Home > Flat Bars > Duplex & Super Duplex Flat Bars
Grades: UNS S31803 (2205) & UNS S32750 (2507) | Supplier & Exporter
Inox Steel India is a trusted manufacturer, supplier, and exporter of Duplex and Super Duplex stainless steel flat bars in India, supplying high-performance Duplex 2205 (UNS S31803 / S32205) and Super Duplex 2507 (UNS S32750) flat bars for severe corrosion and high-strength applications.
Our duplex stainless steel flat bars combine the advantages of austenitic and ferritic stainless steels, offering exceptional mechanical strength, outstanding resistance to chloride-induced corrosion, and superior stress corrosion cracking resistance. These properties make them the preferred choice for marine, offshore, oil & gas, chemical, and desalination environments where conventional stainless steels are inadequate.
Buyers searching for duplex flat bar manufacturers in India, super duplex flat bar price, or flat bars for marine and offshore use rely on Inox Steel India for certified material, technical guidance, and reliable export supply.
Duplex and Super Duplex flat bars are solid rectangular stainless steel bars manufactured from alloys with a balanced austenitic–ferritic microstructure. This unique structure provides nearly twice the yield strength of austenitic stainless steels (like 304 or 316) while significantly improving resistance to pitting, crevice corrosion, and stress corrosion cracking.
⭐ Key Advantages of Duplex & Super Duplex Flat Bars
✔ High strength with reduced material thickness
✔ Excellent resistance to pitting & crevice corrosion
✔ Outstanding stress corrosion cracking resistance
✔ Superior performance in seawater & chloride environments
✔ Better cost-efficiency than high-nickel alloys
✔ Long service life in aggressive operating conditions
These advantages allow designers and engineers to reduce weight, increase safety margins, and extend equipment life.
DUPLEX & SUPER DUPLEX FLAT BARS – MASTER TABLE
| Parameter | Complete Specification |
|---|---|
| Product Name | Duplex & Super Duplex Stainless Steel Flat Bars |
| Product Form | Flat / Rectangular Solid Bars |
| Grades Available | Duplex 2205 (UNS S31803 / S32205), Super Duplex 2507 (UNS S32750) |
| Equivalent Standards | ASTM A240, ASTM A276, ASTM A484 |
| Material Type | Duplex & Super Duplex Stainless Steel |
| Microstructure | Austenitic–Ferritic (Duplex) |
| Manufacturing Process | Hot Rolled, Forged |
| Surface Finish | Hot Rolled (HRAP), Pickled, Rough Machined |
| Edge Condition | Mill Edge, Machined Edge |
| Supply Condition | Solution Annealed |
| Density | 7.8 g/cm³ |
| Chromium Content | Duplex: ~22% · Super Duplex: ~25% |
| Tensile Strength | Duplex: ≥ 620 MPa · Super Duplex: ≥ 800 MPa |
| Yield Strength | Duplex: ≥ 450 MPa · Super Duplex: ≥ 550 MPa |
| Elongation | ≥ 25% |
| Hardness | Duplex: ≤ 290 HB · Super Duplex: ≤ 310 HB |
| PREN Value | Duplex: ≥ 35 · Super Duplex: ≥ 40 |
| Corrosion Resistance | Excellent (chloride, pitting & crevice corrosion) |
| Stress Corrosion Cracking | Very High Resistance |
| Temperature Service | Up to 250–300°C (avoid prolonged higher exposure) |
| Weldability | Good (controlled procedures required) |
| Machinability | Moderate |
| Width Range | 12 mm – 300 mm |
| Thickness Range | 6 mm – 100 mm |
| Length Options | Random Length, 6 Meter, Custom Cut Lengths |
| Standard Commercial Sizes | 25×6, 40×8, 50×10, 65×12, 75×16, 100×20 mm |
| Approx Weight Reference | As per Duplex Flat Bar Weight Chart |
| Typical Applications | Marine structures, offshore platforms, heat exchangers, pressure vessels, desalination plants |
| Industries Served | Oil & Gas, Marine & Offshore, Chemical, Petrochemical, Power, Water Treatment |
| Duplex 2205 Flat Bar Price | ₹380 – ₹480 per kg |
| Super Duplex 2507 Flat Bar Price | ₹520 – ₹680 per kg |
| Price Basis | Ex-Mumbai / Ex-Works India (indicative) |
| HSN / HS Code | 7222 |
| Testing Performed | Chemical Analysis, Tensile, Yield, Hardness, PMI, Ferrite Content |
| Additional Testing | ASTM G48 (Pitting – Super Duplex, on request) |
| Certification | EN 10204 3.1 / 3.2 |
| Third-Party Inspection | SGS, BV, TUV, DNV (on request) |
| Packaging | HDPE wrapped bundles, wooden pallets / crates |
| Dispatch Ports | JNPT (Mumbai), Mundra, Hazira |
| Domestic Supply | Mumbai, Navi Mumbai, Pune, Ahmedabad, PAN India |
| Export Markets | GCC, Middle East, Africa, Europe, North & South America |
Understanding the difference between Duplex and Super Duplex flat bars is essential for correct material selection:
Inox Steel India assists buyers in selecting the correct grade based on chloride level, operating temperature, pressure, and lifecycle cost considerations.
