Alloy C276

UNS N10276 / W.Nr 2.4819

COMMON TRADE NAMES: SMC276®, INCONEL® Alloy C-276, Hastelloy® C-276

Alloy C276 is a nickel-chromium-molybdenum solid solution strengthened super-alloy with a nominal chemical composition of 57% nickel, 16% chromium, and 16% molybdenum, with additions of iron, tungsten, and cobalt. It is commonly referred to by the tradename Hastelloy® C276 and the universal designation UNS N10276. C276 is often used in extremely corrosive environments that other alloys cannot withstand.


Corrosion graphic

Corrosion Resistance

Alloy C276 is one of the most corrosion-resistant alloys available. The nickel, chromium, and molybdenum found in Alloy C276 form a powerful triple threat against almost all forms of corrosion. C276 has excellent resistance to reducing and oxidizing acids, including sulfuric, hydrochloric, and acetic acids. It also performs well in seawater, chlorides, wet chlorine gas, oxidizing salts, and hypochlorite. The molybdenum and tungsten content protects against various forms of localized corrosion, including pitting, crevice corrosion, and chloride stress corrosion cracking. C276 has excellent oxidation resistance at elevated temperatures up to 1900°F (1038°C). C276 is not recommended for extreme oxidizing environments such as that presented by concentrated hot nitric acid.
Service Temperature

Elevated Temperature Resistance

C276 resists oxidation at temperatures up to 1900°F (1038°C).
Mechanical Properties

Mechanical Properties

In the annealed condition, C276 has a yield strength of 41 ksi (345 MPa). However, higher strength may be achieved through the pilger process. C276 maintains excellent toughness at cryogenic temperatures.


C276 is used extensively in the oil and gas industry and is a workhorse in the chemical processing industry, owing to its corrosion resistance in a wide range of aggressive substances. In upstream oil and gas, C276 is used as tubing, casing, or liners in aggressive sour service environments characterized by high levels of H2S, CO2 , and chlorides. It is also used in other industries where harsh environments are encountered, including the pharmaceutical and paper industries. C276 is used for valves in cryogenic service and has been used in superconductors at temperatures as low as -455°F (-271°C).

CRA offers specialty alloy C276 seamless pipe & tube for use in multiple industries and applications, including:

  • Severely corrosive oil and gas wells containing CO2 , H2S, S0 (elemental sulfur), and chlorides
  • Chemical Processing
  • Paper & Pulp Industry
  • Base Pipe for Sand Screens
  • Tubing, Casing, & Liners
  • Pipe for VIT
  • Swell Packers
  • Pharmaceutical Industry
  • Super Conductors
  • Geothermal
  • Carbon Capture and Sequestration (CCS)

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Chemical Composition

≤ 0.0214.5 - 16.5BAL4 - 7≤ 1≤ 0.0815 - 17≤ 2.5≤ 0.03≤ 0.03≤ 0.353 - 4.5
(mass %)

Specified Mechanical Properties

API 5CRA / ISO 13680 Group 4 Category 15-60-16

NACE MR0175/ISO 15156
H2S Sour Service Limits
1101101401251135Table A.14No limit ≤ 400°F,
Refer to table for temperatures up to 450°F
140140160145938140 Grade not recommended for sour service
*Non-standard mechanical properties and grades are made available upon agreement.

Specified Mechanical Properties in Annealed Condition
Per ASTM B622
Tensile StrengthYield StrengthElongation
minimum, ksiminimum, ksiminimum, %
*Higher strength properties can be provided in the cold hardened condition.

Typical Physical Properties

Thermal ExpansionX10-6/°F-
Elastic Modulus103 ksi29.829.128.327.326.425.522.37
Poisson Ratio-0.33-----0.377
Thermal ConductivityBtu-in/h·ft2·°F-7790104117132152
Specific HeatBtu/lb·°F0.102-----0.14
Yield Strengthksi41403834333311
Tensile Strengthksi100999994928744

Manufacturing Process

Steel MakingElectric Arc Furnace followed by Vacuum Oxygen Decarburization (VOD) or Argon Oxygen Decarburization (AOD).
Pipe MakingConventional Seamless Cold Finished Pipe and Tube Manufacturing Processes.
Heat TreatmentCannot be hardened by heat treatment. May be provided in the annealed or cold hardened condition.

Product Availability

MIN OD: 2-1/16″ (2.0625″)
MAX OD: 10-3/4″ (10.750”)
LENGTHS: Up to 70′ (840”)

END FINISH: Plain end, Premium threads, & API threads

Standard & Non-Standard Sizes Available.

Manufactured Material Available as Quickly as 1 Week.

Non-Standard Mill Quantities Accommodated