Monel 400 Seamless Tube

UNS N04400 | 2.4360 | ASTM B165

Monel 400 Seamless Tube (N04400 / 2.4360) is manufactured to ASTM B165 from tube billet, cold-drawn to the required outside diameter and wall thickness. Supplied from our Wenzhou mill with EN 10204 3.1 mill test certificate, PMI and dimensional inspection on request.

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Comprehensive Guide to Seamless Monel 400 (UNS N04400) Tubes

What is a Seamless Monel 400 Tube?

Seamless Monel 400tubes, also known as UNS N04400 tubes or Alloy 400 tubing, are high-performance nickel-copper alloy tubes produced from a solid billet using hot extrusion or rotary piercing processes.

Unlike welded tubing, the seamless production process eliminates weld seams, ensuring superior structural integrity, consistent wall thickness, and improved reliability in high-pressure and corrosive service environments.

Monel 400 (UNS N04400) is a solid-solution strengthened nickel-copper alloy containing approximately 63–70% nickel and 28–34% copper. This alloy is widely recognized for its exceptional resistance to seawater corrosion, hydrofluoric acid (HF), and sulfuric acid, making it one of the most reliable materials for marine and chemical processing applications.

Due to its excellent mechanical strength and corrosion resistance over a wide temperature range, ASTM B163 Monel 400 seamless tubes are widely used in industries requiring high durability and long service life.

Key Features and Engineering Advantages of Monel 400 Tubes

Excellent Seawater Corrosion Resistance

Monel 400 exhibits outstanding resistance to rapidly flowing seawater and brackish water environments. It also demonstrates high resistance to chloride-induced stress corrosion cracking, making it ideal for marine engineering applications.

Wide Temperature Operating Range

Monel 400 maintains excellent mechanical properties from cryogenic temperatures to approximately 1000°F (538°C) without significant loss of strength or toughness.

Feature	Description
Exceptional Chemical Stability	The alloy performs extremely well in reducing environments, including: Hydrofluoric acid (HF) Alkaline solutions Neutral and mildly acidic environments

Feature

Description

Exceptional Chemical Stability

The alloy performs extremely well in reducing environments, including:

Hydrofluoric acid (HF)
Alkaline solutions
Neutral and mildly acidic environments

Low Magnetic Permeability

Monel 400 has very low magnetic permeability, making it suitable for applications requiring non-magnetic materials, such as electronic instrumentation and sensitive equipment.

High Pressure Resistance

The seamless tube production process ensures uniform wall thickness and superior structural consistency, allowing Monel 400 tubing to handle higher working pressures compared with welded tubes.

Monel 400 Product Specifications and Data

To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Monel 400.

The composition of Monel 400 is balanced to provide a blend of corrosion resistance and high strength.

Chemical Composition of Monel 400

Grade	Cu	Fe	Mn	C	Si	S	Ni
N04400	28.00-34.00	≤2.50	≤2.00	≤0.30	≤0.50	≤0.024	≥63.00

Monel 400 is designed to maintain its strength and shape in high-stress applications.

Typical Mechanical Properties of Monel 400

Tensile Strength	Yield Strength	Elongation	Hardness
≥ 550 MPa	≥ 240 MPa	≥ 35%	≤ 192 HBW

These physical properties highlight the material's ability to perform reliably under a wide range of conditions.

Typical Physical Properties of Monel 400

Density	Melting Point	Thermal Expansion	Thermal Conductivity	Modulus of Elasticity	Electrical Resistivity
8.8 g/cm³	1300 - 1350 °C	13.9 µm/m·°C (20-100°C)	21.8 W/m·K (20°C)	179 GPa	0.51 x 10⁻⁶ Ω·m (20°C)

STANDARD	OD[D]	TOLERANCE	THICKNESS[S]	TOLERANCE	LENGTH	TOLERANCE
B163 (N02200,N02201,N04400)	12.7≤D＜15.9	+0.13/0	ave, ±12.5%	min:+25.0%/0	Cut-to-length	+3.2/-0
	15.9≤D≤38.1	±0.13	ave, ±10.0%	min:+20.0%/0
	38.1＜d≤76.2	±0.25	ave, ±10.0%	min:+22.0%/0
B163(for rest)	12.7≤D＜15.9	±0.13	ave, ±12.5%	min:+25.0%/0	Cut-to-length:>9.1m	+6.4/0
	15.9＜d≤38.1	±0.19	ave, ±10.0%	min:+20.0%/0
	38.1＜d≤76.2	±0.25	ave, ±10.0%	min:+22.0%/0

Industrial Applications of Monel 400 Tubes

Due to its excellent resistance to seawater and corrosive chemicals, Monel 400 seamless tubing is widely used across multiple industries.

Item	Details
Marine Engineering	Monel 400 is extensively used for: Seawater piping systems Pump and propeller shafts Marine heat exchangers Desalination plant equipment

Item

Details

Marine Engineering

Monel 400 is extensively used for:

Seawater piping systems
Pump and propeller shafts
Marine heat exchangers
Desalination plant equipment

Item	Details
Oil and Gas Industry	In offshore and refinery environments, Monel 400 tubes are commonly used in: Sour gas service equipment Crude oil distillation units Splash zone protection systems

Item

Details

Oil and Gas Industry

In offshore and refinery environments, Monel 400 tubes are commonly used in:

Sour gas service equipment
Crude oil distillation units
Splash zone protection systems

Item	Details
Chemical Processing Industry	Monel 400 performs exceptionally well in hydrofluoric acid (HF) environments, making it ideal for: HF alkylation units Salt production equipment Acid handling systems

Item

Details

Chemical Processing Industry

Monel 400 performs exceptionally well in hydrofluoric acid (HF) environments, making it ideal for:

HF alkylation units
Salt production equipment
Acid handling systems

Item	Details
Power Generation Industry	The alloy is also used in: Boiler feedwater heaters Steam generator tubing High-pressure heat exchangers

Item

Details

Power Generation Industry

The alloy is also used in:

Boiler feedwater heaters
Steam generator tubing
High-pressure heat exchangers

Quality Assurance and Compliance Testing

To ensure reliability and compliance with international standards, each batch of Monel 400 seamless tubes undergoes comprehensive testing procedures.

Material Certification

Material Test Certificates (MTC) are provided according to EN 10204 3.1 or 3.2 standards.

Positive Material Identification (PMI)

100% PMI testing verifies the chemical composition of the alloy.

Item	Details
Non-Destructive Testing (NDT)	Common inspection methods include: Ultrasonic Testing (UT) Eddy Current Testing (ET) Hydrostatic Pressure Testing

Item

Details

Non-Destructive Testing (NDT)

Common inspection methods include:

Ultrasonic Testing (UT)
Eddy Current Testing (ET)
Hydrostatic Pressure Testing

Item	Details
Mechanical Testing	Additional testing may include: Impact testing Flattening tests Flaring tests Grain size analysis

Item

Details

Mechanical Testing

Additional testing may include:

Impact testing
Flattening tests
Flaring tests
Grain size analysis

Third-Party Inspection

Independent inspection services from organizations such as SGS, TÜV, and Lloyd’s Register can be provided upon request.

Frequently Asked Questions About Monel 400 Seamless Tubes

What is Monel 400 Seamless Tube?

Seamless Monel 400 tubes , also known as UNS N04400 tubes or Alloy 400 tubing , are high-performance nickel-copper alloy tubes produced from a solid billet using hot extrusion or rotary piercing processes.

Which standards does Monel 400 Seamless Tube comply with?

Monel 400 Seamless Tube is produced to ASTM B163, ASTM B165.

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