Home > Duplex Steel > Duplex Steel S31803 Nuts
Duplex Steel S31803 nuts are celebrated for their outstanding strength, corrosion resistance, and reliability, especially in tough industrial settings. Crafted from a well-balanced duplex stainless steel grade, these nuts boast a unique dual-phase ferritic–austenitic structure that significantly boosts their mechanical performance and durability. They’re often the go-to choice for applications that face exposure to chlorides, chemicals, and high stress, where regular stainless steels might fall short. With their impressive resistance to pitting, crevice corrosion, and stress-corrosion cracking, S31803 nuts find their place in various industries, including oil and gas, marine engineering, petrochemicals, and construction. Their long-lasting service life and dependable performance make them a trusted fastening option.
Duplex Steel S31803 nuts generally consist of about 21–23% chromium, 4.5–6.5% nickel, 2.5–3.5% molybdenum, along with controlled nitrogen additions that boost their strength and corrosion resistance. The alloy’s balanced ferritic–austenitic microstructure delivers impressive mechanical properties, such as high tensile and yield strength. These nuts are known for their strong hardness, exceptional fatigue resistance, and stability under pressure and high temperatures. Their corrosion resistance surpasses that of standard stainless steels, particularly against pitting, crevice attack, and chloride-induced cracking. These qualities make S31803 nuts a reliable choice in environments that demand durable and high-performance fastening solutions.
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Material
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Specification
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Standards |
Size
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Length
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Duplex Steel S31803 |
IS BS ASTM |
ASTM / ASME – A/ SA 479 / 479
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3 mm |
M02 to M30 |
| Cr | N | Ni | C | Mn | Si | P | S | Mo | |
|---|---|---|---|---|---|---|---|---|---|
| S31803 | min: 21.0 max: 23.0 | min: 0.08 max: 0.20 | min: 4.5 max: 6.5 | 0.03 max | 2.0 max | 1.0 max | 0.03 max | 0.02 max | min: 2.5 max: 3.5 |
| S32205 | min: 22.0 max: 23.0 | min: 0.14 max: 0.20 | min: 4.5 max: 6.5 | 0.03 max | 2.0 max | 1.0 max | 0.03 max | 0.02 max | min: 3.0 max: 3.5 |
Grade | Tensile Strength (MPa) min | Elongation (% in 50mm) | Yield Strength 0.2% Proof (MPa) min | Hardness Rockwell C (HR C) |
|---|---|---|---|---|
UNS-S 31803 | 650-880 | 25 | 448 | |
UNS-S 32205 | 621 | 25 | 448 | 21 max |
At Bilal Nickel Alloys, we take pride in being the largest supplier, exporter, and manufacturer of Duplex Steel S31803 Nuts in Safat, Kuwait, providing cutting-edge solutions for all your piping needs. Our state-of-the-art production plants are strategically located in the Kuwait, allowing us to maintain a vast inventory of over 16,000 tons of premium-quality materials readily available in stock. We are dedicated to delivering superior products and services, ensuring reliability and excellence for our global clientele.
Contact us to get a quick quote for your requirement.
Duplex Steel S31803 nuts are utilized across various industries where strength, corrosion resistance, and reliability are crucial. They’re commonly found in offshore and marine settings, fastening components that are exposed to seawater and high salinity. In the oil and gas industry, they play a vital role in securing pipelines, valves, wellhead equipment, and subsea structures. Additionally, petrochemical and chemical processing plants rely on S31803 nuts for applications involving heat exchangers, reactors, and pressure vessels. Their robust performance in challenging conditions makes them an essential component in many industrial applications
