Nickel Alloy Inconel 718
UNS N07718 · EN 2.4668 · GB GH4169
The most widely used precipitation-hardened Ni-Fe-Cr superalloy, valued for its excellent strength, weldability, and delayed strengthening response that permits post-weld heat treatment without cracking.
Values for the Solution Annealed condition
Inconel 718 tempers and conditions
Inconel 718 is supplied in 11 conditions, soft to hard. Solution Annealed is the default FabDigit quotes; the values on this page are for it.
- Annealed
- Solution Annealed
- As Fabricated
- HIP
- As Printed
- Hot Rolled
- Stress Relieved
- As Cast
- Cold Drawn
- Aged
- Direct Aged
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
1010–1065 °C mill anneal (soft, tube/sheet condition, AMS 5589/5590) | Softest wrought condition, chosen for tube bending, deep drawing and welded fabrication. | 460 | 900 | 50 | 180 HB | 1.4 % IACS |
Solution AnnealedDefault 954–1010 °C solution treated, quenched (pre-age condition, AMS 5596/5662 base) | Standard stocked condition for forming, machining and welding before customer-performed aging. | 550 | 965 | 45 | 200 HB | — |
As-Fabricated | Mill/as-fabricated UNS N07718 supplied without final solution + precipitation treatment; moderate strength, high ductility, readily formed and welded before aging. | 560 | 965 | 38 | 25 HRC | 1.4 % IACS |
Hot isostatic pressed | Pick for cast or additively built 718 that must be pore-free and fatigue-critical; normally followed by aging. | 620 | 1,030 | 38 | 15 HRC | 1.4 % IACS |
as-built laser powder-bed fusion / DMLS (no heat treatment) | Reference state for AM prints straight off the plate; anisotropic with high residual stress, normally stress relieved + HIP + aged before service. | 700 | 1,010 | 27 | 30 HRC | 11 W/m·K |
as-hot-worked bar and plate | Lowest-cost mill condition for re-forging or for parts that will be solution treated and aged later. | 700 | 1,050 | 30 | 25 HRC | 1.4 % IACS |
870–1065 °C stress relief (cold-worked wrought or as-built AM parts) | Used to remove residual stress from cold work, welding or laser powder-bed builds before machining/aging. | 740 | 1,030 | 30 | 32 HRC | 1.4 % IACS |
investment cast 718 per AMS 5383 | For complex cast housings, casings and manifolds where wrought properties are not required. | 800 | 965 | 8 | 36 HRC | 1.4 % IACS |
cold drawn / cold rolled bar, wire and strip (unaged) | Chosen for close tolerance bar, springs and wire where cold-work strength and good surface are needed. | 1,050 | 1,250 | 12 | 38 HRC | 1.4 % IACS |
Solution treated + precipitation aged | Full-strength service condition for turbine discs, shafts, fasteners and downhole tooling to 650 °C. | 1,170 | 1,375 | 20 | 42 HRC | 11 W/m·K |
hot/cold worked then aged without re-solution | Fine-grain, highest-strength route for discs and fasteners where creep at ≤650 °C and tensile strength dominate. | 1,250 | 1,450 | 15 | 45 HRC | 1.4 % IACS |
What is Inconel 718?
The most widely used precipitation-hardened Ni-Fe-Cr superalloy, valued for its excellent strength, weldability, and delayed strengthening response that permits post-weld heat treatment without cracking. Inconel 718 has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 68% of nickel alloy grades. It melts at 1,260°C (2,300 °F). Inconel 718 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 79% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
What is Inconel 718 used for?
- Gas turbine disks and blades
- High-temperature fasteners and studs
- Turbine casings and seal rings
- Rocket engine injectors and manifolds
- Downhole drilling and completion tooling
- Cryogenic valve stems and springs
- Additively manufactured turbomachinery parts
Advantages
- Polishes to a fine finish — 80/100, better than 97% of nickel alloy grades
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 85% of nickel alloy grades
- High strength — 550 MPa (79.8 ksi), better than 79% of nickel alloy grades
Limitations
- High embodied carbon — 16 kg CO₂/kg, worse than 93% of nickel alloy grades
- Limited service temperature — 540°C (1,004 °F), worse than 75% of nickel alloy grades
Inconel 718 properties
Typical room-temperature values for Inconel 718-Solution Annealed; bars are the position among nickel alloy grades.
Physical3
Inconel 718 has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 68% of nickel alloy grades. It melts at 1,260°C (2,300 °F).
Mechanical15
Inconel 718 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 79% of nickel alloy grades. Elongation at break is 45% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Inconel 718 is rated for continuous service to 540°C (1,004 °F). It conducts heat at 11.4 W/m·K (6.59 BTU/hr·ft·°F), better than 53% of nickel alloy grades. Thermal expansion is 13 µm/m·K (7.22 µin/in·°F).
Electrical3
Inconel 718 conducts electricity at 1.4 % IACS, worse than 65% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 51% of nickel alloy grades.
Sustainability4
Producing a kilogram of Inconel 718 takes about 250 MJ of energy and emits 16 kg of CO₂ — more than 97% of nickel alloy grades. Typical recycled content is 35%.
Manufacturability8
Inconel 718's machinability is poor (18/100, worse than 61% of nickel alloy grades); weldability very good (70/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. Inconel 718 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Inconel 718
Is Inconel 718 easy to machine?
Machine in the solution-annealed state where possible; rigid setups, low speed (20–35 m/min carbide, 150–250 m/min ceramic), heavy positive feed, sharp tools and flood coolant to beat work hardening and notch wear.
Can Inconel 718 be welded?
Very good fusion weldability by GTAW/EBW/LBW with ERNiFeCr-2 (718) filler in the annealed condition; keep heat input low, avoid restrained thick sections, and post-weld solution treat + age to restore full strength.
