What is a Duplex Round Bar?
A Duplex Round Bar is a specialty metal product that combines the numerous benefits of both ferritic and austenitic types of steel. The combinations of these two structures create a material that is much tougher and more durable than the regular ones.
The name “Duplex” comes from this dual-phase microstructure. If you looked at a grade like the S31803 Duplex bar under a microscope, you would see “pools” of austenite surrounded by a solid phase of ferrite. This specific internal makeup was developed to solve the cracking and corrosion issues often found in common 300-series stainless steels, like grade 304.
The standard types like the Duplex 2205 Round Bar are also augmented with nitrogen making them even stronger. Not fitting into any single category of materials, being neither austenitic as 304 nor ferritic as 430, they provide a special compromise of high mechanical strength and the best possible protection against chemical damages.
Looking to buy Super Duplex Steel Round Bars?
Check UNS S32760 Round Bar & UNS S32750 Round Bar Price List in India
Nuts Weight Chart
Duplex Steel Round Bars List
We stock and manufacture several specialized grades to suit different industrial needs.
Duplex Round Bar Specification
Our duplex steel bar products are available in the following technical ranges:
| Feature | Details |
|---|---|
| Standard Sizes | Round: 3mm – 800mm | Square: 4mm – 100mm | Flat: 2mm – 100mm |
| Length | 9 to 12 Meters (Custom lengths available up to 50 feet for forged bars) |
| Tolerance | H8-H11 & G5-G6 |
| Surface Finish | Black, Bright, Mirror, or Hairline |
| Density | 7.88 g/cm³ |
| Melting Point | 1350 °C |
| Hardness | ≤ 270 HB |
Physical Properties of Duplex Steel Forged Bar
| Density (Kg / M3) | Poisson’s Ratio | Modulus of Elasticity (GPa) | Thermal Conductivity (W/moC) | Thermal Capacity (I/KgoC) | Electrical Resistivity |
|---|---|---|---|---|---|
| 7800 | 0.3 | 200 | 15 | 500 | 0.8 |
Duplex Alloy Square Bar Chemical Composition
| Grade | C | Mn | Si | P | Mo | Ni | N | Fe | S | Cr |
|---|---|---|---|---|---|---|---|---|---|---|
| S31803 | 0.030 max | 2.00 max | 1.00 max | 0.030 max | 3.0 – 3.5 | 4.50 – 6.50 | 0.14 – 0.20 | 63.72 min | 0.020 max | 22.0 – 23.0 |
| S32205 | 0.030 max | 2.00 max | 1.00 max | 0.030 max | 2.50 – 3.50 | 4.50 – 6.50 | 0.8 – 0.20 | 63.54 min | 0.020 max | 21.0 – 23.0 |
Duplex Steel Bar Mechanical Properties
| Grade | Yield Strength (0.2%Offset) | Tensile Strength | Elongation | Density | Melting Point |
|---|---|---|---|---|---|
| S31803 / S32205 | Psi – 80000 , MPa – 550 | Psi – 116000 , MPa – 800 | 15 % | 7.8 g/cm3 | 1350 °C (2460 °F) |
Types of Duplex Stainless Steel Forged Rods
Size Chart of Stainless Steel Duplex Round Bars
| sizes in mm | Thickness (mm) | Size (inch) | Thickness (Inches) |
|---|---|---|---|
| 30 | 5 – 20 | 1-3/16 | 3/16 – 4/5 |
| 32 | 6 – 20 | 1-1/4 | 1/4 – 4/5 |
| 22 | 17 & 18 | 7/8 | 2/3 – 5/7 |
| 25 | 5 – 20 | 1 | 3/16 – 4/5 |
| 35 | 5 – 20 | 1-3/8 | 3/16 – 3/16 |
| 40 | 5 – 25 | 1-4/7 | 3/16 – 1 |
| 45 | 5 – 25 | 1-7/9 | 3/16 – 1 |
| 55 | 5 – 25 | 2-1/16 | 3/16 – 1 |
| 47 | 17,25 & 32 | 1-6/7 | 2/3, 1 & 1-1/4 |
| 50 | 5 – 32 | 2 | 3/16 – 1-1/4 |
| 57 | 32 | 2-1/4 | 1-1/4 |
| 65 | 10 – 30 & 35 | 2-5/9 | 3/8 – 1-3/16, & 1-3/8 |
| 70 | 6 – 25 & 40 | 2-3/4 | 1/4 – 1, & 1-4/7 |
| 75 | 8 – 25 | 3 | 5/16 – 1 |
| 60 | 5 – 35 | 2-3/8 | 3/16 – 1-3/8 |
| 63 | 10 – 30 | 2-1/2 | 3/8 – 1-3/16 |
| 80 | 8 – 20 | 3-1/8 | 5/16 – 4/5 |
| 90 | 8 – 20 | 3-1/2 | 5/16- 4/5 |
| 100 | 8, 10, 12 | 4 | 5/16, 3/8, 1/2 |
Duplex Steel Flat Bar ISO Tolerance
| DSS Round Bar Size, diameter | Permitted variation |
|---|---|
| mm | mm |
|
≧ 6 ≦ 18 > 18 ≦ 30 > 120 ≦ 180 > 180 ≦ 250 > 30 ≦ 50 > 50 ≦ 80 > 80 ≦ 120 > 250 ≦ 315 > 315 ≦ 400 > 400 |
