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Duplex 2304 Bolts Manufacturer & Exporter in India

Explore Duplex 2304 Bolts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-50

Min Temp

300

Max Temp

🌡

300

Suitable for continuous service up to approximately 300°C under typical operating conditions.

⚡

800

Typical tensile strength around 800 MPa depending on product form and heat treatment.

🛡

Excellent

Excellent corrosion resistance in a wide range of industrial environments.

⚖

7.8

Typical density is approximately 7.8 g/cm³.

Product Overview

What are Duplex 2304 Bolts?

Duplex 2304 bolts are high-strength, corrosion-resistant fasteners manufactured from UNS S32304 duplex stainless steel bar stock, conforming to ASTM A479 and ASTM A182 standards. This alloy features a balanced dual-phase microstructure of austenite and ferrite, providing superior mechanical strength and enhanced resistance to stress corrosion cracking compared to standard austenitic stainless steels.

With a PREN of 26-28, Duplex 2304 bolts offer excellent pitting and crevice corrosion resistance in chloride-rich environments, making them a cost-effective alternative to 316L and 2205 for many industrial applications. They are widely specified for pressure vessels, piping systems, and structural connections in chemical processing, desalination, and marine industries.

Quick Specifications

MaterialDuplex 2304
UNS NumberS32304
DIN Number1.4362
Material StandardASTM A479 / ASTM A182
Bolt Standard (Metric)DIN 931 / DIN 933 / ISO 4014
Bolt Standard (Inch)ASME B18.2.1
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M100 / ¼"-4"
Tensile Strength600 MPa (87 ksi) min
Yield Strength400 MPa (58 ksi) min
HardnessMax 25 HRC / 240 HB
? All material certified by NABL-accredited laboratory. PMI and ferrite content verification available on request.

Complete the Fastener Set

Other Duplex 2304 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Duplex 2304 fastener range from certified duplex stainless steel bar stock, including Duplex 2304 Nuts, Duplex 2304 Screws, Duplex 2304 Washers, Duplex 2304 Studs, and Duplex 2304 Threaded Rods. All Duplex 2304 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Duplex 2304 Nuts
Duplex 2304 Screws
Duplex 2304 Washers
Duplex 2304 Studs
Duplex 2304 Threaded Rods

Technical Data

Duplex 2304 Bolts Dimensions, Sizes & Thread Standards

Duplex 2304 Bolts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 931 (partial thread) / DIN 933 (full thread) / ISO 4014. Custom lengths in 5mm increments. Inch dimensions available per ASME B18.2.1. All Duplex 2304 bolts dimensions are verified against applicable DIN, ISO, and ASME

Hex Bolt Dimensions - Metric (DIN 931 / ISO 4014)

Size (M)Pitch (mm)A/F (mm)Head Ht (mm)Min L (mm)Max L (mm)
M61.0104.010200
M81.25135.312250
M101.5176.416300
M121.75197.520400
M162.02410.025500
M202.53012.530600
M243.03615.040600
M303.54618.750800
M364.05522.5601000
M424.56526.0801000
M485.07530.01001200
M565.58535.01201500
M646.09540.01402000
M726.010545.01602000
M806.011550.01802500
M1006.014563.02003000

Dimensional & Material Standards

StandardCoversThread
DIN 931Hex bolts, partial threadMetric
DIN 933Hex bolts, full threadMetric
ISO 4014Hex head screws, partialMetric
ISO 4017Hex head screws, fullMetric
ASME B18.2.1Hex & heavy hex boltsUNC/UNF
ASME B16.5Stud bolts for flangesUNC
MSS SP-75Stud bolts, high-pressureUNC
Material StandardRequirement
ASTM A479Bar/rod - UNS S32304
ASTM A182Forged fasteners
ASTM A276General bar stock
NACE MR0175Sour service =25 HRC
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Duplex 2304 Chemical Composition

Duplex 2304 Bolts are produced from a ferritic-austenitic steel with chromium (21–23%), molybdenum (3–3.5%), and nitrogen (0.14–0.20%) controlled per ASTM. Nitrogen is the critical alloying element: it simultaneously raises PREN to ≥ 35 for chloride pitting resistance and strengthens the austenite phase to achieve 450 MPa minimum yield — twice that of SS 316L.

Chemical Composition per ASTM A479

ElementComposition (%)
Chromium (Cr)21.5-24.5%
Nickel (Ni)3.0-5.5%
Molybdenum (Mo)0.05-0.6%
Nitrogen (N)0.05-0.20%
Manganese (Mn)2.5% max
Silicon (Si)1.0% max
Carbon (C)0.03% max
Phosphorus (P)0.035% max
Sulphur (S)0.015% max
Iron (Fe)Balance
? All heats verified by NABL-accredited spectrometry. PMI and ferrite content verification available on request.

