Duplex Fasteners
Unlike ferritic and austenitic alloy grades, what makes duplex alloys special is that they have a mixed microstructure consisting of both ferrite and austenite in an equal proportion. In other words, Duplex 2205 Fasteners often have properties seen in both alloy classes. Duplex stainless steel grades were designed with the intention of overcoming the shortcomings of both ferritic as well as austenitic stainless steel classes. Being a nitrogen enhanced grade, the 2205 duplex stainless steel bolts have superior resistance to pitting as well as crevice corrosion. And in comparison to regular stainless steel grades like 304 stainless steel, duplex steels tend to be much more resilient to chlorine induced stress related corrosion cracking.

The Duplex 2205 hex nuts are particularly useful in building pieces of equipment to be used in Flue gas desulfurization due to several of its advantageous properties. For instance, the Duplex 2205 studs have good weldability characteristics and are known to resist sulphide related stress corrosion. Usually, a corrosive environment of these sorts can be seen in exhaust flue gases of fossil-fuel power plants during the removal of sulfur dioxide from processes such as waste incineration during the emissions of other sulfur oxide emitting.
As opposed to conventional stainless steel grade, the UNS S31803 Hex Bolts do not crack under the stress of these corrosive compounds, which would indicate that duplex alloys often outperform austenitic grades. The hardness of Duplex 2205 Bolts is a property which has been inherited by the ferritic structure present in the alloy. Hence, the Duplex 2205 threaded rod is an alloy that is considered to be a valued addition to not only in equipment of Flue gas desulfurization but also Oil field piping and heat exchangers as well.
Duplex 2205 hex nuts Standard Dimensions

Minimal Size / Dia. of Basic Major Thread | F | G | H | ||||||
Across Flats Width | Across Corners Width |
Thick | |||||||
Max | Basic | Min | Min | Max | Basic | Min | Max | ||
2-3/4 | 2.7500 | 4.125 | 4-1/8 | 3.988 | 4.546 | 4.763 | 2-3/8 | 2.319 | 2.431 |
1/4 | .2500 | .438 | 7/16 | .428 | .488 | .505 | 7/32 | .212 | .226 |
5/16 | .3125 | .500 | 1/2 | .489 | .557 | .577 | 17/64 | .258 | .273 |
3/8 | .3750 | .562 | 9/16 | .551 | .628 | .650 | 21/64 | .479 | .337 |
1/2 | .5000 | .750 | 3/4 | .736 | .840 | .866 | 7/16 | .427 | .448 |
7/16 | .4375 | .688 | 11/16 | .675 | .768 | .794 | 3/8 | .365 | .385 |
9/16 | .5625 | .875 | 7/8 | .861 | .982 | 1.010 | 31/64 | .473 | .496 |
7/8 | .8750 | 1.312 | 1-5/16 | 1.269 | 1.447 | 1.516 | 3/4 | .724 | .776 |
5/8 | .6250 | .938 | 15/16 | .922 | 1.051 | 1.083 | 35/64 | .535 | .559 |
3/4 | .7500 | 1.125 | 1-1/8 | 1.088 | 1.240 | 1.299 | 41/64 | .617 | .665 |
1 | 1.0000 | 1.500 | 1-1/2 | 1.450 | 1.653 | 1.732 | 55/64 | .831 | .887 |
1-1/8 | 1.1250 | 1.688 | 1-11/16 | 1.631 | 1.859 | 1.949 | 31/32 | .939 | .999 |
1-3/8 | 1.3750 | 2.062 | 2-1/16 | 1.994 | 2.273 | 2.382 | 1-11/64 | 1.138 | 1.206 |
2 | 2.0000 | 3.000 | 3 | 2.900 | 3.306 | 3.464 | 1-23/32 | 1.675 | 1.763 |
1-1/2 | 1.500 | 2.250 | 2-1/4 | 2.175 | 2.480 | 2.598 | 1-9/32 | 1.245 | 1.ASTM A194 GR. 8 |
1-5/8 | 1.6250 | 2.438 | 2-7/16 | 2.356 | 2.686 | 2.815 | 1-25/64 | 1.353 | 1.429 |
2-1/4 | 2.2500 | 3.375 | 3-3/8 | 3.263 | 3.719 | 3.897 | 1-15/16 | 1.890 | 1.986 |
1-3/4 | 1.7500 | 2.625 | 2-5/8 | 2.538 | 2.893 | 3.031 | 1-1/2 | 1.460 | 1.540 |
2-1/2 | 2.5000 | 3.750 | 3-3/4 | 3.625 | 4.133 | 4.330 | 2-5/32 | 2.105 | 2.209 |
Physical Properties of Duplex 2205 threaded rod
Density (Kg / M3) | Modulus of Elasticity (GPa) | Poisson’s Ratio | Thermal Conductivity (W/moC) | Thermal Capacity (I/KgoC) | Electrical Resistivity |
7800 | 200 | 0.3 | 15 | 500 | 0.80 |
UNS S32205 Hex Bolts Composition Chart
Gr. | UNS | C | Cr | Ni | P | Si | S | Mo | N | Mn |
2205 | S32205 | < 0.03 | 22.0-23.0 | 4.5-6.5 | 0.03 max | 1 max | 0.02 max | 3.0-3.5 | 0.14-0.20 | < 2.0 |
Mechanical Characteristics of Duplex 2205 studs
Gr. | YS (MPa) | UTS (MPa) | % Elongation | Hardness(BHN) |
2205 | 450 min. | 655 min. | 25 min. | 293 max. |
Equivalent material grade of 2205 Stainless steel screws
Duplex |
Common Name |
Related Specifications |
||
---|---|---|---|---|
DIN |
UNS |
ASTM/ ASME |
||
2205 |
SAF 2205® |
1.4462 |
S32205 |
A479/ SA479 |
Duplex 2205 Fasteners grades and specifications
Sizing | 3/6 inch upto 2 inch | M3 – M56 |
Standard | ASTM A479/ ASME SA479 |
Lengths | M02 to M152.4 |
In Form of: | Round, Threading, Hex, Square as per Gauge Etc. |
---|
- Stainless Steel Fasteners
- Stainless Steel 304 Fasteners
- Stainless Steel 304L Fasteners
- Stainless Steel 316 Fasteners
- Stainless Steel 316L Fasteners
- Stainless Steel 317L Fasteners
- 904L Stainless Steel Fasteners
- A2 70 Hex Head Bolt
- A4-70 Hex Bolt
- 15-5PH Bolts
- 17-4 PH Fasteners
- Alloy Steel Fasteners
- Nickel Fasteners
- Inconel Fasteners
- Inconel 600 Fasteners
- Inconel 625 Fasteners
- Inconel 718 Fasteners
- Monel Fasteners
- Hastelloy Fasteners
- Hastelloy C276 Fasteners
- Copper Fasteners
- Brass Fasteners
- Titanium Fasteners
- Duplex Fasteners
- A182 F51 Bolts
- A182 F53 Bolts
- A182 F55 Bolts
- Super Duplex Fasteners
- ASTM A479 UNS S32750 Bolts
- Zeron 100 Fasteners
- ASTM A453 Grade 660 Bolts
- 1.4980 Bolt
- XM 19 Stainless Steel Bolts