A/B intergranular corrosion testing, specified at the order stage.

JN Alloy supplies Hastelloy C276 in all product forms with full EN 10204 3.1/3.2 certification, heat-by-heat PMI, and dual-designation documentation (UNS N10276 / W.Nr. 2.4819 / NS334). See the Ultimate Guide to Hastelloy C276 for the complete material overview, or the How to Choose Hastelloy C276 Pipes guide for line-pipe specification.

Key Takeaways

● Hastelloy C276 = UNS N10276 = W.Nr. 2.4819 = NiMo16Cr15W = NW 0276 = NS334 = NCF 276, provided the chemistry meets the ASTM limits.

● Specify by UNS N10276 plus the ASTM product-form standard (B575, B619, B622, B626, B574, B564, B366); ASME SB editions govern code work.

● Weld it with ERNiCrMo-4 / ENiCrMo-4 consumables to keep the joint as corrosion-resistant as the parent metal.

● Equivalent grades are identification aliases, not a license for silent substitution - check tolerance ranges and code compliance.

● C22, C-4, C-2000, Alloy 59, and B-2 are related alternatives, not equivalents; each serves a different corrosion envelope.

● Verification = certificate chemistry + heat-number traceability + PMI/XRF + (where critical) ASTM G28 corrosion testing.

Frequently Asked Questions

What is the UNS number of Hastelloy C276?

The UNS number is N10276. It is the single controlling designation, defined by chemistry: balance nickel (~57%), 15-17% Mo, 14.5-16.5% Cr, 3-4.5% W, 4-7% Fe, C max 0.010%, Si max 0.08%.

What is the European equivalent of Hastelloy C276?

The European equivalent is material number 2.4819, named NiMo16Cr15W under EN 10095. It is the same alloy defined by DIN 17744 and the DIN 17750-17752 wrought-product standards.

Is Chinese grade NS334 the same as Hastelloy C276?

Yes - NS334 in GB/T 15008 is the Chinese equivalent of UNS N10276, with matching chemistry limits. Chinese mills often dual-stamp products NS334/N10276. For ASME-code work, verify the heat chemistry against the ASTM specification.

Is Hastelloy C22 equivalent to C276?

No. C22 (UNS N06022) has more chromium (20-22.5%) and less molybdenum and tungsten. It performs better in oxidizing media but is weaker against reducing acids such as concentrated HCl. It is an alternative, not an equivalent.

What is W.Nr. 2.4819?

2.4819 is the German Werkstoffnummer (material number) for Hastelloy C276 under DIN 17744. It appears on European certificates alongside the name NiMo16Cr15W and refers to the identical alloy.

What welding consumables are used for Hastelloy C276?

Use ERNiCrMo-4 filler wire (AWS A5.14) or ENiCrMo-4 covered electrodes (AWS A5.11). They match the parent alloy's corrosion resistance and are also accepted for joining C276 to dissimilar nickel alloys and stainless steels.

How do I verify a supplier's material is genuine Hastelloy C276?

Require an EN 10204 3.1 (or 3.2) mill test certificate with full ladle chemistry, match heat numbers to the product, and run PMI/XRF screening. For critical service, add ASTM G28 intergranular corrosion testing at the order stage.