Hastelloy C276 FastenersASTM B574 UNS 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 — are made from ASTM B574 bar stock to ASME B18 dimensions. 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 every heat
- 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 to ASTM B574 (UNS N10276). 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
- Bar stock
- ASTM B574
- 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 B574 |
|---|---|
| Dimensional standards | ASME B18.2.1 (bolts) · B18.2.2 (nuts) · B18.31.2 (studs) · DIN 931 / 933 / 934 |
| 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 are machined from ASTM B574 bar; 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
| Element | Weight % |
|---|---|
| Nickel | Balance |
| Molybdenum | 15.0 – 17.0 |
| Chromium | 14.5 – 16.5 |
| Iron | 4.0 – 7.0 |
| Tungsten | 3.0 – 4.5 |
| Cobalt | 2.5 max |
| Carbon | 0.010 max |
| Manganese | 1.0 max |
| Vanadium | 0.35 max |
| Silicon | 0.08 max |
Hastelloy C276 Fasteners Mechanical Properties
| Solution-annealed plate & sheet | Value |
|---|---|
| Tensile strength | 690 MPa · 100 ksi |
| Yield strength 0.2% | 283 MPa · 41 ksi |
| Elongation | 40% |
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
Values follow ASTM B575 for UNS N10276. Always check against the edition named on your purchase order.
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. We PMI-test nickel alloys as standard and any grade on request.
| Element | Hastelloy C276 | Hastelloy C22 |
|---|---|---|
| Nickel | Balance | Balance |
| Chromium | 14.5 – 16.5 | 20.0 – 22.5 |
| Molybdenum | 15.0 – 17.0 | 12.5 – 14.5 |
| Tungsten | 3.0 – 4.5 | 2.5 – 3.5 |
| Iron | 4.0 – 7.0 | 2.0 – 6.0 |
| Manganese | 1.0 max | 0.50 max |
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 A276 / A479 | ≈ 42 | Seawater and high-chloride service where strength also matters |
| Inconel 625 | ASTM B446 | ≈ 51 | Seawater, high strength and high temperature in one alloy |
| Hastelloy C22 | ASTM B574 | ≈ 65 | Mixed oxidising and reducing acids, and weld overlays |
| Hastelloy C276 | ASTM B574 | ≈ 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 and material is PMI-tested before processing.
- 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?
Yes. Alloy C-276, UNS N10276, W.Nr 2.4819 all refer to the same material, and fasteners is ordered to ASTM B574 whichever name is on the enquiry.
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?
A heavy hex nut machined from the same Hastelloy C276 bar (ASTM B574), unless the project specifies otherwise.
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