Duplex S31803 Round Bars Supplier | UNS S31803 Duplex Steel Bar
Duplex S31803 Round Bars Supplier | UNS S31803 Duplex Steel Bar
Stellar Alloys is a trusted manufacturer, supplier, and exporter of Duplex S31803 Round Bars to buyers across the oil and gas, chemical processing, desalination, and marine sectors. We maintain ready stock in UNS S31803 round bar from 3 mm to 500 mm diameter, available in annealed condition with full ASTM A276 and ASTM A479 compliance. Every bar ships with mill test certificates (MTC), heat number traceability, and third-party inspection on request. We offer competitive ex-works pricing, short lead times, and flexible cut-to-length service for both small trial orders and bulk project supply. If your project specifies 2205 duplex bar S31803, request a quote from Stellar Alloys today and our technical sales team will respond within 24 hours.
When engineers browse our Duplex Steel Round Bars range, the grade they most often inquire about is UNS S31803. However, duplex 2205 round bar is produced to two UNS designations: UNS S31803 and the tighter UNS S32205.This material belongs to the duplex family of stainless steels, featuring a balanced dual-phase microstructure of roughly 50 percent austenite and 50 percent ferrite. That two-phase structure is the source of its key advantages: yield strength approximately twice that of standard austenitic grades such as 316L, combined with strong resistance to stress corrosion cracking and chloride-induced pitting. For procurement teams sourcing a duplex steel bar supplier that can certify composition and mechanical performance to international standards, UNS S31803 is one of the most specified duplex grades in service today.
Table of Contents
- UNS S31803 Round Bars Specifications
- Types of Duplex S31803 Round Bars
- S31803 vs S32205 Round Bars Comparison
- Chemical Composition of UNS S31803 Duplex Steel Bar
- Mechanical Properties of Duplex S31803 Round Bars
- Duplex S31803 Round Bar Equivalent Grades
- Duplex S31803 Round Bar Size Dimensions
- Applications of Duplex S31803 Round Bars
- Related Products
- Frequently Asked Questions About UNS S31803 Round Bars
UNS S31803 Round Bars Specifications
| Specifications | ASTM A276, A479 / ASME SA276, SA479 |
| Grade | Duplex Steel UNS S31803 F51 |
| Technique | uns S31803 Cold Drawn, Hot Rolled, Forged Round Bar, Rod, Cold Rolled |
| Tolerance | H8, H9, H10, H11, H12, H13K9, K10, K11, K12 or as per clients’ requirements |
| Finish | Cold (bright) drawn, centreless ground, hot rolled, smooth turned, peeled, slit rolled edge, hot rolled annealed, Rough Turned, Bright, Polish, Grinding, Centreless Ground & Black |
| Round bar size | Diameter: 3-~800mm |
| Hex Bar size | 2-100mm A/F |
| Flat bar size | Thickness: 2 -100mm |
| Width: 10 to 500mm | |
| Square bar size | 4 to 100mm |
| Billet Size | 1/2″ to 495mm Diameter |
| Channel Bar | 80 x 40mm to 150 x 75mm section; 5.0 to 6.0mm thickness |
| Hollow Bar | 32mm OD x 16mm ID to 250mm OD x 200mm ID) |
| Angle bar size | 3mm*20mm*20mm~12mm*100mm*100mm |
| Section | 3.0 to 12.0mm thickness |
| Form | Precision Ground Bar, Flat Bar, Square, Round, Half Round Bar, Rod, Rectangle, Hex (A/F), T-Bar, Channel Bar,Blocks, Round Rod, Threaded, Profiles, Billet, Ingot, I/H Bar, Forging, Rings, Hollow, Triangle etc. |
| Rectangles Size | 33 x 30mm to 295 x 1066mm |
| Surface | Cold Drawn, Bright, Sand Blasting Finished, Hot Rolled Pickled, Hairline, Polished |
| Processing | Bar cutting to 650mm |
| Certificates | ASTM A923 (Method A/B/C — intermetallic phase detection) available on request. Confirm project requirement at RFQ stage. |
| Condition | Solution Annealed (1020–1100°C, rapid quench) |
| Heat Treatment | Solution Anneal: 1020–1100°C (1870–2010°F), water quench or rapid air cool. Heat treatment confirmed on EN 10204 3.1 MTC. |
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Our uns S31803 Round bar conforms to NACE MR0175/ISO 15156 |
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Types of Duplex S31803 Round Bars
Duplex S31803 Bright Bars
Duplex Steel S31803 Flat Bars
Duplex S31803 Hex Bars
Duplex Steel S31803 Forged Bars
ASTM A276 S31803 Black Bars
UNS S31803 Polished Bars
Duplex Steel 2205 Rods
Duplex S31803 Square Bars
UNS S31803 Polished Bars
Request a Quote for Duplex S31803 Round Bars
Ready stock in 3 mm to 500 mm dia. ASTM A276 / A479 certified. Mill test certificates included.
