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.
Duplex 2205 (UNS S31803 / S32205) offers excellent corrosion resistance with high strength for most marine and chemical environments.
Super Duplex 2507 (UNS S32750) provides even higher chromium, molybdenum, and nitrogen content, delivering superior performance in extreme chloride and seawater conditions.
These advantages allow designers and engineers to reduce weight, increase safety margins, and extend equipment life.
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 & 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.
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:
Inox Steel India supplies duplex and super duplex flat bars in standard stock sizes and project-specific custom dimensions.
Standard Size Range:
Width: 12 mm – 300 mm
Thickness: 6 mm – 100 mm
Length: Random Length / 6 Meter / Custom Cut Lengths
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
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 Code: 7222
Used for domestic invoicing and international export documentation.
All duplex and super duplex flat bars undergo stringent quality checks before dispatch:
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:
Our duplex flat bars are engineered to deliver long service life, reduced maintenance, and high safety margins in aggressive environments.
Duplex & Super Duplex flat bars are packed to preserve surface integrity and corrosion resistance:
Export Destinations:
UAE · Saudi Arabia · Oman · Qatar · Europe · Africa · North & South America
Whether you need Duplex 2205 flat bars for marine fabrication or Super Duplex 2507 flat bars for offshore and desalination projects, our technical team will assist with grade selection, compliance, pricing, and delivery schedules.
52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004
steel@inoxsteelindia.in
+91 9930796690
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?
Inox Steel India is a leading manufacturer & supplier of duplex and super duplex flat bars (UNS S31803, S32750). Get marine-grade flat bars with EN 10204 certification & export supply.