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Monel 400 Washers Manufacturer & Exporter in India

Explore Monel 400 Washers Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-200

Min Temp

550

Max Temp

🌡

550

Suitable for continuous service up to approximately 550°C under typical operating conditions.

⚡

550

Typical tensile strength around 550 MPa depending on product form and heat treatment.

🛡

Excellent

Excellent corrosion resistance in a wide range of industrial environments.

⚖

8.8

Typical density is approximately 8.8 g/cm³.

Product Overview

What are Monel 400 Washers?

Monel 400 washers are nickel-copper alloy fastener components manufactured from UNS N04400 bar or plate stock conforming to ASTM B127 or ASTM B564. The alloy’s single-phase solid-solution structure – comprising 63-70% nickel and 28-34% copper – delivers exceptional resistance to seawater, hydrofluoric acid, and alkaline media without requiring any heat treatment to achieve its corrosion performance.

With a tensile strength of 480 MPa minimum in the annealed condition and near-immunity to stress corrosion cracking in chloride environments, Monel 400 washers are specified for marine hardware, chemical process flanges, and offshore piping systems where standard stainless steel washers fail prematurely. They are fully compliant with NACE MR0175/ISO 15156 for sour-service bolted assemblies worldwide.

Quick Specifications

MaterialMonel 400
UNS NumberN04400
DIN Number2.4360
Material StandardASTM B127 / ASTM B564
Washer Standard (Metric)DIN 125 / DIN 9021 / ISO 7089
Washer Standard (Inch)ASME B18.21.1 / ASME B18.22.1
TypePlain / Flat / Spring / Fender / Dock
Diameter RangeM6-M100 / ¼"-4"
Tensile Strength480 MPa (70 ksi) min
Yield Strength170 MPa (25 ksi) min
HardnessMax 241 HB
? All material certified by NABL-accredited laboratory. PMI available on request.

Complete the Fastener Set

Other Monel 400 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Monel 400 fastener range from certified nickel-copper alloy bar stock, including Monel 400 Bolts, Monel 400 Nuts, Monel 400 Screws, Monel 400 Studs, and Monel 400 Threaded Rods. All Monel 400 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Monel 400 Bolts
Monel 400 Nuts
Monel 400 Screws
Monel 400 Studs
Monel 400 Threaded Rods

Technical Data

Monel 400 Washers Dimensions, Sizes & Thread Standards

Monel 400 Washers are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 125 (flat washers) / DIN 9021 (large OD washers) / ISO 7089. Custom OD and thickness available. Inch dimensions per ASME B18.21.1 and ASME B18.22.1. All Monel 400 washers dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Flat Washer Dimensions - Metric (DIN 125 / ISO 7089)

Bolt Size (M)Inner Dia (mm)Outer Dia (mm)Thickness (mm)Standard
M66.412.01.6DIN 125A
M88.416.01.6DIN 125A
M1010.520.02.0DIN 125A
M1213.024.02.5DIN 125A
M1617.030.03.0DIN 125A
M2021.037.03.0DIN 125A
M2425.044.04.0DIN 125A
M3031.056.04.0DIN 125A
M3637.066.05.0DIN 125A
M4243.078.07.0DIN 125A
M4850.092.08.0DIN 125A
M5658.0105.09.0DIN 125A
M6466.0115.09.0DIN 125A
M7274.0125.010.0DIN 125A
M8082.0140.012.0DIN 125A
M100104.0175.014.0DIN 125A

Dimensional & Material Standards

StandardCoversSystem
DIN 125Plain flat washers, normal seriesMetric
DIN 9021Large OD (fender) washersMetric
ISO 7089Plain washers, 200 HV seriesMetric
ISO 7090Plain washers, chamferedMetric
ASME B18.21.1Helical spring lock washersInch
ASME B18.22.1Plain washers, type A & BInch
ASME B16.5Washers for flange bolt setsInch
Material StandardRequirement
ASTM B127Plate/sheet/strip - UNS N04400
ASTM B564Forgings - UNS N04400
ASTM F467Fastener mechanical properties
NACE MR0175Sour service hardness =241 HB
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Monel 400 Chemical Composition

Monel 400 Washers are produced from a nickel-copper alloy containing 63% minimum nickel and 27–34% copper, with elemental limits certified to ASTM. The nickel base delivers seawater and HF acid immunity; copper additions enhance ductility; and in Monel K500, aluminium and titanium additions enable age-hardened strength above 896 MPa.

Chemical Composition per ASTM B127

ElementComposition (%)
Nickel (Ni)63.0% min
Copper (Cu)28.0-34.0%
Iron (Fe)2.5% max
Manganese (Mn)2.0% max
Carbon (C)0.30% max
Silicon (Si)0.50% max
Sulfur (S)0.024% max
? All heats verified by NABL-accredited spectrometry. PMI available on request.

Why Monel 400 Alloy Composition Matters for Washers

Ni (63% min) — Stress Corrosion Cracking Immunity
The high nickel base of Monel 400 provides near-complete immunity to chloride-induced stress corrosion cracking — a critical advantage for washers used under sustained bolt load in marine and offshore environments where austenitic stainless steel washers routinely fail.
Cu (28–34%) — Hydrofluoric Acid Resistance
The copper content gives Monel 400 washers outstanding resistance to hydrofluoric acid at all concentrations below the boiling point, making them the preferred choice for HF alkylation unit flanges and fluorochemical process equipment where no other common alloy performs reliably.
Single-Phase Microstructure — No Heat Treatment Required
Unlike duplex or precipitation-hardened alloys, Monel 400 is a single-phase solid solution. Washers achieve full corrosion resistance in the annealed condition with no post-fabrication heat treatment, simplifying supply chain qualification and reducing lead times for critical projects.

