Hastelloy C-276 round bar (UNS N10276 / W.Nr. 2.4819) is a high-nickel, chromium-molybdenum-tungsten alloy chosen when severe chemical corrosion resistance and reliable weldability are required. For corrosive chemical processing, chloride-bearing environments, and mixed oxidizing/reducing media, C-276 offers one of the broadest service envelopes of commercially available corrosion-resistant alloys. MWAlloys supplies certified Hastelloy C-276 round bars from Chinese mills at factory pricing, stocked for fast delivery to global customers.
What is Hastelloy C-276 round bar?
Hastelloy C-276 is a wrought nickel-chromium-molybdenum alloy with tungsten that combines exceptional resistance to pitting, crevice corrosion and stress-corrosion cracking in a wide range of media; the round bar form is supplied for machined components, shafts, shafts for chemical service, valve stems, fasteners, and custom forgings. The alloy retains corrosion resistance in both oxidizing and reducing environments and resists chloride-induced attack that damages many stainless steels. Major alloy producers publish extensive data showing C-276’s long track record in chemical process systems.
Practical buyer note: Choose C-276 round bar when project conditions include mixed acids, oxidizing halide solutions, high chloride content, or environments where welded components must maintain full corrosion resistance in the heat-affected zone.
Key performance summary
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UNS designation: N10276; W. No.: 2.4819.
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Typical density: ≈ 8.89 g/cm³ (0.321 lb/in³).
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Corrosion behaviour: Excellent resistance to pitting, crevice corrosion, and stress-corrosion cracking across oxidizing and reducing environments.
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Weldability: Very good in the as-welded condition due to low carbon and controlled impurities. Post-weld solution treatment not normally required for corrosion resistance.
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Typical tensile & yield: Room-temperature values for annealed material typically show ultimate tensile strength ~690–790 MPa (100–115 ksi) and 0.2% offset yield ~310–355 MPa (45–52 ksi), depending on product form.
Chemical composition (typical ranges)
The composition below represents typical continuous-cast/wrought limits used by major producers. For contract work, always specify the certified mill test report (MTR) values.
| Element | Typical composition (wt%) — Hastelloy C-276 (typical ranges) |
|---|---|
| Nickel (Ni) | Balance (approx. 55–59%) |
| 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) | trace — up to ~2.5% (varies by producer) |
| Manganese (Mn) | ≤ 1.0 |
| Silicon (Si) | ≤ 0.08 |
| Carbon (C) | ≤ 0.01 (very low to preserve weld corrosion resistance) |
| Phosphorus (P) | ≤ 0.025 |
| Sulfur (S) | ≤ 0.01 |
Notes: Exact limits are defined in product standards (e.g., ASTM B574/B575/B619 for bars, rods and fasteners) and in mill specifications published by Haynes, Special Metals and other high-performance alloy makers. The high Mo and W contents create resistance to localized attack; the very low carbon reduces carbide precipitation on welding.
Material & mechanical properties
Below are representative properties used for design and procurement. Always use supplier MTR values for final calculations.
| Property | Typical value (room temp, annealed) |
|---|---|
| Density | 8.89 g/cm³ (0.321 lb/in³) |
| Modulus of elasticity | ≈ 205 GPa (29,700 ksi) |
| Ultimate tensile strength (annealed) | ~690–790 MPa (100–115 ksi), product dependent |
| 0.2% offset yield | ~310–355 MPa (45–52 ksi) |
| Elongation (50 mm) | Typical ≥ 40% (good ductility) |
| Melting range | Approx 1370°C (≈ 2500°F), solidus/liquidus vary by producer. |
| Thermal expansion (20–100°C) | ~11.2 µm/m·°C (approx. reference) depending on source. |
Hardness and typical heat states
Hastelloy C-276 is normally supplied annealed or solution treated. Hardness depends on cold working and heat treatment.
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Typical annealed hardness: Rockwell B ~82–95 HRB (approximately Brinell 150–210 HB or Vickers 160–220 HV in many stock charts).
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Cold-worked or spring-temper conditions can produce much higher hardness and tensile properties; for spring or highly cold-worked states, tensile strength and hardness can increase dramatically (consult producer temper tables).
When specifying components that require specific hardness or strength, state whether you require annealed, cold-drawn, or specified tensile/hardness limits on the PO.
Hastelloy C-276 equivalents and trade names
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UNS: N10276.
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W. No. (EN/DIN): 2.4819.
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Trademark / trade names: HASTELLOY® C-276 (Haynes International), INCONEL® Alloy C-276 (Special Metals has historically referenced similar grades) — check brand/trademark usage and mill of origin for MTR traceability.
