Hastelloy C22 FastenersUNS 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 — available in this alloy. May be machined from ASTM B574 bar (UNS N06022), where applicable; finished fastener requirements are to the purchase specification or project drawing. Dimensions to ASME B18 where applicable, or your drawing. State the finished fastener specification your project requires on the order. 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 request
- 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 (UNS N06022). May be machined from ASTM B574 bar (UNS N06022), where applicable; finished fastener requirements are to the purchase specification or project drawing. 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
- Material
- May be machined from ASTM B574 bar (UNS N06022), where applicable; finished fastener requirements are to the purchase specification or project drawing
- 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
- Mixed oxidising and reducing acids, and weld overlays
Hastelloy C22 Fasteners Specification & Sizes
| Material | May be machined from ASTM B574 bar (UNS N06022), where applicable; finished fastener requirements are to the purchase specification or project drawing |
|---|---|
| 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 C22 Stud Bolts: Grade & Nut Pairing
Hastelloy C22 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 C22 Fasteners Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel | As specified |
| Chromium | As specified |
| Molybdenum | 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 N06022.
Hastelloy C22 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 N06022 — Solution-annealed plate & sheet.
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
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. PMI can be arranged on request — state it on your enquiry.
Under technical review for TDS.
| Element | Hastelloy C22 | Hastelloy C276 |
|---|---|---|
| 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 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 | May be machined from ASTM B425 bar (UNS N08825), where applicable; finished fastener requirements are to the purchase specification or project drawing | ≈ 31 | Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas |
| 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 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 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 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?
Alloy C-22, UNS N06022, W.Nr 2.4602 are names used for Hastelloy C22 (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: may be machined from ASTM B574 bar (UNS N06022), where applicable.
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?
Usually a heavy hex nut in the same Hastelloy C22 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 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