1. Product Properties
Monel 400 (UNS N04400 / W.Nr. 2.4360 & 2.4361) is a solid-solution nickel-copper alloy wire that delivers exceptional corrosion resistance paired with high strength and toughness over a wide temperature range. Cold working is the only means of increasing strength, as this alloy cannot be hardened by heat treatment. It is approved for ASME Boiler and Pressure Vessel Code construction and listed in NACE MR01-75 for oil and gas service.
| Product Name |
Monel 400 Nickel-Copper Alloy Wire |
| UNS Number |
N04400 |
| Werkstoff Number |
2.4360 / 2.4361 |
| Alloy Type |
Nickel-Copper, Solid-Solution (Cold-Work Hardenable Only) |
| Available Forms |
Round Wire, Flat Wire, Spring Wire, Rivet Wire |
| Diameter Range |
0.1 mm – 12.0 mm (0.004 – 0.472 in) |
| Temper Conditions |
Annealed, 1/4 Hard, 1/2 Hard, Full Hard, Spring Temper |
| NACE Compliance |
MR01-75 for Oil & Gas Service |
| ASME Approval |
Section III / VIII Div.1 & Div.2 |
| Brand |
DINGSCO |
2. Material Overview
Monel 400 is a versatile nickel-copper alloy (approximately 63% Ni, 28–34% Cu) that has been a cornerstone material in marine and chemical processing industries for decades. As a solid-solution alloy that can only be hardened by cold working, it offers a unique combination of high strength, excellent ductility, and outstanding corrosion resistance without the complexity of precipitation heat treatment.
The alloy exhibits exceptional resistance to hydrofluoric acid in all concentrations up to the boiling point — it is widely considered the most resistant of all commonly used engineering alloys to HF acid. Monel 400 also performs exceptionally well in seawater, sulfuric and hydrochloric acids under reducing conditions, and alkaline environments. A notable characteristic is that its Curie temperature (21–49°C) lies within the ambient range, meaning magnetic behavior can vary at room temperature. For applications requiring guaranteed non-magnetic properties, Monel K-500 should be considered.
Key Advantage: Monel 400 wire combines the fabrication simplicity of a solid-solution alloy with world-class resistance to seawater and hydrofluoric acid — making it the material of choice for marine fasteners, chemical processing equipment, and electronic components where reliability over decades of service is essential.
3. Chemical Composition
| Element |
Ni+Co |
Cu |
Fe |
Mn |
Si |
C |
S |
| Content (%) |
63.0 min |
28.0–34.0 |
2.5 max |
2.0 max |
0.5 max |
0.3 max |
0.024 max |
4. Physical Properties
| Density |
8.80 g/cm³ (0.318 lb/in³) |
| Melting Range |
1300 – 1350°C (2370 – 2460°F) |
| Modulus of Elasticity (Tension) |
179 GPa (26.0 * 10³ ksi) |
| Modulus of Elasticity (Compression) |
179 GPa (26.0 * 10³ ksi) |
| Modulus of Rigidity (Torsion) |
65 GPa (9.5 * 10³ ksi) |
| Poisson's Ratio |
0.32 |
| Curie Temperature |
21 – 49°C (70 – 120°F) |
| Electrical Resistivity (20°C) |
0.51 µΩ·m |
5. Mechanical Properties
| Condition |
Tensile Strength |
Yield Strength (0.2%) |
Elongation % |
Hardness |
| Annealed |
≥ 480 MPa (70 ksi) |
≥ 170 MPa (25 ksi) |
≥ 35 |
≥ 331 HB |
| 1/4 Hard |
550–690 MPa (80–100 ksi) |
275–480 MPa (40–70 ksi) |
15–25 |
— |
| 1/2 Hard |
620–760 MPa (90–110 ksi) |
415–620 MPa (60–90 ksi) |
8–15 |
— |
| Full Hard |
760–900 MPa (110–130 ksi) |
620–830 MPa (90–120 ksi) |
2–8 |
— |
| Spring Temper |
830–1030 MPa (120–150 ksi) |
690–965 MPa (100–140 ksi) |
1–4 |
— |
6. Corrosion Resistance — Performance Comparison
Monel 400 wire delivers exceptional corrosion performance in reducing environments, seawater, and hydrofluoric acid. The table below compares its corrosion behavior against common engineering alloys in key service media:
| Alloy |
UNS |
Seawater |
HF Acid |
H₂SO₄ (Reducing) |
NaOH (Alkaline) |
SCC (Cl⁻) |
| 316L SS |
S31603 |
Moderate |
Poor |
Moderate |
Good |
Susceptible |
| Alloy 400 |
N04400 |
Excellent |
Excellent |
Very Good |
Excellent |
Immune |
| Alloy K-500 |
N05500 |
Excellent |
Excellent |
Very Good |
Excellent |
Immune |
| Inconel 625 |
N06625 |
Excellent |
Good |
Excellent |
Excellent |
Immune |
| 90/10 Cu-Ni |
C70600 |
Very Good |
Moderate |
Poor |
Fair |
Resistant |
Monel 400 is the most resistant of all commonly used engineering alloys to hydrofluoric acid across all concentrations up to the boiling point. It also resists stress corrosion cracking and pitting in most fresh and industrial waters. While corrosion rates are very low in flowing seawater, stagnant seawater conditions may induce crevice attack — a consideration easily managed by maintaining adequate flow velocity (>1.5 m/s) in service.
