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Ferralium 255 Bolts Manufacturer & Exporter in India

Explore Ferralium 255 Bolts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-196

Min Temp

870

Max Temp

🌡

870

Suitable for continuous service up to approximately 870°C under typical operating conditions.

⚡

620

Typical tensile strength around 620 MPa depending on product form and heat treatment.

🛡

Very Good

Very Good corrosion resistance in a wide range of industrial environments.

⚖

8

Typical density is approximately 8.0 g/cm³.

Product Overview

What are Ferralium 255 Bolts?

Ferralium 255 bolts are high-performance super duplex stainless steel fasteners manufactured from UNS S32550 bar stock, conforming to ASTM A276 and ASTM A479. With a dual-phase microstructure and a PREN (Pitting Resistance Equivalent Number) of 40+, Ferralium 255 bolts offer outstanding resistance to pitting, crevice, and stress corrosion cracking in aggressive chloride and acidic environments.

These bolts deliver a minimum tensile strength of 800 MPa and are widely specified for critical bolted joints in seawater, desalination, chemical processing, and offshore oil & gas applications. Ferralium 255 bolts are NORSOK M-650 and NACE MR0175/ISO 15156 compliant for sour service and are trusted for their superior mechanical strength and corrosion resistance compared to standard duplex and austenitic stainless steels.

Quick Specifications

MaterialFerralium 255 (Super Duplex Stainless Steel)
UNS NumberS32550
DIN Number1.4507
Material StandardASTM A276 / ASTM A479
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 Strength800 MPa (116 ksi) min
Yield Strength570 MPa (83 ksi) min
HardnessMax 290 HB
? All material certified by NABL-accredited laboratory. PMI and ferrite content verification available on request.

Complete the Fastener Set

Other Ferralium 255 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Ferralium 255 fastener range from certified super duplex stainless steel bar stock, including Ferralium 255 Nuts, Ferralium 255 Screws, Ferralium 255 Washers, Ferralium 255 Studs, and Ferralium 255 Threaded Rods. All Ferralium 255 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Ferralium 255 Nuts
Ferralium 255 Screws
Ferralium 255 Washers
Ferralium 255 Studs
Ferralium 255 Threaded Rods

Technical Data

Ferralium 255 Bolts Dimensions, Sizes & Thread Standards

Ferralium 255 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 Ferralium 255 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 A276Bar/rod - UNS S32550
ASTM A479Fastener mechanical
NACE MR0175Sour service =290 HB
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Ferralium 255 Chemical Composition

Ferralium 255 Bolts are manufactured from a high-alloy ferritic-austenitic steel containing chromium (24–26%), molybdenum (3.5–5%), and nitrogen (0.24–0.32%) per ASTM. These precise elemental limits produce PREN ≥ 40 — confirming seawater pitting immunity — and deliver the 550 MPa minimum yield strength required for NORSOK M-630 subsea qualification.

Chemical Composition per ASTM A276 / A479

ElementComposition (%)
Chromium (Cr)24.0-26.0%
Nickel (Ni)4.5-6.5%
Molybdenum (Mo)2.9-3.5%
Copper (Cu)1.5-2.0%
Nitrogen (N)0.10-0.25%
Silicon (Si)1.0% max
Manganese (Mn)1.5% max
Carbon (C)0.04% max
Phosphorus (P)0.04% max
Sulphur (S)0.03% max
Iron (Fe)Balance
? All heats verified by NABL-accredited spectrometry. PMI and ferrite testing available on request.

Why Ferralium 255 Alloy Composition Matters for Bolts

High Chromium & Molybdenum — Pitting & Crevice Resistance
The elevated chromium (24–26%) and molybdenum (2.9–3.5%) content gives Ferralium 255 bolts a PREN of 40+, ensuring superior resistance to pitting and crevice corrosion in seawater, brine, and aggressive chemical environments.
Copper & Nitrogen — Acid & Chloride Resistance
Copper (1.5–2.0%) enhances resistance to sulphuric and phosphoric acids, while nitrogen increases strength and resistance to chloride-induced stress corrosion cracking, making Ferralium 255 bolts ideal for harsh process conditions.
Dual-Phase Structure — Strength & Toughness
The duplex (ferrite-austenite) microstructure provides a unique combination of high strength and toughness, allowing Ferralium 255 bolts to outperform standard austenitic and duplex stainless steel fasteners in demanding applications.

Fastener Performance

Ferralium 255 Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Ferralium 255 Bolts per ASTM. Ferralium 255 bolts achieve 620 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)
M121108838
M1626020892
M20520416148
M24900720214
M3018001440340
M3631202496494
M4249803984680
M4873805904894
?? Anti-galling: Use molybdenum-based or PTFE anti-seize. Lubricated values assume K=0.15. Do not use copper-based anti-seize on duplex stainless steels in chloride service.

Industry Applications

Ferralium 255 Bolts Applications — Industries & End Uses

Ferralium 255 Bolts from RealBolt are specified across subsea oil and gas, FPSOs, desalination, and offshore where very good corrosion resistance and 620 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
Ferralium 255 stud bolts and nuts are specified for ASME B16.5/B16.47 flanged connections, subsea manifolds, and riser systems where high strength and resistance to chloride-induced corrosion are critical. Fully compliant with NACE MR0175 for sour service and NORSOK M-650 for offshore structures.
Hex bolts and fasteners for seawater reverse osmosis (SWRO) plants, evaporators, and brine concentrators. Ferralium 255 bolts provide long-term resistance to pitting and crevice corrosion in high-chloride, high-pressure environments.
Flange bolts and stud sets for phosphoric acid, sulphuric acid, and urea reactors, as well as heat exchanger channel covers and pressure vessel nozzles where standard stainless steels fail due to aggressive process media.
Ferralium 255 bolts are used in propeller shaft couplings, hull penetrations, and deck equipment exposed to seawater splash and immersion, offering superior corrosion resistance and mechanical strength over 316L and 2205 duplex.

Ferralium 255 Bolts Standards & International Certifications

Ferralium 255 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 Ferralium 255 Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Ferralium 255 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.
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Answers for Buyers

Ferralium 255 Bolts — Frequently Asked Questions

Browse expert answers to common questions about Ferralium 255 Bolts from RealBolt — covering PREN ≥ 40, NORSOK M-630, NACE MR0175, ASTM A182 F53/F55, sizes, and EN 10204 3.2 third-party documentation. Contact our technical team directly for project-specific guidance on Ferralium 255 bolts selection and pricing.
Ferralium 255 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 Ferralium 255 bolts to prevent galling and facilitate disassembly. Avoid copper-based anti-seize in chloride environments to prevent galvanic corrosion. Lubricated torque values should be reduced by 20% compared to dry assembly.
Yes – Ferralium 255 bolts have a PREN of 40+ and are highly resistant to pitting and crevice corrosion in seawater, brine, and chloride-rich environments. They are widely used in desalination, offshore, and marine applications without the need for additional coatings or cathodic protection.
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. ASME B16.5 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