Monel 404 Alloy | Nickel-Copper High-Strength Corrosion-Resistant Alloy
Supplied by Huaxiao-Alloy – Your Trusted Global Alloy Partner
1. Product Overview
Monel 404 Alloy is a nickel-copper alloy engineered for high strength, excellent corrosion resistance, and stable performance in both industrial and electrical applications. It combines the corrosion-resistant characteristics of Monel 400 with improved mechanical properties and higher electrical resistivity, making it suitable for marine, chemical, oil & gas, and precision engineering applications.
At Huaxiao-Alloy, Monel 404 is supplied in all standard forms — pipes, tubes, plates, sheets, bars, wires, and custom fittings — manufactured according to ASTM B164 / B165 / UNS N04404 / DIN 2.4360 and equivalent international standards.
The alloy’s high nickel content (≈63%) and copper content (≈30%) give it exceptional resistance to seawater, brine, and a wide range of acids and alkalis, while also providing stable electrical and mechanical performance under stress, high temperature, and corrosive conditions.
2. Chemical Composition (Typical %)
| Element | Nickel (Ni) | Copper (Cu) | Iron (Fe) | Manganese (Mn) | Carbon (C) | Silicon (Si) | Sulfur (S) |
|---|---|---|---|---|---|---|---|
| Content (%) | 63 min | 28–34 | 2.5 max | 2.0 max | 0.15 max | 0.5 max | 0.02 max |
Notes:
High nickel ensures excellent corrosion resistance.
Copper enhances resistance to seawater and non-oxidizing acids.
Minor elements (Fe, Mn, Si, C, S) improve mechanical properties, workability, and thermal stability.
3. Mechanical Properties
| Property | Condition | Typical Value |
|---|---|---|
| Tensile Strength | Annealed | 480–620 MPa (70–90 ksi) |
| Yield Strength (0.2% offset) | Annealed | 170–275 MPa (25–40 ksi) |
| Elongation | 50 mm | 35–45% |
| Hardness | Brinell | 120 max |
| Density | — | 8.83 g/cm³ |
| Melting Point | — | 1300–1350°C |
Monel 404 exhibits excellent toughness and ductility, even at sub-zero temperatures, making it ideal for marine and electrical applications requiring both corrosion resistance and mechanical stability.
4. Equivalent Grades
| Standard | Grade |
|---|---|
| UNS | N04404 |
| ASTM / ASME | B164, B165 |
| DIN | 2.4360 |
| ISO | NiCu30Fe |
| JIS | NW4404 |
| BS | NA 13 |
5. Key Features & Benefits
Superior Corrosion Resistance – Effective against seawater, brine, and most non-oxidizing acids.
High Mechanical Strength – Maintains strength across a wide temperature range.
Electrical Properties – Offers higher resistivity than Monel 400, suitable for precision engineering.
Good Fabrication & Weldability – Machinable and weldable using standard Monel filler metals.
Non-Magnetic & Stable – Remains non-magnetic even at low temperatures.
Durable & Reliable – Resistant to stress corrosion cracking, cavitation, and erosion.
Versatile Applications – Ideal for marine, chemical, oil & gas, and electrical components.
6. Available Product Forms
| Product Form | Size Range | Remarks |
|---|---|---|
| Pipe & Tube | OD 6–219 mm, WT 0.5–12 mm | Seamless or welded, ASTM B165 |
| Sheet & Plate | 0.5–50 mm | Hot or cold rolled, pickled or polished |
| Bar & Rod | 3–200 mm | Round, hex, square |
| Wire | 0.1–10 mm | Coil or spool, bright annealed |
| Coil / Strip | 10–1200 mm width | Precision rolled finish |
| Fittings & Flanges | Custom sizes | Forged or machined |
All Monel 404 products come with export-grade packaging, mill certificates, and ISO-compliant documentation.
7. Typical Applications
Marine & Offshore:
Pump shafts, impellers, and valves
Heat exchanger and condenser tubing
Piping systems exposed to seawater
Chemical Processing:
Reactors, tanks, and piping handling acids or brine
Evaporators and chemical processing equipment
Oil & Gas:
Tubing, fittings, and valves for offshore operations
High-pressure pumping and heat-resistant components
Electrical / Engineering Applications:
Resistors, connectors, and control elements
Instrumentation and sensor housings
Heating elements requiring high corrosion resistance
8. Electrical Properties
| Property | Typical Value |
|---|---|
| Electrical Resistivity | 49–52 µΩ·cm |
| Thermal Conductivity | 22 W/m·K |
| Seebeck Coefficient | 2.5 µV/°C |
| Magnetic Behavior | Non-magnetic |
These properties make Monel 404 highly suitable for electronic, heating, and precision components in aggressive environments.
9. Fabrication & Welding Guidelines
Forming: Cold or hot forming is possible; intermediate annealing recommended for heavy deformation.
Machining: Monel 404 work-hardens; low cutting speeds, sharp tools, and proper coolant are required.
Welding:
Filler metals: Monel 60 or ENiCu-7
Methods: TIG, MIG, SMAW
Preheating: Not required; post-weld annealing optional
Heat Treatment: Annealing at 870°C (1600°F) restores ductility and corrosion resistance.
10. Corrosion Resistance
Monel 404 offers excellent resistance to:
Seawater and chloride-rich environments
Non-oxidizing acids (HCl, HF, H2SO4)
Alkaline and brine solutions
Stress corrosion cracking and erosion
It outperforms many stainless steels under marine and chemical conditions, making it ideal for long-lasting industrial components.
11. Quality Assurance & Certifications
Huaxiao-Alloy ensures Monel 404 meets strict international standards:
✅ ISO 9001:2015 certified production
✅ ASTM B164 / B165, UNS N04404, DIN 2.4360 compliance
✅ PMI, hardness, tensile, and hydrostatic testing
✅ EN 10204 3.1 / 3.2 mill certificates
✅ Export-grade protective packaging
Our Wuxi, Foshan, and Shanghai Baoshan factories guarantee precision dimensions, corrosion-free finishes, and global shipping readiness.
12. Why Choose Huaxiao-Alloy
Comprehensive Alloy Solutions: Monel, Inconel, Hastelloy, stainless steel
Factory-Direct Pricing: Cost-effective, ISO-certified, export-ready
Technical Support: Material selection, fabrication, and welding guidance
Global Supply Chain: Fast delivery to Europe, Middle East, and Asia
Certifications: ISO, SGS, BV, TUV, ABS, DNV
Huaxiao-Alloy is a trusted global supplier of Monel 404, offering both technical and commercial support for demanding applications.
A: Marine, chemical, oil & gas, and electrical engineering applications requiring corrosion resistance and high resistivity.
A: Monel 404 has slightly higher electrical resistivity and better machinability while maintaining corrosion resistance.
A: Yes. Standard Monel filler metals are recommended; preheat not required.
A: ASTM B164/B165, UNS N04404, DIN 2.4360, ASME SB164/SB165.
A: No, non-magnetic in all conditions.
A: Typically up to 500°C (930°F).
A: Pickled, polished, bright-annealed, or brushed.
A: Yes, Huaxiao-Alloy provides cut-to-size, machined, or custom fittings.
A: Superior performance in chloride-rich environments, longer service life, and higher resistivity for electrical applications.
A: Email export@huaxiao-alloy.com with specifications or submit an inquiry online.
Monel 404 Alloy | Nickel-Copper High-Strength Corrosion-Resistant Alloy
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