Incoloy 800 Seamless Tube

UNS N08800 | 1.4876 | ASTM B407

Incoloy 800 Seamless Tube (N08800 / 1.4876) is manufactured to ASTM B407 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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Seamless Incoloy 800 / 800H / 800HT Tubes

High-TemperatureNickel Alloy Tubing – Specifications, Properties & Applications

What is a Seamless Incoloy 800 Tube?

A SeamlessIncoloy 800 Tube (UNS N08800) is a high-temperature nickel-iron-chromium alloy tube produced from a solid billet through a seamless hot or cold forming process. Because the tube is produced without longitudinal weld seams, it provides superior structural integrity, pressure resistance, and leak-free performance compared with welded tubing.

Incoloy 800 alloy is specifically engineered for applications requiring excellent resistance to oxidation, carburization, and nitriding in elevated-temperature environments.

For high-temperature structural service, two enhanced grades are widely used:

Incoloy 800H (UNS N08810) – optimized carbon content and grain structure for improved creep rupture strength
Incoloy 800HT (UNS N08811) – further controlled chemistry and grain size for maximum creep and stress rupture resistance above 600°C (1100°F)

These alloys are widely used in heat exchangers, furnace components, petrochemical processing equipment, and power generation systems.

Key Features of Seamless Incoloy 800 / 800H / 800HT Tubes

Excellent High-Temperature Corrosion Resistance

The high nickel (Ni) and chromium (Cr) content provides strong resistance to oxidizing and reducing atmospheres, making the alloy suitable for demanding thermal environments.

Outstanding Thermal Stability

Incoloy 800 series alloys maintain mechanical strength and metallurgical stability during prolonged exposure to temperatures up to 1100°C (2012°F), while minimizing sigma phase embrittlement.

High Pressure Capability

The seamless production process ensures uniform wall structure, enabling compliance with ASME and ASTM pressure vessel standards, and allowing the tubing to withstand higher internal pressure compared to welded alternatives.

Feature	Description
Good Fabrication and Weldability	Seamless Incoloy 800 tubes can be welded using common industrial processes including: GTAW (TIG welding) GMAW (MIG welding) They also exhibit good formability and machinability for fabrication of complex components.

Feature

Description

Good Fabrication and Weldability

Seamless Incoloy 800 tubes can be welded using common industrial processes including:

GTAW (TIG welding)
GMAW (MIG welding)

They also exhibit good formability and machinability for fabrication of complex components.

Incoloy 800 Technical Specifications

Feature	Description
Production Standards	Typical international standards for Seamless Incoloy 800 / 800H / 800HT Tubes include: ASTM B407 – Seamless Nickel-Iron-Chromium Alloy Tube ASME SB407 EN / DIN equivalent specifications

Feature

Description

Production Standards

Typical international standards for Seamless Incoloy 800 / 800H / 800HT Tubes include:

ASTM B407 – Seamless Nickel-Iron-Chromium Alloy Tube
ASME SB407
EN / DIN equivalent specifications

To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Seamless Incoloy 800 Tube.

The composition of Incoloy 800 is balanced to provide a blend of corrosion resistance and high-temperature strength.

Chemical Composition of Seamless Incoloy 800 Tube

Grade	Ni	Cu	Fe	Mn	C	Si	S	Cr	Al	Ti	P	Others
800	30.00-35.00	≤0.75	≥39.50	≤1.50	≤0.10	≤1.00	≤0.015	19.00-23.00	0.15-0.60	0.15-0.60	≤0.045	-
800H	30.00-35.00	≤0.75	≥39.5	≤1.50	0.05-0.10	≤1.00	≤0.015	19.00-23.00	0.15-0.60	0.15-0.60	-	-
800HT	30.00-35.00	≤0.75	≥39.5	≤1.50	0.06-0.10	≤1.00	≤0.015	19.00-23.00	0.25-0.60	0.25-0.60	≤0.045	AL+Ti= 0.85-1.2

Incoloy 800 is designed to maintain its strength and shape in high-stress, high-temperature applications.

Typical Mechanical Properties of Seamless Incoloy Alloy Steel 800 Tube

Tensile Strength	Yield Strength	Elongation	Hardness
≥ 520 MPa	≥ 205 MPa	≥ 30%	≤ 90 HRB

These physical properties highlight the material's ability to perform reliably under extreme thermal conditions.

