Hastelloy C-276 (UNS N10276): Instrumentation Fittings, Valves & Tubing
Hastelloy C-276 is a nickel-molybdenum-chromium-tungsten (Ni-Mo-Cr-W) corrosion-resistant superalloy, designated UNS N10276 and W.Nr. 2.4819. It's the material of choice where wet chlorine, hot acids, chlorides and sour gas would eat through stainless steel. Crestflo supplies this grade as instrumentation tube and compression fittings, instrumentation valves, and instrumentation tubing. Every batch carries heat and lot-number traceability, and the parts are built as drop-in replacements for the major brands. Delivery runs 6-8 weeks, serving the US market. The composition, mechanical, PREN and corrosion figures below come from standard published data for the alloy, drawn from the applicable ASTM specification, and can be adjusted to suit specific requirements.
Scope: Hastelloy C-276 here refers specifically to the instrumentation-grade Ni-Mo-Cr-W alloy used for fluid-system tube fittings, compression ferrules and instrumentation valves, it doesn't cover electrical or wire ferrules, nor plumbing and HVAC fittings. Crestflo supplies this alloy only in instrumentation fitting, valve and tubing forms. Mill bar, sheet, plate and pipe aren't part of the offering.
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Hastelloy® is a registered trademark of Haynes International, Inc.
Hastelloy C-276 Also Known As: UNS N10276, Alloy C276 & W.Nr. 2.4819
On drawings, datasheets and purchase orders, the same alloy shows up under several trade names and standard designations. A print might call out "Alloy C-276," "N10276 alloy," or "NiMo16Cr15W", but all three point to the same Ni-Mo-Cr-W corrosion-resistant grade.
| Designation type | Value |
|---|---|
| Trade / common names | Hastelloy C-276, Hastelloy C276, Alloy C-276, Alloy C276, C-276, C276 |
| UNS number | UNS N10276 (N10276) |
| Werkstoff (W.Nr.) | 2.4819 (Werkstoff 2.4819) |
| ISO designation | NiMo16Cr15W |
| Alloy family | Nickel-base, Ni-Mo-Cr-W corrosion-resistant alloy |
| Spaced / reversed forms | Alloy C 276, C276 Hastelloy, N10276 alloy |
UNS N10276 is the US designation. W.Nr. 2.4819 is its European counterpart. Both point to the same alloy, so whichever way a part gets specified, it's still the same Hastelloy C-276.
Hastelloy C-276 Chemical Composition (Ni-Mo-Cr-W, per ASTM)
C-276's corrosion performance comes down to its nickel matrix, loaded with high molybdenum and tungsten content. Chromium handles the oxidising resistance. What really sets the alloy apart is one of the lowest carbon and silicon limits of any wrought nickel alloy, and that's precisely what keeps corrosion resistance intact in welds and the areas right next to them.
| Element | wt % (per ASTM B574 / B622) |
|---|---|
| Nickel (Ni) | Balance (~57) |
| Molybdenum (Mo) | 15.0–17.0 |
| Chromium (Cr) | 14.5–16.5 |
| Iron (Fe) | 4.0–7.0 |
| Tungsten (W) | 3.0–4.5 |
| Cobalt (Co) | 2.5 max |
| Manganese (Mn) | 1.0 max |
| Vanadium (V) | 0.35 max |
| Carbon (C) | 0.010 max |
| Silicon (Si) | 0.08 max |
| Phosphorus (P) | 0.04 max |
| Sulfur (S) | 0.03 max |
Ranges follow the applicable ASTM product-form specification. Crestflo verifies the actual heat chemistry on the EN 10204 material test certificate that comes with every order.
Hastelloy C-276 Mechanical & Physical Properties
In the solution-annealed condition, C-276 pairs high strength with the ductility and toughness needed for forming fittings and valves. It holds onto that toughness from cryogenic temperatures on up. The figures below are standard published minimums, along with nominal physical data for the alloy.
Mechanical properties (solution-annealed, room temperature)
| Property | Value |
|---|---|
| Tensile strength | ≥ 100 ksi (690 MPa) |
| Yield strength (0.2% offset) | ≥ 41 ksi (283 MPa) |
| Elongation | ≥ 40% |
| Hardness | ≤ ~90 HRB |
Physical properties
| Property | Value |
|---|---|
| Density | 8.89 g/cm³ (0.321 lb/in³) |
| Melting range | 1325–1370 °C (2415–2500 °F) |
| Structure | Face-centered cubic (austenitic nickel matrix) |
Mechanical minimums follow ASTM B574 / B622 for the solution-annealed condition. Final certified properties for a given heat aren't found there, though; they're stated on the material test certificate.
