Nickel Alloy 718 Cast
Grade
UNS N07718 · EN 2.4668, NiCr19Fe19Nb5Mo3 · GB GH4169
Cast = as cast
Complex-geometry housings, casings and valve bodies; strength and ductility below wrought due to dendritic segregation and Laves phase.
Values for the Cast condition
Other 718 tempers and conditions
718 is listed in 10 conditions; see the grade overview at 718.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest supply condition for forming, deep drawing, machining or welding before final aging. | 500 | 965 | 45 | 200 HB | — |
Hot Finished | As-forged or hot-rolled bar bought for re-forging or for parts that will be solution treated and aged by the customer. | 640 | 1,050 | 35 | 24 HRC | 1.4 % IACS |
Additive as-built | Printed condition with columnar grains and Laves phase; adequate for prototypes but anisotropic and low in yield strength until heat treated. | 700 | 1,030 | 27 | 30 HRC | 1.3 % IACS |
CastThis page As cast | Complex-geometry housings, casings and valve bodies; strength and ductility below wrought due to dendritic segregation and Laves phase. | 880 | 1,030 | 9 | 35 HRC | — |
Cold drawn | Straight, close-tolerance bar and wire with work-hardened strength; use when tight size and moderate strength are needed without aging. | 930 | 1,140 | 18 | 33 HRC | 1.4 % IACS |
STA | Coarser grain, slightly lower tensile but better creep-rupture life, notch ductility and fracture toughness for hot rotating parts. | 1,050 | 1,275 | 21 | 38 HRC | — |
Additive + HIP + homogenize/solution + double age (AMS 5662-equivalent) | Fully densified and homogenized printed parts reaching wrought-like strength; the standard route for flight and downhole AM 718 hardware. | 1,160 | 1,380 | 16 | 43 HRC | 1.4 % IACS |
STADefault Solution treated and aged | Default aerospace/oil-field condition: fine grain plus full γ″ hardening for maximum room- and mid-temperature strength. | 1,170 | 1,375 | 18 | 42 HRC | — |
Direct aged | Retains hot-work substructure for the highest tensile/LCF strength; used for turbine discs, fasteners and downhole tools where fine grain and strength dominate. | 1,250 | 1,450 | 15 | 45 HRC | — |
Cold worked + aged strip/wire | Cold-rolled or drawn then aged for springs, seals, bellows and fasteners needing the highest hardness in thin sections. | 1,350 | 1,520 | 10 | 47 HRC | 1.4 % IACS |
What is 718 Cast?
718 Cast is 718 in the Cast grade — complex-geometry housings, casings and valve bodies; strength and ductility below wrought due to dendritic segregation and Laves phase. 718 Cast has a yield strength of 880 MPa (128 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 93% of nickel alloy grades. Elongation at break is 9% and the elastic modulus is 204 GPa (29.6 Msi). 718 Cast 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). STA is the default condition FabDigit quotes; Cast is available on request or by drawing note.
Advantages
- High strength — 880 MPa (128 ksi), better than 93% of nickel alloy grades
Limitations
- Limited ductility — 9%, worse than 86% of nickel alloy grades
- Limited formability — 15/100, worse than 81% of nickel alloy grades
718 Cast properties
Typical room-temperature values for 718 Cast; 10 are specific to this condition. Other listed values are 718 reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
718 Cast 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).
Mechanical16
718 Cast has a yield strength of 880 MPa (128 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 93% of nickel alloy grades. Elongation at break is 9% and the elastic modulus is 204 GPa (29.6 Msi).
Thermal6
718 Cast is rated for continuous service to 650°C (1,202 °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
718 Cast 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 718 Cast takes about 175 MJ of energy and emits 12.5 kg of CO₂ — more than 65% of nickel alloy grades. Typical recycled content is 40%.
Manufacturability8
718 Cast's machinability is poor (17/100, worse than 69% of nickel alloy grades); weldability good (65/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 718 Cast
Is 718 easy to machine?
Machine in the annealed state where possible; when aged use rigid setups, low speeds (10–30 m/min carbide, 150–300 m/min ceramic), heavy positive feeds to cut under the work-hardened layer and high-pressure coolant.
Can 718 be welded?
Best weldability of the age-hardenable superalloys (GTAW/EBW/laser with ERNiFeCr-2 filler); weld in solution-annealed condition, keep interpass heat low and post-weld solution + double age to restore properties.
Can 718 be formed, bent or molded?
Cold form only in the annealed condition with high forces and frequent intermediate anneals; hot work at 1010–1120 °C and finish above ~950 °C to avoid δ-phase-driven cracking.
What surface finishes work on 718?
Grind/EDM with care for recast layer removal; shot peen critical fillets for fatigue, passivate or electropolish for corrosion service — no anodizing, plating and PVD coatings are used instead.
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 |
|---|---|---|
| NiNi + Co | 50 – 55 | 53 |
| Cr | 17 – 21 | 19 |
| NbNb + Ta; γ″ former | 4.75 – 5.5 | 5.1 |
| Mo | 2.8 – 3.3 | 3 |
| 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 | 0.01 |
| S | ≤ 0.02 | 0 |
| Febalance, typically ~18.5 % | balance | — |
718 Cast — frequently asked
What is 718 Cast used for?
718 Cast is typically used for turbine disks, aerospace fasteners, gas turbine casings, oil & gas downhole components and cryogenic tanks. In short: best-weldable age-hardening superalloy; 1170 MPa yield when aged; workhorse turbine disk alloy.
What is the yield strength of 718 Cast?
718 Cast has a typical yield strength of 880 MPa (128 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 93% of nickel alloy grades. Strength varies by condition: see the 10 listed tempers.
Is 718 Cast easy to machine?
Not especially — machinability is rated poor (17/100, worse than 69% of nickel alloy grades). Machine in the annealed state where possible; when aged use rigid setups, low speeds (10–30 m/min carbide, 150–300 m/min ceramic), heavy positive feeds to cut under the work-hardened layer and high-pressure coolant.
Can 718 Cast be welded?
Yes — weldability is rated good (65/100). Best weldability of the age-hardenable superalloys (GTAW/EBW/laser with ERNiFeCr-2 filler); weld in solution-annealed condition, keep interpass heat low and post-weld solution + double age to restore properties.
What surface finishes work on 718 Cast?
Grind/EDM with care for recast layer removal; shot peen critical fillets for fatigue, passivate or electropolish for corrosion service — no anodizing, plating and PVD coatings are used instead.
Can 718 Cast be formed, bent or molded?
Cold form only in the annealed condition with high forces and frequent intermediate anneals; hot work at 1010–1120 °C and finish above ~950 °C to avoid δ-phase-driven cracking.
What is the maximum service temperature of 718 Cast?
718 Cast is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 718-STA and 718-ANN?
STA is the default condition — default aerospace/oil-field condition: fine grain plus full γ″ hardening for maximum room- and mid-temperature strength. ANN: softest supply condition for forming, deep drawing, machining or welding before final aging. Yield strength is 1,170 MPa in STA versus 500 MPa in ANN.
Sources
- INCONEL alloy 718 Technical Bulletin — Special Metals Corporation (2007)
- AMS 5662/5663/5664 — Nickel Alloy Bars, Forgings and Rings, 718 — SAE International (2020)
- ASTM B637 — Precipitation-Hardening Nickel Alloy Bars, Forgings and Forging Stock — ASTM International (2018)
- ASM Handbook Vol.1 & Vol.19 — Superalloys, Fatigue and Fracture — ASM International (1996)
- MMPDS-17 Nickel Alloy Design Allowables — Battelle/FAA (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.