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Ferralium 255 Screws Manufacturer & Exporter in India

Explore Ferralium 255 Screws 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 Screws?

Ferralium 255 screws are high-performance super duplex stainless steel fasteners manufactured from UNS S32550 bar stock, conforming to ASTM A276 and ASTM A479. This alloy features a balanced austenitic-ferritic microstructure, with high chromium (24-26%), molybdenum (3-4%), and copper (1.5-2.0%) content, 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 screws outperform standard duplex and 316 stainless steel in seawater, brine, and chemical process applications. They are widely specified for critical bolted joints in desalination, offshore, and chemical plant equipment where both mechanical strength and corrosion resistance are paramount.

Quick Specifications

MaterialFerralium 255 (Super Duplex Stainless Steel)
UNS NumberS32550
DIN Number1.4507
Material StandardASTM A276 / ASTM A479
Screw Standard (Metric)DIN 912 / DIN 7991 / ISO 4762
Screw Standard (Inch)ASME B18.3
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M64 / ¼"-2½"
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 testing 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 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 Bolts
Ferralium 255 Nuts
Ferralium 255 Washers
Ferralium 255 Studs
Ferralium 255 Threaded Rods

Technical Data

Ferralium 255 Screws Dimensions, Sizes & Thread Standards

Ferralium 255 Screws are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 912 (socket head cap), DIN 7991 (countersunk), ISO 4762. Custom lengths in 5mm increments. Inch dimensions available per ASME B18.3. All Ferralium 255 screws dimensions are verified against applicable DIN, ISO, and ASME B18 standards

Socket Head Cap Screw Dimensions - Metric (DIN 912 / ISO 4762)

Size (M)Pitch (mm)Head Dia (mm)Head Ht (mm)Hex Socket (mm)Min L (mm)Max L (mm)
M61.0106.0510120
M81.25138.0612160
M101.51610.0816200
M121.751812.01020250
M162.02416.01425300
M202.53020.01730350
M243.03624.01940400
M303.54530.02250500
M364.05436.02760600
M424.56342.03280800
M485.07248.0361001000
M565.58456.0411201200
M646.09664.0461401500

Dimensional & Material Standards

StandardCoversThread
DIN 912Socket head cap screwsMetric
DIN 7991Countersunk socket screwsMetric
ISO 4762Socket head cap screwsMetric
ASME B18.3Socket cap, button, flat headUNC/UNF
ISO 14579Hexalobular socket screwsMetric
Material StandardRequirement
ASTM A276Bar/rod - UNS S32550
ASTM A479Forged/rolled bar
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC
NACE MR0175Sour service =28 HRC

Material Chemistry

Ferralium 255 Chemical Composition

Ferralium 255 Screws 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 / UNS S32550

ElementComposition (%)
Chromium (Cr)24.0-26.0
Nickel (Ni)4.5-6.5
Molybdenum (Mo)3.0-4.0
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 content available on request.

Why Ferralium 255 Alloy Composition Matters for Screws

High Chromium & Molybdenum — Pitting & Crevice Resistance
The elevated chromium (24–26%) and molybdenum (3–4%) content gives Ferralium 255 screws a PREN >40, ensuring outstanding resistance to pitting and crevice corrosion in seawater, brine, and chloride-rich process streams.
Copper Addition — Acid & Seawater Durability
Copper (1.5–2.0%) enhances resistance to sulphuric and phosphoric acids, making Ferralium 255 screws ideal for chemical processing and desalination plant applications.
Balanced Duplex Structure — Strength & SCC Resistance
The duplex microstructure (austenite + ferrite) provides high mechanical strength and excellent resistance to chloride stress corrosion cracking, outperforming 316L and standard duplex grades in critical bolted joints.

Fastener Performance

Ferralium 255 Screws Mechanical Properties & Torque Reference

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

Screw SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M8322518
M10635029
M121108842
M1627021685
M20530424133
M24920736192
M3018001440314
M3632002560453
?? Anti-galling: Use molybdenum-based or PTFE anti-seize. Lubricated values assume K=0.16. Avoid copper-based anti-seize to prevent galvanic corrosion in chloride service.

Industry Applications

Ferralium 255 Screws Applications — Industries & End Uses

Ferralium 255 Screws 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 screws are the preferred choice for high-pressure reverse osmosis (RO) vessel closures, seawater intake screens, and brine concentrator assemblies. Their superior pitting and crevice corrosion resistance ensures long-term reliability in saline and brackish water environments.
Socket head and countersunk screws for offshore platform handrails, splash zone equipment, and marine pump assemblies where high chloride resistance and mechanical strength are critical for safety and longevity.
Used in acid reactor closures, heat exchanger channel covers, and fertilizer plant piping systems exposed to sulphuric, phosphoric, and nitric acids, where standard stainless steel fasteners fail due to localized corrosion.
Ferralium 255 screws are specified for autoclave closures, leaching vessel flanges, and slurry pump assemblies in mining operations, providing resistance to acidic, abrasive, and chloride-rich process streams.

Ferralium 255 Screws Standards & International Certifications

Ferralium 255 Screws 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 912 DIN 913 DIN 914 DIN 915 DIN 916 ISO 4762 ISO 10642 ASME B18.3 EN ISO 4762 IS 1367 IS 12427
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

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

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

Browse expert answers to common questions about Ferralium 255 Screws 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 screws selection and pricing.
Ferralium 255 socket head screws are available to DIN 912 (metric), ISO 4762, DIN 7991 (countersunk), and ASME B18.3 (inch series). Button head and flat head screws can be supplied to ISO 7380 and ISO 10642. Custom thread forms (UNC, UNF, BSW) are available on request with a typical lead time of 2-3 weeks.
Molybdenum-based or PTFE anti-seize is recommended for Ferralium 255 screws, especially in chloride or seawater service. Avoid copper-based anti-seize to prevent galvanic corrosion. Apply to threads and bearing surfaces to reduce galling and ensure accurate preload. Lubricated torque values should be used for assembly.
Yes – Ferralium 255 screws have a PREN >40 and are highly resistant to pitting, crevice, and stress corrosion cracking in seawater, brine, and high-chloride environments. They are widely specified for desalination, marine, and offshore applications where 316L and standard duplex fasteners are inadequate.
No formal MOQ for standard sizes (M8-M24) held ex-stock – we supply from single pieces for urgent maintenance. Custom sizes and non-standard threads have an MOQ of 10 kg. Quantity price breaks are available 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