Hastelloy C276 Grade Guide — Composition, Properties & Uses

Short answer

Hastelloy C276 is a nickel–molybdenum–chromium alloy with tungsten, chosen for the most aggressive mixed acids, wet chlorine and hypochlorite. UNS N10276, W.Nr 2.4819, PREN ≈ 68, density 8.89 g/cm³.

FIGURE 01Overview diagram for Hastelloy C276: properties, composition, uses and standards

What is Hastelloy C276?

Hastelloy C276 is a nickel–molybdenum–chromium alloy with tungsten. Engineers choose it for the most aggressive mixed acids, wet chlorine and hypochlorite. It is also known as Alloy C-276, UNS N10276, W.Nr 2.4819, Nicrofer 5716.

UNS: N10276
W.Nr: 2.4819
EN: NiMo16Cr15W
Trade names: Hastelloy C-276 · Nicrofer 5716
Density: 8.89 g/cm³
Melting range: 1323 – 1371 °C
Magnetic: Non-magnetic
PREN (approx.): ≈ 68

FIGURE 02Product-form overview related to Hastelloy C276: properties, composition, uses and standards

Chemical composition and what each element does

Under technical review for TDS.

Element	Current requirement
Nickel	As specified
Molybdenum	As specified
Chromium	As specified
Iron	As specified
Tungsten	As specified
Cobalt	As specified
Carbon	As specified
Manganese	As specified
Vanadium	As specified
Silicon	As specified

Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM B575 for UNS N10276.

Mo 16%Reducing acids

Very high molybdenum handles hydrochloric and sulphuric acid where other alloys fail.

CrOxidising media

Chromium adds resistance to oxidising acids, wet chlorine and hypochlorite.

WLocalised attack

Tungsten further improves pitting and crevice resistance.

Low CAs-welded use

Very low carbon and silicon let C276 be used as-welded.

Hastelloy C276 at a glance

DESIGNATIONSsame alloy, different systems

See the Hastelloy C276 product page for every form we supply and its standard.

Mechanical properties

Under technical review for TDS.

Property	Current requirement
Tensile strength	As specified
Yield strength 0.2%	As specified
Elongation	As specified

Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM B575 for UNS N10276 — Solution-annealed plate & sheet.

Where Hastelloy C276 is used

Chemical processing. Reactors, heat exchangers and piping for mixed acids. Industry →
Flue-gas desulphurisation. Scrubbers, dampers and stack liners. Industry →
Pharmaceutical. Reactors handling chlorinated compounds. Industry →
Pulp & paper. Bleach plants. Industry →
Sour gas. Downhole and surface equipment in severe H₂S. Industry →

Welding C276

The matching filler is ERNiCrMo-4 (AWS A5.14). ENiCrMo-4 electrode.

Keep heat input moderate and interpass temperature low, clean joints thoroughly, and pickle or passivate after welding where the service is corrosive.

Hastelloy C276 compared with similar grades

Grade	PREN	Choose it for
Hastelloy C276	≈ 68	The most aggressive mixed acids, wet chlorine and hypochlorite
Inconel 625	≈ 51	Seawater, high strength and high temperature in one alloy
Hastelloy C22	≈ 65	Mixed oxidising and reducing acids, and weld overlays
Super Duplex 2507	≈ 42	Seawater and high-chloride service where strength also matters

Hastelloy C276 standards by product

Product	Standard
Hastelloy C276 sheet	ASTM B575
Hastelloy C276 plate	ASTM B575
Hastelloy C276 coil	ASTM B575
Hastelloy C276 pipe & tube	ASTM B622 · ASTM B619
Hastelloy C276 fittings	ASTM B366 WPHC276 · ASTM B462 / B564
Hastelloy C276 flanges	ASTM B462 / B564
Hastelloy C276 fasteners	ASTM F468 (N10276) where specified for applicable bolts, hex cap screws, socket-head cap screws and studs (0.250–1.500 in.), and ASTM F467 for applicable nuts (0.250–1.500 in.); for other types, material may be supplied to ASTM B574 bar where applicable, subject to the purchase specification

Buying Hastelloy C276: what to specify

The product standard and the UNS or designation — for example ASTM B575 UNS N10276.
Size, thickness or schedule, and quantity in pieces and kg or metres.
Heat-treatment condition where the standard offers a choice.
Certificate: EN 10204 3.1 or 3.2 available on request / as specified in the PO; ask for 3.2 if a third party must witness.
NACE MR0175 / ISO 15156 compliance if the service contains H₂S.

Questions buyers ask

Is Hastelloy C276 magnetic?

Non-magnetic.

What is the UNS number of Hastelloy C276?

UNS N10276.

What is the European equivalent of Hastelloy C276?

W.Nr 2.4819 (NiMo16Cr15W).

Can Hastelloy C276 be welded?

Yes. The matching filler is ERNiCrMo-4 (AWS A5.14); eNiCrMo-4 electrode.

What is the difference between Hastelloy C276 and Inconel 625?

Hastelloy C276 is chosen for the most aggressive mixed acids, wet chlorine and hypochlorite; Inconel 625 is chosen for seawater, high strength and high temperature in one alloy.