A precipitation-hardenable nickel-chromium grade, Alloy 718, also known as Inconel® 718 (UNS N07718 / 2.4668), is a high strength superalloy used at temperatures up to 648°C. Available in standard and Alloy 718 API specification.
NeoNickel is a leading Alloy 718 supplier, offering premium-grade material designed for outstanding performance under high stress, high heat, and corrosive environments. Known also as Inconel® 718, this precipitation-hardenable nickel-chromium alloy excels in aerospace, energy, and industrial applications.
Alloy 718, also referred to as Inconel® 718 (a registered trademark of Special Metals Corporation), is a precipitation-hardenable nickel-chromium alloy engineered for exceptional mechanical strength and corrosion resistance in extreme environments. With the addition of niobium, molybdenum, titanium, and aluminium, Alloy 718 maintains outstanding tensile, yield, and creep-rupture strength at temperatures up to 648°C (1200°F).
Its excellent weldability, resistance to post-weld cracking, and stable long-term performance under high stress and corrosive conditions make Alloy 718 a trusted choice for mission-critical applications. NeoNickel supplies Alloy 718 in a variety of forms and conditions, including annealed material to facilitate machining, followed by appropriate heat treatments to achieve optimal strength levels. NeoNickel also stocks Alloy 718 to API specification, and alternatively with restricted chemistry and careful heat treatment with increased strength to 150 KSI 0.2% PS, for demanding oil and gas environments.
Key Material Properties:
We supply Alloy 718 in a variety of product forms to suit different applications and fabrication methods, including plate, round bar, sheet, coil and welding wire. To view available sizes and submit an inquiry, use the dropdown selector below. Round Bar is also available to Alloy 718 API specification (NACE MR0175 / ISO 15156-3). Our expert team can assist with custom sizing, machining, and material certification for your specific requirements.
Our expert team can assist with custom sizing, machining, and material certification for your specific requirements.
| % | Ni+Co | Cr | Mo | Cu | Co | C | Mn | Si | P | S | Fe | Ti | Al | Nb+Ta | B |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 50 | 17 | 2.8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Balance | 0.65 | 0.2 | 4.75 | 0 |
| Max | 55 | 21 | 3.3 | 0.3 | 1 | 0.08 | 0.35 | 0.35 | 0.015 | 0.015 | Balance | 1.15 | 0.8 | 5.5 | 0.006 |
| % | Ni | Cr | Mo | Mn | Cu | Si | C | S | P | Co | Cb+Ta | Pb | Se | B | Mg | Ti | Al | Fe |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 50 | 17 | 2.8 | - | - | - | - | - | - | - | 4.87 | - | - | - | - | 0.8 | 0.4 | - |
| Max | 55 | 21 | 3.3 | 0.35 | 0.23 | 0.35 | 0.045 | 0.01 | 0.01 | 1.0 | 5.2 | 1000ppm | 0.0005ppm | 50ppm | 0.0006ppm | 1.15 | 0.6 | Balance |
| Mechanical & Physical Properties | -196°C | 21°C | 93°C | 204°C | 316°C | 538°C | 649°C | 760°C |
|---|---|---|---|---|---|---|---|---|
| Coefficient of Thermal Expansion µm/m⁰C | 10.62 | - | 13.1 | 13.5 | 13.9 | 14.6 | 15.1 | 16 |
| Thermal Conductivity /kcal/(hr.m.°C) | - | 9.5 | 10.7 | 12.2 | 13.8 | 16.8 | 18.3 | 19.8 |
| Modulus of Elasticity / x105 MPa | - | 2 | 1.93 | 1.86 | 1.79 | 1.72 | 1.65 | 1.52 |
| Mechanical & Physical Properties | 21°C | 93°C | 204°C | 316°C | 538°C | 649°C |
|---|---|---|---|---|---|---|
| Coefficient of Thermal Expansion µm/m⁰C | - | 13.4 | 13.5 | 13.9 | 14.6 | 15.1 |
| Thermal Conductivity /kcal/(hr.m.°C) | 9.5 | 10.7 | 12.2 | 13.8 | 16.8 | 18.3 |
| Modulus of Elasticity/ x105 MPa | 2 | 1.96 | 1.9 | 1.84 | 1.71 | 1.63 |
| 135 | Ultimate tensile strength, ksi |
|---|---|
| 70 | 0.2% yield strength, ksi |
| 45 | Elongation, % |
| 100 | Hardness, Rockwell B |
| Temperature, °C | 21°C | 204°C | 427°C | 538°C | 649°C | 760°C |
|---|---|---|---|---|---|---|
| Ultimate Tensile Strength, ksi | 210 | 198 | 191 | 185 | 168 | 111 |
| 0.2% Yield Strength, ksi | 175 | 163 | 156 | 155 | 149 | 110 |
| Elongation, % | 22 | 20 | 19 | 18 | 19 | 27 |
| Hardness, Rockwell C | 42-44 | - | - | 40-41 | 40-41 | 33-34 |
| 593°C | 649°C | 704°C | 760°C | |
|---|---|---|---|---|
| 100 Hours, ksi | 170 | 110 | 75 | 44 |
| 1,000 Hours, ksi | 130 | 85 | 55 | 25 |
| Minimum | Maximum | |
|---|---|---|
| Ultimate tensile strength, ksi | 150 | - |
| 0.2% yield strength, ksi | 120 | 145 |
| Elongation, % | 20% | - |
| Reduction of area, % | 35% | - |
| Impact Strength*Min average/ min single, ft-lbs | 40/35 | - |
| Hardness, Rockwell C | 32 | 40 |
Alloy 718 (Inconel® 718) is one of the most widely deployed nickel superalloys across industry, chosen for its exceptional combination of high-temperature strength, corrosion resistance, and weldability. It performs reliably from cryogenic temperatures up to 648°C, making it suitable for some of the most demanding environments in engineering.
