Monel 400 Overview
Monel 400 is a nickel-copper alloy primarily composed of nickel and copper, containing approximately 63% to 70% nickel and 28% to 34% copper, with small amounts of iron, manganese, and other elements. It has excellent corrosion resistance and mechanical properties. It performs exceptionally well in many harsh environments, especially in marine and chemical industries.
Equivalent Grades of Monel 400
| Standard System | Equivalent Grade / Material Name | Remarks |
| UNS (United States Numbering System) | N04400 | Standard UNS number for Monel 400 |
| ASTM / ASME | ASTM B164, ASTM B165 | Common standards for Monel 400 |
| AMS (Aerospace Material Specification) | AMS 4622 | Similar material used in aerospace |
| DIN (German Standard) | 2.436 | Approximate German equivalent |
| JIS (Japanese Industrial Standard) | SNB2 | Japanese equivalent material |
| ISO | NiCu30Fe | International standard classification |
| BS (British Standard) | 2.436 | Same as DIN, commonly used in UK |
Monel 400 Data Sheet
Monel 400 Chemical Composition (approximate % by weight):
- Nickel (Ni): 63.0 – 70.0%
- Copper (Cu): 28.0 – 34.0%
- Iron (Fe): ≤ 2.5%
- Manganese (Mn): ≤ 2.0%
- Silicon (Si): ≤ 0.5%
- Carbon (C): ≤ 0.30%
- Sulfur (S): ≤ 0.024%
Monel 400 Physical Properties:
- Density: Approximately 8.80 g/cm³ (0.318 lb/in³)
- Melting Point: 1300 – 1350 °C (2372 – 2462 °F)
- Electrical Resistivity: 49.5 micro-ohm·cm (at 20 °C)
- Thermal Conductivity: 21.9 W/m·K (at 20 °C)
- Coefficient of Thermal Expansion: 13.1 µm/m·°C (20–100 °C)
Monel 400 Mechanical Properties:
| Condition | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Brinell Hardness (HB) |
| Annealed (solution treated) | 550 – 650 | 240 – 350 | 30 – 50 | 120 – 180 |
Monel 400 Corrosion Resistance
Excellent resistance to seawater, hydrofluoric acid, alkaline substances, and various organic and inorganic chemicals.
Strong resistance to stress corrosion cracking and pitting.
Monel 400 Typical Applications
- Marine engineering
- Chemical processing equipment
- Heat exchangers
- Valves, pumps, and fasteners
- Aerospace and nuclear reactor industries
Monel 400 Welding Properties
- Can be welded using conventional methods such as TIG, MIG, and arc welding.
- Proper cleaning of the weld area and control of heat input are required to avoid cracking.
Inconel 625 vs monel 400
- Inconel 625 is a high-performance nickel-based superalloy designed for extreme environments requiring high strength and excellent corrosion resistance at elevated temperatures. It contains added chromium, molybdenum, and niobium to enhance strength and corrosion resistance.
- Monel 400 is a nickel-copper alloy known for its excellent corrosion resistance in seawater and many chemical environments but with lower mechanical strength and temperature tolerance compared to Inconel 625.
| Feature | Inconel 625 | Monel 400 |
| Base Metal | Nickel-Chromium-Molybdenum alloy | Nickel-Copper alloy |
| Chemical Composition | Ni (58%+), Cr (20-23%), Mo (8-10%), Fe, Nb | Ni (63-70%), Cu (28-34%), Fe, Mn |
| Corrosion Resistance | Excellent resistance to oxidizing and reducing environments, especially in high temperature and aggressive chemical media (strong acids, seawater) | Excellent resistance to seawater, alkalis, acids (except strong oxidizers) |
| Temperature Range | Suitable for very high temperatures (up to ~980°C / 1800°F) | Good performance up to ~600°C (1112°F) |
| Mechanical Strength | Higher strength, especially at elevated temperatures | Good strength but lower than Inconel 625 |
| Typical Applications | Aerospace, chemical processing, marine, nuclear, heat exchangers, turbine parts | Marine equipment, chemical valves, pumps, fasteners, heat exchangers |
| Weldability | Good, requires careful control due to alloy complexity | Good, easier to weld than Inconel 625 |
| Cost | Generally more expensive | Generally less expensive |
Contact MT.BOLTS
MT.BOLTS specializes in the manufacturing and supply of industrial fasteners including screws, bolts, nuts, and washers. Our products conform to international standards (ANSI / ASTM / DIN / ISO / JIS) and are available in various materials, dimensions, and surface finishes.
Contact us today to learn more about fasteners and to procure high-quality products. Our technical team is ready to provide expert support and custom selection solutions.