Contact Stellar Alloys | 24-Hour Response Guarantee
S31803 vs S32205 Round Bars Comparison
| Property | UNS S31803 | UNS S32205 | Interchangeability Note |
| Cr Min (%) | 21.0 | 22.0 | S32205 higher floor |
| Mo Min (%) | 2.5 | 3.0 | S32205 higher floor |
| N Min (%) | 0.08 | 0.14 | S32205 higher floor |
| PREN Floor | 34 | 35+ | Check project specification |
| Interchangeable? | No | No | Written client approval required |
Chemical Composition of UNS S31803 Duplex Steel Bar
| Element | Min (%) | Max (%) |
| Carbon (C) | 0.030 | |
| Chromium (Cr) | 21.0 | 23.0 |
| Nickel (Ni) | 4.50 | 6.50 |
| Molybdenum (Mo) | 2.50 | 3.50 |
| Nitrogen (N) | 0.08 | 0.20 |
| Manganese (Mn) | 2.00 | |
| Silicon (Si) | 1.00 | |
| Phosphorus (P) | 0.030 | |
| Sulfur (S) | 0.020 |
Mechanical Properties of Duplex S31803 Round Bars
Property | Metric (MPa) | Imperial (ksi) | Condition |
Tensile Strength (UTS) | 620 MPa min | 90 ksi min | Annealed |
Yield Strength (0.2% offset) | 450 MPa min | 65 ksi min | Annealed |
Elongation in 2 in / 50 mm | 25% min | 25% min |
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Hardness | 293 HB max | 293 HB max |
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UNS S31803 in the solution-annealed condition typically exhibits 40–60% ferrite (FN 40–60 per ASTM A923 Method A). Ferrite number can be reported on the MTC on request. Excessively high ferrite (>65%) increases susceptibility to embrittlement at elevated temperatures. Confirm ferrite requirement with your project QCP.
Duplex S31803 Round Bar Equivalent Grades
STANDARD | WERKSTOFF NR. | UNS |
Duplex Steel S31803 | 1.4462 | S31803 |
Dimensions of Duplex S31803 Round Bar
Duplex S31803 Round Bar Size Dimensions
Diameter (mm) | Standard Length (mm) | Tolerance |
3 | 1000–6000 | ASTM A276 |
5 | 1000–6000 | ASTM A276 |
6 | 1000–6000 | ASTM A276 |
8 | 1000–6000 | ASTM A276 |
10 | 1000–6000 | ASTM A276 |
12 | 1000–6000 | ASTM A276 |
16 | 1000–6000 | ASTM A276 |
20 | 1000–6000 | ASTM A276 |
25 | 1000–6000 | ASTM A276 |
32 | 1000–6000 | ASTM A276 |
40 | 1000–6000 | ASTM A276 |
50 | 1000–6000 | ASTM A276 |
63 | 1000–6000 | ASTM A276 |
75 | 1000–6000 | ASTM A276 |
100 | 1000–6000 | ASTM A276 |
125 | 1000–6000 | ASTM A276 |
150 | 1000–6000 | ASTM A276 |
200 | 1000–6000 | ASTM A276 |
250 | 1000–6000 | ASTM A276 |
300 | 1000–6000 | ASTM A276 |
400 | 1000–6000 | ASTM A276 |
500 | 1000–6000 | ASTM A276 |
Cut-to-length available. Larger diameters up to 800 mm on request. Tolerances per ASTM A276; tighter tolerances available on request.