Alloy 718 was originally developed for aerospace, and it remains its largest application sector. Its high strength-to-weight ratio, resistance to fatigue, and weldability make it the preferred material for:
Learn more about how Alloy 718 excels in aerospace: Why Alloy 718 is the Go-To Material in Aerospace Applications
Alloy 718 API is widely used in the oil and gas industry. Where wells have high concentrations of hydrogen sulphide, carbon dioxide and chlorides at high pressures and temperatures, Alloy 718 API is the alloy of choice. It provides high strength while meeting the maximum hardness requirements of NACE MR0175, MR0103 and ISO 15156-3 for use in oil tools in sour service. Whether designing a subsea manifold, a tubing hanger, or a compressor rotor, Alloy 718 offers the combination of corrosion resistance, mechanical strength, and regulatory compliance needed to perform in extreme environments.
Alloy 718's ability to maintain mechanical integrity under high stress and elevated temperatures makes it a trusted material for power generation equipment exposed to cyclic thermal loading and corrosive gases.
The alloy's resistance to chloride stress corrosion cracking and pitting makes it suitable for offshore and naval applications operating in seawater and humid salt-laden environments.
In high-performance and motorsport applications, Alloy 718 is selected for components that must endure elevated temperatures and mechanical fatigue over sustained operating cycles.
Alloy 718's corrosion resistance in aggressive chemical media and its long-term mechanical stability make it a reliable choice for process industry equipment.
With its combination of strength, toughness, and corrosion resistance, the versatility of Alloy 718 is ideal for:
Alloy 718 offers a unique combination of mechanical strength, corrosion resistance, and fabrication flexibility, providing critical advantages across aerospace, energy, marine, and industrial sectors.
Exceptional High-Temperature Strength: Maintains mechanical integrity at temperatures up to 648°C (1200°F), ensuring reliable performance and reducing the risk of material failure in demanding high-heat environments.
Outstanding Corrosion and Oxidation Resistance: Protects components exposed to harsh chemicals and extreme conditions, extending service life and lowering replacement costs.
Excellent Weldability: Reduces the risk of post-weld cracking, simplifying manufacturing processes and enabling more efficient fabrication.
Proven Versatility Across Industries: Suitable for aerospace, energy, marine, and high-performance engineering applications, offering flexibility for a wide range of critical projects.
Long-Term Mechanical Stability: Delivers consistent strength and toughness over prolonged service periods, minimising maintenance requirements and ensuring operational reliability. Sour Service Performance (API Grade): Available to API specification, meeting the maximum hardness requirements of NACE MR0175, MR0103 and ISO 15156-3 for use in oil tools in sour service environments with high concentrations of hydrogen sulphide, carbon dioxide and chlorides.
Alloy 718’s balance of strength, corrosion resistance, and weldability makes it the ideal material for mission-critical components operating under extreme conditions. For more advice or a quote, contact our team today.
Standard Alloy 718 is supplied to AMS and ASTM specifications (AMS 5662/5663, ASTM B637) for aerospace, energy, and industrial applications requiring exceptional high-temperature strength and corrosion resistance.
Alloy 718 API is the same base alloy (UNS N07718 / Werkstoff 2.4668) processed to meet the additional hardness and chemistry requirements of NACE MR0175, MR0103 and ISO 15156-3. This API specification is required for use in oil and gas sour service environments where components are exposed to high concentrations of hydrogen sulphide, carbon dioxide and chlorides at elevated pressures and temperatures.
NeoNickel stocks both grades and can advise on the correct specification for your application. Contact our team for a quote.
Yes, alloy 718 and Inconel® 718 refer to the same material: a precipitation-hardenable nickel-chromium alloy designated UNS N07718 / Werkstoff 2.4668. Inconel® is a registered trademark of Special Metals Corporation; most suppliers use the generic designation Alloy 718.
Alloy 718 is used across aerospace (gas turbine engine parts, rocket motors, fasteners), oil and gas (sour service components to API specification), power generation, marine, nuclear, automotive, and chemical processing industries. Its combination of high-temperature strength, corrosion resistance, and weldability makes it suited to mission-critical applications in extreme environments.
Standard Alloy 718 is produced to AMS and ASTM specifications for high-temperature applications. Alloy 718 API is the same base alloy processed to meet the additional requirements of NACE MR0175, MR0103 and ISO 15156-3, making it suitable for use in oil and gas sour service environments containing hydrogen sulphide, carbon dioxide and chlorides.
Alloy 718 maintains its mechanical integrity at temperatures up to 648°C (1200°F), making it suitable for high-temperature aerospace and energy applications. It also retains strength and ductility at cryogenic temperatures.
Alloy 718 is a nickel-chromium alloy with additions of niobium, molybdenum, titanium, and aluminium. These elements enable precipitation hardening, giving the alloy its outstanding tensile, yield, and creep-rupture strength. The full chemical composition is shown in the table above.
Looking for high-quality Alloy 718 suppliers? NeoNickel offers extensive stock, fast turnaround, and precision services. Get a Quote or speak with one of our experts
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