Typical Physical Properties of Seamless Incoloy Alloy Steel 800 Tube

Density	Melting Point	Thermal Expansion	Thermal Conductivity	Modulus of Elasticity	Electrical Resistivity
8.03 g/cm³	1357 - 1400 °C approx.	15.0 µm/m·°C (20-100°C)	11.2 W/m·K (20°C)	196 GPa	1.06 x 10⁻⁶ Ω·m (20°C)

Table 4: The Standard of Seamless Incoloy 800HT Pipe ASTM B407 Size Tolerance Chart :

Cold-Finished Pipes and Tubes:

Specified/Calculated Nominal OD (Inches)	Permissible Variation (Inches)	Specified/Calculated Nominal OD (mm)	Permissible Variation (mm)
0.500 to 5⁄8, excl.	±0.005	12.7 to 15.8, excl.	±0.127
5⁄8 to 1 1⁄2, incl.	±0.0075	15.8 to 38.1, incl.	±0.190
Over 1 1⁄2 to 3 1⁄2, incl.	±0.010	Over 38.1 to 88.9, incl.	±0.254
Over 3 1⁄2 to 4 1⁄2, incl.	±0.015	Over 88.9 to 114.3, incl.	±0.381
Over 4 1⁄2 to 6, incl.	±0.020	Over 114.3 to 152.4, incl.	±0.508
Over 6 to 6 5⁄8, incl.	±0.025	Over 152.4 to 168.3, incl.	±0.635

Specified/Calculated Nominal OD (Inches)	Permissible Variation (Inches)	Specified/Calculated Nominal OD (mm)	Permissible Variation (mm)
2 1⁄2 to 5 1⁄2, excl.	±0.031	63.5 to 139.7, excl.	±0.787
5 1⁄2 to 9 1⁄4, incl.	±0.047	139.7 to 234.9, incl.	±1.19

Condition	Specified/Calculated Nominal OD (Inches)	Permissible Variation (Wall Thickness)
Cold-Finished	0.500 to 5⁄8, excl.	±15.0%
	5⁄8 to 4 1⁄2, incl.	±10.0%
	Over 4 1⁄2 to 6 5⁄8, incl.	±12.5%
Hot-Finished	2 1⁄2 to 9 1⁄4, incl.	±12.5%

Industrial Applications

Due to their excellent high-temperature strength and corrosion resistance, Seamless Incoloy 800 series tubes are widely used in the following industries:

Item	Details
Petrochemical & Chemical Processing	Heat exchanger tubing Furnace pigtails Process piping systems
Power Generation	Superheater tubes Reheater tubes Nuclear and fossil fuel power plant components

Item	Details
Thermal Processing Equipment	Furnace retorts Radiant tubes Industrial muffles
Aerospace and Defense	High-temperature exhaust systems Structural components exposed to extreme heat

Quality Assurance and Testing

All Seamless Incoloy 800 / 800H / 800HT Tubes undergo strict inspection procedures to ensure compliance with international quality standards.

Typical inspection and testing include:

Item	Details
Material Test Certification	EN 10204 3.1 / 3.2 certificates

Item	Details
Non-Destructive Testing (NDT)	Ultrasonic Testing (UT) Eddy Current Testing (ET) Hydrostatic Pressure Testing

Positive Material Identification (PMI)

100% alloy composition verification using spectrometric analysis.

Item	Details
Mechanical Testing	Impact testing Flattening test Flare test Grain size examination These quality control procedures ensure reliable performance in high-temperature and high-pressure industrial environments.

Item

Details

Mechanical Testing

Impact testing
Flattening test
Flare test
Grain size examination

These quality control procedures ensure reliable performance in high-temperature and high-pressure industrial environments.

Frequently Asked Questions About Incoloy 800 Seamless Tubes

What is Incoloy 800 Seamless Tube?

A Seamless Incoloy 800 Tube (UNS N08800) is a high-temperature nickel-iron-chromium alloy tube produced from a solid billet through a seamless hot or cold forming process. Because the tube is produced without longitudinal weld seams , it provides superior structural integrity, pressure resistance, and leak-free performance compared with welded tubing.

Which standards does Incoloy 800 Seamless Tube comply with?

Incoloy 800 Seamless Tube is produced to ASTM B407, ASME SB407.

Request a Incoloy 800 Tube Quotation

Send us your specification for Seamless Incoloy seamless tube — OD, wall thickness, standard and quantity — and our engineering team will reply with a quotation within 24 hours.