Hastelloy C276 FastenersUNS N10276 · Manufacturer, stockist & exporter, India
Also sold as Alloy C-276 · UNS N10276 · W.Nr 2.4819 · Nicrofer 5716
Hastelloy C276 fasteners — stud bolts, hex bolts, nuts and washers — available in this alloy. 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. Dimensions to ASME B18 where applicable, or your drawing. State the finished fastener specification your project requires on the order. It is a nickel–molybdenum–chromium alloy with tungsten, chosen for the most aggressive mixed acids, wet chlorine and hypochlorite. Kanak Steel & Engineering Co. supplies it with EN 10204 3.1 mill certificates from Mumbai to buyers across India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on request
- NACE MR0175 on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Hastelloy C276 Fasteners?
Hastelloy C276 fasteners is a nickel–molybdenum–chromium alloy with tungsten supplied as fasteners (UNS N10276). 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. Buyers specify it for the most aggressive mixed acids, wet chlorine and hypochlorite. It is also sold as Alloy C-276, UNS N10276, W.Nr 2.4819.
- What it is
- Nickel–molybdenum–chromium alloy with tungsten
- Material
- 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
- Feedstock (bar)
- ASTM B574, where applicable
- Dimensions
- ASME B18.2.1 · B18.2.2 · B18.31.2
- Threads
- UNC · UN-8 · metric
- Sizes
- M10 – M64 · ½" – 4"
- Best at
- The most aggressive mixed acids, wet chlorine and hypochlorite
Hastelloy C276 Fasteners Specification & Sizes
| Material | 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 |
|---|---|
| Material / feedstock | ASTM B574 — a bar specification, where applicable; it covers the bar, not the finished fastener |
| Manufacturing route | By type: bolts, studs, cap screws and nuts may be machined from bar, where applicable; threaded rod, U-bolts, eye bolts, anchor and foundation bolts are route-dependent; washers not asserted — all to the purchase specification or project drawing |
| Dimensional standards | ASME B18.2.1 (bolts) · B18.2.2 (nuts) · B18.31.2 (studs) · DIN 931 / 933 / 934 (legacy DIN) |
| Types | Stud bolt · Hex bolt · Heavy hex nut · Hex nut · Washer · Threaded rod · U-bolt · Eye bolt · Anchor bolt · Foundation bolt · Socket head cap screw · Machine screw |
| Threads | UNC, UN-8 and metric coarse |
| Coating | Plain · PTFE on request |
| Documents | EN 10204 3.1 |
Hastelloy C276 Stud Bolts: Grade & Nut Pairing
Hastelloy C276 studs and nuts may be machined from ASTM B574 bar, where applicable; the finished fastener specification is to the purchase specification or project drawing, and the nut is usually the same alloy.
Torque (T = K × F × d), stud length and coatings are covered in the fasteners guide.
| Galling | Stainless and nickel-alloy threads gall — always use anti-seize, and avoid high-speed tightening |
|---|---|
| Coatings | Usually supplied plain; PTFE coating on request to ease tightening |
| Marking | Grade symbol and maker's mark on each stud end and nut, as the standard requires |
| Certificates | EN 10204 3.1 for the bar heat; mechanical test reports on the finished bolts on request |
Hastelloy C276 Fasteners Chemical Composition
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.
Hastelloy C276 Fasteners 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.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8.89 g/cm³ |
| Melting range | 1323 – 1371 °C |
| Magnetic | Non-magnetic |
| PREN (approx.) | ≈ 68 |
Hastelloy C276 Equivalent Grades
Six-digit Harmonized System heading (nickel alloy, chapter 75). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify Hastelloy C276 Fasteners with PMI
Positive material identification with a handheld XRF gun confirms the alloy on the piece itself, in seconds, before it is cut or welded. Hastelloy C276 is most often mixed up with Hastelloy C22 — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen; those come from the mill certificate or optical emission (OES) testing. PMI can be arranged on request — state it on your enquiry.
