For procurement managers in the aerospace and defense sectors, heat treatment cycles are a major pain point. Most suppliers only stock materials that meet AMS 5662 (solution treatment) standards. If your project requires materials that meet AMS 5663 (full aging) standards, you typically have to:
Wait 2-4 weeks for external heat treatment.
There is a risk of dimensional deformation or surface oxidation during the aging process.
In-house handling of the extremely complex 16-hour double aging cycle.
At Gnee Alloy, we eliminate these delays. We have a large wholesale stock of fully aging GH4169 bars that meet the stringent requirements of AMS 5663 standard 36-44 HRC. Our bars are ready for immediate thread rolling and CNC machining, ensuring your material reaches maximum strength from the very beginning of its lifecycle.
Click to order AMS 5663 GH4169 forged bar stock now – View stock availability
AMS 5663 Nickel Alloy GH4169: Properties and Applications
AMS 5663 Nickel Alloy GH4169: Properties and Applications
AMS 5663 (commonly known as GH4169 or Alloy 718) is a premium precipitation-hardening nickel-chromium alloy supplied in the aged condition, offering high strength and corrosion resistance up to 700°C (1300°F). It is primarily used in critical aerospace turbine components, oil/gas drilling, and high-stress fasteners, exhibiting exceptional tensile strength, creep resistance, and fracture resistance.
What is the special Inconel 718 AMS 5663 material?
AMS 5663 is a grade of alloy 718. This alloy is a nickel-chromium alloy with high strength, corrosion resistance, and oxidation resistance, and exhibits excellent tensile and impact strength at low temperatures. AMS 5663 is a pre-aged (precipitation hardening) bar stock.
1. AMS 5663 GH4169 alloy range and applicable standards
| Parameter | Description |
|---|---|
| Specification | AMS 5663 (Aerospace Material Specification) |
| Material | GH4169 (UNS N07718 / Inconel 718) |
| Product Form | Bar, Forgings, Rings, and Tubing |
| Condition | Solution Treated + Aged (Precipitation Hardened) |
Note: AMS 5663 is the primary aerospace specification for Inconel 718 bars, forgings, and rings. It requires a dual melting process (vacuum arc melting + vacuum heat treatment) to ensure the highest cleanliness and high-temperature reliability. This specification covers materials in both solution-treated and aging states.
2. Chemical composition (wt%) of AMS 5663 (UNS N07718)
| Element | Content (%) | AMS 5663 Requirement | Function |
|---|---|---|---|
| Nickel (Ni) | 50.0 – 55.0 | 50.0 – 55.0 | Matrix element; provides high-temperature stability and corrosion resistance |
| Chromium (Cr) | 17.0 – 21.0 | 17.0 – 21.0 | Oxidation and corrosion resistance |
| Iron (Fe) | Balance (~18-20) | Balance | Fe-Ni-Cr base alloy |
| Niobium (Nb) | 4.75 – 5.50 | 4.75 – 5.50 | Core strengthening element – forms γ″ phase (Ni₃Nb) |
| Molybdenum (Mo) | 2.80 – 3.30 | 2.80 – 3.30 | Solid-solution strengthening; enhances creep resistance |
| Titanium (Ti) | 0.65 – 1.15 | 0.65 – 1.15 | Forms γ′ strengthening phase (Ni₃(Al,Ti)) |
| Aluminum (Al) | 0.20 – 0.80 | 0.20 – 0.80 | Forms γ′ strengthening phase; improves oxidation resistance |
| Carbon (C) | ≤ 0.08 | ≤ 0.08 | Low carbon for toughness and fatigue resistance |
| Manganese (Mn) | ≤ 0.35 | ≤ 0.35 | Deoxidizer |
| Silicon (Si) | ≤ 0.35 | ≤ 0.35 | Deoxidizer |
| Phosphorus (P) | ≤ 0.015 | ≤ 0.015 | Ensures toughness |
| Sulfur (S) | ≤ 0.015 | ≤ 0.015 | Ensures hot workability |
| Boron (B) | 0.002 – 0.006 | 0.002 – 0.006 | Grain boundary strengthener; critical for creep life |
| Cobalt (Co) | ≤ 1.00 | ≤ 1.00 | Residual element |
| Copper (Cu) | ≤ 0.30 | ≤ 0.30 | Residual element |
| Tantalum (Ta) | ≤ 0.05 | ≤ 0.05 | Residual element (often counted with Nb) |
AMS 5663 GH4169 (Uns N07718) Chemical composition
Click to download the GH4169 alloy PDF file now
3. Physical properties of AMS 5663 GH4169
| Property | Value | Significance |
|---|---|---|
| Density | 8.19 g/cm³ (0.296 lb/in³) | Weight calculation for aerospace |
| Melting Range | 1260 – 1336°C (2300-2440°F) | Fire resistance margin |
| Thermal Conductivity (20°C) | 11.4 W/m·K | Heat dissipation |
| Thermal Conductivity (500°C) | ~16.0 W/m·K | High-temperature performance |
| Coefficient of Thermal Expansion (20-100°C) | 13.0 × 10⁻⁶/°C | Fitting compatibility |
| Coefficient of Thermal Expansion (20-600°C) | ~14.5 × 10⁻⁶/°C | High-temperature design |
