AMS 5662 - Inconel 718 (UNS N07718) Bars, Forgings & Rings (Solution Treated)
What is AMS 5662?
AMS 5662 is the SAE International aerospace material specification for Inconel 718 (UNS N07718), a precipitation-hardenable nickel-chromium-iron superalloy with niobium, molybdenum, aluminum, and titanium, supplied in the forms of bars, forgings, and rings in the solution treated condition.
The nominal composition is 52.5Ni-19.0Cr-5.1Nb-3.0Mo-1.0Ti-0.5Al-18.5Fe. In the solution treated condition per AMS 5662, Inconel 718 achieves a minimum tensile strength of 150 ksi (1034 MPa) and a minimum yield strength of 75 ksi (517 MPa) with a minimum elongation of 30%. The solution treated condition provides maximum ductility and machinability, making AMS 5662 material the preferred starting stock for complex rough machining, near-net-shape processing, and deep-hole boring operations before final precipitation hardening.
Parts procured to AMS 5662 in the solution treated condition can be subsequently precipitation heat treated per AMS 2774 to achieve the full precipitation hardened mechanical properties required by AMS 5663.
AMS 5662 is the standard procurement specification for Inconel 718 round bar, flat bar, and forging stock used in jet engine discs, shafts, turbine rings, rotating compressor hardware, and high-strength structural aerospace components.
AMS 5662 Available Forms and Stocked Sizes
AMS 5662 covers Inconel 718 in long and forged product forms. The SAE/AMS product form definitions are:
Solid section of uniform cross-section (round, rectangular, square, or hexagonal); length significantly greater than cross-section dimension; supplied hot-rolled or cold-finished in random or cut lengths
A part or starting stock shaped by controlled deformation of a heated metal billet under compressive force (hammering or pressing); forgings exhibit improved grain flow and mechanical properties compared to bar stock of equivalent cross-section
A toroidal (donut-shaped) forging produced by a ring-rolling process or open-die forging; used for turbine containment rings, flanges, casings, and structural ring components
Fighter Jet Metals supplies Inconel 718 per AMS 5662 in round bar from 0.125″ to 14.00″ diameter, flat bar in various cross-sections, forging stock and billets to customer requirement, and rolled or forged ring forms to customer drawings.
All material is supplied in the solution treated condition with full certified mill test reports (CMTR) and certificates of conformance.
Applications of AMS 5662
Aerospace & Gas Turbine Applications
- Jet engine compressor discs, turbine discs, and spacers machined from round bar stock in solution treated condition before final heat treatment
- Engine shafts, stub shafts, and high-speed rotating hardware requiring fatigue resistance in the precipitation hardened condition
- Turbine rings and ring forgings for hot-section containment and structural support
- Compressor and turbine wheel hubs and integral blisks
- High-strength bolts, studs, and fasteners for engine and airframe applications
- Structural engine casings and flanges requiring complex machining before heat treatment
- Launch vehicle and spacecraft structural hardware requiring high strength-to-weight ratio
Oil & Gas and Industrial Applications
- High-pressure wellhead and downhole tool components in sour gas (H2S) service
- Pump shafts and compressor components for subsea processing equipment
- High-temperature valve bodies and actuator hardware
- Nuclear power plant structural hardware requiring combined strength and corrosion resistance
Defense Applications
- Military aircraft engine components requiring high-temperature fatigue resistance
- Missile guidance and structural hardware operating at elevated temperatures
- Gas turbine components for naval propulsion systems
- Defense hardware requiring full OEM certification traceability (Boeing, GE, Pratt & Whitney, Airbus)
Chemical Composition - AMS 5662
The following chemical composition limits apply to Inconel 718 (UNS N07718) per AMS 5662:
| Element | Symbol | Minimum % | Maximum % |
|---|---|---|---|
| Nickel + Cobalt | Ni + Co | 50.0 | 55.0 |
| Chromium | Cr | 17.0 | 21.0 |
| Iron | Fe | Balance | - |
| Niobium + Tantalum | Nb+Ta | 4.75 | 5.50 |
| Molybdenum | Mo | 2.80 | 3.30 |
| Cobalt | Co | - | 1.00 |
| Titanium | Ti | 0.65 | 1.15 |
| Aluminum | Al | 0.20 | 0.80 |
| Carbon | C | - | 0.08 |
| Manganese | Mn | - | 0.35 |
| Silicon | Si | - | 0.35 |
| Phosphorus | P | - | 0.015 |
| Sulfur | S | - | 0.015 |
| Boron | B | - | 0.006 |
| Copper | Cu | - | 0.30 |
Niobium + Tantalum (4.75–5.50%) is the most critical alloying element in Inconel 718. Niobium forms the Ni₃Nb gamma-double-prime (γ”) phase, which is the primary hardening precipitate responsible for the exceptional strength achieved after precipitation heat treatment.