+ 0 to – 0.070 + 0 to – 0.085 + 0 to – 0.160 + 0 to – 0.185 + 0 to – 0.100 + 0 to – 0.120 + 0 to – 0.140 + 0 to – 0.210 + 0 to – 0.230 + 0 to – 0.250 |
Duplex Stainless Steel Round Bar Weight Chart
| Size | Kgs / Mtr | Kgs / Foot | Size | Kgs / Mtr | Kgs / Foot | Size | Kgs / Foot |
|---|---|---|---|---|---|---|---|
| 3mm | 0.055 | 0.017 | 20mm | 2.47 | 0.753 | 3″ | 10.9 |
| 1/8″ | 0.062 | 0.019 | 22mm | 2.979 | 0.908 | 3-1/4″ | 12.8 |
| 5mm | 0.154 | 0.047 | 1″ | 3.97 | 1.21 | 4-1/4″ | 21.908 |
| 7/32″ | 0.19 | 0.058 | 26mm | 4.17 | 1.271 | 4-1/2″ | 24.4487 |
| 6mm | 0.223 | 0.068 | 27mm | 4.49 | 1.368 | 4-3/4″ | 27.366 |
| 1/4″ | 0.249 | 0.076 | 1-1/8″ | 5.033 | 1.534 | 5″ | 30.461 |
| 5/32″ | 0.095 | 0.029 | 7/8″ | 3.038 | 0.926 | 3-1/2″ | 14.85 |
| 4mm | 0.098 | 0.03 | 24mm | 3.543 | 1.08 | 3-3/4″ | 17.001 |
| 3/16″ | 0.141 | 0.043 | 25mm | 3.871 | 1.18 | 4″ | 19.306 |
| 7mm | 0.298 | 0.091 | 30mm | 5.548 | 1.691 | 5-1/2″ | 36.69 |
| 5/16″ | 0.387 | 0.118 | 1-1/4″ | 6.349 | 1.924 | 6″ | 43.86 |
| 10mm | 0.62 | 0.189 | 36mm | 7.999 | 2.438 | 8″ | 77.586 |
| 11mm | 0.748 | 0.228 | 38mm | 8.903 | 2.792 | 10″ | 121.048 |
| 7/16″ | 0.761 | 0.232 | 1-1/2″ | 8.951 | 2.715 | – | – |
| 8mm | 0.398 | 0.12 | 32mm | 6.314 | 1.894 | 6-1/2″ | 51.093 |
| 9mm | 0.498 | 0.152 | 1-3/8″ | 7.55 | 2.303 | 7″ | 59.432 |
| 3/8″ | 0.557 | 0.17 | 35mm | 7.553 | 2.39 | 7-1/2″ | 68.226 |
| 12mm | 0.889 | 0.271 | 40mm | 9.872 | 3.009 | – | – |
| 1/2″ | 0.994 | 0.303 | 1-5/8″ | 10.449 | 3.2 | – | – |
| 9/16″ | 1.256 | 0.383 | 1-7/8″ | 13.977 | 4.26 | – | – |
| 13mm | 1.043 | 0.318 | 1-3/4″ | 12.179 | 3.712 | – | – |
| 14mm | 1.207 | 0.368 | 45mm | 12.555 | 3.807 | – | – |
| 15mm | 1.391 | 0.424 | 48mm | 14.205 | 4.33 | – | – |
Making Process of Duplex Steel Round Bars
- Melting & Casting: Raw iron is melted with chromium, nickel, molybdenum, and nitrogen in an electric arc furnace at temperatures exceeding 2800°F to ensure a precise chemical balance.
- Hot Forming: Heated billets pass through high-speed rollers, reducing thickness and shaping the metal into uniform round rods.
- Heat Treatment: Bars undergo solution annealing to restore the perfect 50/50 balance between austenite and ferrite phases, maximizing toughness.
- Descaling: We use pickling or mechanical descaling to remove the “mill scale” oxidized layer, leaving a clean surface.
- Cutting / Machining: Bars are sawn or sheared to length. Precision machining is available for clients requiring exact dimensional tolerances.
- Packaging & Delivery: Every duplex steel bar is wrapped securely to prevent surface scratches during transit and export.
HS Code of Duplex Steel Bar
| Grade | HS Code |
|---|---|
| Duplex Steel | 72221119 |
Testing & Quality Assurance
Every Duplex Alloy Rod we supply comes with full documentation, including:
- Test Certificates: NABL approved certificates, Mill Test Reports (MTR), and Intergranular Corrosion (IGC) tests.
- Methods: We perform Tensile, Hardness, and Non-Destructive Testing (NDT) to ensure the bar won’t fail under pressure.
- Marking: Each bar is marked with its heat code, material designation, and rating for full traceability.
Applications of Duplex Steel Round Bars
Duplex steel round bars are used in applications where high strength and strong corrosion resistance are required at the same time. Their balanced austenitic–ferritic structure makes them reliable in demanding environments.
- Oil & Gas Industry
- Marine & Offshore Structures
- Chemical & Petrochemical Plants
- Power Generation
- Construction & Structural Engineering
- Desalination & Water Treatment Plants
- Pulp & Paper Industry
- Automotive & Heavy Engineering
- Fastener Manufacturing
- Food Processing Equipment
Contact Jade Alloys today for a quick quote on custom sizes and immediate stock availability for Duplex Steel Round Bars.
