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Monel 400 Nuts Manufacturer & Exporter in India

Explore Monel 400 Nuts 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 Nuts?

Monel 400 nuts are nickel-copper alloy fasteners manufactured from UNS N04400 bar stock conforming to ASTM B164. The alloy’s single-phase solid-solution structure – comprising 63-70% nickel and 28-34% copper – delivers exceptional resistance to seawater, hydrofluoric acid, and reducing acids across a broad temperature range from cryogenic conditions up to 480°C in continuous service.

With a PREN sufficient to resist chloride-induced pitting in marine splash zones and a natural immunity to stress corrosion cracking in most chloride environments, Monel 400 nuts are specified under NACE MR0175/ISO 15156 for sour-service piping systems, offshore platform structural connections, and marine heat exchanger assemblies worldwide.

Quick Specifications

MaterialMonel 400
UNS NumberN04400
DIN Number2.4360
Material StandardASTM B164
Nut Standard (Metric)DIN 934 / DIN 6915 / ISO 4032
Nut Standard (Inch)ASME B18.2.2
Thread FormISO Metric / UNC / UNF
Size RangeM6-M100 / ¼"-4"
Tensile Strength482 MPa (70 ksi) min
Yield Strength193 MPa (28 ksi) min
HardnessMax 35 HRC / 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 Screws, Monel 400 Washers, 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 Screws
Monel 400 Washers
Monel 400 Studs
Monel 400 Threaded Rods

Technical Data

Monel 400 Nuts Dimensions, Sizes & Thread Standards

Monel 400 Nuts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 934 (hex nuts) / DIN 6915 (heavy hex nuts) / ISO 4032. Custom thread pitches available. Inch dimensions per ASME B18.2.2. All Monel 400 nuts dimensions are verified against applicable DIN, ISO, and ASME B18

Hex Nut Dimensions - Metric (DIN 934 / ISO 4032)

Size (M)Pitch (mm)A/F (mm)Nut Height (mm)A/C (mm)
M61.0105.011.05
M81.25136.514.38
M101.5178.018.90
M121.751910.020.03
M162.02413.026.75
M202.53016.032.95
M243.03619.039.55
M303.54624.050.85
M364.05529.060.79
M424.56534.071.30
M485.07538.082.60
M565.58545.093.56
M646.09551.0104.86
M726.010558.0116.16
M806.011564.0127.46
M1006.014580.0160.00

Dimensional & Material Standards

StandardCoversThread
DIN 934Hex nuts, standard heightMetric
DIN 6915Heavy hex nuts, structuralMetric
ISO 4032Hex nuts, style 1Metric
ISO 4033Hex nuts, style 2 (tall)Metric
ASME B18.2.2Hex & heavy hex nutsUNC/UNF
ASME B16.5Heavy hex nuts for flangesUNC
MSS SP-75Heavy hex nuts, high-pressureUNC
Material StandardRequirement
ASTM B164Bar/rod - UNS N04400
ASTM F467Fastener mechanical properties
NACE MR0175Sour service hardness control
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Monel 400 Chemical Composition

Monel 400 Nuts 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 B164

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 Nuts

Ni (63% min) — Corrosion Resistance in Reducing Environments
The high nickel base gives Monel 400 nuts outstanding resistance to hydrofluoric acid, alkalis, and reducing acids. Unlike stainless steels, Monel 400 does not require an oxidising environment to maintain its passive film, making it the preferred choice for HF alkylation unit fasteners.
Cu (28–34%) — Seawater & Marine Immunity
The copper content provides natural biofouling resistance and immunity to dealloying in seawater. Monel 400 nuts resist pitting and crevice corrosion under nut bearing faces in continuous seawater immersion — a failure mode that eliminates standard stainless steel nuts within months in offshore environments.
Single-Phase Solid Solution — No Sensitisation Risk
Monel 400 is a single-phase alloy with no carbide precipitation risk during welding or elevated-temperature service. Nuts retain full corrosion resistance in the heat-affected zone of welded assemblies without post-weld heat treatment, simplifying fabrication quality control.

