Monel 404 Flanges
Monel 404 Flanges (UNS N04404) Monel Flanges
Monel 404 Flanges (UNS N04404) are nickel-copper alloy flanges specially designed for electronic, electrical, and high-temperature industrial components. This alloy provides excellent thermal and electrical conductivity, good corrosion resistance, and controlled thermal expansion. Monel 404 is widely used for electrical components, electronic tubes, and specialized industrial assemblies.
With its higher copper content and controlled chemistry, Monel 404 delivers superior brazing characteristics and retains exceptional mechanical stability across a wide temperature range. These flanges are ideal for applications requiring consistent performance in both high-heat and cryogenic environments.
Key Features
High electrical & thermal conductivity
Excellent corrosion resistance in marine, neutral, and alkaline environments
Superior brazing properties for electrical components
Controlled thermal expansion performance
Good mechanical strength and toughness
Stable performance in high-temperature applications
Excellent resistance to dealkalization & stress cracking
Non-magnetic in annealed condition
Specification
| Specification | Details |
|---|---|
| Standard | ASTM B164 / ASME SB164 |
| UNS | N04404 |
| Flange Types | WNRF, SORF, BLRF, SWRF, Threaded, LJRF, RTJ |
| Size Range | ½″ to 48″ |
| Pressure Rating | 150#, 300#, 600#, 900#, 1500#, 2500# |
| Dimension Standards | ASME B16.5, B16.47, B16.48 |
| Manufacturing Method | Forged / Plate / Machined |
Equivalent Grades
| Standard | Grade |
|---|---|
| UNS | N04404 |
| ISO / EN / Werkstoff | – |
| BS / AFNOR | – |
Available Sizes
Flange Size: ½″ – 48″
Thickness: SCH 10 – SCH XXS
Custom-made flanges available on request
Chemical Composition
| Element | % |
|---|---|
| Nickel (Ni) | 52 – 57 |
| Copper (Cu) | 43 – 48 |
| Iron (Fe) | ≤ 2.0 |
| Manganese (Mn) | ≤ 0.10 |
| Aluminum (Al) | ≤ 0.50 |
| Carbon (C) | ≤ 0.15 |
| Silicon (Si) | ≤ 0.50 |
| Sulfur (S) | ≤ 0.02 |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 380 – 550 MPa |
| Yield Strength | 125 – 240 MPa |
| Elongation | 30% min |
| Hardness | 70–90 HRB |
| Density | 8.8 g/cm³ |
Physical Properties
| Property | Value |
|---|---|
| Melting Range | 1280 – 1350°C |
| Electrical Resistivity | 0.52 μΩ·m |
| Thermal Conductivity | 22 W/m·K |
| Specific Heat | 0.39 J/g·°C |
| Modulus of Elasticity | 179 GPa |
| Magnetic Behavior | Non-magnetic (annealed condition) |
Types of Monel 404 Flanges
Weld Neck Flanges (WNRF)
Slip-On Flanges (SORF)
Blind Flanges (BLRF)
Socket Weld Flanges (SWRF)
Threaded / Screwed Flanges
Lap Joint Flanges
RTJ (Ring Type Joint) Flanges
Long Weld Neck Flanges
Orifice Flanges
Custom Machined Flanges
Corrosion Resistance
Monel 404 offers excellent corrosion resistance in:
Marine & freshwater environments
Alkaline and neutral salt solutions
Mild acids
High-humidity and atmospheric conditions
Caustic solutions
Dealkalization & dezincification environments
It resists stress-corrosion cracking and pitting much better than standard stainless steels.
Heat Resistance
Performs well up to 600°C in continuous exposure
Good oxidation resistance
Excellent strength retention at high temperatures
Stable electrical and thermal properties across varying temperatures
Heat Treatment
Annealing: 850–1000°C followed by slow cooling
Stress Relieving: 500–650°C
Monel 404 is not age-hardenable; strengthening is achieved through cold working.
Welding
Weldable using common methods: GTAW, SMAW, GMAW
No preheating required
Post-weld annealing recommended for critical service
Common filler material: Monel 67
Fabrication
Good machinability (better than Monel 400 due to controlled composition)
Cold and hot forming possible
Hot working temperature: 900–1150°C
Moderate work-hardening rate
Suitable for brazing and deep-drawing
Applications
Electronic components & precision instruments
Electrical wire sheathing
High-temperature sensors & connectors
Transmission tubes & electronic grid applications
Furnace and heat treatment equipment
Marine components
Condensers & heat exchangers
Oil & gas instrumentation
Chemical processing equipment
Aerospace sensors & connectors