Hastelloy C-276 PREN (Pitting Resistance Equivalent Number)
Calculated from nominal composition, C-276's pitting resistance equivalent number comes out to roughly 68 using PREN = Cr + 3.3 × Mo. Factor in tungsten (Cr + 3.3 × (Mo + 0.5 × W)) and it climbs to about 74, comfortably ahead of 6-molybdenum austenitics and super-duplex stainless steels. PREN is just a calculated ranking index, though. Real-world corrosion behavior in C-276 comes down to its full Ni-Mo-Cr-W chemistry, not PREN alone. For a cross-alloy view, see the PREN comparison table.
Hastelloy C-276 Corrosion Resistance by Media
C-276 stands out as one of the few alloys that holds up against both oxidising and reducing media. It's also highly resistant to pitting, crevice corrosion and chloride stress-corrosion cracking, the very failure modes that limit stainless steel. The table below draws on standard alloy corrosion literature to summarise typical service suitability.
| Media / service | Suitability | Note |
|---|---|---|
| Wet chlorine (Cl₂), hypochlorite | Excellent | A defining application for the grade |
| Chlorine dioxide (ClO₂) | Excellent | Bleaching, pulp & paper |
| Hydrochloric acid (HCl), contaminated | Good–Excellent | Resists hot, impure HCl where stainless fails |
| Sulfuric acid (H₂SO₄) | Good | Including hot and contaminated conditions |
| Ferric & cupric chloride (FeCl₃ / CuCl₂) | Excellent | Strong resistance to pitting/crevice attack |
| Acetic & formic acids | Excellent | Organic-acid process streams |
| Seawater / brackish water | Excellent | Resists chloride pitting and crevice corrosion |
| Flue-gas desulfurization (FGD) | Excellent | Scrubber and absorber environments |
| Chloride stress-corrosion cracking | Highly resistant | Key advantage over austenitic stainless |
If you're choosing a material for a specific process, check the corrosion-by-media × alloy matrix.
Hastelloy C-276 for Sour Service (NACE MR0175 / ISO 15156)
In the solution-annealed condition, UNS N10276 counts as an accepted nickel-base corrosion-resistant alloy for sour (H₂S-containing) service under NACE MR0175 / ISO 15156-3. Check the hardness and material-condition limits in the standard against your specific application before you commit. Crestflo stocks NACE MR0175 / ISO 15156-compliant Hastelloy C-276 fittings and valve material options. For more detail, see the NACE MR0175 and ISO 15156 standard pages, along with the sour-service selection guide.
Hastelloy C-276 Temperature & Pressure Suitability
C-276 holds up across a huge temperature range, from cryogenic conditions all the way to roughly 1000 °F (538 °C), staying tough and strong through sustained service in many different environments. Pressure rating works differently, though: it comes down to the product form and wall thickness of the finished part, not the grade itself. That's why working-pressure figures are listed on each individual tube-fitting, valve and tubing page, set against the applicable standard and adjustable to what the job calls for.
Hastelloy C-276 Product-Form Standards (ASTM B622, B574, B366 & ASME SB-)
Crestflo makes instrumentation components, fittings, valves, tubing, from certified material. The underlying alloy falls under a family of ASTM specifications, one for each product form, and each carries a matching ASME SB- designation. Those specifications define the grade itself.
| Product form | ASTM | ASME equivalent |
|---|---|---|
| Seamless pipe & tube | B622 | SB-622 |
| Welded pipe | B619 | SB-619 |
| Welded tube | B626 | SB-626 |
| Rod & bar | B574 | SB-574 |
| Plate, sheet & strip | B575 | SB-575 |
| Forgings | B564 | SB-564 |
| Wrought fittings | B366 (WPHC276) | SB-366 |
Values and grades follow the applicable ASTM/ASME specification. Every order ships with its material certificates.
When to Choose Hastelloy C-276 vs C-22, Inconel 625 & 316L
C-276 is the workhorse alloy for chemical service that swings between reducing and oxidising conditions. Broad and dependable, it's built for exactly that combination. The comparison below sets it against the alloys buyers most often weigh against it, and each one links to its own material or comparison page.
| Alloy | Key strength | Choose when | More detail |
|---|---|---|---|
| Hastelloy C-276 (N10276) | Broad resistance in reducing + oxidising media; Cl-SCC immunity | Mixed acids, wet chlorine, sour service, seawater, the general severe-service default | This page |
| Hastelloy C-22 (N06022) | Higher chromium; strongly oxidising / mixed-acid duty | Oxidising acid mixtures and hot oxidising chlorides need extra Cr | Hastelloy C-22 |
| Inconel 625 (N06625) | High-temperature strength with good corrosion resistance | Elevated-temperature strength is the governing requirement | Inconel 625 · Hastelloy vs Inconel |
| 316 / 316L (S31600 / S31603) | Cost-effective general instrument service | Standard, mildly corrosive service, no chloride/acid upgrade needed | 316 / 316L |
For the head-to-head decision, read the Hastelloy vs Inconel guide.
