+912267437972

+919022636025

enquiry@real-bolt.com

Contact Us
ISO 9001:2015 · UNS N04400–N05500 · ASTM B164–B865

Monel Fasteners Manufacturer, Supplier & Exporter of Corrosion Resistant Fasteners

Monel fasteners combine excellent corrosion resistance with high strength. We manufacture Monel 400 and Monel K500 fasteners for marine, chemical, and offshore applications worldwide.
Request a Quote
View Products

2

Grades

12

Products

-196°C

Min Temp

450°C

Max Temp

896 MPa

Min tensile strength · Monel K500 per ASTM B865

Excellent

Seawater & HF acid resistant · Ni-Cu alloy

8.83 g/cm³

Density (avg) · nickel-copper alloy

The marine & HF-resistant Ni-Cu alloy explained

What is Monel Fasteners?

Monel is a nickel-copper alloy series containing 63% minimum nickel and 27–34% copper, making it one of the most corrosion-resistant alloys available for seawater, hydrofluoric acid and caustic service. Developed by the International Nickel Company, Monel alloys combine the corrosion resistance of nickel with the ductility and workability of copper, providing outstanding performance across a wider range of pH than either pure nickel or copper alone. Monel fasteners are specified for HF alkylation units, marine sea cock hardware, brine evaporator internals and instrument components where seawater immunity and non-magnetic properties are simultaneously required. Monel 400 (UNS N04400) is the standard corrosion-resistant grade, while Monel K500 (UNS N05500) provides age-hardened yield strength of 586 MPa for propeller shaft nuts and pump fasteners requiring structural load-bearing capability.
PropertySpecification
Base ElementNickel (Ni) 63% min
Cu Content27–34%
GradesMonel 400 & K500
Max Service Temperature450°C
Density8.44–8.83 g/cm³
ASTM StandardsB164 (400), B865 (K500)

Monel grades — 400 or K500?

Multiple fastener grades and material grades of Monel Fasteners exist, each tailored to specific mechanical properties, corrosion resistance, temperature capability, and strength demands in industrial fasteners and engineering applications. Compare the available grades below to align material selection with operating environment, process media, service temperature, and design requirements.

Grade UNS Cu % Key property Max temp Best application
Monel 400 (Most popular) UNS N04400 28–34% HF acid + seawater 450°C Marine, HF alkylation View grade
Monel K500 UNS N05500 27–33% Age-hardened strength 450°C Propeller shafts, pumps View grade
Monel 400
Monel K500

Monel Fasteners — International Standards & Material Certifications

Monel Fasteners from RealBolt Engineering Industries are manufactured to ASME SB-164 (Monel 400) and SB-865 (Monel K500) material standards. Naval orders are supplied to MIL-N-894 with Lloyds Register or DNV certification; all batches ship with EN 10204 MTC 3.1 and NACE MR0175 documentation on request.
Standards
DIN 931 DIN 933 DIN 912 DIN 938 DIN 939 DIN 976-1 DIN 934 DIN 125A DIN 127 ISO 4014 ISO 4017 ISO 4762 ISO 4032 ASME B18.2.1 ASME B18.3 ASME B18.31.2 ASME B18.2.2 BS 1768 BS 3692 IS 1364 IS 1367
Certifications
ISO 9001:2015 NACE MR0175 NABL Lab Lloyds Register MTC 3.1 / 3.2

Monel Fasteners Applications — Industries & Use Cases

Monel Fasteners from RealBolt Engineering Industries are specified by engineers and procurement teams across demanding industries where exceptional resistance to seawater corrosion, hydrofluoric acid at all concentrations, and marine biofouling is critical to fastener performance and service life. Primary end-use sectors for Monel Fasteners include oil and gas HF alkylation, marine shipbuilding, desalination plants, chemical processing, and naval defence — click each industry below to see specific application details and recommended grades.
Monel 400 is uniquely resistant to hydrofluoric (HF) acid at virtually all temperatures and concentrations. It is the material of choice for fasteners in HF alkylation unit reactors, acid settlers and heat exchangers in petroleum refining.
Monel K500 combines the seawater corrosion immunity of Monel 400 with age-hardened yield strength of 586 MPa, making it the standard for marine propeller shaft nuts, pump shaft fasteners and seawater-cooled condenser bolting.
Monel 400 fasteners are used in multi-effect distillation (MED) and multi-stage flash (MSF) evaporator internals and tube-bundle support fasteners where seawater chloride and elevated temperature coexist.
Monel 400 is highly resistant to caustic soda (NaOH), seawater, salt solutions and hydrofluoric acid. Used in caustic evaporator vessel fasteners, brine heaters and chloride-rich process equipment.
Monel K500 is specified for ship instrument fittings, valve trim, pump impellers and precision fasteners in naval applications where non-magnetic properties and seawater corrosion resistance are both required.

