Grades: UNS S31803, UNS S32750
Inox Steel India is a manufacturer, supplier, and exporter of duplex and super duplex stainless steel hex bars, supplying to oil & gas, marine, offshore, and process industries across India, GCC countries, the Middle East, Africa, Europe, and the Americas.
Duplex and super duplex hex bars are supplied in UNS S31803 and UNS S32750 grades, manufactured as per ASTM A276 / ASTM A479 standards. These grades are selected for applications requiring high mechanical strength combined with excellent resistance to pitting, crevice corrosion, and stress corrosion cracking.
With controlled melting, solution annealing, and dimensional processing, duplex and super duplex hex bars supplied by Inox Steel India provide uniform microstructure, consistent mechanical properties, and reliable performance in aggressive service environments.
Duplex and super duplex hex bars are solid long products with a hexagonal (six-sided) cross section, manufactured from duplex stainless steels containing a balanced austenitic–ferritic microstructure. This structure provides higher strength than conventional austenitic stainless steels along with improved resistance to chloride-induced corrosion.
Duplex and super duplex hex bars are produced from stainless steel billets using hot rolling, forging, or cold drawing, followed by solution annealing to achieve the required phase balance and corrosion resistance.
Manufacturing Steps:
1️⃣ Billet Selection & Heating
Billets of UNS S31803 or UNS S32750 are selected and heated under controlled conditions.
2️⃣ Hot Rolling / Forging
Billets are rolled or forged through hexagonal passes to achieve the required across-flat dimensions.
3️⃣ Cold Drawing (Where Required)
Bars may be cold drawn to improve dimensional tolerance and surface finish.
4️⃣ Solution Annealing
Bars are solution annealed to restore corrosion resistance and mechanical properties.
5️⃣ Straightening & Cutting
Bars are straightened and cut to standard or custom lengths.
6️⃣ Final Inspection
Chemical analysis, mechanical testing, and PMI are carried out prior to dispatch.
These properties make duplex and super duplex hex bars suitable for critical and corrosive service applications.
🧩 Grades & Standards Available
Duplex and super duplex hex bars are supplied in the following grades:
Materials are supplied as per ASTM A276 / ASTM A479 specifications.
👉 (Refer to the approved Master Technical Data Sheet for chemical composition, mechanical properties, PREN values, and standard hex bar sizes in mm.)
When selecting duplex or super duplex hex bars, the following parameters should be evaluated:
1️⃣ Chloride Content and Corrosive Environment
2️⃣ Mechanical Strength Requirement
3️⃣ Operating Temperature and Pressure
4️⃣ Fabrication and Machining Conditions
5️⃣ Compliance with Project and Industry Standards
Correct grade selection ensures long service life and operational reliability in aggressive environments.
🌍 Usage & Demand Overview
In India, duplex and super duplex hex bars are widely used by oil & gas companies, offshore fabricators, marine equipment manufacturers, and chemical processing plants, particularly for applications exposed to seawater and chloride-bearing media.
Export demand is driven by offshore platforms, subsea equipment, desalination plants, and petrochemical facilities requiring ASTM-compliant duplex stainless steel products.
⚙ Applications and Technical Specifications by Grade
Duplex and super duplex hex bars supplied by Inox Steel India are used where high strength, chloride resistance, and reliability in aggressive environments are required. Grade selection depends on corrosion severity, pressure, and service conditions.
🧩 Applications by Grade / Type
Duplex Stainless Steel S31803 Hex Bars
Service Use: General chloride-bearing and moderate corrosive environments.
Typical Applications: Valves, fasteners, shafts, pumps, heat exchanger components.
Industry Sectors: Oil & Gas | Chemical | Marine | Power
Super Duplex Stainless Steel S32750 Hex Bars
Service Use: Highly corrosive and high-chloride environments.
Typical Applications: Offshore fasteners, subsea components, desalination equipment, flanges and fittings.
Industry Sectors: Offshore | Marine | Desalination | Petrochemical
📐 Duplex & Super Duplex Hex Bar Sizes & Dimensions
Duplex and super duplex hex bars are supplied in standard metric hex bar sizes in accordance with ASTM tolerances.
(Refer to standard hex bar sizes in mm PDF and hex bar size chart in mm India for detailed dimensions and weights.)
⚖ Duplex & Super Duplex Hex Bar Weight Chart (Indicative)
| AF Size (mm) | Approx. Weight (kg/m) |
|---|---|
| 8 | 0.43 |
| 10 | 0.68 |
| 12 | 0.98 |
| 16 | 1.74 |
| 20 | 2.72 |
| 25 | 4.25 |
| 30 | 6.11 |
| 40 | 10.86 |
| 50 | 16.90 |
| 60 | 24.60 |
Weights are indicative and may vary based on tolerance and surface finish.
💰 Duplex & Super Duplex Hex Bars Price (Indicative – India)
| Grade | Approx. Price Range (INR / kg) |
|---|---|
| UNS S31803 | ₹ 420 – ₹ 650 |
| UNS S32750 | ₹ 650 – ₹ 950 |
Prices vary based on size, finish (black / bright / polished), quantity, and prevailing market conditions.
🔢 Duplex & Super Duplex Hex Bar HSN / HS Code
HSN Code: 7222.20.11
Applicable for stainless steel bars and rods under Indian and international trade classification.
🧪 Testing & Quality Inspection
Duplex and super duplex hex bars are inspected and tested to ensure compliance with applicable standards.
Testing includes:
Material can be supplied with EN 10204 3.1 / 3.2 certification on request.
🏭 Why Choose Inox Steel India
Inox Steel India supplies duplex and super duplex stainless steel hex bars with controlled metallurgy, solution annealing, and documented traceability. Material is processed and inspected to meet project requirements for corrosive and high-strength service conditions.
Key supply features:
🧩 Industries Served
Duplex and super duplex hex bars are supplied to the following industries:
Grade selection is aligned with chloride exposure, pressure conditions, and service life requirements.
📦 Packaging & Supply
Duplex and super duplex hex bars are packed and dispatched as per standard industrial and export practices.
Dispatch supported through JNPT (Mumbai), Mundra, and Hazira ports for export shipments.
Standard across-flat sizes range from 8 mm to 60 mm. Other sizes can be supplied on request. Yes, these grades offer high to very high resistance to pitting, crevice corrosion, and stress corrosion cracking. The applicable HSN code is 7222.20.11. Yes, custom cut lengths are available as per requirement. Material can be supplied with EN 10204 3.1 / 3.2 test certification on request. What are the standard hex bar sizes in mm?
Are duplex and super duplex hex bars corrosion resistant?
What is the HSN code for duplex & super duplex hex bars?
Are custom cut lengths available?
Is test certification provided with supply?