Hastelloy C-276 Product Forms from Crestflo: Fittings, Valves & Tubing
Crestflo carries UNS N10276 across three instrumentation product lines, and each one gets its own detail page covering sizes, ratings and how to order. The grade shows up in compression and ferrule fittings. It also goes into needle, ball and manifold valves, plus seamless instrumentation tubing.
- Hastelloy C-276 tube & compression fittings, available in single and double ferrule (twin-ferrule) styles, hardened or non-hardened, in imperial and metric sizes, with end connections up to 2" (50 mm) OD. You'll also see these listed as C-276 compression fittings, C276 ferrule fittings, and UNS N10276 fittings. Compression tube fittings are performance-qualified per ASTM F1387.
- Hastelloy C-276 instrumentation valves, needle, ball, check, and 2/3/5-way manifold valves, all in C-276, ranging from 1/16" to 1". The pressure-boundary design follows ASME B16.34, with seat-leak and test practice per API seat guidelines.
- Seamless Hastelloy C-276 instrumentation tubing, seamless C-276 / N10276 tubing, offered in a range of imperial and metric OD and wall combinations.
Each Crestflo C-276 part carries a heat/lot number, and it ships with an EN 10204 material test certificate. Size, ferrule type and thread standard are set to match whatever the job calls for.
Why Crestflo for Hastelloy C-276
We Engineer Confidence, and for an exotic alloy like C-276, that means chemistry verified through PMI, sourcing you can trust and real interchange. Extractable specs, not something buried in a PDF.
- Drop-in interchange for Swagelok®, Parker®, Hoke® and Hy-Lok®: the dimensions match, and the compression fitting ends carry ASTM F1387 performance qualification (these are interchange/equivalent parts, not "compatible" or "intermix" parts). Need a comparison? Request your Swagelok®/Parker® cross-reference from our engineering team through the Swagelok cross-reference page.
- Lead time of 6-8 weeks, against 20+ weeks typical for the majors. Details sit on the lead-time capability page.
- Full traceability: a heat/lot number on every part, EN 10204 MTC 3.1 as standard (3.2 on request), and PMI to confirm the material really is N10276. We back this with in-house testing too.
- NACE MR0175 / ISO 15156 material options are available on every fitting, along with single and double ferrules (hardened or non-hardened) in both imperial and metric.
- ISO 9001 / 14001 / 45001 & PED certified, with in-house CNC / VMC / EDM machining; small MOQs and private-label options round things out.
- The heritage behind the brand: Crestflo is the instrumentation division of a four-decade-old, Government-of-India-recognized export house with a proven Middle-East delivery track record. New manufacturing capability, paired with deep export pedigree. Read more about Crestflo.
Stock & delivery: Standard items ship from ready stock. Specials are made to order, and those typically take 6-8 weeks. Origin: Material is of Indian origin. US and European melt can be arranged on request, and we provide full material traceability (origin & compliance).
Buyers: Request a Quote or Sample (end users, EPC, panel fabricators) · Talk to an engineer / send a print (equipment manufacturers, OEMs) · Become a distributor. Serving oil & gas and petrochemical & chemical processing across the US.
Hastelloy C-276 FAQs
What is Hastelloy C-276?
Hastelloy C-276 is a nickel-molybdenum-chromium-tungsten (Ni-Mo-Cr-W) alloy built to resist corrosion, designated UNS N10276 and W.Nr. 2.4819. Fabricators specify it for instrumentation fittings, valves and tubing wherever conditions turn severe: chemical processing, marine environments, sour-gas service. Stainless can't hold up in these settings. This Hastelloy grade can. It shrugs off pitting, crevice corrosion and chloride stress-corrosion cracking, the failure modes that finish off lesser alloys.
What is the chemical composition of Alloy C-276?
The alloy is nominally balance nickel, with roughly 16% molybdenum, 15.5% chromium, 3.75% tungsten, and 4–7% iron. Carbon stays capped at 0.010% max, silicon at 0.08% max. For the full ASTM ranges, check the composition table above.
Is UNS N10276 the same as W.Nr. 2.4819?
