Inconel® alloy 718

UNS N07718
W.Nr 2.4668


Springs, valves, and aircraft and land-based turbine engines.


Inconel® 718 is an age-hardenable Nickel-Chromium-Columbium (Niobium)-Molybdenum alloy with high strength, corrosion-resistance, and good fabrication characteristics. Inconel® 718 has high tensile, yield, and creep-rupture properties at high temperatures and can operate at cryogenic temperatures up to 1200°F (650°C).

Industries Supplied

Oil & Gas Extraction, Nuclear, Aerospace, Defense and Automotive.

Nominal Composition

Ni: 50.0 - 55.0
Cr: 17.0 - 21.0
Cb (Nb): 4.75 - 5.5
Mo: 2.8 - 3.3
Ti: 0.65 - 1.15
Fe: balance
Co: 1.0 max
Al: 0.2 - 0.8
Mn: 0.35 max
Si: 0.35 max
Cu: 0.3 max

Physical Properties

Density: 0.296 lb/in3, (8.19 g/cm3)

Modulus of Elasticity (E): 
At 70°F (20°C): 29.0 x 103 ksi (200 GPa)

Modulus of Rigidity (G): 
At 70°F (20°C): 11.6 x 103 ksi (80 GPa)

Coefficient of Expansion:
7.7 µin/in.-°F (70°F to 600°F)
13.9 µm/m-°C (20°C to 300°C)

Electrical Resistivity: 47.5 µΩ.in, (121 µΩ.cm)

Thermal Conductivity: 79 Btu-in/ft2hr-°F, (11.4 W/m-K)

Applicable Specifications

Wire & Bar: AMS 5662, AMS 5663, AMS 5664, AMS 5832, AMS 5962, ASME SB-637, ASTM B637, AWS A5.14, NACE MR0175 (ISO 15156-3).

Typical Mechanical Properties – Spring Applications

  • Annealed
    • Heat Treatment: 1800°F (980°C)
    • Tensile Strength: 115 - 145 ksi; (790-1000 MPa)
    • Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C)

  • Spring Temper
    • Tensile Strength: 190 – 220 ksi; (1310 – 1515 MPa)
    • Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C​)

    • Spring Temper + Aged
    • Heat Treatment: After spring coiling. Age: 1325°F (720°C) for 8 hours, furnace cool to 1150°F and hold for a total aging time of 18 hours.
    • Tensile Strength: 220 ksi minimum; (1515 MPa)
      • Suggested Operating Conditions: -330°F to 1200°F (-200°C to 650°C​)

    Inconel® is a registered trademark of the Special Metals Corporation group of companies.

    For further information Contact:

    Phone: 1 847 695 1900 
    Elgiloy Specialty Metals - Wire Products
    356 N.Cross Street
    Sycamore, IL 60178 USA 

    Inconel® 718 Additional Information

  • If you are working in an industry that needs wire that will hold up in the most extreme temperature conditions, consider Inconel® 718 wire for your job. Through its chemical makeup and the processing by which it is made, 718 wire can withstand the most brutal of temperatures, both hot and cold. It is also trusted by some of the most scientifically advanced industries in the world, who must rely on their equipment to be completely operational at all times.

    The makeup of Inconel® 718 wire alloy is what separates it from other wire found in the industry. It is a Nickel-Chromium alloy, which also has trace amounts of Iron, Columbium, and Molybdenum. Furthermore, there is also small amounts of Aluminum and Titanium. This also means that it can maintain its strength and integrity as a wire in very high temperatures, sometimes even as high as 1300 degrees. The wire is formable, takes well to soldering, and outperforms most other nickel alloy wires that are formed from precipitation hardening. It is not magnetic, but has a high level of corrosion and oxidation resistance, which makes it extremely valuable in certain industries.

    One of the largest industries that utilize Inconel® 718 is Aerospace. Rockets and pieces that have to work well in space must be able to withstand extreme temperatures. This is specifically true in jet engines and engine turbines. Obviously, during takeoff, jet engines become extremely hot. It is also vital that nothing fails during the process or they risk catastrophic failure. Therefore; engineers and scientists must be able to trust that the pieces involved in making these wonders of modern science are going to work perfectly every time it is used. Furthermore, many places in space are extremely cold, but 718 Inconel® wire can still work at peak performance, even in temperatures as low as -400 degrees.  Many metals will begin to lose strength when exposed to such temperatures, but this alloy maintains its integrity.

    It is not just Aerospace that uses 718 wire. Many industries that utilize high powered gas turbines as standard equipment must also be able to trust that the wiring they are using can withstand extreme temperatures. This is because creeping and stress corrosion can significantly damage wires that are exposed to temperatures that are extremely high. Inconel® 718 has a strong resistance to both of these highly damaging problems. It may seem like a minor issue, but trusting that your equipment will work without fail means that the people working on these pieces of equipment will spend more time doing what they need to do and less time doing maintenance or wondering if it will hold up at all.

    Elgiloy supplies Inconel® 718 wire at competitive prices and in varying sizes. No matter what you are building, the size area you have to work with, or the amount of wire you need, there is high probability that Elgiloy can supply it.