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Ferralium 255 Studs Manufacturer & Exporter in India

Explore Ferralium 255 Studs 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 Studs?

Ferralium 255 studs are high-performance duplex stainless steel fasteners manufactured from UNS S32550 bar stock, conforming to ASTM A276 and ASTM A479. This super duplex alloy contains approximately 25% chromium, 5% nickel, 3.5% copper, and 2% molybdenum, delivering exceptional resistance to pitting, crevice, and stress corrosion cracking in aggressive chloride and acidic environments.

With a PREN (Pitting Resistance Equivalent Number) of 40+, Ferralium 255 studs are specified for critical bolted joints in seawater, desalination, chemical processing, and offshore oil & gas applications where standard 316L or 2205 duplex fasteners are inadequate. The alloy’s high strength and corrosion resistance make it ideal for flange connections, pressure vessels, and structural assemblies exposed to harsh service conditions.

Quick Specifications

MaterialFerralium 255 (Super Duplex Stainless Steel)
UNS NumberS32550
DIN Number1.4507
Material StandardASTM A276 / ASTM A479
Stud Standard (Metric)DIN 976 / ISO 898-1
Stud Standard (Inch)ASME B16.5 / B18.31.2
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M100 / ¼"-4"
Tensile Strength800 MPa (116 ksi) min
Yield Strength570 MPa (83 ksi) min
HardnessMax 28 HRC / 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 Bolts, Ferralium 255 Nuts, Ferralium 255 Screws, Ferralium 255 Washers, 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 Bolts
Ferralium 255 Nuts
Ferralium 255 Screws
Ferralium 255 Washers
Ferralium 255 Threaded Rods

Technical Data

Ferralium 255 Studs Dimensions, Sizes & Thread Standards

Ferralium 255 Studs are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 976 (metric) / ASME B16.5 (inch) for stud bolts. Custom lengths available in 5mm increments. Inch dimensions per B18.31.2. All Ferralium 255 studs dimensions are verified against applicable DIN, ISO, and ASME B18 standards before

Stud Bolt Dimensions - Metric (DIN 976)

Size (M)Pitch (mm)Thread Length (mm)Min L (mm)Max L (mm)
M61.01820200
M81.252225250
M101.52630300
M121.753035400
M162.03840500
M202.54450600
M243.05460600
M303.56670800
M364.078801000
M424.590901200
M485.01021001500
M565.51141201800
M646.01261402000
M726.01381602000
M806.01501802500
M1006.01902003000

Dimensional & Material Standards

StandardCoversThread
DIN 976Stud bolts, full threadMetric
ASME B16.5Stud bolts for flangesUNC
ASME B18.31.2Continuous thread studsUNC/UNF
ISO 898-1Mechanical propertiesMetric
Material StandardRequirement
ASTM A276Bar/rod - UNS S32550
ASTM A479Fastener mechanical
NACE MR0175Sour service =28 HRC
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Ferralium 255 Chemical Composition

Ferralium 255 Studs 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)1.5-2.0%
Copper (Cu)1.5-2.5%
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 content available on request.

Why Ferralium 255 Alloy Composition Matters for Studs

Cr (24–26%) — Pitting & Crevice Resistance
High chromium content gives Ferralium 255 studs a PREN of 40+, ensuring outstanding resistance to pitting and crevice corrosion in seawater, brine, and chloride-rich chemical environments.
Cu (1.5–2.5%) — Acid & Chloride Resistance
Copper enhances resistance to sulphuric, phosphoric, and organic acids, making Ferralium 255 studs ideal for chemical process and desalination plant bolting.
Duplex Structure — Strength & SCC Resistance
The duplex microstructure (austenite + ferrite) provides high mechanical strength and excellent resistance to chloride stress corrosion cracking, outperforming standard austenitic stainless steels in critical bolted joints.

Fastener Performance

Ferralium 255 Studs Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Ferralium 255 Studs per ASTM. Ferralium 255 studs achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Stud SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M121108838
M1626020885
M20520416140
M24900720210
M3018001440340
M3631002480500
M4249503960690
M4873505880920
?? Anti-galling: Use molybdenum-based or PTFE anti-seize. Lubricated values assume K=0.15. Avoid copper-based anti-seize on duplex stainless steels.

Industry Applications

Ferralium 255 Studs Applications — Industries & End Uses

Ferralium 255 Studs 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 studs are specified for ASME B16.5/B16.47 flange connections, riser systems, and subsea pipeline assemblies in offshore oil & gas platforms. Their high PREN and resistance to chloride-induced stress corrosion cracking make them ideal for splash zone and submerged bolting.
Used in high-pressure reverse osmosis (RO) vessels, seawater intake structures, and brine concentrators, Ferralium 255 studs provide long-term resistance to pitting and crevice corrosion in saline and brackish water environments.
Stud bolts for heat exchanger channel covers, reactor closures, and acid storage tank nozzles in phosphoric acid, sulphuric acid, and mixed chloride process streams where 316L and 2205 duplex fail.
Ferralium 255 studs are used in bleach plant piping, digester closures, and chemical recovery systems where resistance to chloride and acidic attack is critical for bolted joints.

Ferralium 255 Studs Standards & International Certifications

Ferralium 255 Studs 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 938 DIN 939 DIN 976-1 ASME B18.31.2 IS 1364 IS 1367 IS 12427
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

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

Partner with RealBolt — India’s leading manufacturer of certified Ferralium 255 Studs — 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 Studs — Frequently Asked Questions

Browse expert answers to common questions about Ferralium 255 Studs 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 studs selection and pricing.
Ferralium 255 studs are manufactured to DIN 976 (metric), ASME B16.5/B18.31.2 (inch), and ISO 898-1 for mechanical properties. Material is supplied to ASTM A276/A479 (UNS S32550) with full EN 10204 3.1 or 3.2 certification. Custom thread forms (BSW, BSF, Whitworth) are available on request.
Use a molybdenum-based or PTFE anti-seize compound (such as Molykote 1000 or Loctite LB 8014) on Ferralium 255 studs and nuts. Avoid copper-based anti-seize to prevent galvanic corrosion. Lubricated torque values should be reduced by 20% compared to dry assembly.
Yes – Ferralium 255 has a PREN of 40+ and is highly resistant to pitting, crevice, and stress corrosion cracking in seawater, brine, and desalination plant environments. It is widely specified for offshore, marine, and desalination bolting applications.
No formal MOQ for standard sizes (M12-M36) held in stock – we supply from single pieces for urgent maintenance. Custom sizes or non-standard thread forms have an MOQ of 10 kg. Flange stud bolt sets are supplied per 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