Duplex Steel Fasteners
Stockist, importer and exporter of duplex steel fasteners in Mumbai, India — M6 – M64 and 1/4" – 2.1/2", lengths to 1500 mm, produced to ASTM A193 / A194 / F593 / B637, ASME B18.2.1, DIN / ISO, with EN 10204 3.1 / 3.2 certification and export to 40+ countries.
What is Duplex Steel Fasteners?
Duplex Steel Fasteners is duplex steel supplied in fasteners form — fasteners are studs, bolts, nuts, screws and washers machined or cold-formed in matching alloy, used to bolt flanged joints, structures and equipment in corrosive or high-temperature service. Steelco Metal & Alloys stocks duplex steel fasteners in Mumbai, India in M6 – M64 and 1/4" – 2.1/2", lengths to 1500 mm, produced to ASTM A193 / A194 / F593 / B637, ASME B18.2.1, DIN / ISO, in grades including Duplex 2205, Super Duplex 2507, Zeron 100. Every dispatch carries an EN 10204 3.1 mill test certificate (3.2 with third-party witness on request), PMI verification and heat-number traceability, and we export to more than 40 countries.
All grades we stock in duplex steel fasteners.
Click any grade for its full chemical composition, mechanical properties, equivalents and typical applications. Every grade ships with EN 10204 3.1 / 3.2 certification from our Mumbai stockyard.
Why Choose Duplex Steel Fasteners
Made in matching alloy
Studs, nuts and washers cut from the same alloy family as the pipework, avoiding galvanic pairing at the joint.
Thread quality
Rolled threads to 6g / 2A class with hardness testing to the applicable A193 / A194 requirement.
Coated to order
PTFE (xylan), zinc, hot-dip galvanised or bare finishes, colour coded by grade for site identification.
Technical Specifications
| Attribute | Details |
|---|---|
| Product | Duplex Steel Fasteners |
| Size range | M6 – M64 and 1/4" – 2.1/2", lengths to 1500 mm |
| Thickness / wall | M6 – M64 and 1/4" – 2.1/2", lengths to 1500 mm |
| Finish / condition | As per specification |
| Standards | ASTM A193 / A194 / F593 / B637, ASME B18.2.1, DIN / ISO |
| Grades stocked | Duplex 2205, Super Duplex 2507, Zeron 100 |
| Certification | EN 10204 3.1 as standard, 3.2 with TÜV / SGS / BV / Lloyd's / IRS witness on request |
| Origin | Mill-direct from approved Indian, European, Japanese and Korean producers |
| Dispatch | Ex-stock Mumbai, India; export via Nhava Sheva (JNPT), Mundra and Mumbai ports |
Use our free metal weight calculator — bars, sheets, plates, pipes and sections.
Grade chemistry and mechanical properties supplied in duplex steel fasteners.
Chemical composition and mechanical properties are grade properties, not form properties — the same grade keeps the same chemistry whether it is supplied as sheet, plate or coil. The tables below list the specified limits for each grade we stock in duplex steel fasteners, tested and certified to ASTM A193 / A194 / F593 / B637, ASME B18.2.1, DIN / ISO. Values are weight percent (maximum unless a range is shown); mechanical values are minima in the annealed condition.
Chemical composition (weight %)
| Grade | C | Cr | Ni | Mo | N | Mn | Si | P | Cu | W |
|---|---|---|---|---|---|---|---|---|---|---|
| Duplex 2205UNS S31803 / S32205 | 0.030 | 22.0–23.0 | 4.5–6.5 | 3.0–3.5 | 0.14–0.20 | 2.00 | 1.00 | 0.030 | — | — |
| Super Duplex 2507UNS S32750 | 0.030 | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | 0.24–0.32 | 1.20 | — | 0.035 | 0.50 | — |
| Zeron 100UNS S32760 | 0.030 | 24.0–26.0 | 6.00–8.00 | 3.00–4.00 | 0.20–0.30 | 1.00 | — | — | 0.50–1.00 | 0.50–1.00 |
Balance iron. Single figures are maximum limits. Mill test certificates to EN 10204 3.1 are issued with every dispatch.
Mechanical properties (annealed, minimum)
| Grade | Tensile Strength (min) | Yield Strength (0.2%) | Elongation in 50 mm | Hardness (Rockwell C) | PREN |
|---|---|---|---|---|---|
| Duplex 2205 | 620 MPa (90 ksi) | 450 MPa (65 ksi) | 25% min | 31 max (NACE MR0175) | — |
| Super Duplex 2507 | 795 MPa (116 ksi) | 550 MPa (80 ksi) | 15% min | 32 max (NACE MR0175) | — |
| Zeron 100 | 750 MPa (109 ksi) | 550 MPa (80 ksi) | 25% min | — | 40 minimum |
Typical annealed values; actual results are stated on the heat-specific mill test certificate.
