Monel 404 · UNS N04404
Monel 404 (N04404): composition, properties, fittings and flanges
Monel 404 (N04404) is Controlled low-permeability nickel-copper alloy. Monel 404 is specified at Nickel 52.0 - 57.0, Copper Balance, Aluminium 0.05 max. Monel 404 is the brazing and welding filler grade of the Monel family: tightly controlled iron, manganese and aluminium give a very low Curie temperature and stable…
- UNS
- N04404
- W. Nr.
- -
- Density
- 8.91 g/cm³ (0.322 lb/in³)
- Key strength
- 414 MPa / 60 ksi
Identification and standards
| Short form | Monel 404 · UNS N04404 |
|---|---|
| Classification | Controlled low-permeability nickel-copper alloy |
| UNS | N04404 |
| Werkstoff number | - |
| Material family | Monel Alloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | 52.0 - 57.0 | Matrix |
| Copper (Cu) | Balance | Matrix |
| Iron (Fe) | 0.50 max | Controlled for permeability |
| Manganese (Mn) | 0.10 max | Controlled for permeability |
| Carbon (C) | 0.15 max | - |
| Silicon (Si) | 0.10 max | - |
| Aluminium (Al) | 0.05 max | Controlled for brazeability |
| Sulphur (S) | 0.024 max | Machinability |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (annealed) | 414 MPa / 60 ksi |
|---|---|
| 0.2 % yield strength, min | 172 MPa / 25 ksi |
| Elongation in 2 in, min | 35 % |
| Typical hardness, annealed | 100 - 150 HB |
| Curie temperature | Below room temperature (non-magnetic) |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 8.91 g/cm³ (0.322 lb/in³) |
|---|---|
| Melting range | 1290 - 1350 °C (2355 - 2460 °F) |
| Modulus of elasticity | 179 GPa (26.0 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 21.0 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 13.9 µm/m·°C |
| Specific heat capacity | 410 J/kg·K |
Specifications by product form
| Forgings & flanges | To order under ASTM B564 chemistry |
|---|---|
| Butt weld fittings | To order |
| Seamless pipe & tube | To order |
| Plate / sheet / strip | ASTM B127 family |
| Bar / rod | ASTM B164 |
| Welding consumables | Used as filler; ERNiCu-7 for general Monel joints |
| UNS / EN / China | UNS N04404 |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Forged flanges blanks and finished flanges to ASME B16.5, B16.47 Series A/B and B16.36
- Butt weld elbows, tees, reducers, caps and stub ends to ASME B16.9 and MSS SP-43
- Seamless pipe and tube to the applicable ASTM / ASME pipe specification
- Forged rings, discs and hubs machined to your drawing
Typical applications
- Brazing filler for Monel and nickel assemblies
- Non-magnetic instrument and electronic parts
- Cryogenic and low-temperature hardware
- Specialty chemical and marine components
Welding, forming and machining
- Welding
- Used principally as filler metal. Weld Monel parent metal with ERNiCu-7 and clean oxide thoroughly before and between passes.
- Heat treatment
- Anneal at 760 - 925 °C; the alloy is not age-hardenable.
- Hot and cold forming
- Hot work in the range stated by the mill for this grade, then re-solution or re-age before final machining so that the delivered condition matches the certificate.
- Machining
- Machine with sharp carbide or high-speed steel tooling, positive rake, constant feed and ample coolant. Never dwell - the surface work-hardens quickly.
Buy Monel 404 from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.