Yes. UNS N10276 is the American designation. W.Nr. 2.4819 is its European, or Werkstoff, counterpart. They're the same alloy: Hastelloy C-276, also known as Alloy C-276, with the ISO designation NiMo16Cr15W.
Is Hastelloy C-276 suitable for sour (NACE) service?
In the solution-annealed condition, N10276 is accepted as a nickel-base corrosion-resistant alloy for sour service under NACE MR0175 / ISO 15156-3. Confirm the hardness and material-condition limits in the standard before applying it to your project. Crestflo supplies NACE-compliant C-276 fittings, along with valve material options.
What corrosion environments is C-276 used for?
It handles wet chlorine, hypochlorite and chlorine dioxide without any trouble. Hot, contaminated hydrochloric and sulfuric acids don't faze it, and neither do ferric and cupric chlorides. Acetic acid and formic acid are no problem either, and the same goes for seawater and flue-gas desulfurization. Oxidising media, reducing media: it holds up in both.
What is the PREN of Hastelloy C-276?
Based on nominal composition, PREN works out to roughly 68 using Cr + 3.3 × Mo, and climbs to about 74 once the tungsten term gets factored in. That's well above 6-moly and super-duplex stainless grades. Still, PREN is just a calculated ranking figure. C-276's actual corrosion behavior depends on its full chemistry, not on PREN alone.
Which ASTM/ASME specs cover C-276 product forms?
Seamless pipe and tube fall under ASTM B622. Welded tube gets its own number, B626, and welded pipe isn't far behind at B619. Rod and bar are covered by B574. Plate, sheet, and strip fall under B575, forgings under B564. Wrought fittings, including the WPHC276 grade, carry the designation B366. Each of these forms also has a matching ASME SB- designation.
When should I choose C-276 over C-22 or Inconel 625?
C-276 works well as the broad workhorse for chemical service that mixes reducing and oxidising conditions. For strongly oxidising or mixed-acid duty, C-22 is the better call, since that's the kind of service that needs higher chromium. Where high-temperature strength governs the choice, though, Inconel 625 takes over. Check the comparison table and the Hastelloy-vs-Inconel guide for more detail.
What sizes and forms does Crestflo offer in C-276?
We supply compression and tube fittings up to 2" (50 mm) OD, available in single or double ferrule, hardened or non-hardened. Instrumentation valves span from 1/16" to 1". Seamless instrumentation tubing rounds out the range, offered in both imperial and metric. Everything can be customized to your requirement.
Can I get material certificates and heat traceability for C-276?
Crestflo issues EN 10204 3.1 certificates as standard, with 3.2 available on request. Every part gets stamped with a heat and lot number, so you can trace it all the way back. PMI confirms the alloy, and testing runs through Crestflo's in-house QA regime.
Can Crestflo C-276 fittings replace Swagelok or Parker parts?
Yes. Crestflo C-276 fittings are dimensional interchange/equivalent parts for the major brands, and their compression fitting ends carry ASTM F1387 performance qualification. Swagelok® and Parker® are trademarks held by their respective owners. These parts are interchange/equivalent, not "compatible/intermix." Need a cross-reference for a particular brand? Just ask.
What is the price and lead time for Hastelloy C-276 fittings?
Pricing runs by quotation only, there's no online cart to click through. Standard items ship from ready stock; specials get made to order, and delivery on those runs 6-8 weeks. Standard product comes from India. If you need US or European melt instead, that's available on request, and it comes with full traceability. To get a configured part number and price, submit an RFQ with size, form, material and rating.
Related Alloys & Resources
- Hastelloy C-22: a higher-chromium relative within the Hastelloy line, suited to strongly oxidising and mixed-acid environments.
- Inconel 625: a nickel alloy valued for its high-temperature strength and solid corrosion resistance.
- 316 / 316L stainless, the standard-service baseline before an alloy upgrade.
- Hastelloy B-2 · Hastelloy B-3 · Hastelloy X, grades related to Hastelloy.
- Hastelloy vs Inconel and the corrosion-alloy matrix will help you decide between options.
- Want the full lineup? Check the instrumentation valves hub and the materials hub.
Request a Hastelloy C-276 Quote
Tell us the form you need: fittings, valves or tubing. Include the size, end connections and line conditions as well. From there, the Crestflo Engineering Team will send back a configured part number, ratings and price.
Request a Quote · Request a Sample · Browse the materials hub sales@crestflousa.com · +1 346 594 9005 · Houston, TX
Datasheets and CAD files are available to customers on request. The Crestflo Engineering Team reviewed this material before release. Hastelloy® is a registered trademark of Haynes International, Inc., while Swagelok® and Parker® remain trademarks of their respective owners.