| Specific Heat (20°C) | 435 J/kg·K | Thermal capacity |
| Specific Heat (600°C) | ~500 J/kg·K | High-temperature thermal capacity |
| Modulus of Elasticity (20°C) | ~200 GPa (29.0 × 10⁶ psi) | Stiffness |
| Modulus of Elasticity (600°C) | ~175 GPa (25.4 × 10⁶ psi) | Hot stiffness |
| Modulus of Elasticity (700°C) | ~165 GPa (23.9 × 10⁶ psi) | High-temperature stiffness |
| Poisson's Ratio | 0.29 – 0.30 | Stress analysis |
| Electrical Resistivity | 1.25 µΩ·m | – |
| Magnetic Permeability | ~1.005 (slightly magnetic) | – |
4. Heat Treatment Schedule per AMS 5663
| Step | Treatment | Temperature | Time | Cooling | Atmosphere |
|---|---|---|---|---|---|
| 1. Solution Treatment | Full solution | 954 – 982°C (1750-1800°F) | 1 hour per 25mm thickness | Rapid cooling (water or air) | Controlled atmosphere (vacuum or protective gas) |
| 2. First Aging | Age hardening | 718°C (1325°F) ± 8°C | 8 hours ± 15 min | Furnace cool to 621°C (50-55°C/h) | Controlled atmosphere |
| 3. Second Aging | Age hardening | 621°C (1150°F) ± 8°C | 8 hours ± 15 min | Air cool | – |
Click to learn about the manufacturing process of Gnee Alloy GH4169 products
5. Key characteristics of AMS 5663/GH4169
High strength: Yield strength > 150 ksi (1034 MPa), tensile strength > 185 ksi (1275 MPa).
Heat resistance: Excellent fatigue and creep resistance at temperatures up to 700°C (1300°F), and excellent oxidation resistance at temperatures up to 1800°F.
Corrosion resistance: Excellent resistance to chloride stress corrosion cracking and various inorganic/organic acids.
Condition: Supplied after full heat treatment (precipitation hardening) to ensure maximum strength and dimensional stability of the parts.
6. AMS 5663 GH4169 alloy is primarily used in the following areas
Aerospace: Turbine disks, shafts, housings, engine mounts, and fasteners.
Oil & Gas: Downhole tools, high-pressure valves, and fasteners.
Power Generation: Gas turbine and steam turbine blades.
General Engineering: High-strength, corrosion-resistant components requiring toughness from low to high temperatures.
7. AMS 5663 Nondestructive Testing (NDT) Requirements for GH4169 Alloy
| Test Method | Requirement | Standard | Acceptance Criteria |
|---|---|---|---|
| Ultrasonic Testing (UT) | 100% (for bars ≥ 12mm) | ASTM E2375 | No defects exceeding 0.8mm |
| Eddy Current Testing (ET) | As specified | ASTM E426 | No relevant indications |
| Liquid Penetrant Inspection (LPI) | As specified | ASTM E1417 | No relevant indications |
| Visual Inspection | 100% | ASTM E543 | No surface defects |
Why choose Gnee Alloy, a Tier 1 aerospace supplier?
As an AS9100 Certified Manufacturer, we provide total quality transparency for your Aviation Grade requirements:
✅️Precision Finishing: Every rod is Centerless Ground to h9 or h10 tolerances, ready for automatic Swiss-lathes and feeders.
✅️Zero-Defect Inspection: 100% Ultrasonic Testing (UT) to AMS 2154 Class A standards. We guarantee zero internal porosity or segregation.
✅️Total Traceability: Every bar is marked with its heat number and accompanied by an EN 10204 3.1 Mill Test Certificate (MTC).
✅️Immediate Dispatch: We specialize in supporting Aerospace Overhaul (MRO) programs with same-week shipping on in-stock diameters.
Gnee Steel GH4169 Certificate
📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Steel GH4169 Product Packing
Contact us for the latest export price quote for GH4169 Alloy
FAQ
Q1: Is GH4169 fully aged material harder to machine?
A: Yes. At 40 HRC, it is more abrasive than solution-treated bars. However, using our Precision Ground rods with specialized carbide or ceramic tooling ensures a Smooth Finish and predictable tool life, while eliminating the risk of warping that occurs if you age the part after machining.
Q2: Does your material meet the grain size requirements of AMS 5663?
A: Absolutely. Our controlled forging and heat treatment processes guarantee a grain size of ASTM E112 Level 8 or finer, which is essential for the fatigue resistance required in engine bolts.
Q3: Can I use AMS 5663 for high-pressure oil and gas tools?
A: Yes. When the hardness is controlled within the NACE MR0175 limits (typically max 40 HRC for certain conditions), AMS 5663 GH4169 is the premier choice for high-strength downhole components.
Q4: Do you offer bulk discounts for aerospace maintenance contracts?
A: Yes. We offer tiered Wholesale Pricing and dedicated inventory reserves for our long-term MRO and OEM partners worldwide.
