Excellence in Duplex Steel Fastening
At Dalloyed, we manufacture fasteners from Duplex Stainless Steel, which features a mixed microstructure of Austenite and Ferrite. This unique combination provides twice the yield strength compared to standard austenitic stainless steels (like SS 316L).
Our UNS S31803 (Duplex 2205) and UNS S32750 (Super Duplex 2507) fasteners are highly resistant to stress corrosion cracking (SCC), pitting, and crevice corrosion. These properties make them essential for Marine Engineering, Chemical Cargo Tanks, and Desalination infrastructure.
- High Resistance to Pitting
- Superior Tensile Strength
- Stress Corrosion Immunity
- Precision Machined Threads
Specialized Duplex Grades
High-integrity bolting components for specialized industrial needs.
UNS S31803 / S32205
The most widely used duplex grade. Features excellent fatigue strength and resistance to SCC in chloride environments.
UNS S32750
Highly alloyed steel for extreme service. Exceptional resistance to acids and highly saline seawater environments.
UNS S32760
Contains Tungsten and Copper for enhanced corrosion resistance in aggressive chemical processing plants.
Technical Properties Sheet
| Property Type | Duplex 2205 (F51) | Super Duplex 2507 (F53) |
|---|---|---|
| Tensile Strength (min) | 620 MPa (90 ksi) | 795 MPa (116 ksi) |
| Yield Strength (min) | 450 MPa (65 ksi) | 550 MPa (80 ksi) |
| Hardness (max) | 290 HBW (31 HRC) | 310 HBW (32 HRC) |
| PREN Value (Min) | 34 | 40 |
| Density | 7.8 g/cm³ | 7.8 g/cm³ |
*PREN (Pitting Resistance Equivalent Number) determines the material's resistance to pitting in salt water.
Marine & Offshore Experts
We specialize in Duplex bolting for subsea applications. Every order comes with full traceability and MTC EN 10204 3.1 reports.