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Drawing No. EH–MT–017 // Engineering Materials

INCONEL 718 Properties

Reviewed August 2026

INCONEL 718 is a precipitation-hardenable nickel superalloy used where high strength, fatigue/creep resistance and corrosion resistance are required over a broad temperature range.

UNS N07718 · precipitation-hardened referencePrecipitation-hardened nickel superalloyReference data — verify design allowables

Representative properties

The stated basis, temperature and direction are part of the value. Switch units without changing the physical reference.

Density
8,190 kg/m³
Reference value / stated test basis
Young’s modulus
205 GPa
Reference value / stated test basis
Poisson ratio
≈0.284–0.294 · product/orientation dependent
Reference value / stated test basis
Yield strength
1,100 MPa
Reference value / stated test basis
Tensile / comparison strength
1,375 MPa
Reference value / stated test basis
Thermal conductivity
11.4 W/(m·K)
Reference value / stated test basis
Specific heat
435 J/(kg·K)
Reference value / stated test basis
Thermal expansion
13 µm/(m·K)
Reference value / stated test basis
Melting / transition temperature
1,260–1,336 °C
Reference value / stated test basis
Why this basis matters: The displayed strength corresponds to a precipitation-hardened reference. Solution-annealed or additively manufactured material before final heat treatment can be markedly different.

What changes these properties?

Engineering variability

  • Heat treatment strongly controls γ′/γ″ strengthening and therefore yield/tensile properties.
  • Elastic properties are anisotropic at the single-crystal grain level; wrought product values are engineering averages.
  • Thermal conductivity is low compared with steels and rises with temperature.
  • For turbine/aerospace design, use product-form-specific fatigue, creep and rupture data.

Selection note

A benchmark aerospace and high-temperature alloy for turbine disks, fasteners, rocket components, springs and high-strength corrosion-resistant hardware.

Where a property is shown as qualitative rather than numeric, that is intentional: the selected source or the material physics does not justify a single comparable scalar.

How to interpret this material

Stiffness

Young’s modulus describes elastic stiffness. For crystals and composites, orientation can make one scalar modulus only a directional reference.

Strength / failure

Ductile metals can use yield and tensile strength. Brittle ceramics/semiconductors and anisotropic composites require fracture, flexural or directional strength descriptions instead.

Thermal response

Conductivity, heat capacity and expansion are temperature dependent. The last column is a melting or transition descriptor only where that physical concept is appropriate.

Technical sources

The database favors manufacturer, industry, government or academic technical references and labels secondary condition-specific datasets when a primary source does not expose a complete property set.

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