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Monel K500 Washers Manufacturer & Exporter in India

Explore Monel K500 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 K500 Washers?

Monel K500 washers are precipitation-hardened nickel-copper alloy fastener components manufactured from UNS N05500 bar stock conforming to ASTM B865. The alloy combines the corrosion resistance of Monel 400 with significantly enhanced mechanical strength achieved through the addition of aluminium (2.30-3.15%) and titanium (0.35-0.85%), which form the Ni3(Al,Ti) gamma-prime precipitate during age-hardening treatment.

With a minimum tensile strength of 1100 MPa in the age-hardened condition and outstanding resistance to seawater corrosion, Monel K500 washers are specified for offshore fastener assemblies, marine shaft hardware, and chemical process flanges where standard stainless steel washers fail through pitting, stress corrosion cracking, or inadequate load-bearing capacity. These washers comply with NACE MR0175/ISO 15156 for sour-service environments and are widely used across subsea, naval, and petrochemical applications worldwide.

Quick Specifications

MaterialMonel K500
UNS NumberN05500
DIN Number2.4375
Material StandardASTM B865
Washer Standard (Metric)DIN 125 / DIN 9021 / ISO 7089
Washer Standard (Inch)ASME B18.22.1 / ASME B18.21.1
Washer TypesPlain / Flat / Spring / Lock / Fender
Diameter RangeM6-M64 / ¼"-2½"
Tensile Strength1100 MPa (160 ksi) min (Age-Hardened)
Yield Strength790 MPa (115 ksi) min
HardnessMax 35 HRC / 300 HB
? All material certified by NABL-accredited laboratory. PMI available on request.

Complete the Fastener Set

Other Monel K500 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Monel K500 fastener range from certified nickel-copper alloy bar stock, including Monel K500 Bolts, Monel K500 Nuts, Monel K500 Screws, Monel K500 Studs, and Monel K500 Threaded Rods. All Monel K500 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Monel K500 Bolts
Monel K500 Nuts
Monel K500 Screws
Monel K500 Studs
Monel K500 Threaded Rods

Technical Data

Monel K500 Washers Dimensions, Sizes & Thread Standards

Monel K500 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 B18.22.1. All Monel K500 washers dimensions are verified against applicable DIN, ISO, and ASME

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

Bolt Size (M)ID (mm)OD (mm)Thickness (mm)Large OD DIN 9021 (mm)
M66.4121.618
M88.4161.624
M1010.5202.030
M1213.0242.537
M1617.0303.050
M2021.0373.060
M2425.0444.072
M3031.0564.092
M3637.0665.0110
M4243.0787.0130
M4850.0928.0150
M5658.01059.0175
M6466.01159.0200

Dimensional & Material Standards

StandardCoversSystem
DIN 125Plain flat washers, normal seriesMetric
DIN 9021Large OD flat washersMetric
ISO 7089Plain washers, 200 HV seriesMetric
ISO 7090Plain washers with chamferMetric
ASME B18.22.1Plain washers, inch seriesInch
ASME B18.21.1Lock washers, inch seriesInch
ASME B16.5Flange washer setsInch
Material StandardRequirement
ASTM B865Bar/rod - UNS N05500
ASTM B127Plate/sheet - UNS N04400/N05500
NACE MR0175Sour service hardness compliance
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Monel K500 Chemical Composition

Monel K500 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 B865

ElementComposition (%)
Nickel + Cobalt (Ni+Co)63.0% min
Copper (Cu)27.0-33.0%
Aluminium (Al)2.30-3.15%
Titanium (Ti)0.35-0.85%
Iron (Fe)2.0% max
Manganese (Mn)1.5% max
Carbon (C)0.25% max
Silicon (Si)0.50% max
Sulphur (S)0.010% max
? All heats verified by NABL-accredited spectrometry. PMI available on request.

Why Monel K500 Alloy Composition Matters for Washers

Al (2.30–3.15%) + Ti (0.35–0.85%) — Precipitation Hardening
Aluminium and titanium combine during age-hardening to form the Ni3(Al,Ti) gamma-prime phase, raising tensile strength to 1100 MPa minimum. This allows Monel K500 washers to sustain high clamp loads under bolt heads without embedding or creep — critical in gasketed flange assemblies.
Cu (27–33%) — Seawater Corrosion Immunity
The high copper content gives Monel K500 washers exceptional resistance to seawater, brine, and hydrofluoric acid. Unlike stainless steel, Monel K500 does not pit or crevice-corrode under washer bearing surfaces in immersed marine environments, eliminating the need for protective coatings.
Low Fe and S — Non-Magnetic & Sour-Service Compliant
Controlled iron and sulphur levels keep Monel K500 washers non-magnetic in the annealed condition and compliant with NACE MR0175 hardness limits when properly age-hardened. This makes them suitable for both sour-service oil and gas applications and magnetically sensitive instrumentation environments.