Can Inconel 718 be formed, bent or molded?
Hot work at 1010–1120 °C; cold form only from annealed stock with high tooling forces and intermediate anneals — springback and tool wear are severe.
Manufacturability
The process limits FabDigit's quote engine applies to Inconel 718. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Poor18 / 100 |
|---|---|
| ISO material group | S.1 |
| Cutting speed (rough / finish) | 40 / 55 m/min |
| Minimum wall | 1.5 mm |
| Minimum internal radius | 2 mm |
| Drill depth limit | 3× diameter |
| Best surface (machined / polished) | Ra 1.6 / 0.8 µm |
| Hardenable after machining | Yes |
Sheet metal
| Formability | Fair55 / 100 |
|---|---|
| Weldability | Better70 / 100 |
| Bendable | Yes |
| Minimum bend radius | 1.5× thickness |
| Sheet thickness range | 0.5 – 6 mm |
| Spring-back | High |
3D printing
| Technologies | DMLS |
|---|---|
| Layer height | 20 – 60 µmdefault 30 µm |
| Minimum wall / feature | 0.5 / 0.3 mm |
| Build envelope | 250 × 250 × 325 mm |
| Supports | Yes |
| Anisotropy | Mild |
| Mandatory post-processing | heat treatment |
Inconel 718 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Niplus Co if reported | 50 – 55 | 53 |
| Cr | 17 – 21 | 19 |
| NbNb + Ta | 4.75 – 5.5 | 5.13 |
| Mo | 2.8 – 3.3 | 3.05 |
| Ti | 0.65 – 1.15 | 0.9 |
| Al | 0.2 – 0.8 | 0.5 |
| Co | ≤ 1 | 0.3 |
| C | ≤ 0.08 | 0.04 |
| Mn | ≤ 0.35 | 0.1 |
| Si | ≤ 0.35 | 0.1 |
| Cu | ≤ 0.3 | 0.05 |
| B | ≤ 0.01 | 0 |
| P | ≤ 0.02 | |
| S | ≤ 0.02 | |
| Tamax, when specified separately | ≤ 0.05 | |
| Febalance, typically 17–20 % | balance |
What surface finishes work on Inconel 718?
Not anodizable; use pickling/passivation, electropolishing, abrasive blasting or shot peening for fatigue, plus diffusion or PVD coatings for high-temperature wear.
Surface treatments FabDigit runs on nickel alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Equivalent designations
Standards and trade names that resolve to Nickel Alloy Inconel 718 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- N07718
- EN / DIN / Werkstoff-Nr.
- 2.4668
- GB (China)
- GH4169
- Also called
- NA51
How much does Inconel 718 cost?
Inconel 718 is a premium-cost nickel alloy ($$$), cheaper than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Inconel 718 — frequently asked
What is Inconel 718 used for?
Inconel 718 is typically used for gas turbine disks and blades, high-temperature fasteners and studs, turbine casings and seal rings, rocket engine injectors and manifolds, downhole drilling and completion tooling and cryogenic valve stems and springs. In short: workhorse aerospace superalloy.
What is the yield strength of Inconel 718?
Inconel 718 has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 79% of nickel alloy grades. Strength varies by condition: see the 11 listed tempers.
Is Inconel 718 easy to machine?
Not especially — machinability is rated poor (18/100, worse than 61% of nickel alloy grades). Machine in the solution-annealed state where possible; rigid setups, low speed (20–35 m/min carbide, 150–250 m/min ceramic), heavy positive feed, sharp tools and flood coolant to beat work hardening and notch wear.
Can Inconel 718 be welded?
Yes — weldability is rated very good (70/100). Very good fusion weldability by GTAW/EBW/LBW with ERNiFeCr-2 (718) filler in the annealed condition; keep heat input low, avoid restrained thick sections, and post-weld solution treat + age to restore full strength.
What surface finishes work on Inconel 718?
Not anodizable; use pickling/passivation, electropolishing, abrasive blasting or shot peening for fatigue, plus diffusion or PVD coatings for high-temperature wear.
Can Inconel 718 be formed, bent or molded?
Hot work at 1010–1120 °C; cold form only from annealed stock with high tooling forces and intermediate anneals — springback and tool wear are severe.
What is the maximum service temperature of Inconel 718?
Inconel 718 is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Inconel 718 Solution Annealed and Inconel 718 Aged?
Solution Annealed is the default condition — standard stocked condition for forming, machining and welding before customer-performed aging. Aged: full-strength service condition for turbine discs, shafts, fasteners and downhole tooling to 650 °C. Yield strength is 550 MPa in Solution Annealed versus 1,170 MPa in Aged.
How much does Inconel 718 cost?
Inconel 718 is a premium-cost nickel alloy ($$$), cheaper than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in Inconel 718?
Yes — Inconel 718 is available for CNC machining, sheet metal and 3D printing with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- INCONEL alloy 718 technical bulletin — Special Metals Corporation (2007)
- AMS 5662 / AMS 5663 — Nickel Alloy Bars, Forgings and Rings, 718 — SAE International (2020)
- ASTM B637 — Precipitation-Hardening Nickel Alloy Bars, Forgings and Forging Stock for High-Temperature Service — ASTM (2018)
- ASTM B670 / AMS 5596 — Alloy 718 Plate, Sheet and Strip — ASTM / SAE (2019)
- AMS 5383 — Nickel Alloy Castings, Investment, 718 — SAE International (2018)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- MMPDS-17 — Metallic Materials Properties Development and Standardization — Battelle/FAA (2022)
- EOS NickelAlloy IN718 material data sheet — EOS GmbH (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.