ARK Stainless Inc. is a trusted manufacturer and supplier of premium Duplex & Super Duplex Steel Fasteners, designed to deliver exceptional strength, superior corrosion resistance, and outstanding performance in demanding industrial environments. These fasteners are engineered to withstand high mechanical stress and harsh corrosive conditions, making them ideal for critical applications.
We manufacture fasteners using advanced duplex and super duplex steel grades such as Duplex S31803/S32205 Fasteners and UNS S32750/S32760 Fasteners. These grades offer remarkable resistance to pitting, crevice corrosion, and stress corrosion cracking, making them highly suitable for high-pressure and corrosive environments, including seawater and chemical processing applications.
Our Duplex and Super Duplex Steel Fasteners are available in various types including hex bolts, stud bolts, socket head cap screws, hex nuts, heavy hex nuts, spring washers, flat washers, anchor bolts, knurled nuts, and threaded studs. They are manufactured in compliance with international standards such as ASTM F593, ASTM F594, ASTM A193, and ASTM A194 to guarantee the highest quality and long-lasting durability.
These fasteners are widely used in industries such as oil & gas, petrochemical, marine, chemical processing, power generation, and infrastructure projects. With their excellent corrosion resistance, high strength, and durability, our duplex and super duplex steel fasteners are the perfect choice for applications in aggressive environments, offering minimal maintenance and ensuring reliable performance over an extended service life.
| Grade | Common Name | C% | Mn% | Si% | P% | S% | Cr% | Ni% | Mo% | N% | Others |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2205 | S31803 | 0.030 | 2.00 | 1.00 | 0.030 | 0.020 | 21.0-23.0 | 4.5-6.5 | 2.5-3.5 | 0.08-0.20 | S=0.001 |
| S32205 | 0.030 | 2.00 | 1.00 | 0.030 | 0.020 | 22.0-23.0 | 4.5-6.5 | 3.0-3.5 | 0.14-0.20 | ||
| Super Duplex | S32750/S32760 | 0.020 | - | - | - | - | 25 | 7 | 4.0 | 0.27 | S=0.001 |
| Mechanical Properties | Duplex Steel (ASME SA182) | Super Duplex Steel (ASME SA182) |
|---|---|---|
| Tensile Strength, ksi | 90 min | 116 min |
| 0.2% Yield Strength, ksi | 65 min | 80 min |
| Elongation, % | 25 min | 15 min |
| Hardness [HRC] | 293 max | 32 max |
| Impact Energy, ft.-lbs. | - | 74 min |
| 0.1% Offset Yield Strength, ksi | - | 91 min |
Duplex Steel S31803/S32205 Fasteners are engineered from a superior ferrous, nickel, and chromium-based alloy, combining the properties of both austenitic and ferritic structures. These fasteners exhibit exceptional strength, high toughness, excellent weldability, and remarkable corrosion resistance, making them ideal for use in pressure vessels and various demanding industrial applications. Duplex Steel Fasteners are available in several types including bolts, nuts, screws, washers, threaded rods, and studs, meticulously manufactured to suit a range of service conditions. Developed from the austenitic-ferritic duplex alloy, these fasteners possess outstanding features such as superior resistance to general and localized corrosion, excellent pitting resistance due to controlled carbon content, high ductility, stability at elevated temperatures, and enhanced durability. This makes Duplex Steel S31803/S32205 Fasteners highly suitable for elevated temperature applications and critical environments in industries like offshore oil drilling, power generation, petrochemicals, heat exchangers, gas processing, pharmaceuticals, and seawater equipment. To ensure top-notch quality and performance, our Duplex Steel Fasteners undergo rigorous testing procedures such as intergranular corrosion (IGC) testing, pitting resistance testing, flaring test, micro and macro examination, flattening test, positive material identification (PMI) test, chemical analysis, hardness testing, and mechanical tensile testing. We also provide detailed documentation including the quality assurance plan, MTC-En10204/3.1b, third-party inspection reports, and radiography test reports for complete customer satisfaction. For safe delivery, Duplex Steel S31803/S32205 Fasteners are carefully packed using high-quality materials such as wooden pallets and cases, ensuring protection against damage during transportation and preserving the integrity of the products till they reach our esteemed customers.
| STANDARD | UNS | WNR. |
|---|---|---|
| Duplex Steel 2205 | S31803 / S32205 | 1.4462 |
The manufacturer and supplier of Super Duplex Steel S32750/S32760 Fasteners provide these products in various types and sizes as per client requirements. These fasteners are known for their outstanding properties such as high strength, better workability, good weldability, excellent fatigue resistance, and higher thermal conductivity, making them highly durable and ideal for critical applications. Although processing this alloy is challenging due to the presence of elements like nickel, nitrogen, chromium, and molybdenum, these fasteners are carefully manufactured to ensure superior performance. They are widely demanded in industries like chemical processing, desalination equipment, marine applications, oil and gas industry, and gas scrubbing systems. To guarantee the highest quality, various tests such as mechanical tests, positive material identification tests, creep tests, torsion tests, compression tests, flexure tests, fatigue tests, proof load tests, axial tensile strength tests, hardness tests, pitting corrosion tests, radiographic tests, ultrasonic tests, flaring tests, intergranular corrosion tests, chemical analysis, and micro/macro tests are conducted. The packaging is meticulously done using individual wrapping with strong film, spiral wound paper tubes, pallets, cartons, wooden boxes, and crates to ensure the fasteners reach customers safely and in excellent condition.
| STANDARD | UNS | WNR. |
|---|---|---|
| Super Duplex Steel 2507 | S32750 / S32760 | 1.4410 |