The γ” phase has relatively slow precipitation kinetics at service temperature – this is what gives Inconel 718 outstanding weldability and resistance to strain-age cracking compared to other precipitation-hardened nickel alloys. Chromium (17.0–21.0%) provides oxidation and corrosion resistance.
Molybdenum (2.80–3.30%) contributes solid-solution strengthening to the nickel-iron matrix.
Aluminum (0.20–0.80%) and titanium (0.65–1.15%) form the secondary gamma-prime (γ’) phase, which provides additional precipitation hardening response alongside the dominant γ” phase.
Iron (balance, nominally ~18%) makes Inconel 718 one of the most cost-effective nickel superalloys for high-volume aerospace production applications.
Mechanical Properties - AMS 5662
Minimum mechanical properties required by AMS 5662 for Inconel 718 bars, forgings, and rings in the solution treated condition:
| Property | Imperial | Metric |
|---|---|---|
| Tensile Strength (min) | 150,000 psi (150 ksi) | 1034 MPa |
| Yield Strength, 0.2% offset (min) | 75,000 psi (75 ksi) | 517 MPa |
| Elongation in 2 in. or 4D (min) | 30% | 30% |
Elevated Temperature Properties - AMS 5662
The elevated temperature properties below are for Inconel 718 in the precipitation hardened condition, which is the service condition for parts originally procured as AMS 5662 solution treated stock and subsequently heat treated.
These representative typical values are from published literature (Special Metals Technical Bulletin):
| Temperature | Tensile Strength (typical) | Yield Strength (typical) | Elongation (typical) |
|---|---|---|---|
| Room Temp (70°F / 21°C) | 200 ksi (1379 MPa) | 170 ksi (1172 MPa) | 20% |
| 400°F (204°C) | 190 ksi (1310 MPa) | 162 ksi (1117 MPa) | 19% |
| 800°F (427°C) | 183 ksi (1262 MPa) | 158 ksi (1089 MPa) | 18% |
| 1000°F (538°C) | 181 ksi (1248 MPa) | 156 ksi (1075 MPa) | 17% |
| 1200°F (649°C) | 170 ksi (1172 MPa) | 148 ksi (1020 MPa) | 15% |
| 1300°F (704°C) | 155 ksi (1069 MPa) | 135 ksi (931 MPa) | 14% |
Physical Properties - AMS 5662
| Property | Value (Imperial) | Value (Metric) |
|---|---|---|
| Density | 0.296 lb/in³ | 8.19 g/cm³ |
| Melting Range | 2300°F–2437°F | 1260°C–1336°C |
| Modulus of Elasticity | 29.0 × 10⁶ psi | 200 GPa |
| Thermal Conductivity | 6.5 BTU/(hr·ft·°F) | 11.2 W/(m·K) |
| Thermal Conductivity (1000°F) | 9.8 BTU/(hr·ft·°F) | 17.0 W/(m·K) |
| Coefficient of Thermal Expansion | 7.2 × 10⁻⁶ /°F | 13.0 × 10⁻⁶ /°C |
| Specific Heat | 0.104 BTU/(lb·°F) | 435 J/(kg·K) |
| Max Service Temperature (Mechanical Load) | 1300°F | 704°C |
| Max Service Temperature (Oxidation Resistance) | 1800°F | 982°C |
| Melt Practice | VIM + VAR (double melt) | - |
AMS 5662 vs AMS 5663 vs AMS 5664 - Which Specification Do You Need?
