Nickel 718 vs. AISI 321 Stainless Steel
Nickel 718 belongs to the nickel alloys classification, while AISI 321 stainless steel belongs to the iron alloys. They have 47% of their average alloy composition in common. There are 30 material properties with values for both materials. Properties with values for just one material (7, in this case) are not shown.
For each property being compared, the top bar is nickel 718 and the bottom bar is AISI 321 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 12 to 50 | |
| 34 to 50 |
| Fatigue Strength, MPa | 460 to 760 | |
| 220 to 270 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 75 | |
| 77 |
| Shear Strength, MPa | 660 to 950 | |
| 420 to 460 |
| Tensile Strength: Ultimate (UTS), MPa | 930 to 1530 | |
| 590 to 690 |
| Tensile Strength: Yield (Proof), MPa | 510 to 1330 | |
| 220 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 310 | |
| 290 |
| Maximum Temperature: Mechanical, °C | 980 | |
| 870 |
| Melting Completion (Liquidus), °C | 1340 | |
| 1430 |
| Melting Onset (Solidus), °C | 1260 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 450 | |
| 480 |
| Thermal Conductivity, W/m-K | 11 | |
| 16 |
| Thermal Expansion, µm/m-K | 13 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 1.4 | |
| 2.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 1.5 | |
| 2.7 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 75 | |
| 16 |
| Density, g/cm3 | 8.3 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 13 | |
| 3.2 |
| Embodied Energy, MJ/kg | 190 | |
| 45 |
| Embodied Water, L/kg | 250 | |
| 140 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 140 to 390 | |
| 190 to 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 660 to 4560 | |
| 130 to 310 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 23 | |
| 25 |
| Strength to Weight: Axial, points | 31 to 51 | |
| 21 to 25 |
| Strength to Weight: Bending, points | 25 to 35 | |
| 20 to 22 |
| Thermal Diffusivity, mm2/s | 3.0 | |
| 4.1 |
| Thermal Shock Resistance, points | 27 to 44 | |
| 13 to 15 |
Alloy Composition
| Aluminum (Al), % | 0.2 to 0.8 | |
| 0 |
| Boron (B), % | 0 to 0.0060 | |
| 0 |
| Carbon (C), % | 0 to 0.080 | |
| 0 to 0.080 |
| Chromium (Cr), % | 17 to 21 | |
| 17 to 19 |
| Cobalt (Co), % | 0 to 1.0 | |
| 0 |
| Copper (Cu), % | 0 to 0.3 | |
| 0 |
| Iron (Fe), % | 11.1 to 24.6 | |
| 65.3 to 74 |
| Manganese (Mn), % | 0 to 0.35 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 2.8 to 3.3 | |
| 0 |
| Nickel (Ni), % | 50 to 55 | |
| 9.0 to 12 |
| Niobium (Nb), % | 4.8 to 5.5 | |
| 0 |
| Nitrogen (N), % | 0 | |
| 0 to 0.1 |
| Phosphorus (P), % | 0 to 0.015 | |
| 0 to 0.045 |
| Silicon (Si), % | 0 to 0.35 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.030 |
| Titanium (Ti), % | 0.65 to 1.2 | |
| 0 to 0.7 |