Fastener Performance

Monel K500 Washers Mechanical Properties & Hardness Reference

The table below lists mechanical properties and hardness reference for Monel K500 Washers per ASTM. Monel K500 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 - Age-Hardened Condition

Washer SizeID (mm)OD (mm)Thickness (mm)Max Bearing Load (kN)
M1213.0242.548
M1617.0303.095
M2021.0373.0148
M2425.0444.0215
M3031.0564.0340
M3637.0665.0490
M4243.0787.0670
M4850.0928.0880
?? Anti-galling note: Apply nickel-based anti-seize to washer bearing faces in high-temperature or immersed service. Never use copper-based compounds on Monel alloys.

Industry Applications

Monel K500 Washers Applications — Industries & End Uses

Monel K500 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 K500 washers application details and RealBolt stock availability.
Monel K500 washers are specified as part of complete ASME B16.5 flange bolt sets for subsea wellhead connections, BOP stack assemblies, and Christmas tree flanges. Their age-hardened strength prevents washer embedding under high bolt preload, while the nickel-copper composition provides full immunity to H2S and chloride corrosion per NACE MR0175/ISO 15156.
Flat and large-OD washers in Monel K500 are used extensively in propeller shaft assemblies, rudder pintles, sea chest valve flanges, and offshore mooring hardware. The alloy’s resistance to seawater corrosion under bearing surfaces – where crevice conditions are most severe – makes it the preferred choice over duplex stainless steel in permanently immersed marine structures.
Monel K500 washers are used in heat exchanger channel cover bolt sets, reactor closure flanges, and pump casing assemblies handling hydrofluoric acid, sulphuric acid, and chlorinated organic solvents. The age-hardened condition provides the load-bearing capacity needed to maintain gasket seating stress in high-pressure process equipment.
In multi-stage flash (MSF) and reverse osmosis (RO) desalination plants, Monel K500 washers are specified for seawater intake piping flanges, brine heater connections, and high-pressure membrane housing assemblies. The alloy resists both the chloride-rich seawater and the chemical cleaning agents used in membrane maintenance cycles.

Monel K500 Washers Standards & International Certifications

Monel K500 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 K500 Washers from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Monel K500 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 K500 Washers — Frequently Asked Questions

Browse expert answers to common questions about Monel K500 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 K500 washers selection and pricing.
Monel K500 flat washers are manufactured to DIN 125 (normal series), DIN 9021 (large OD series), ISO 7089, and ISO 7090 (chamfered) in metric sizes. Inch-series washers are produced per ASME B18.22.1 (plain washers) and ASME B18.21.1 (lock washers). Custom OD and thickness combinations outside standard series are available with 10-15 working day lead time and full dimensional certification.
Monel 400 (UNS N04400) and Monel K500 (UNS N05500) share the same nickel-copper base composition and corrosion resistance. The critical difference is mechanical strength: Monel 400 washers have a tensile strength of approximately 480 MPa in the annealed condition, while Monel K500 washers achieve 1100 MPa minimum after age-hardening due to the addition of aluminium and titanium. For high bolt-preload applications – such as ASME B16.5 Class 900 and above flanges – Monel K500 is specified to prevent washer embedding and loss of gasket seating stress. Monel 400 is used where lower clamp loads are acceptable and cost is a priority.
Monel K500 washers are non-magnetic in the annealed condition. After age-hardening, a slight increase in magnetic permeability may occur, but the alloy remains effectively non-magnetic for most practical applications. For magnetically critical applications – such as submarine hull fittings, MRI facility construction hardware, or sensitive instrumentation enclosures – specify annealed-only material and confirm permeability values with the mill test certificate. We supply permeability test reports on request.
Yes – Monel K500 washers are listed under NACE MR0175/ISO 15156 for sour-service applications when the hardness is controlled to a maximum of 35 HRC. Our age-hardening process is controlled to produce washers within this hardness limit, and each batch is supplied with a hardness survey report. Monel K500 is immune to sulphide stress cracking (SSC) at the hardness levels achievable through standard age-hardening, making it suitable for H2S-containing wellhead and pipeline flange assemblies.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
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  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
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