Excerpt:
Monel 401 (UNS N04401) supplier — low-electrical-resistivity nickel-copper alloy. Used in electrical and electronic components, resistance elements. Bar and strip forms available.
Shanghai Hangbo Alloy Group Co., Ltd. is an ISO 9001:2015 certified manufacturer and global supplier of premium Monel 401 (UNS N04401) round bars, plates, sheets, strips and wires. Monel 401 is a specialized nickel-copper electrical-resistance alloy with a controlled manganese content, delivering high, stable electrical resistivity with a low temperature coefficient — the trusted material for precision resistors, rheostats, heating elements and marine electrical equipment.
Standards
- ASTM B164 — Rod, Bar, Wire (Hot-Worked / Annealed)
- ASTM B127 — Plate, Sheet, Strip
- UNS N04401 / W.Nr. 2.4057
- ASME SB164 / SB127 — Pressure Vessel Applications
Precise ASTM Chemical Composition (%)
| Element | Range / Max |
|---|---|
| Copper (Cu) | Balance |
| Nickel (Ni) | 40.0 – 45.0 |
| Manganese (Mn) | 1.25 – 2.25 |
| Iron (Fe) | 0.75 max |
| Silicon (Si) | 0.10 max |
| Carbon (C) | 0.10 max |
| Sulfur (S) | 0.015 max |
Physical & Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength (Annealed Bar) | 483 MPa (70 ksi) min |
| Yield Strength (0.2% Offset) | 172 MPa (25 ksi) min |
| Elongation (in 2") | 35% min |
| Electrical Resistivity (Annealed) | ~47 µΩ·cm |
| Temperature Coefficient of Resistance | Low — stable over service range |
| Density | 8.80 g/cm³ |
| Melting Range | 1330 – 1350 °C |
Depth Characteristics
- High Stable Resistivity: Controlled manganese content delivers a high and reproducible electrical resistivity of ~47 µΩ·cm.
- Low Temperature Coefficient: Resistance remains stable across the operating temperature range, essential for precision electrical instruments.
- Excellent Corrosion Resistance: Inherits the Ni-Cu family's strong resistance to seawater, salt spray, alkalis and mild acids.
- Good Mechanical Strength: Suitable for drawn wire, wound elements and structural electrical components without excessive softening.
- Readily Formable: Excellent drawing, winding and brazing characteristics for resistor and heating-element manufacture.
Manufacturing Process — Forging & Heat Treatment
Monel 401 is melted with tightly controlled manganese and trace-element chemistry to guarantee reproducible electrical properties. The alloy is hot-forged at 870–1175°C and finished above 700°C, then annealed at 760–870°C with air cooling. Wire is drawn to final gauge with intermediate anneals, and resistivity is verified per unit length on every coil. Bars are straightened, peeled and surface-inspected before release.
Testing & Inspection Methods — PMI / UT / RT
- PMI (Positive Material Identification): 100% XRF/arc-OES verification of Ni, Cu, Mn, Fe on all delivered material.
- UT (Ultrasonic Testing): Ultrasonic examination of bar per ASTM E213 where internal soundness is specified.
- RT (Radiographic Testing): Radiographic inspection of welded assemblies per ASME Section V when required.
- Plus: electrical resistivity measurement per unit length, tensile/hardness testing, grain-size evaluation and dimensional inspection; EN 10204 3.1/3.2 mill certificates supplied with every order.
High-Frequency Application Scenarios
- Precision Resistors: Wire-wound resistors, potentiometers and rheostats for marine and industrial instruments.
- Heating Elements: Resistance heaters, heating cables and temperature sensors requiring corrosion resistance.
- Electrical Contacts & Connectors: Springs, terminals and contact parts in salt-laden environments.
- Ballast & Load Resistors: Power-dissipation elements for railway and industrial traction equipment.
- Marine Instrumentation: Shaft grounding brushes, thermocouple sheaths and corrosion-resistant instrument parts.
6+ Professional FAQs
1. What makes Monel 401 different from Monel 400?
Monel 401 is a nickel-copper ELECTRICAL-resistance alloy (40-45% Ni) with controlled manganese, optimized for stable resistivity (~47 µΩ·cm) rather than maximum corrosion resistance.
2. Why is manganese controlled in Monel 401?
Manganese stabilizes and tunes the electrical resistivity and its temperature coefficient, giving predictable resistance behavior in precision components.
3. Is Monel 401 corrosion-resistant?
Yes — it retains excellent resistance to seawater, salt spray, alkalis and mild acids, allowing electrical components to survive harsh marine environments.
4. What product forms are available?
Round bar (ASTM B164), plate/sheet/strip (ASTM B127), wire and ribbon — with resistivity verified per unit length.
5. Can Monel 401 be used for heating elements?
Yes — its stable resistivity and corrosion resistance make it suitable for resistance heating elements and ballast resistors, though Ni-Cr alloys are preferred for very high temperatures.
6. Is Monel 401 weldable?
It can be joined by standard techniques including brazing and TIG welding; for electrical joints, brazing or mechanical connections are commonly used to preserve resistance characteristics.
7. What heat treatment is applied?
Annealing at 760–870°C with air cooling restores softness and consistent electrical properties after cold working.
Supply List
- Round Bar: Φ6mm – Φ200mm, peeled/ground
- Wire: Φ0.1mm – 10mm, resistivity-tested per coil
- Ribbon / Strip: For wound elements and connectors
- Plate / Sheet: Thickness 0.5mm – 40mm
- Custom Drawn Profiles: Per drawings
Need certified Monel 401 for your electrical or marine application? Contact Shanghai Hangbo Alloy Group for instant quotations, stock availability and mill certificates — quick response within 10 minutes.
