The Super Duplex Fasteners are high-strength stainless steel fasteners that are meant for use in applications in which ordinary stainless steel bolts would lack adequate corrosion resistance and/or load capacity. The PREN of around 25% chromium with molybdenum, nickel, and nitrogen is ≥40, and the duplex metallurgy is made up of 50% austenite and 50% ferrite. Generally, the below mentioned grades are used for a severe chloride environment: UNS S32750, UNS S32760, ASTM A182 F53 & F55. These fasteners include heavy hex bolts, studs, nuts, threaded rods, washers and custom fasteners all made of superduplex fasteners materials. The materials of superduplex fasteners feature high strength, high toughness and outstanding resistance to pitting and crevice corrosion. Jade Alloys is the leading manufacturer, supplier and stockist of Super Duplex Fastener and other materials in India.
Specifications of Super Duplex Fasteners
| Attribute | Details |
|---|---|
| Grade | Super Duplex Steel UNS S32750 |
| Specifications | ASTM / ASME F53, A479 / SA479 |
| Standards | DIN, ASTM, BS, and all International Standards |
| Size Range | M3 – M56 | 3/16″ to 2″ | Custom Sizes |
| Length Range | 3 mm to 200 mm |
Chemical Compositions of Super Duplex Fasteners
| Element | Cr | Ni | Mo | Mn (max) | Si (max) | Cu (max) | N | P (max) | C (max) | S (max) | Fe |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Content (%) | 24 – 26 | 6 – 8 | 3 – 5 | 1.20 | 0.80 | 0.50 | 0.24 – 0.32 | 0.035 | 0.030 | 0.020 | Balance |
Equivalent Standards of Super Duplex Fasteners
| STANDARD | WERKSTOFF NR. | UNS |
|---|---|---|
| Super Duplex S2507 | 1.4410 | S32750 / S32950 |
Different Types of Super Duplex Fasteners
Super Duplex Fasteners Mechanical Properties
| Grade | Tensile Strength (Min) | Yield Strength 0.2% Offset (Min) | Elongation (Min, 2 inches / 50mm) | Hardness (Max) | Impact Energy (Charpy V-Notch at -40°C) |
|---|---|---|---|---|---|
| 2507 / UNS S32750 | 795 MPa (116 ksi) | 550 MPa (80 ksi) | 15% | 310 HBW / 32 HRC | 80 J |
| UNS S32760 | 750 MPa (108 ksi) | 550 MPa (80 ksi) | 25% | 270 – 320 HBW | 80 J |
| Ferralium 255 | 760 MPa (110 ksi) | 550 MPa (80 ksi) | 15% | 297 HBW / 31 HRC | 60 J |
Super Duplex Fastener Grades
| Grade / Material | UNS / Werkstoff | Governing Spec | PREN |
|---|---|---|---|
| Super Duplex 2507 | UNS S32750 / 1.4410 | ASTM A276 / A479 | ≥ 42 |
| S32760 / Zeron 100 | UNS S32760 / 1.4501 | ASTM A276 / A479 | ≥ 40 |
| Ferralium 255 | UNS S32550 / 1.4507 | ASTM A276 / A479 | ≥ 38 |
| F53 | UNS S32750 / 1.4410 | ASTM A182 (Forgings) | ≥ 42 |
| F55 | UNS S32760 / 1.4501 | ASTM A182 (Forgings) | ≥ 40 |
Applicational and Industrial Uses of Super Duplex Fasteners
- Oil & Gas Industry
- Chemical Processing Industry
- Marine & Offshore Industry
- Desalination & Water Treatment
- Petrochemical Industry
- Power Generation Industry
- Pulp & Paper Industry
- Mining & Mineral Processing Industry
Frequently Asked Questions
1. What are Super Duplex Fasteners?
2. What are Super Duplex Fasteners used for?
3. What is the difference between duplex and super duplex?
4. What is super duplex material?
5. Is 2205 duplex or super duplex?
6. Can Monel 400 Fasteners be used in hydrofluoric acid service?
