Nickel 718 vs. SAE-AISI 4340 Steel
Nickel 718 belongs to the nickel alloys classification, while SAE-AISI 4340 steel belongs to the iron alloys. They have a modest 21% of their average alloy composition in common, which, by itself, doesn't mean much. There are 30 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is nickel 718 and the bottom bar is SAE-AISI 4340 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 12 to 50 | |
| 12 to 22 |
| Fatigue Strength, MPa | 460 to 760 | |
| 330 to 740 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 75 | |
| 73 |
| Shear Strength, MPa | 660 to 950 | |
| 430 to 770 |
| Tensile Strength: Ultimate (UTS), MPa | 930 to 1530 | |
| 690 to 1280 |
| Tensile Strength: Yield (Proof), MPa | 510 to 1330 | |
| 470 to 1150 |
Thermal Properties
| Latent Heat of Fusion, J/g | 310 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 980 | |
| 430 |
| Melting Completion (Liquidus), °C | 1340 | |
| 1460 |
| Melting Onset (Solidus), °C | 1260 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 470 |
| Thermal Conductivity, W/m-K | 11 | |
| 44 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 1.4 | |
| 7.5 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 1.5 | |
| 8.6 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 75 | |
| 3.5 |
| Density, g/cm3 | 8.3 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 13 | |
| 1.7 |
| Embodied Energy, MJ/kg | 190 | |
| 22 |
| Embodied Water, L/kg | 250 | |
| 53 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 390 | |
| 79 to 170 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 660 to 4560 | |
| 590 to 3490 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 23 | |
| 24 |
| Strength to Weight: Axial, points | 31 to 51 | |
| 24 to 45 |
| Strength to Weight: Bending, points | 25 to 35 | |
| 22 to 33 |
| Thermal Diffusivity, mm2/s | 3.0 | |
| 12 |
| Thermal Shock Resistance, points | 27 to 44 | |
| 20 to 38 |
Alloy Composition
| Aluminum (Al), % | 0.2 to 0.8 | |
| 0 |
| Boron (B), % | 0 to 0.0060 | |
| 0 |
| Carbon (C), % | 0 to 0.080 | |
| 0.38 to 0.43 |
| Chromium (Cr), % | 17 to 21 | |
| 0.7 to 0.9 |
| Cobalt (Co), % | 0 to 1.0 | |
| 0 |
| Copper (Cu), % | 0 to 0.3 | |
| 0 |
| Iron (Fe), % | 11.1 to 24.6 | |
| 95.1 to 96.3 |
| Manganese (Mn), % | 0 to 0.35 | |
| 0.6 to 0.8 |
| Molybdenum (Mo), % | 2.8 to 3.3 | |
| 0.2 to 0.3 |
| Nickel (Ni), % | 50 to 55 | |
| 1.7 to 2.0 |
| Niobium (Nb), % | 4.8 to 5.5 | |
| 0 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.035 |
| Silicon (Si), % | 0 to 0.35 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.040 |
| Titanium (Ti), % | 0.65 to 1.2 | |
| 0 |