Do not substitute blindly: Some suppliers offer "C276 equivalents" from regional mills; confirm chemistry and MTR traceability before acceptance for critical service.
Specifications, certifications and common standards (round bar)
Common product standards that buyers reference when purchasing C-276 round bar or rod:
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ASTM B574 — Standard Specification for Nickel- and Nickel-Iron-Chromium-Molybdenum-Tungsten Alloys (for bars, forgings etc.).
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ASTM B575 — Nickel and Nickel Alloys (Rolled or Cold-Worked Strip, Sheet, and Plate) — sometimes cited for strip/coil.
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ASTM B619 — Nickel alloy bars and rods for general engineering use.
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ISO / EN equivalents: check EN material number 2.4819 and ISO specifications.
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NACE/ISO 15156 (NACE MR 0175) — for sour environment suitability; some C-276 product forms are used in sour service; confirm NACE acceptance per MTR and heat treatment.
When placing orders, specify the ASTM/EN product spec, required test reports (chemical, mechanical, PMI, intergranular corrosion where applicable), surface finish, length tolerance and any special machining or straightness requirements.
Size & weight — practical table (density used: 8.89 g/cm³)
Use the table for quick procurement and lifting estimates. Values are weight per 1 m length and lb per ft for common diameters of solid round bar.
| Diameter (mm) | Weight (kg/m) | Weight (lb/ft) |
|---|---|---|
| 6 mm | 0.2514 kg/m | 0.169 lb/ft |
| 10 mm | 0.6982 kg/m | 0.469 lb/ft |
| 12 mm | 1.0054 kg/m | 0.676 lb/ft |
| 16 mm | 1.7874 kg/m | 1.201 lb/ft |
| 20 mm | 2.7929 kg/m | 1.877 lb/ft |
| 25.4 mm (1") | 4.5046 kg/m | 3.027 lb/ft |
| 30 mm | 6.2840 kg/m | 4.223 lb/ft |
| 50 mm | 17.4555 kg/m | 11.729 lb/ft |
| 100 mm | 69.8219 kg/m | 46.918 lb/ft |
| 200 mm | 279.2876 kg/m | 187.673 lb/ft |
Formula used: weight = density (8,890 kg/m³) × cross-sectional area × 1 m length. Density reference: major alloy datasheets.
Global price snapshot 2025
Nickel-based superalloys are priced on metal indices, alloy premia and producer availability. Prices move with nickel and molybdenum markets and regional demand/supply.
High-level 2025 indicators (examples / typical ranges):
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China (FOB / ex-works) — typical quoted range for C-276 raw material and small-lot round bars: USD 30–40 / kg (USD 30,000–40,000 / MT) according to recent FOB Shanghai offers.
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North America (delivered ex-dock or domestic quotes) — industry index readings Q1–Q2 2025 show ~USD 51,000–52,000 / MT for some C-276 forms; that converts to roughly USD 51–52 / kg. Wholesale/stock bar premiums, machining and testing add to the final price.
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India / Middle East / UAE — distributor quotes vary; sample supplier listings in 2025 show USD 40–75 / kg depending on quantity, form and certification.
| Region / market | Typical 2025 indicative price (USD) |
|---|---|
| China (FOB Shanghai) | $30–40 / kg (FOB quotes for plate/rod) |
| North America (index) | ~$51,000 / MT → $51 / kg (Q1-Q2 2025 index snapshot) |
| Europe (stockist) | $45–70 / kg (distributor, small lots) |
| India / UAE (distributor) | $40–75 / kg (varies by MOQ & certification) |
Buyer tips for price control
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Bulk orders and regular contracts provide the best unit rates.
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FOB Shanghai and EXW China figures exclude freight, import duties, machining, NDE and MTR testing.
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For critical service, pay for certified MTRs and third-party inspection rather than selecting lowest price only.
(Market data sources: industry price indices and supplier quotes; prices change rapidly — always request current quotes.)
Fabrication, welding and testing
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Welding: C-276 is intentionally designed for weldability: low carbon and controlled silicon reduce HAZ sensitization. Preferred filler metals include matching C-276 weld wire (INCO-WELD Filler C-276) or similar nickel-chromium-molybdenum filler systems. GTAW (TIG) and GMAW (MIG) techniques commonly used; good shielding gas coverage recommended. Post-weld solution anneal is usually not required to restore corrosion resistance; follow mill and welding procedure specifications.
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Machining: C-276 is tougher than common stainless steels and is abrasive owing to Mo/W content; use rigid set-ups, sharp carbide tooling, and reduced chip load. Use flood cooling and plan for slower cycles than carbon steel.
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NDE & testing: Require chemical and mechanical MTRs (EN 10204 3.1/3.2 where applicable), PMI verification for critical orders, and optionally intergranular corrosion testing if project standards call for it.
