In core components of turbine engines or high-pressure reactors, tubing is among the most vulnerable. For engineers and purchasing managers, key pain points when sourcing GH4169 (equivalent to Inconel 718) seamless tubing include:
Internal oxide scale contamination: Standard annealing processes leave a layer of black oxide inside the tubing. Under high-flow-rate fuel, this oxide scale can flake off, clogging sensitive fuel injectors and sensors, ultimately leading to catastrophic failure.
Wall thickness eccentricity: Poor concentricity creates "weak points" that are prone to failure under high-pressure hydraulic loads (above 700 bar).
Alternative risks: Using "commercial-grade" tubing, which lacks the VIM+VAR dual-melt purity required for aerospace-grade safety.
At Gnee Alloy, we offer zero-defect tubing. Our specialized manufacturing processes ensure that every meter of tubing meets the structural integrity requirements of your mission-critical systems.
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GH4169 (Inconel 718) - Aerospace Seamless Tube Manufacturer
GH4169 (Inconel 718) - Aerospace Seamless Tube Manufacturer
GH4169 (Inconel 718) seamless tube is a high-quality, high-strength nickel-chromium-iron superalloy widely used in the aerospace industry due to its excellent creep resistance and oxidation resistance (up to 700°C). It is commonly used in high-pressure hydraulic lines and jet engine components (AMS 5589/5590). This precipitation-hardening alloy is designed to withstand extreme thermal and mechanical loads, exhibiting high yield strength (up to 1100 MPa) and excellent corrosion resistance.
Are Alloy 718 and Inconel 718 the same?
Inconel 718 (Alloy 718) is a precipitation-hardening nickel-chromium superalloy (UNS N07718). There is no difference between Alloy 718 and Inconel 718-their chemical compositions are exactly the same. "Inconel" is a registered trademark, while "Alloy 718" is a generic name.
1. Chemical composition(wt.%) of GH4169 Pipe
| Elements | Min.(≥) | Max.(≤) | Similar | Remarks |
|---|---|---|---|---|
| C | - | 0.03 | ||
| Cr | 17.0 | 21.0 | ||
| Mo | 2.80 | 3.30 | ||
| Ni | 50.0 | 55.0 | ||
| Al | 0.20 | 0.60 | ||
| Nb | 4.75 | 5.50 | ||
| Fe | - | Remainder | ||
| Si | - | 0.35 | ||
| Mn | - | 0.35 | ||
| P | - | 0.015 | ||
| S | - | 0.015 | ||
| B | - | 0.006 |
2. Mechanical properties of grade GH4169 Tube
| Proof strength Rp0.2 (MPa) |
Tensile strength Rm (MPa) |
Impact energy KV (J) |
Elongation at fracture A (%) |
Reduction in cross section on fracture Z (%) |
As-Heat-Treated Condition | Brinell hardness (HBW) |
|---|---|---|---|---|---|---|
| 777 (≥) | 985 (≥) | 13 | 43 | 24 | Solution and Aging, Annealing, Ausaging, Q+T,etc | 313 |
3. Physical properties of GH4169 seamless Pipe
| Property | Density kg/dm3 |
Temperature T °C/F |
Specific heat J / kgK |
Thermal conductivity W/mK |
Electric resistance µΩ·cm |
Modulus of elasticity kN/mm2 |
Expansion rate |
|---|---|---|---|---|---|---|---|
| 581 (≥) | 287 (≥) | 22 | 43 | 23 | Solution and Aging, Annealing, Ausaging, Q+T,etc | 321 | |
| Temp. °C/°F |
Creep strain limit (10000h) (Rp1,0) N/mm2 |
Creep rupture strength (10000h) (Rp1,0) N/mm2 |
|||||
| 151 | 625 | 645 |
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4. GH4169 pipe dimensions and surface specifications
| Parameter | Manufacturing Capability | Typical Application |
| Outer Diameter (OD) | 0.5 mm to 219.0 mm | Capillary to Main Fuel Lines. |
| Wall Thickness (WT) | 0.05 mm to 25.0 mm | High-pressure Rated (XXS). |
| Tolerance Class | h8, h9, h10, h11 | Precision instrumentation. |
| Surface Finish (Ra) | ≤ 0.4 μm (Mirror BA) | Prevents scaling & fluid drag. |
| Length | Up to 18,000 mm | U-bending and long-run coils. |
5. GH4169 Seamless Tube Main Characteristics and Technical Data
Material: GH4169 / UNS N07718 / 2.4668.
Main Standards: AMS 5589 (Seamless Tube), AMS 5590, ASTM B637.
Dimensions: Outer diameter (OD) ranges from 6mm to 219mm, wall thickness (WT) ranges from 0.5mm to 25.0mm.
Physical Properties: High fatigue resistance, excellent corrosion resistance in harsh environments, and good low-temperature performance.
Manufacturing Process: Typically employs vacuum induction melting (VIM) and vacuum arc remelting (VAR) processes to achieve high purity.
6. GH4169 Seamless Steel Tube Applications
Aerospace: Turbine blades, combustion chambers, exhaust pipes.
Power Generation: Gas turbines, steam turbines, and heat exchangers.
Chemical Industry: Equipment for handling corrosive chemicals.
Oil & Gas Industry: Downhole equipment, pipelines, and valves exposed to extreme conditions.
7. Why choose to source GH4169 tubing from our Tier 1 supplier, Gnee Alloy?
✅️Wholesale Prices: Factory direct pricing is available for bulk purchases and long-term MRO contracts.
✅️100% Non-Destructive Testing: Every meter of tubing undergoes ultrasonic testing (UT) and eddy current testing (ET) to ensure zero defects on the surface and internally.
✅️Fast Global Shipping: We maintain a large wholesale inventory of standard sizes (Sch 40, Sch 80) and capillary sizes, enabling 5-7 day global shipping.
✅️Custom Processing: We offer precision cutting, deburring, and special end forming services to meet your assembly line drawing requirements.
Contact us now to get the latest export price for GH4169 in 2026
FAQ
Q1: Is your GH4169 tube equivalent to Inconel 718?
A: Yes. GH4169 is the technical equivalent of UNS N07718. It is globally interchangeable and meets all international requirements for aerospace propulsion and nuclear energy blueprints.
Q2: Can I use these tubes for cryogenic fuel transport?
A: Absolutely. One of the greatest strengths of GH4169 is its versatility. It maintains exceptional toughness and ductility down to -253°C, making it the premier choice for liquid hydrogen (LH2) systems.
Q3: How do you ensure the tubes are clean enough for oxygen service?
A: Our Vacuum Bright Annealing ensures no oxidation, and we can provide additional ASTM G93 compliant cleaning and degreasing for high-purity gas and oxygen service.
Q4: Do you support small trial orders for R&D?
A: Yes. As a Reliable Supplier, we support innovation. We offer flexible MOQs for non-standard wall thicknesses to help with your prototype validation.
