Hastelloy C22 FastenersASTM B574 UNS N06022 · Manufacturer, stockist & exporter, India
Also sold as Alloy C-22 · UNS N06022 · W.Nr 2.4602 · Nicrofer 5621
Hastelloy C22 fasteners — stud bolts, hex bolts, nuts and washers — are made from ASTM B574 bar stock to ASME B18 dimensions. It is a nickel–chromium–molybdenum alloy with tungsten, chosen for mixed oxidising and reducing acids, and weld overlays. 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 C22 Fasteners?
Hastelloy C22 fasteners is a nickel–chromium–molybdenum alloy with tungsten supplied as fasteners to ASTM B574 (UNS N06022). Buyers specify it for mixed oxidising and reducing acids, and weld overlays. It is also sold as Alloy C-22, UNS N06022, W.Nr 2.4602.
- What it is
- Nickel–chromium–molybdenum 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
- Mixed oxidising and reducing acids, and weld overlays
Hastelloy C22 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 C22 Stud Bolts: Grade & Nut Pairing
Hastelloy C22 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 C22 Fasteners Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | Balance |
| Chromium | 20.0 – 22.5 |
| Molybdenum | 12.5 – 14.5 |
| Iron | 2.0 – 6.0 |
| Tungsten | 2.5 – 3.5 |
| Cobalt | 2.5 max |
| Carbon | 0.015 max |
| Manganese | 0.50 max |
| Vanadium | 0.35 max |
| Silicon | 0.08 max |
Hastelloy C22 Fasteners Mechanical Properties
| Solution-annealed plate & sheet | Value |
|---|---|
| Tensile strength | 690 MPa · 100 ksi |
| Yield strength 0.2% | 310 MPa · 45 ksi |
| Elongation | 45% |
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 8.69 g/cm³ |
| Melting range | 1357 – 1399 °C |
| Magnetic | Non-magnetic |
| PREN (approx.) | ≈ 65 |
Hastelloy C22 Equivalent Grades
Values follow ASTM B575 for UNS N06022. 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 C22 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 C22 is most often mixed up with Hastelloy C276 — 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 C22 | Hastelloy C276 |
|---|---|---|
| Nickel | Balance | Balance |
| Chromium | 20.0 – 22.5 | 14.5 – 16.5 |
| Molybdenum | 12.5 – 14.5 | 15.0 – 17.0 |
| Tungsten | 2.5 – 3.5 | 3.0 – 4.5 |
| Iron | 2.0 – 6.0 | 4.0 – 7.0 |
| Manganese | 0.50 max | 1.0 max |
Hastelloy C22 fasteners by type
Hastelloy C22 Fasteners Applications
Hastelloy C22 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 C22 Fasteners vs C276, 625 and 825
| Grade | Fasteners standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| Inconel 825 | ASTM B425 | ≈ 31 | Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas |
| 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 C22 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 C22 fits.
Higher chromium than C276 gives better resistance to oxidising acids and ferric/cupric chlorides.
Molybdenum keeps strong resistance in reducing acids.
Tungsten improves pitting and crevice resistance.
C22 filler is widely used to weld and overlay other alloys.
How your C22 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 C22 Fasteners
Hastelloy C22 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ERNiCrMo-10 (AWS A5.14) |
|---|---|
| Over-alloyed filler | ENiCrMo-10 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 C22 fittings and C22 flanges for the matching pipe-system parts.
How to Order Hastelloy C22 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 C22 fasteners for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiHastelloy C22 fasteners — questions buyers ask
Is Hastelloy C22 the same as Alloy C-22?
Yes. Alloy C-22, UNS N06022, W.Nr 2.4602 all refer to the same material, and fasteners is ordered to ASTM B574 whichever name is on the enquiry.
Why use Hastelloy C22 bolts instead of B7 carbon steel?
On Hastelloy C22 flanges in corrosive service, carbon-steel bolts corrode first. Matching-alloy bolting avoids galvanic corrosion and bolt failure.
What nut goes with Hastelloy C22 stud bolts?
A heavy hex nut machined from the same Hastelloy C22 bar (ASTM B574), unless the project specifies otherwise.
How do I stop Hastelloy C22 bolts galling?
Use an anti-seize compound on threads and nut faces, tighten at moderate speed, and do not reuse galled nuts.
Hastelloy C22 or Inconel 825 — which should I choose?
Hastelloy C22 is chosen for mixed oxidising and reducing acids, and weld overlays. Inconel 825 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