Fastener Performance

Monel 400 Nuts Mechanical Properties & Torque Reference

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

Tightening Torque Reference - Monel 400 Nuts

Bolt/Nut SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12524219
M1612510046
M2024519673
M24425340106
M30850680168
M3614801184244
M4223601888336
M4835002800442
?? Anti-galling: Use nickel-based anti-seize (Molykote P-37 or Bostik Never-Seez Pure Nickel). Lubricated values assume K=0.15. Never use copper-based anti-seize on nickel-copper alloys - it masks galvanic activity and accelerates thread corrosion.

Industry Applications

Monel 400 Nuts Applications — Industries & End Uses

Monel 400 Nuts 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 nuts application details and RealBolt stock availability.
Monel 400 heavy hex nuts are the industry-standard specification for hydrofluoric acid alkylation unit piping flanges, valve bonnets, and pressure vessel nozzle connections. NACE MR0175 compliant for H2S sour service. Specified under Shell DEP and ExxonMobil EMSP for refinery process piping in HF service.
Hex nuts and heavy hex nuts for offshore platform structural connections, seawater cooling system flanges, marine heat exchanger channel covers, and propeller shaft assemblies. Monel 400 nuts resist biofouling and pitting corrosion under bearing faces in continuous seawater immersion without cathodic protection or protective coatings.
Flange nut sets for reactor closures, heat exchanger channel covers (TEMA Class B/C), and pressure vessel nozzle connections in hydrochloric acid, sulfuric acid (dilute), phosphoric acid, and caustic soda process environments where stainless steel nuts suffer accelerated corrosion or stress corrosion cracking.
Monel 400 nuts are specified for multi-stage flash (MSF) and reverse osmosis (RO) desalination plant piping flanges, brine heater connections, and seawater intake screen assemblies. The alloy’s resistance to chloride-bearing brackish water and elevated-temperature brine makes it the preferred fastener material for GCC desalination projects.

Monel 400 Nuts Standards & International Certifications

Monel 400 Nuts 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 934 ISO 4032 ASME B18.2.2 BS 1768 BS EN ISO 4032 IS 1364 IS 1367
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

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

Partner with RealBolt — India’s leading manufacturer of certified Monel 400 Nuts — 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 Nuts — Frequently Asked Questions

Browse expert answers to common questions about Monel 400 Nuts 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 nuts selection and pricing.
Monel 400 hex nuts are available to DIN 934 (standard hex, metric), DIN 6915 (heavy hex, metric), ISO 4032 (style 1) and ISO 4033 (style 2 tall), and ASME B18.2.2 (inch hex and heavy hex). Heavy hex nuts for ASME B16.5 flange stud bolt sets are supplied per ASME B18.2.2 with proof load testing per ASTM F467. Custom thread forms including BSW, BSF, and BSPP are available on request with a 15 working day lead time.
Yes – Monel 400 is one of the very few engineering alloys with genuine resistance to anhydrous and aqueous hydrofluoric acid across a wide concentration range. Monel 400 nuts are the standard specification for HF alkylation unit piping flanges and valve bonnets in petroleum refining. The alloy must be used in the annealed condition (hardness below 35 HRC) to avoid stress corrosion cracking in HF environments. Cold-worked or work-hardened nuts are not acceptable for HF service.
Yes – Monel 400 nuts resist pitting and crevice corrosion in seawater at ambient temperature, including under nut bearing faces and under washers where crevice conditions are most severe. The alloy is listed in NORSOK MDS D45 for offshore structural fasteners and is accepted under Shell DEP for seawater piping systems. No special coating or cathodic protection is required for Monel 400 nuts in seawater service, though nickel-based anti-seize should always be applied to threads before assembly.
Monel 400 (UNS N04400) is the standard annealed nickel-copper alloy with a tensile strength of 482 MPa minimum. Monel K-500 (UNS N05500) is an age-hardened variant with aluminium (2.3-3.15%) and titanium (0.35-0.85%) additions that raise tensile strength to 930 MPa minimum after precipitation hardening. Monel K-500 nuts are specified where higher mechanical strength is required – for example, subsea wellhead connections and high-pressure valve stems – while Monel 400 nuts are preferred for chemical process applications where maximum corrosion resistance and ductility are the primary requirements.

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
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  • UAE
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  • Oman
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