All three are SAE AMS specifications for Inconel 718 (UNS N07718) in bar and forging product forms, but they differ in condition, heat treatment, and intended use:
| Feature | AMS 5662 | AMS 5663 | AMS 5664 |
|---|---|---|---|
| Alloy | Inconel 718 (UNS N07718) | Inconel 718 (UNS N07718) | Inconel 718 (UNS N07718) |
| Product Forms | Bars, Forgings, Rings | Bars, Forgings, Rings | Bars, Forgings |
| Condition | Solution Treated | Precipitation Hardened (Double Aged) | Cold Drawn |
| Tensile Min | 150 ksi (1034 MPa) | 185 ksi (1276 MPa) | See current revision |
| Yield Strength (min) | 75 ksi (517 MPa) | 150 ksi (1034 MPa) | See current revision |
| Elongation (min) | 30% | 12% | See current revision |
| Primary Use | Rough machining stock; starting material to be heat treated to AMS 5663 after machining | Final components at full design strength — parts delivered in service-ready condition | Cold-drawn bars requiring tighter diameter tolerances and controlled surface condition |
| Key Advantage | Maximum machinability and ductility for complex machining operations | Maximum tensile, yield, and fatigue strength for service in rotating engine hardware | Tighter dimensional tolerances and better surface finish than hot-finished bar |
Specify AMS 5662 when procuring bar stock for machining before heat treatment, or when the engineering drawing requires solution treated delivery condition.
Specify AMS 5663 when the final part must be delivered in the fully precipitation hardened condition with all mechanical properties verified. Specify AMS 5664 for cold-drawn bar applications requiring tight diameter tolerances.
Approved Mill Producers
Fighter Jet Metals sources AMS 5662 Inconel 718 bars, forgings, and ring stock from AS9100D-certified mill producers.
All material is supplied with full certified mill test reports (CMTR), heat/lot numbers, chemical analysis reports, and mechanical test certifications traceable to the originating mill heat and melt practice (VIM+VAR confirmed on CMTR).
AMS 5662 Machining Guidelines
One of the primary reasons for procuring Inconel 718 in the solution treated condition per AMS 5662 is machinability.
The solution treated condition is significantly easier to machine than the precipitation hardened condition (AMS 5663), because:
- Lower hardness: Solution treated Inconel 718 has hardness in the range of ~35 HRC compared to ~40+ HRC in the precipitation hardened condition
- Better chip formation: The higher ductility in the solution treated condition reduces tool chipping and extends tool life
- Dimensional stability: Complex features (deep bores, thin walls, intricate contours) are better achieved before heat treatment; final precipitation hardening causes minimal distortion when done correctly
Machining guidelines for solution treated AMS 5662 bar stock:
- Work hardening: Inconel 718 work-hardens rapidly even in the solution treated condition – use sharp, positive-rake tooling and maintain continuous cuts; do not dwell in the cut
- Cutting speeds: 60–120 SFM for carbide tooling (faster than precipitation hardened condition)
- Feeds: Aggressive feeds recommended to reduce dwell and heat buildup at the cutting edge
- Tooling: Premium carbide grades (C-2 through C-5) or coated carbide (PVD TiAlN coating recommended); ceramic tooling can be used for roughing passes
- Coolant: High-pressure flood coolant required; sulfurized cutting oils provide best tool life
- Turning: Parts should be well-supported and fixtures rigid; long slender shafts require steady rest support
- Drilling: Use premium cobalt or carbide drills; high-pressure coolant through the tool required for deep holes
- Chip control: Inconel 718 produces tough, stringy chips – chip breakers are critical for automated machining
Weldability of AMS 5662
Inconel 718 per AMS 5662 is one of the most weldable precipitation-hardenable nickel superalloys available.
Its excellent weldability arises from the slow precipitation kinetics of the γ” phase (controlled by the niobium content), which resists strain-age cracking in the heat-affected zone during welding:
- TIG (GTAW): Primary welding process for Inconel 718 bar and forging assemblies; argon or helium-argon shielding required; filler metal ERNiCrMo-1 or matching Inconel 718 filler recommended
- MIG (GMAW): Used for higher deposition rate fabrications; Ar + He shielding gas recommended
- Electron Beam (EBW): Used in vacuum environments for critical aerospace welds requiring minimal heat input and narrow heat-affected zoneFriction Welding / Inertia Welding: Used for turbine disc and shaft assembly in engine manufacturing
- Pre-weld condition: Welding is best performed on material in the solution treated (AMS 5662) condition; welding in the precipitation hardened condition increases susceptibility to heat-affected zone cracking
- Post-weld heat treatment: Full solution treat + precipitation age per AMS 2774 is required to restore the mechanical properties of the weld and heat-affected zone for structural aerospace applications
- Contrast with other nickel alloys: Inconel 718’s resistance to strain-age cracking is superior to alloys such as Waspaloy, Rene 41, or A286 because the γ” phase is slower to re-precipitate during post-weld cooling
Melt Practice - AMS 5662
To produce Inconel 718 per AMS 5662, double melting is required. The primary melt is performed by Vacuum Induction Melting (VIM), which establishes precise chemistry control in a vacuum environment, removing dissolved oxygen and nitrogen.