Applications of Duplex S31803 Round Bars
- Offshore and Topside Structures: Structural bolting, hangers, and tie rods on FPSO and fixed platform topsides, where seawater exposure demands better than standard 316L performance.
- Chemical Process Equipment: Agitator shafts, pump impellers, and valve stems handling corrosive process streams containing chlorides, acids, or mixed solvents.
- Desalination Plants: High-pressure pump shafts and feed pipe flanges in reverse-osmosis plants where high-chloride brine demands a PREN above 30.
- Pulp and Paper Mills: Digesters, bleach plant equipment, and washers where hot acid solutions attack standard austenitic grades but duplex provides adequate resistance.
Buyers sourcing higher-alloy bar for the most aggressive environments should also evaluate our Super Duplex Round Bar and Super Duplex S32750 Round Bars pages for grades with PREN above 40. For complementary alloy bar products, our Nickel Alloy Round Bars section provides high-performance alternatives. Further background on duplex metallurgy is available on our Duplex Steel Material Page.
Related Products
Our stainless steel round bars serve mission-critical applications across multiple industries due to their exceptional strength, corrosion resistance, and reliability in harsh environments:
Common applications include:
- Oil and Gas Industry – Downhole pump shafts, valve stems, instrumentation components, and wellhead equipment
- Chemical Processing Plants – Reactor vessel shafts, agitator components, pump impellers, and corrosion-resistant fasteners
- Marine and Offshore Structures – Propeller shafts, deck equipment, rigging hardware, and saltwater-resistant fittings
- Automotive and Mechanical Engineering – Engine components, transmission shafts, precision machined parts, and suspension elements
- Pump and Valve Manufacturing – Valve stems, pump shafts, piston rods, and high-pressure fittings
- Construction and Structural Frameworks – Architectural supports, railing systems, and load-bearing structural members
- Food Processing Equipment – Mixer shafts, conveyor components, sanitary fittings, and hygienic processing machinery
- Aerospace Components – Landing gear parts, high-strength fasteners, precision machined aircraft components
Ready to Source Duplex S31803 Round Bars?
Stellar Alloys offers certified UNS S31803 round bar in all sizes from 3 mm to 500 mm.
ASTM A276 | ASTM A479 | EN 10204 3.1 MTC | Third-Party Inspection Available
Submit Your RFQ Today
Frequently Asked Questions About UNS S31803 Round Bars
Check your spec carefully. If it says 2205 without a UNS number, request clarification. S32205 carries higher Cr, Mo, and N than S31803. Submitting S31803 without written approval may trigger non-conformance at inspection.
ASTM A276 covers hot and cold-finished round bar. ASTM A479 covers bar for pressure vessels. Both include UNS S31803. Stellar Alloys supplies dual-certified stock to A276 and A479 on request.
PREN for UNS S31803 ranges from 34 to 36, calculated as Cr + 3.3xMo + 16xN. It measures chloride pitting resistance. S31803 outperforms austenitic grades, but confirm the heat cert if specs require a PREN floor of 35.
Sizes 10 to 100 mm ship in 3 to 7 working days from stock. Up to 500 mm on mill-run basis. Documentation includes EN 10204 3.1 MTC, heat traceability, and dimensional report. Third-party inspection available on request.