🌍 Demand & Usage – India and Global Markets
In India, duplex and super duplex flat bars are in high demand in Mumbai, Navi Mumbai, Gujarat, Chennai, and Vizag, driven by offshore fabrication yards, refineries, and water treatment projects.
Globally, Super Duplex 2507 flat bars are widely exported to UAE, Saudi Arabia, Oman, Qatar, Europe, and North America, where stringent corrosion resistance and certification requirements apply.
With dispatch from JNPT (Mumbai), Mundra, and Hazira ports, Inox Steel India ensures timely delivery, export-grade packaging, and full material traceability.
Duplex and Super Duplex stainless steel flat bars supplied by Inox Steel India are engineered for high-strength and highly corrosive service conditions, where standard austenitic stainless steels are not sufficient.
| Industry Segment | Typical Applications |
|---|---|
| Oil & Gas | Offshore platforms, subsea structures, manifolds |
| Marine & Offshore | Ship structures, mooring systems, seawater exposure |
| Chemical & Petrochemical | Reactors, heat exchangers, pressure vessels |
| Desalination Plants | Evaporators, brine handling equipment |
| Power & Energy | Cooling systems, high-pressure components |
| Water Treatment | Chloride-rich piping & structural supports |
Grade-wise application guidance:
📐 Duplex & Super Duplex Flat Bar Sizes
Inox Steel India supplies duplex and super duplex flat bars in standard stock sizes and project-specific custom dimensions.
Standard Size Range:
Common Commercial Sizes (mm):
25×6 | 40×8 | 50×10 | 65×12 | 75×16 | 100×20
📥 Duplex & Super Duplex Flat Bar Sizes PDF available on request
| Size (mm) | Approx. Weight (kg/m) |
|---|---|
| 25 × 6 | 1.18 |
| 40 × 8 | 2.51 |
| 50 × 10 | 3.93 |
| 65 × 12 | 6.12 |
| 75 × 16 | 9.42 |
| 100 × 20 | 15.70 |
📥 Duplex & Super Duplex Flat Bar Weight Chart PDF available
💰 Duplex & Super Duplex Flat Bar Price (Indicative – India)
Prices vary based on grade, size, finish, and certification level. Indicative ranges:
| Grade | Price INR / Kg |
|---|---|
| Duplex 2205 Flat Bar | ₹380 – ₹480 |
| Super Duplex 2507 Flat Bar | ₹520 – ₹680 |
🧾 Prices are Ex-Mumbai / Ex-Works India and subject to alloy surcharge and certification requirements (NACE / G48 testing).
🔢 HSN / HS Code – Duplex & Super Duplex Flat Bars
🧪 Testing & Quality Assurance
All duplex and super duplex flat bars undergo stringent quality checks before dispatch:
📄 Certification supplied: EN 10204 3.1 / 3.2
🔍 Third-party inspection: SGS / BV / TUV / DNV (on request)
When sourcing duplex and super duplex flat bars, buyers prioritize material authenticity, corrosion performance, certification, and export reliability. Inox Steel India delivers consistently across all these parameters.
Key Advantages:
✅ Complete range of Duplex 2205 (UNS S31803 / S32205) and Super Duplex 2507 (UNS S32750)
✅ Supplied in solution annealed condition for optimal corrosion resistance
✅ High strength with excellent pitting & crevice corrosion resistance
✅ NACE-compliant material available on request
✅ EN 10204 3.1 / 3.2 Mill Test Certificates with full traceability
✅ Third-party inspection: SGS / BV / TUV / DNV
✅ Competitive duplex & super duplex flat bar pricing
✅ Strong domestic & export logistics support
Our duplex flat bars are engineered to deliver long service life, reduced maintenance, and high safety margins in aggressive environments.
Yes. Duplex and Super Duplex flat bars offer excellent resistance to seawater, chlorides, and stress corrosion cracking. EN 10204 3.1 / 3.2 MTCs are supplied. NACE and ASTM G48 testing can be provided on request. Yes. Custom cut lengths are supplied as per drawing or project requirement. Yes. We regularly export to GCC, Africa, Europe, and the Americas. Are duplex flat bars suitable for marine environments?
What certifications are provided with duplex flat bars?
Can you supply custom cut lengths of duplex flat bars?
Do you export duplex & super duplex flat bars?