Monel vs Cupro Nickel vs Stainless Steel

This comparison table helps marine engineers and offshore procurement teams evaluate Monel Fasteners against Cupro Nickel and Stainless Steel Fasteners — covering HF acid resistance, seawater immunity, biofouling resistance, tensile strength, non-magnetic properties, NACE compliance, and relative cost, so the right alloy is selected for your marine or chemical process environment. Use this data to make an informed alloy selection for your specific operating environment, design code, and budget — or contact RealBolt’s technical team for a project-specific recommendation.
Property Monel 400 Cupro Nickel 70/30 SS 316L
HF acid resistance Excellent Poor Poor
Seawater resistance Excellent Excellent Moderate
Tensile strength (min) 517 MPa 380 MPa 485 MPa
Non-magnetic Yes Yes Conditionally
Relative cost High Medium Medium
NACE MR0175 compliant Yes N/A Conditional

Verdict: Monel 400 is the only practical choice for HF acid environments while also providing excellent seawater resistance. Cupro Nickel 70/30 is preferred for purely marine hardware at lower cost. SS 316L is adequate for general corrosion service only.

Need Monel fasteners? Get a competitive price today.

Partner with RealBolt Engineering Industries for certified Monel Fasteners backed by full EN 10204 material test reports, competitive pricing, and reliable global delivery from our Mumbai facility. Our technical team can assist with Monel 400 vs K500 selection, NACE MR0175 compliance documentation, and custom-machined Monel Fasteners in sizes M6–M100 and UNC/UNF thread forms with full EN 10204 3.1 or 3.2 material test reports and Lloyds/DNV certification on request. Request a quote today and receive a competitive price within 24 hours.
022-6743-7972
+91 90226 36025
Email Us

Monel Fasteners — Common Questions Answered by Our Technical Team

Browse the expert answers below to the most frequently asked questions about Monel Fasteners — covering Monel 400 vs K500 selection, HF acid and seawater service guidance, ASTM B164/B865 standards, galvanic compatibility with stainless steel, non-magnetic properties, available sizes, and MTC documentation. If your question is not answered here, contact the RealBolt technical team directly for grade-specific guidance, project support, and competitive pricing on Monel Fasteners.
Monel 400 (UNS N04400) is the standard grade — excellent corrosion resistance in seawater and HF acid, 517 MPa tensile, 172 MPa yield. Monel K500 (UNS N05500) is age-hardened with Al (2.3–3.15%) and Ti additions, providing 896 MPa tensile and 586 MPa yield — approximately 3× the yield strength — while retaining the same corrosion resistance. Choose K500 for structural marine components like propeller shafts.
Monel 400 is one of the few alloys resistant to HF acid across all concentrations and temperatures. It is preferred over SS 316L, Hastelloy B2 and Hastelloy C276 for aqueous HF service. Note: Monel is not suitable for oxidizing acids (HNO₃, H₂SO₄ above certain concentrations) or moist chlorine/fluorine gas.
Monel 400 has excellent seawater corrosion resistance and is cathodically protected in seawater when in contact with steel structures. In galvanic couples, Monel is nobler than carbon steel and will accelerate steel corrosion. When mated with stainless steel, the galvanic potential difference is small and acceptable. Use insulating bushings when bolting Monel to carbon steel structures.
Monel 400 and K500 fasteners are available in metric (ISO) threads from M6 to M100, and unified (UNC/UNF) threads from ¼″ to 4″. ACME, BSW (Whitworth) and special thread profiles are available on request with 3–4 week lead time.

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