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Rajgranth Metal & AlloysRAJGRANTH
FastenersGrade profile

Duplex / Super Duplex Fasteners

A duplex microstructure delivers what austenitics cannot: high strength and high chloride resistance at the same time. 2205 (S31803/S32205) is the workhorse; the super duplex grades 2507 (S32750) and Zeron-type S32760 push PREN above 40 for seawater and sour service. The strength advantage often allows a thinner wall, which recovers much of the cost premium on a large project.

UNS S31803 / S32205 / S32550 / S32750 / S32760EN 1.4462 / 1.4507 / 1.4501AISI F51 / F60 / F53 / F55JIS SUS329J3LX2CrNiMoN22-5-3 / X2CrNiMoCuWN25-7-4

Properties

Duplex
PREN
41

Pitting resistance equivalent. Higher resists chlorides better.

Relative cost
2.60×

Indexed to 304. Indicative, for specification triage.

Max service temp
300 °C
Magnetic
Partially
Weldability
Procedure required
Machinability
Difficult
01Product description

Duplex and Super Duplex Stainless Steel fasteners: manufacturer, stockist and exporter in Mumbai, India

Rajgranth Metal & Alloys manufactures, stocks, supplies and exports Duplex and Super Duplex Stainless Steel fasteners (UNS S31803 / S32205 / S32550 / S32750 / S32760) from Mumbai. Roughly equal austenite and ferrite. Around twice the yield strength of 316L. Rajgranth Metal & Alloys has been trading since 1980, is self-funded and debt-free, and despatches most orders from its Mumbai stockyard within two days.

What is Duplex / Super Duplex?

A duplex microstructure delivers what austenitics cannot: high strength and high chloride resistance at the same time. 2205 (S31803/S32205) is the workhorse; the super duplex grades 2507 (S32750) and Zeron-type S32760 push PREN above 40 for seawater and sour service. The strength advantage often allows a thinner wall, which recovers much of the cost premium on a large project.

Designations

Duplex and Super Duplex Stainless Steel is also designated UNS S31803 / S32205 / S32550 / S32750 / S32760, EN 1.4462 / 1.4507 / 1.4501, AISI F51 / F60 / F53 / F55, JIS SUS329J3L, GB S22053 and Werkstoff X2CrNiMoN22-5-3 / X2CrNiMoCuWN25-7-4. Quote the designation your specification uses and we will supply to it.

Why choose Duplex / Super Duplex fasteners

Yield strength roughly double that of 316L, allowing thinner sections, Excellent resistance to chloride stress corrosion cracking, Super duplex PREN above 40 for seawater service and Good resistance to erosion and cavitation. It is partially, with requires-procedure weldability and difficult machinability, and is used in continuous service in air up to about 300 °C.

Limitations to specify around

Hard upper service limit near 300 degrees C — 475 degrees C embrittlement, Welding requires controlled heat input to maintain phase balance, Ferromagnetic, which rules it out where magnetic permeability matters and Machining is demanding and tool wear is high. We state these plainly so the grade is chosen for the right service.

Duplex / Super Duplex fasteners: sizes, standards and finishes

Our published range covers size M3, M64, property class A2-70, A2-80, A4-70, A4-80, thread Metric coarse to UNF and drive Hex to Phillips. Standards include ASTM A193 / ASME SA-193, ASTM A194 / ASME SA-194, ASTM F593, ASTM F594, ISO 3506, DIN 931, DIN 933 and DIN 934. Finishes and conditions include Bright, Passivated, Electropolished and Black.

Applications and industries

offshore and subsea piping, seawater cooling and desalination, chemical tankers and cargo systems, sour gas service and pressure vessels where weight matters. Typical industries: oil & gas, marine & shipbuilding, chemical, petrochemical and power & energy. We supply across India and export to markets in the Middle East, Africa, Europe, Asia, North America and South America.

Buy Duplex / Super Duplex fasteners from Rajgranth

Material is supplied with documentation, tested in house across 18 listed testing facilities, and covered by our ISO 9001:2015 quality management system. Rajgranth Metal & Alloys has been trading since 1980, is self-funded and debt-free, and despatches most orders from its Mumbai stockyard within two days.

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  • UNS S31803 / S32205 / S32550 / S32750 / S32760 fasteners
  • Duplex and Super Duplex Stainless Steel stainless steel fasteners
01Specification

Duplex / Super Duplex fasteners — available range

Dimensional range

04 rows
Size
M3M64
Property class
A2-70A2-80A4-70A4-80
Thread
Metric coarseMetric fineBSWUNCUNF
Drive
HexSocketTorxSlottedPhillips

Surface finishes

04
  • Bright
  • Passivated
  • Electropolished
  • Black

Standards

08
  • ASTM A193 / ASME SA-193
  • ASTM A194 / ASME SA-194
  • ASTM F593
  • ASTM F594
  • ISO 3506
  • DIN 931
  • DIN 933
  • DIN 934

Other grades in fasteners

Need Duplex / Super Duplex fasteners?

Send the size, quantity and standard. We will confirm availability against stock and come back with price.

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