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Surface finish & passivation: C-276 generally does not require passivation like stainless steel, but pickling and clean water rinses after welding are standard practice in chemical plant fabrication.
Typical applications and common failure modes
Applications
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Chemical process equipment (reactors, piping components, mixers) handling mixed acids and chlorides.
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Pollution control systems and flue gas desulfurization components.
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Marine and desalination equipment exposed to aggressive brines.
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Valves, shafts, fasteners, and instrumentation in process plants.
Failure modes to watch
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Improper material substitution (using lower Mo/W alloys) that leads to localized attack.
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Inadequate weld procedures or use of incompatible filler metal can produce weak HAZs.
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Mechanical overloading or fretting corrosion in poorly supported shafts or studs.
Why choose MWAlloys for Hastelloy C-276 round bar?
MWAlloys provides direct-from-mill procurement from reputable Chinese producers with:
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Factory pricing: We sell at 100% factory price principle for standard stock items; quote includes MTRs on request.
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Stock availability: Common diameters and lengths kept in regional stock for quick global dispatch; lead times for stocked items are typically shorter than specialized forged orders.
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Traceability: Each shipment includes full MTR and certificate to support critical service acceptance.
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Quality control: Pre-shipment PMI and mechanical test verification available; optional third-party inspection on request.
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Technical support: MWAlloys offers consulting on temper, machining allowances and welding procedures to optimize component lifetime.
Frequently Asked Questions
Hastelloy C-276: Brand vs. Grade & Engineering FAQ
1. What is the difference between “Hastelloy” and “C-276”?
Hastelloy® is a registered trademark brand family (owned by Haynes International). C-276 is the specific alloy grade within that family. Because the patent has expired, many high-quality mills produce this chemistry under the generic designation Alloy C-276. When ordering, the critical identifier is the UNS N10276 number, which guarantees the chemistry regardless of the brand name on the crate.
2. What does UNS N10276 mean?
UNS N10276 is the Unified Numbering System identifier for this specific Nickel-Moly-Chrome alloy. In the European market, it is commonly referred to by its Werkstoff number 2.4819 or the EN designation NiMo16Cr15W. All these codes point to the same high-performance material specification.
3. What hardness should I expect for an annealed C-276 bar?
4. Is C-276 suitable for welded assemblies without post-heat treatment?
Yes. One of the premier advantages of C-276 is its ability to be used in the "as-welded" condition. Its ultra-low carbon content prevents the formation of grain-boundary precipitates in the weld heat-affected zone, maintaining its legendary corrosion resistance without the need for complex post-weld solution annealing.
5. How do I specify a formal procurement order for C-276?
To ensure zero errors in your supply chain, include:
- Grade: Alloy C-276 / UNS N10276.
- Specification: ASTM B574 (Bar), B575 (Plate), or B619 (Pipe).
- Condition: Solution Annealed & Descaled.
- Documentation: EN 10204 3.1 Mill Test Certificate.
- Special Requirements: e.g., Positive Material Identification (PMI) or specific ultrasonic testing (UT).
6. Are there common equivalents to C-276?
While C-276 is the standard, similar high-performance alloys include Inconel Alloy C-276 and Nicrofer 5716. Always verify the Mill Test Report (MTR) to ensure the chemical composition (specifically Molybdenum and Tungsten levels) meets your project's specific ASTM requirements.
7. What operating temperature limits apply to C-276?
C-276 is primarily used for its aqueous corrosion resistance rather than high-temperature strength. However, it can be used in oxidizing atmospheres up to 1040°C (1900°F). For pressure-bearing applications, ASME codes typically provide allowable stress values up to 675°C (1250°F).
8. How is the price formed for C-276 bar material?
The price of C-276 is highly volatile and is dictated by LME (London Metal Exchange) indices for Nickel and Molybdenum. Additionally, the "surcharge" is influenced by the fabrication complexity (e.g., centerless grinding vs. hot rolled) and the total lot size.
9. Can MWAlloys supply certified MTRs and third-party inspection?
Yes. 100% of our C-276 shipments are accompanied by a full 3.1 MTR. If your project requires 3.2 certification, we can arrange for third-party inspection (SGS, TUV, or Lloyd’s) at our facility prior to shipment to verify heat numbers and mechanical properties.
10. When should I select C-22 or Inconel 625 instead of C-276?
- Choose C-22: If you face highly oxidizing acids (like nitric acid) or mixed acid streams where C-276 might show slightly higher corrosion rates.
- Choose Inconel 625: If your primary concern is mechanical strength and fatigue resistance at high temperatures rather than extreme chemical pitting resistance.
C-276 remains the most cost-effective "all-rounder" for general aggressive chemical processing.