Why Duplex 2304 Alloy Composition Matters for Bolts

Cr (21.5–24.5%) — Pitting & Crevice Resistance
High chromium content gives Duplex 2304 bolts a PREN of 26–28, ensuring strong resistance to pitting and crevice corrosion in chloride-laden environments, outperforming 316L in many marine and chemical applications.
Dual-Phase Microstructure — Stress Corrosion Cracking Resistance
The balanced austenite-ferrite structure provides excellent resistance to chloride stress corrosion cracking, making Duplex 2304 bolts ideal for piping and pressure vessel connections exposed to aggressive process media.
Low Carbon & Nitrogen Addition
Low carbon and controlled nitrogen additions prevent intergranular corrosion and enhance mechanical strength, ensuring reliable performance in welded assemblies and high-load bolted joints.

Fastener Performance

Duplex 2304 Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Duplex 2304 Bolts per ASTM. Duplex 2304 bolts achieve 800 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Bolt SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12756028
M1618014462
M2036028899
M24620496144
M301240992229
M3621501720333
M4234202736459
M4850804064604
?? Anti-galling: Use molybdenum-based or PTFE anti-seize. Lubricated values assume K=0.16. Avoid copper-based anti-seize for chloride service.

Industry Applications

Duplex 2304 Bolts Applications — Industries & End Uses

Duplex 2304 Bolts from RealBolt are specified across offshore platforms, desalination, pulp and paper, and chemical processing where excellent corrosion resistance and 800 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
Duplex 2304 bolts are widely used in desalination plants, reverse osmosis skids, and water treatment piping systems where high chloride resistance and cost-effectiveness are required over 316L.
Specified for filter housings, pump assemblies, and brine recirculation lines.
Hex bolts and stud bolts for heat exchanger channel covers, pressure vessel nozzles, and reactor closures in organic acid, caustic, and mixed salt environments where stress corrosion cracking resistance is critical.
Flange bolts and fasteners for digesters, bleach plant piping, and black liquor recovery systems, offering superior resistance to chloride-induced corrosion and crevice attack compared to standard stainless steels.
Duplex 2304 bolts are used in bridges, coastal structures, and architectural facades where high strength, atmospheric corrosion resistance, and aesthetic finish are required.

Duplex 2304 Bolts Standards & International Certifications

Duplex 2304 Bolts from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.2 (third-party), NACE MR0175/ISO 15156, NORSOK M-630, Charpy impact certificates, and PMI (XRF) reports — available on request for all orders.
Standards
DIN 931 DIN 933 ISO 4014 ISO 4017 ASME B18.2.1 EN ISO 4014 EN ISO 4017 IS 1364 IS 1367 IS 12427
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

Buy Duplex 2304 Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Duplex 2304 Bolts — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
022-6743-7972
+91 90226 36025
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Answers for Buyers

Duplex 2304 Bolts — Frequently Asked Questions

Browse expert answers to common questions about Duplex 2304 Bolts from RealBolt — covering PREN ≥ 35, NACE MR0175, ASTM A182 F60, sigma-phase limits, sizes, and EN 10204 3.1/3.2 documentation. Contact our technical team directly for project-specific guidance on Duplex 2304 bolts selection and pricing.
Duplex 2304 hex bolts are available to DIN 931 (metric partial thread), DIN 933 (metric full thread), ISO 4014/4017, and ASME B18.2.1 (inch hex and heavy hex). Stud bolts are supplied per ASME B16.5 or MSS SP-75 for flange applications. Custom thread forms (BSW, BSF, Whitworth, BSPP) are available on request with 15 working day lead time.
Molybdenum-based or PTFE anti-seize is recommended for Duplex 2304 bolts, especially in chloride environments. Apply to threads and nut bearing face. Reduce torque values by 20% vs dry assembly. Avoid copper-based anti-seize in chloride service to prevent galvanic corrosion.
Yes – Duplex 2304 bolts have a PREN of 26-28 and are highly resistant to pitting and crevice corrosion in seawater and brine at ambient temperatures. They are widely used in desalination, marine, and water treatment applications. For continuous immersion in hot seawater, consider higher alloy duplex grades.
No formal MOQ for standard sizes (M12-M36) held ex-stock – we supply from single pieces for urgent maintenance. Custom sizes have an MOQ of 10 kg minimum. Flange stud bolt sets are supplied by the set with no minimum. Quantity price breaks at 50 pcs, 200 pcs, and 500 pcs.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
  • Canada
  • Mexico
  • Germany
  • UK
  • France
  • Italy
  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
  • Nigeria
  • Australia
  • New Zealand
  • Singapore
  • Malaysia
  • Indonesia
  • Thailand
  • Vietnam
  • South Korea
  • Japan
  • Brazil