Fastener Performance

Monel 400 Washers Mechanical Properties & Torque & Proof Load Reference

The table below lists mechanical properties and proof load reference for Monel 400 Washers per ASTM. Monel 400 washers achieve 550 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Washer Bearing Load Reference

Washer SizeInner Dia (mm)Outer Dia (mm)Thickness (mm)Max Bearing Load (kN)
M1213.024.02.538
M1617.030.03.068
M2021.037.03.0108
M2425.044.04.0155
M3031.056.04.0245
M3637.066.05.0355
M4243.078.07.0490
M4850.092.08.0645
?? Galvanic compatibility: Always pair Monel 400 washers with Monel 400 or other nickel-copper alloy fasteners. Avoid direct contact with carbon steel in immersed seawater service to prevent accelerated galvanic corrosion of the steel.

Industry Applications

Monel 400 Washers Applications — Industries & End Uses

Monel 400 Washers from RealBolt are specified across marine, HF alkylation, desalination, and chemical processing where excellent corrosion resistance and 550 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples. Select an industry below to see specific Monel 400 washers application details and RealBolt stock availability.
Monel 400 flat and fender washers are the standard specification for offshore platform deck fittings, marine pipeline flange bolt sets, and splash-zone structural connections. Their immunity to seawater pitting and crevice corrosion under the washer bearing face eliminates the premature failure mode that affects 316L stainless steel washers in tidal and immersed zones.
Washers for HF alkylation unit flanges, phosphoric acid reactor closures, and chlorinated solvent process piping where Monel 400 is the only commercially viable alloy. Specified under TEMA Class R for heat exchanger channel cover bolt sets in halide-bearing process streams that attack stainless steel within months.
Monel 400 washers are used in multi-stage flash (MSF) and reverse osmosis (RO) desalination plant piping, pump casing flanges, and valve bonnet assemblies. The alloy’s resistance to brackish water, brine, and chlorinated seawater at elevated temperatures makes it the preferred choice over duplex stainless steel in high-salinity service.
Flat washers and dock washers for ASME B16.5 flange bolt sets in sour gas gathering systems, wellhead Christmas tree assemblies, and subsea production manifolds. Fully compliant with NACE MR0175/ISO 15156 at hardness levels well below the 241 HB maximum, with no risk of hydrogen embrittlement in H2S-bearing service.

Monel 400 Washers Standards & International Certifications

Monel 400 Washers 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 3.1/3.2, Lloyds Register or DNV certification, NACE MR0175, and PMI (XRF) reports — available on request for all orders.
Standards
DIN 125A DIN 126 DIN 127 DIN 128 ISO 7089 ISO 7090 ASME B18.21.1 EN ISO 7089 BS 4320 IS 5372 IS 1367
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

Buy Monel 400 Washers from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Monel 400 Washers — 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

Monel 400 Washers — Frequently Asked Questions

Browse expert answers to common questions about Monel 400 Washers from RealBolt — covering Monel 400 vs K500 selection, seawater and HF acid resistance, ASTM B164/B865, sizes, and MTC documentation. Contact our technical team directly for project-specific guidance on Monel 400 washers selection and pricing.
Monel 400 flat washers are available to DIN 125A (metric plain washers), DIN 9021 (large OD fender washers), ISO 7089 (200 HV series), and ISO 7090 (chamfered face). Inch series washers are supplied per ASME B18.21.1 (spring lock) and ASME B18.22.1 (plain, Type A and B). Flange bolt set washers are dimensioned per ASME B16.5 for Class 150 through Class 2500. Custom OD and thickness combinations are available with 10-15 working day lead time.
Yes – Monel 400 is one of very few commercially available alloys with reliable resistance to hydrofluoric acid at all concentrations below the boiling point. Monel 400 washers are routinely specified for HF alkylation unit flanges, fluoropolymer reactor closures, and HF acid storage vessel nozzle connections. The alloy must be used in the annealed condition; cold-worked material can be susceptible to stress corrosion cracking in concentrated HF. All washers are supplied in the fully annealed condition per ASTM B127.
Monel 400 washers can be used with austenitic stainless steel fasteners in atmospheric and mildly corrosive environments without significant galvanic risk. However, in immersed seawater or continuously wet chloride service, the galvanic potential difference between Monel 400 and 316L stainless steel can accelerate corrosion of the less noble material. For full compatibility and optimum corrosion performance in marine and offshore service, we recommend pairing Monel 400 washers with Monel 400 bolts and nuts throughout the bolt set.
Monel 400 washers are suitable for continuous service up to 480°C. Above this temperature, the alloy can experience reduced ductility due to ordering reactions in the nickel-copper matrix. For elevated temperature applications above 480°C, Monel K-500 (age-hardened) or Inconel 625 washers are recommended. At cryogenic temperatures, Monel 400 retains excellent toughness and is used in LNG plant piping and cryogenic valve assemblies down to -196°C without embrittlement.

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