7. Material Characteristics
HF Acid Champion: The most resistant engineering alloy to hydrofluoric acid — irreplaceable for HF alkylation units and fluorine-based chemical processing.
Seawater Excellence: Very low corrosion rates in flowing seawater. Proven in decades of marine service — propeller shafts, pump components, and heat exchangers.
SCC Immunity: Virtually immune to chloride stress corrosion cracking, a critical advantage over austenitic stainless steels in marine and chemical applications.
Cold Work Hardenable: Strength levels from annealed (480 MPa) to spring temper (up to 1030 MPa) achieved purely through cold drawing — no heat treatment required.
Cryogenic Toughness: Retains excellent ductility and tough fracture characteristics down to -320°F (-196°C), proven by U.S. Navy tear tests.
Alkaline Resistance: Exceptional resistance to caustic soda (NaOH) and other alkaline media across wide concentration and temperature ranges.
ASME Code Approved: Listed in ASME Section II Part D for Section III (≤800°F), Section VIII Div.1 (≤900°F), and Section VIII Div.2 (≤800°F) construction.
Dissimilar Metal Capable: Excellent galvanic compatibility with copper alloys in seawater systems. Weldable to itself and carbon steel using ERNiCu-7 filler.
8. Product Image Gallery
9. Available Forms
Bar / Rod Forging Parts
10. Typical Applications
| Marine Engineering |
Propeller shafts, pump shafts, marine fixtures, fasteners, springs, wire rope, and heat exchanger tube supports for seawater service |
| Chemical Processing |
Valve components, pump impellers, HF acid alkylation equipment, caustic soda handling, and sulfuric acid process vessels |
| Oil & Gas |
Crude petroleum still internals, process piping, boiler feedwater heaters, deaerating heaters, and NACE-compliant components |
| Electronics |
Electrical and electronic components, connectors, resistance wire, and electromagnetic shielding |
| Automotive & Aerospace |
Gasoline and fresh water tanks, fuel system components, and cryogenic fasteners |
| Desalination |
Multi-stage flash (MSF) and reverse osmosis (RO) plant components, salt production equipment |
11. DINGSCO — Professional Nickel Alloy Manufacturer
DINGSCO — Your Trusted Nickel Alloy Partner
DINGSCO is a premier manufacturer and supplier of high-performance nickel alloy wire and bar products, serving global customers across marine, chemical processing, oil & gas, electronics, and desalination industries. With decades of metallurgical expertise and in-house wire drawing, cold working, and heat treatment capabilities, we deliver consistently superior nickel alloy wire products to exacting specifications.
QUALITY ASSURANCE:
Our mission is to provide our customers only with the best quality products. As an ISO 9001:2015, PED 2014/68/EC, and API 6A certified manufacturer, we enforce strict quality control at every production stage — from raw material inspection and chemical composition verification to final dimensional inspection and tensile testing. Every shipment is accompanied by full Mill Test Reports (MTR) and material certifications.
ISO 9001:2015 PED 2014/68/EC API 6A
SCIENCE AND TECHNOLOGY INNOVATION STRATEGY:
We pay close attention to customer needs, implement product innovation, and further leverage our company's full range of product types and material grades to provide customers with one-stop service — including FeCrAl alloy series, NiCr alloy series, and CuNi alloy series alongside our core nickel alloy wire offerings. We pursue continuous improvement through material research, process optimization, and equipment upgrades.
COOPERATION:
We are pleased to help others and glad to acquire the hand of others. We actively participate in team meetings and support decision-making. We share our experience with each other and excel at cooperating with different types of colleagues across global markets.
12. Material Selection — Other Alloy Wires Available
DINGSCO maintains a comprehensive inventory of specialty alloy wire products. In addition to Monel 400 (UNS N04400), we supply the following series:
Monel K-500UNS N05500
Age-hardenable, 3* strength
Marine fasteners & springs
Inconel 625UNS N06625
High-temp superalloy wire
Aerospace & chemical
Inconel 718UNS N07718
Age-hardenable, max strength
Gas turbine components
Incoloy 825UNS N08825
General corrosion resistance
Chemical processing wire
Hastelloy C-276UNS N10276
Extreme corrosion resistance
Severe chemical environments
CuNi 70/30C71500
Marine-grade copper-nickel
Seawater piping & HX
Nichrome 80/20Cr20Ni80
High-resistance heating wire
Industrial furnaces
FeCrAl Alloy0Cr25Al5
High-temp resistance wire
Up to 1250°C service
ConstantanCuNi44
Low TCR resistance alloy
Precision instruments
13. Customized Products
DINGSCO offers comprehensive customization services for Monel 400 wire and related products:
- Custom Diameters: Non-standard wire diameters from 0.05 mm ultra-fine to 12.0 mm, drawn to your exact specification with tight tolerance control
- Precision Cold Working: Custom temper conditions — from dead-soft annealed to full-hard spring temper with controlled mechanical properties
- Straightening & Cutting: Precision straightened and cut lengths with ±0.5 mm tolerance for automated assembly
- Special Surface Finishes: Bright finish, matte, pickled, or coated surfaces per application requirements
- Custom Packing: Spools, coils, reels, or straight lengths packaged to your specifications with rust-preventive protection
- Full Traceability: Heat lot traceability with chemical and mechanical test certification for every shipment
- Expedited Delivery: Priority production scheduling for urgent project and shutdown maintenance timelines
Contact DINGSCO today for a competitive quote on Monel 400 alloy wire — we respond to all inquiries within 24 hours.
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