The primary melt ingot is then remelted using Vacuum Arc Remelting (VAR). This VIM+VAR double-melt process eliminates segregation and macro-inclusions that are unacceptable in rotating aerospace hardware, and produces a clean, homogeneous ingot with uniform chemistry and mechanical properties from center to surface.
For the most demanding rotating components (engine discs, turbine shafts), some procurement standards require triple-melt processing (VIM + ESR + VAR) to further improve cleanliness and fatigue life.
Always confirm the melt practice on the certified mill test report before procurement.
AMS 5662 Cross-Reference Specifications
SHEET & PLATE
Inconel 718 flat-rolled specifications for aerospace sheet metal fabrication in solution annealed and precipitation hardened conditions.
BARS & FORGINGS
Inconel 718 bars, forgings, and rings in complementary heat treatment conditions for high-strength rotating and structural aerospace components.
BOEING SPECIFICATIONS
Boeing material and process specifications for Inconel 718 bars, forgings, and structural components in airframe and engine applications.
GE AVIATION
GE Aviation engine material specifications for Inconel 718 in high-temperature rotating turbine and compressor hardware.
MTU AERO ENGINES
MTU Aero Engines specifications for Inconel 718 bar and forging stock with controlled heat treatment and dimensional requirements for gas turbine engines.
PRATT & WHITNEY PWA
Pratt & Whitney engine material specifications for Inconel 718 bars, forgings, and rings in engine shafts, discs, and high-stress rotating components.
AIRBUS
Airbus material specification for Inconel 718 bars, forgings, and rings meeting Airbus commercial aerospace manufacturing standards.
SNECMA / SAFRAN
Safran / Snecma engine material specifications for Inconel 718 in French-designed turbofan engine rotating and structural components.
ISRAEL AEROSPACE INDUSTRIES
Israel Aerospace Industries specifications for Inconel 718 in defense and aerospace programs requiring strict chemical, mechanical, and traceability compliance.
Trade Names and Equivalent Designations
Inconel 718 per AMS 5662 is known by many trade names and equivalent designations across different standards systems:
| Designation | System | Notes |
|---|---|---|
| Inconel 718 | Trade name | Special Metals / Precision Castparts registered trademark - most widely used commercial name |
| Nickel 718 / Nickel Alloy 718 | Common name | Generic material designation used in procurement |
| ASTM B637 | ASTM specification | Rod, bar, and wire per ASTM system |
| ASTM B670 | ASTM specification | Plate, sheet, and strip per ASTM system |
| UNS N07718 | UNS (Unified Numbering System) | Standard material identifier in North America |
| DIN 2.4668 / W.Nr. 2.4668 | Werkstoff Nr. (German) | European material number designation |
| NiCr19Fe19Nb5Mo3 | DIN/EN alloy designation | German/European compositional shorthand |
| AMS 5662 | SAE AMS | Solution treated bars, forgings, and rings - this specification |
| AMS 5663 | SAE AMS | Precipitation hardened bars, forgings, and rings |
| AMS 5664 | SAE AMS | Cold drawn bars, forgings |
Why Source AMS 5662 from Fighter Jet Metals?
Full mill certifications on every order
Heat number, lot number, chemical analysis, and mechanical test reports included with every shipment
Complete heat-lot traceability
Full chain-of-custody documentation from mill to your door
AS9100-certified aerospace sourcing
Material from AS9100-certified mills only
OEM specification support
Stock and supply to Boeing BMS/DMS, Gulfstream GMS, Honeywell EMS, Safran DMD, and Airbus AIPS requirements
In-house processing
Plate saw cutting, shearing, and laser cutting available; custom-cut sizes to your dimensions
Same-day quote response
Competitive pricing with rapid quote turnaround
Certified Material for Critical Service
Materials supplied in 6Al-4V titanium must meet strict aerospace certification and traceability requirements. Fighter Jet Metals supports sourcing across a wide range of AMS, MIL, and OEM specifications, ensuring compliance with industry standards.
All material is supplied with full mill certifications, complete heat-lot traceability, and detailed documentation. This ensures reliability and suitability for safety-critical aerospace, defense, and high-performance engineering applications.