Home > Duplex Steel Nuts S31803
Duplex Steel S31803 Nuts are tough, corrosion-resistant fasteners crafted for the rigors of industrial settings that demand both strength and durability. Constructed from Duplex S31803, these nuts boast a well-balanced microstructure that provides excellent defense against pitting, crevice corrosion, and chloride stress-corrosion cracking. Their remarkable mechanical strength, paired with outstanding resistance to harsh chemicals and seawater, makes them ideal for high-pressure and high-temperature scenarios. You’ll find Duplex S31803 Nuts in offshore structures, chemical processing facilities, desalination plants, and oil & gas systems, ensuring dependable and long-lasting fastening performance for critical assemblies and equipment.
Duplex Steel S31803 Nuts are crafted from a ferritic-austenitic alloy that includes about 22% chromium, 5–6% nickel, and 3% molybdenum, with added nitrogen to boost strength. This unique blend provides exceptional resistance to chloride-induced corrosion, oxidation, and chemical damage. The alloy delivers nearly double the yield strength compared to standard stainless steels, along with high hardness and impressive impact toughness. Its dual-phase microstructure guarantees stability even under high temperatures and stress, making S31803 nuts perfect for demanding industrial applications that require both mechanical strength and corrosion resistance.
| S31803 | Density | Melting Point | Yield Strength (0.2%Offset) | Tensile Strength | Elongation |
| 7.8 g/cm3 | 1350 °C (2460 °F) | Psi – 80000 , MPa – 550 | Psi – 116000 , MPa – 800 | 15 % |
| S31803 | C | N | P | Si | Mn | Mo | Fe | Cr | S | Ni |
| 1.0 | 0.03 | 0.02 | 2.0 | 3.0 – 3.5 | 22.0 – 23.0 | 0.03 | 4.5 – 6.5 | 0.14 – 0.2 | Bal |
| Specifications | ASTM A479 / ASME SA479 |
| Standards | DIN, ASTM, BS and all International Standards |
| Length | 3 mm to 200 mm |
| Size | M3 – M56 | 3/6″ to 2″ | Custom Sizes |
| Type | Hex Head Bolts, Square Bolts, U bolts, Eyebolts, T bolt, Hex Bolt, Lag Bolts, Countersunk Bolts, Hex Head nuts, Square nuts, Locknuts, Eye nuts, wing nuts, T nuts, Panel Nuts, Coupling Nuts, Dome nuts, Acorn Nuts |
Duplex Steel S31803 Nuts find their place in various industries where components face harsh, corrosive, or high-pressure conditions. In the oil & gas industry, they’re essential for pipelines, valves, pumps, wellheads, and offshore structures. The marine and desalination sectors depend on them for seawater systems, heat exchangers, and subsea equipment due to their resistance to chlorides. Chemical and petrochemical plants utilize these nuts in reactors, storage tanks, and processing equipment, ensuring reliable performance in challenging environments.
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
