Differences between GH4169, ASTM B637, AMS 5662, and AMS 5663
GH4169, ASTM B637, AMS 5662, and AMS 5663 all refer to the same base material, namely the nickel-chromium superalloy Inconel 718 (UNS N07718), but they differ in their source/standard body, product form, and most importantly, heat treatment conditions and specified mechanical properties.
What is the difference between AMS 5662 and AMS 5663?
AMS 5662 is the raw state of 718 aluminum alloy and the softest state in the AMS series. It can be heat-treated to transform into AMS 5663. This heat treatment can be achieved in two ways to obtain specific properties, such as optimal impact resistance or optimal tensile and creep rupture properties.
Of these standards, ASTM B637, AMS 5662, and AMS 5663 are the most frequently cited. However, although they all refer to the same base alloy-GH4169-significant differences exist in their mechanical properties, heat treatment, and application requirements.
Standard Overview: ASTM B637, AMS 5662, and AMS 5663
ASTM B637
ASTM B637 is a general material specification covering nickel-based forging alloys such as GH4169 (Inconel 718), including bars, forgings, and billets. It specifies acceptable ranges of chemical composition, mechanical properties, heat treatment conditions, and permissible deviations in dimensions and mass.
This standard is widely used in industries such as power generation, aerospace, and chemical processing. Furthermore, its flexibility in the range of mechanical properties makes it suitable for a wide range of applications.
Key Points:
General specification
Allows different heat treatment states
Suitable for high-strength and medium-strength applications
Provides basic chemical and mechanical property requirements
AMS 5662
AMS 5662 is an aerospace materials specification that defines the requirements for GH4169 (Inconel 718) in the solution-annealed (annealed) state. This means the material is supplied in a soft state, ideal for subsequent forming or machining, followed by aging to achieve final strength.
The solution-annealed state improves machinability and workability, but the strength is lower than that of fully heat-treated materials.
Applications:
Parts requiring extensive post-machining
Forgings and billets requiring aging by the end user
Aerospace parts requiring dimensional stability before heat treatment
Key characteristics:
Supply only in the solution-annealed state
Strength lower than that of aged materials
Requires additional aging to achieve full mechanical properties
AMS 5663
AMS 5663 defines GH4169 (Inconel 718) in the precipitation-treated state (solution annealing + age hardening). This is the most common heat treatment state used in aerospace and high-performance components, which require extremely high strength and fatigue resistance.
Materials in this state undergo specific aging cycle heat treatment to form a uniformly distributed γ″ and γ′ precipitate microstructure, resulting in excellent mechanical strength, creep resistance, and fatigue life.
Applications:
Turbine engine components
Fasteners
High-strength structural components
Subsea oil and gas components
Key characteristics:
Delivered fully heat-treated
High tensile strength and yield strength
Excellent fatigue resistance and stress corrosion resistance
Key Differences:
GH4169: This is the Chinese standard code for Inconel 718 under the GB standard system, representing the corresponding Chinese standard for this alloy.
ASTM B637: This is an American standard (ASTM International Standard) applicable to precipitation-hardening nickel-based alloy bars, forgings, and billets in high-temperature environments. It covers the general requirements for alloys in various states and allows for different heat treatment processes to meet specific performance requirements.
AMS 5662: This is the Aerospace Materials Specification (AMS), applicable to alloys in the solution-annealed state (before final aging treatment). Materials conforming to AMS 5662 are relatively soft, easy to machine and manufacture (forming, welding), but require subsequent heat treatment (aging treatment) to achieve their full strength properties. After the required heat treatment, their mechanical properties must meet the AMS 5663 standard.
AMS 5663: This is also an AMS specification applicable to alloys in the fully precipitation-hardened (aging treated) state. The material is delivered in its final high-strength state without the need for post-processing heat treatment, thus avoiding the risk of dimensional changes.
Why Choose Gnee Nickel Alloy (Supplier Example)?
✅ Large stock of GH4169 alloy tubes/bars/plates/fittings available for fast shipping.
✅ Factory direct sales, highly competitive prices, excellent value for money.
✅ Comprehensive quality assurance: Material Testing Certificate (MTC), Chemical Composition Certificate, and Mechanical Properties Certificate.
✅ Value-added services: Slitting, cutting, polishing, surface treatment.
✅ Worldwide shipping, secure and reliable packaging, and provision of export-required documents.
Email: ss@gneemetal.com
Gnee Steel is a supplier of GH4169 alloy, offering a wide range of products including: seamless pipe (sizes: 4-219 mm; thickness: 0.5-20 mm); welded pipe (sizes: 5.0-1219.2 mm; thickness: 0.5-20 mm); plates (thickness: 0.1 to 100 mm; width: 10-2500 mm); strips; alloy round bars (diameter: 3-800 mm); flat bars (thickness: 2-100 mm; width: 10-500 mm); hexagonal bars (size: 2-100 mm); wire rods; and extruded profiles. We collaborate with steel mills to provide our customers with GH4169 alloy products that meet or exceed numerous leading industry standards, including ASTM, ASME, SAE, AMS, ISO, DIN, EN, and BS standards.
Gnee Steel stocks and sells GH4169, pipes, plates, strips, round bars, flat bars, forged billets, hexagonal steel, wire rods, and extruded profiles. Please feel free to contact us at ss@gneesteel.com for a quote.