Under technical review for TDS.
| Element | Hastelloy C276 | Hastelloy C22 |
|---|---|---|
| Nickel | As specified | As specified |
| Chromium | As specified | As specified |
| Molybdenum | As specified | As specified |
| Tungsten | As specified | As specified |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
Hastelloy C276 fasteners by type
Hastelloy C276 Fasteners Applications
Hastelloy C276 is specified when the cheaper grade will not survive the service but a higher alloy would be more than the job needs. These are the jobs our buyers use it for.
Hastelloy C276 Fasteners vs 625, C22 and 2507
| Grade | Fasteners standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Super Duplex 2507 | ASTM A1082 (S32750) where specified for applicable duplex bolts, studs, cap screws and nuts; for other types, material may be supplied to ASTM A276 / A479 bar where applicable, subject to the purchase specification | ≈ 42 | Seawater and high-chloride service where strength also matters |
| Inconel 625 | ASTM F468 (N06625) 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 B446 bar where applicable, subject to the purchase specification | ≈ 51 | Seawater, high strength and high temperature in one alloy |
| Hastelloy C22 | May be machined from ASTM B574 bar (UNS N06022), where applicable; finished fastener requirements are to the purchase specification or project drawing | ≈ 65 | Mixed oxidising and reducing acids, and weld overlays |
| Hastelloy C276 | 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 | ≈ 68 | The most aggressive mixed acids, wet chlorine and hypochlorite |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Hastelloy C276 Corrosion Resistance — Element by Element
Each alloying addition has a job. Knowing which one protects against your medium is the quickest way to judge whether C276 fits.
Very high molybdenum handles hydrochloric and sulphuric acid where other alloys fail.
Chromium adds resistance to oxidising acids, wet chlorine and hypochlorite.
Tungsten further improves pitting and crevice resistance.
Very low carbon and silicon let C276 be used as-welded.
How your C276 fasteners order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked against your order; PMI before processing is available on request.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked.
- 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
- 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.
Welding & Fabricating Hastelloy C276 Fasteners
Hastelloy C276 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ERNiCrMo-4 (AWS A5.14) |
|---|---|
| Over-alloyed filler | ENiCrMo-4 electrode |
| Preheat | Not required; keep interpass temperature low |
| Cutting | Thermal or abrasive cutting; grind off heat-tinted edges before welding |
Follow your approved WPS; this is general guidance. See also C276 fittings and C276 flanges for the matching pipe-system parts.
How to Order Hastelloy C276 Fasteners: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Fastener type, size and length
- Thread form
- Material and marking
- Quantity in sets
- Certificate type
- Delivery port and date
Hastelloy C276 fasteners for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiHastelloy C276 fasteners — questions buyers ask
Is Hastelloy C276 the same as Alloy C-276?
Alloy C-276, UNS N10276, W.Nr 2.4819 are names used for Hastelloy C276 (W.Nr / EN numbers and older UNS variants are the closest designations; their limits can differ slightly, so specify the UNS number and ASTM grade on the order). Whichever name is on the enquiry, 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.).
Why use Hastelloy C276 bolts instead of B7 carbon steel?
On Hastelloy C276 flanges in corrosive service, carbon-steel bolts corrode first. Matching-alloy bolting avoids galvanic corrosion and bolt failure.
What nut goes with Hastelloy C276 stud bolts?
Usually a heavy hex nut in the same Hastelloy C276 alloy — it may be machined from ASTM B574 bar, where applicable; finished requirements are to the purchase specification or project drawing.
How do I stop Hastelloy C276 bolts galling?
Use an anti-seize compound on threads and nut faces, tighten at moderate speed, and do not reuse galled nuts.
Hastelloy C276 or Super Duplex 2507 — which should I choose?
Hastelloy C276 is chosen for the most aggressive mixed acids, wet chlorine and hypochlorite. Super Duplex 2507 is the step up when you need more pitting resistance or strength. See the comparison table on this page, or ask us with your process conditions.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026