Application Sectors
Oil & Gas
Flowlines, manifolds, separator internals and subsea hardware to NACE MR0175.
Desalination
High-pressure piping, RO vessels and brine handling in 2205.
Chemical & Fertiliser
Urea plant piping, storage tanks and process vessels.
Pulp & Paper
Digesters, bleach washers and chloride-bearing white liquor service.
Bridges & Structures
Rebar, cladding, tie rods and coastal structural steelwork.
Marine
Ballast tanks, chemical tanker cargo tanks and seawater systems.
Cut, finished and certified to your drawing.
Material leaves our Mumbai facility finished to your specification — not as raw stock.
Why buy from Steelco.
Steelco Metal & Alloys is a Mumbai-based stockist, importer and exporter of stainless steel and nickel alloys, shipping certified material worldwide.
Quality & testing on every dispatch
- EN 10204 3.1 mill test certificate on every dispatch
- 3.2 certification with TÜV / SGS / BV / Lloyd's / IRS / IBR witness on request
- Positive Material Identification (PMI) with portable XRF / OES
- Dye-penetrant (DPT), ultrasonic (UT) and hydro testing on request
- NACE MR0175 / ISO 15156 compliance for sour service
- PED 2014/68/EU compliance for pressure equipment
- Heat-number stencilling and marking for full traceability
Deep ready stock
Ready stock of duplex steel fasteners in 3 grades at our Mumbai warehouse, so standard sizes ship the same week rather than waiting on a mill rolling programme.
Mill-direct sourcing
Approved supply from Jindal, JSL, Outokumpu, Aperam, Acerinox, Sandvik and leading Japanese and Korean mills — every item traceable to a named producer.
Full certification
EN 10204 3.1 mill test certificate as standard, 3.2 with TÜV, SGS, BV, Lloyd's, IRS or IBR witness, plus PMI, DPT and UT reports on request.
On-time worldwide delivery
Regular export shipments to the GCC, Africa, Southeast Asia, Europe, Latin America and the USA via Nhava Sheva (JNPT), Mundra and Mumbai ports.
How your material is packed and shipped.
Every consignment leaves our Mumbai facility protected for transit and documented for customs, whether it moves by road within India or by sea to an overseas port.
Domestic & export packing
- Wooden crates, pallets or steel bundles depending on section and weight
- Plastic caps, PVC film and VCI paper to protect surfaces and ends in transit
- Heat number and grade stencilled on every piece or bundle tag
- Seaworthy ISPM-15 treated packing for export consignments
Global shipments
- HS Code: 7318
- FOB / CFR / CIF terms via Nhava Sheva (JNPT), Mundra and Mumbai ports
- Documentation: commercial invoice, packing list, MTC, bill of lading, COO, insurance
- Regular exports to the GCC, Africa, Southeast Asia, Europe, Latin America and the USA
Ready to price your requirement?
Share grade, size and quantity — our Mumbai desk responds with pricing, stock position and lead time, usually the same working day.
Frequently asked questions.
Answers to the questions our Mumbai desk is asked most often.
What is duplex steel fasteners?
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Duplex Steel Fasteners is fasteners are studs, bolts, nuts, screws and washers machined or cold-formed in matching alloy, used to bolt flanged joints, structures and equipment in corrosive or high-temperature service, produced in duplex steel to ASTM A193 / A194 / F593 / B637, ASME B18.2.1, DIN / ISO. Steelco stocks it in Mumbai in M6 – M64 and 1/4" – 2.1/2", lengths to 1500 mm across grades such as Duplex 2205, Super Duplex 2507, Zeron 100.
Which grades of fasteners do you stock?
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We hold 3 grades in ready stock: Duplex 2205 (S31803 / S32205), Super Duplex 2507 (S32750), Zeron 100 (S32760). Other grades are rolled or forged to order against a mill programme.
What sizes of duplex steel fasteners are available?
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Stock covers M6 – M64 and 1/4" – 2.1/2", lengths to 1500 mm, with thickness or wall from M6 – M64 and 1/4" – 2.1/2", lengths to 1500 mm in as per specification condition. Non-standard sizes are cut, machined or mill-rolled to your requirement.
What is the price of duplex steel fasteners in India?
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Price is quoted per kilogram and moves with the alloy surcharge, the grade and the size. Send the grade, size, quantity and certification you need and our Mumbai desk replies the same working day with price, stock position and lead time.
Do you supply fasteners with test certificates?
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Yes. Every consignment ships with an EN 10204 3.1 mill test certificate showing chemistry and mechanical results against ASTM A193 / A194 / F593 / B637, ASME B18.2.1, DIN / ISO. EN 10204 3.2 certification witnessed by TÜV, SGS, BV, Lloyd's, IRS or IBR is arranged on request, along with PMI, dye-penetrant and ultrasonic reports.