Duplex 2205 FastenersASTM A276 UNS S32205 · Manufacturer, stockist & exporter, India
Also sold as UNS S32205 / S31803 · W.Nr 1.4462 · F51 / F60 · SAF 2205
Duplex 2205 fasteners — stud bolts, hex bolts, nuts and washers — are made from ASTM A276 / A479 bar stock to ASME B18 dimensions. It is a duplex (austenitic-ferritic) stainless steel, chosen for strength with chloride resistance at a stainless-steel budget. 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 Duplex 2205 Fasteners?
Duplex 2205 fasteners is a duplex (austenitic-ferritic) stainless steel supplied as fasteners to ASTM A276 / A479 (UNS S32205). Buyers specify it for strength with chloride resistance at a stainless-steel budget. It is also sold as UNS S32205 / S31803, W.Nr 1.4462, F51 / F60.
- What it is
- Duplex (austenitic-ferritic) stainless steel
- Bar stock
- ASTM A276 / A479
- Dimensions
- ASME B18.2.1 · B18.2.2 · B18.31.2
- Threads
- UNC · UN-8 · metric
- Sizes
- M10 – M64 · ½" – 4"
- Best at
- Strength with chloride resistance at a stainless-steel budget
Duplex 2205 Fasteners Specification & Sizes
| Material | ASTM A276 / A479 |
|---|---|
| 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 |
Duplex 2205 Fasteners Chemical Composition
| Element | Weight % |
|---|---|
| Chromium | 22.0 – 23.0 |
| Nickel | 4.5 – 6.5 |
| Molybdenum | 3.0 – 3.5 |
| Nitrogen | 0.14 – 0.20 |
| Carbon | 0.030 max |
| Manganese | 2.00 max |
| Silicon | 1.00 max |
| Phosphorus | 0.030 max |
| Sulphur | 0.020 max |
| Iron | Balance |
Duplex 2205 Fasteners Mechanical Properties
| Solution-annealed plate & sheet | Value |
|---|---|
| Tensile strength | 655 MPa · 95 ksi |
| Yield strength 0.2% | 450 MPa · 65 ksi |
| Elongation | 25% |
| Hardness | 293 HB max |
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.8 g/cm³ |
| Melting range | 1385 – 1445 °C |
| Magnetic | Magnetic (ferritic phase) |
| PREN (approx.) | ≈ 35 |
Duplex 2205 Equivalent Grades
Values follow ASTM A240 for UNS S32205. Always check against the edition named on your purchase order.
Six-digit Harmonized System heading (iron and steel, chapter 72–73). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify Duplex 2205 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. Duplex 2205 is most often mixed up with Super Duplex 2507 — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen, so it cannot confirm the nitrogen that duplex depends on: that comes from the mill certificate or optical emission (OES) testing. We PMI-test nickel alloys as standard and any grade on request.
| Element | Duplex 2205 | Super Duplex 2507 |
|---|---|---|
| Nickel | 4.5 – 6.5 | 6.0 – 8.0 |
| Chromium | 22.0 – 23.0 | 24.0 – 26.0 |
| Molybdenum | 3.0 – 3.5 | 3.0 – 5.0 |
| Copper | residual | 0.50 max |
| Iron | Balance | Balance |
| Manganese | 2.00 max | 1.20 max |
Duplex 2205 fasteners by type
Duplex 2205 Fasteners Applications
Duplex 2205 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.
Duplex 2205 Fasteners vs 316L, 904L and 2507
| Grade | Fasteners standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| SS 316 / 316L | ASTM A193 B8M · A194 8M | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| SS 904L | ASTM B649 | ≈ 35 | Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water |
| Duplex 2205 | ASTM A276 / A479 | ≈ 35 | Strength with chloride resistance at a stainless-steel budget |
| Super Duplex 2507 | ASTM A276 / A479 | ≈ 42 | Seawater and high-chloride service where strength also matters |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Duplex 2205 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 2205 fits.
A roughly 50/50 austenite-ferrite structure gives about twice the yield strength of 316L, so walls can be thinner.
Chromium, molybdenum and nitrogen give a PREN around 35 — well above 316L.
The ferrite phase gives far better resistance to chloride stress-corrosion cracking than austenitic grades.
Keep service below about 300 °C to avoid embrittlement.
How your 2205 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 Duplex 2205 Fasteners
Duplex 2205 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ER2209 (AWS A5.9) |
|---|---|
| Over-alloyed filler | Control heat input 0.5–2.5 kJ/mm to keep the phase balance |
| Preheat | Not required; keep interpass temperature low |
| Cutting | Plasma or waterjet; grind off heat-tinted edges before welding |
Follow your approved WPS; this is general guidance. See also 2205 fittings and 2205 flanges for the matching pipe-system parts.
How to Order Duplex 2205 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
Duplex 2205 fasteners for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiDuplex 2205 fasteners — questions buyers ask
Is Duplex 2205 the same as UNS S32205 / S31803?
Yes. UNS S32205 / S31803, W.Nr 1.4462, F51 / F60 all refer to the same material, and fasteners is ordered to ASTM A276 / A479 whichever name is on the enquiry.
Why use Duplex 2205 bolts instead of B7 carbon steel?
On Duplex 2205 flanges in corrosive service, carbon-steel bolts corrode first. Matching-alloy bolting avoids galvanic corrosion and bolt failure.
Duplex 2205 or Super Duplex 2507 — which should I choose?
Duplex 2205 is chosen for strength with chloride resistance at a stainless-steel budget. 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