Nickel Alloy 718 (N07718, NA51)
Nickel 718 is a nickel alloy formulated for primary forming into wrought products. NA51 is the British Standard (BS) designation for this material. N07718 is the UNS number. And Nickel Alloy 718 is the common industry name.
It has a moderately low melting temperature among wrought nickels. In addition, it can have a moderately high tensile strength and has a moderately high embodied energy.
The properties of nickel 718 include five common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare nickel 718 to: wrought nickels (top), all nickel alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
12 to 50 %
Fatigue Strength
460 to 760 MPa 67 to 110 x 103 psi
Fracture Toughness
220 MPa-m1/2 200 x 103 psi-in1/2
Poisson's Ratio
0.29
Reduction in Area
34 to 64 %
Rockwell C Hardness
40
Shear Modulus
75 GPa 11 x 106 psi
Shear Strength
660 to 950 MPa 96 to 140 x 103 psi
Tensile Strength: Ultimate (UTS)
930 to 1530 MPa 130 to 220 x 103 psi
Tensile Strength: Yield (Proof)
510 to 1330 MPa 74 to 190 x 103 psi
Thermal Properties
Curie Temperature
-110 °C -170 °F
Latent Heat of Fusion
310 J/g
Maximum Temperature: Mechanical
980 °C 1790 °F
Melting Completion (Liquidus)
1340 °C 2440 °F
Melting Onset (Solidus)
1260 °C 2300 °F
Specific Heat Capacity
450 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
11 W/m-K 6.5 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
1.5 % IACS
Otherwise Unclassified Properties
Base Metal Price
75 % relative
Density
8.3 g/cm3 520 lb/ft3
Embodied Carbon
13 kg CO2/kg material
Embodied Energy
190 MJ/kg 80 x 103 BTU/lb
Embodied Water
250 L/kg 30 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
140 to 390 MJ/m3
Resilience: Unit (Modulus of Resilience)
660 to 4560 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
23 points
Strength to Weight: Axial
31 to 51 points
Strength to Weight: Bending
25 to 35 points
Thermal Diffusivity
3.0 mm2/s
Thermal Shock Resistance
27 to 44 points
Alloy Composition
| Ni | 50 to 55 | |
| Cr | 17 to 21 | |
| Fe | 11.1 to 24.6 | |
| Nb | 4.8 to 5.5 | |
| Mo | 2.8 to 3.3 | |
| Ti | 0.65 to 1.2 | |
| Co | 0 to 1.0 | |
| Al | 0.2 to 0.8 | |
| Mn | 0 to 0.35 | |
| Si | 0 to 0.35 | |
| Cu | 0 to 0.3 | |
| C | 0 to 0.080 | |
| P | 0 to 0.015 | |
| S | 0 to 0.015 | |
| B | 0 to 0.0060 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
Welding Metallurgy and Weldability of Nickel-Base Alloys, John C. Lippold et al., 2009
ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys, Joseph R. Davis (editor), 2000
Aerospace Materials, Brian Cantor et al. (editors), 2001
Engineering Properties of Nickel and Nickel Alloys, John L. Everhart, 1971
Nickel Alloys, Ulrich Heubner (editor), 1998