Our duplex steel threaded rods conform to ASTM A193 and utilize 2205 duplex material. This results in a tensile strength of 700-850 MPa, significantly higher than ordinary stainless steel rods, and are extremely resistant to rust in saline or chemical environments.
We offer two surface treatments: pickling (per ASTM A380) for improved corrosion resistance, and oiling (light mineral oil) to protect the threads during storage. The pickling process removes mill scale produced during manufacturing.
Our threads are precision-machined: UNC threads (ASME B1.1). We can cut the rod to custom lengths (1 to 6 meters) using high-speed saws to ensure smooth rod ends. Each rod is thread gauge checked (per ASME B1.1) before shipment to ensure the correct thread size.
As a Chinese manufacturer with experience serving European and American industrial customers, we have dedicated threading lines and heat treatment furnaces, with an annual production capacity of 3,000 tons. Our raw materials undergo a special annealing process to achieve a perfect 50-50 ferrite/austenite ratio and are inspected in-house using magnetic particle detectors.
Our warehouse holds 600-800 tons of inventory, covering diameters from 1/4 inch to 2 inches in standard lengths of 3 and 6 meters. Our website updates inventory twice daily, and bar shipments from stock can be shipped within 5 days.
Orders over 40 tons get a 5% discount, free processing service.
Here's our guarantee: If any Duplex Steel Threaded Rod fails to meet ASTM A193 strength standards or shows significant corrosion (more than 0.01mm/year) in standard tests within 3 years, we'll replace it within 7 days and cover all shipping costs. We also lock prices for 40 days on confirmed orders, so you don't have to worry about sudden price jumps affecting your margins.
Duplex Stainless Steel S31803 (UNS S31803; equivalent to 2205, DIN 1.4462)
Chemical Composition
Cr: 21.0-23.0%, Ni: 4.5-6.5%, Mo: 2.5-3.5%, N: 0.14-0.20%, C: ≤0.03%, Mn: ≤2.0%, Si: ≤1.0%, P: ≤0.03%, S: ≤0.02%
Mechanical Properties
Tensile Strength: 700-850 MPa
Yield Strength: ≥450 MPa
Hardness: ≤290 HB (Brinell); ≤31 HRC
Elongation: ≥25%
Corrosion Resistance
Superior resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in chloride-rich environments (e.g., seawater, brines). Outperforms 316 in harsh chemical and marine settings.
Temperature Range
Service temp: -50°C to 250°C (optimal for subsea/offshore; limited high-temp ductility).
Magnetic Property
Magnetic (duplex microstructure: 50-60% ferrite + 40-50% austenite).
Metric Size (M)
Thread Pitch (mm)
Thread Type
Length Range (mm)
Imperial Equivalent
Imperial Thread Type
Length Range (inches)
Metric Coarse (ISO)
UNC (3/16"-24)
Metric Coarse (ISO)
UNC (5/16"-18)
Metric Coarse (ISO)
UNC (3/8"-16)
Metric Coarse (ISO)
UNC (1/2"-13)
Metric Coarse (ISO)
UNC (5/8"-11)
Metric Coarse (ISO)
UNC (3/4"-10)
Compliance Standards
Key Applications
ASTM A193 B8S, ASME SA193, ISO 898-1, DIN 975
Offshore oil/gas: subsea pipelines, wellhead equipment, risers
Marine: shipbuilding, seawater systems, propeller shafts
Desalination: reverse osmosis (RO) plants, brine handling
Chemical processing: chloride-based solvents, acid reactors
Pulp/paper: bleaching lines (chlorine dioxide environments)
S31803 (2205) Threaded Rods
316 Stainless Steel Rods
Carbon Steel Rods (Zinc-Plated)
High yield strength (450+ MPa) – ideal for high-load, high-pressure joints.
Moderate (yield ~205 MPa) – suitable for low-stress uses.
High tensile but poor corrosion resistance.
Corrosion Resistance
Excellent in seawater/chlorides – no coating needed.
Good in mild chemicals but limited in high chlorides.
Requires coating; prone to rust in moist environments.
Premium (due to alloy content).
Lowest, but higher lifecycle costs in harsh environments.
20+ years in offshore/marine settings.
10-15 years in similar environments
Frequently Asked Questions
Q: What payment terms do you support?
A: We support T/T, L/C, and Western Union. For regular customers, we can also discuss more flexible terms.
Q: Do you have stock for standard-sized products?
A: Yes, we keep stock for most standard-sized pipes, flanges, and fittings to ensure quick delivery.
Q: How do you ensure the accuracy of product specifications?
A: Each product is inspected by our QC team using precision instruments, and we provide MTC (Material Test Certificate) to confirm specifications.
