2218 Aluminum vs. SAE-AISI 8620 Steel
2218 aluminum belongs to the aluminum alloys classification, while SAE-AISI 8620 steel belongs to the iron alloys. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is 2218 aluminum and the bottom bar is SAE-AISI 8620 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 95 to 110 | |
| 150 to 210 |
| Elastic (Young's, Tensile) Modulus, GPa | 73 | |
| 190 |
| Elongation at Break, % | 6.8 to 10 | |
| 13 to 31 |
| Fatigue Strength, MPa | 110 | |
| 270 to 360 |
| Poisson's Ratio | 0.33 | |
| 0.29 |
| Shear Modulus, GPa | 27 | |
| 73 |
| Shear Strength, MPa | 210 to 250 | |
| 340 to 420 |
| Tensile Strength: Ultimate (UTS), MPa | 330 to 430 | |
| 520 to 690 |
| Tensile Strength: Yield (Proof), MPa | 260 to 310 | |
| 360 to 570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 390 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 220 | |
| 410 |
| Melting Completion (Liquidus), °C | 640 | |
| 1460 |
| Melting Onset (Solidus), °C | 510 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 470 |
| Thermal Conductivity, W/m-K | 140 | |
| 39 |
| Thermal Expansion, µm/m-K | 22 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 37 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 110 | |
| 8.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 11 | |
| 2.6 |
| Density, g/cm3 | 3.1 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.2 | |
| 1.5 |
| Embodied Energy, MJ/kg | 150 | |
| 20 |
| Embodied Water, L/kg | 1130 | |
| 50 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 27 to 31 | |
| 86 to 150 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 450 to 650 | |
| 340 to 880 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 45 | |
| 24 |
| Strength to Weight: Axial, points | 30 to 39 | |
| 18 to 24 |
| Strength to Weight: Bending, points | 34 to 41 | |
| 18 to 22 |
| Thermal Diffusivity, mm2/s | 52 | |
| 10 |
| Thermal Shock Resistance, points | 15 to 19 | |
| 15 to 20 |
Alloy Composition
| Aluminum (Al), % | 88.8 to 93.6 | |
| 0 |
| Carbon (C), % | 0 | |
| 0.18 to 0.23 |
| Chromium (Cr), % | 0 to 0.1 | |
| 0.4 to 0.6 |
| Copper (Cu), % | 3.5 to 4.5 | |
| 0 |
| Iron (Fe), % | 0 to 1.0 | |
| 96.9 to 98 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 0 |
| Manganese (Mn), % | 0 to 0.2 | |
| 0.7 to 0.9 |
| Molybdenum (Mo), % | 0 | |
| 0.15 to 0.25 |
| Nickel (Ni), % | 1.7 to 2.3 | |
| 0.4 to 0.7 |
| Phosphorus (P), % | 0 | |
| 0 to 0.035 |
| Silicon (Si), % | 0 to 0.9 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 | |
| 0 to 0.040 |
| Zinc (Zn), % | 0 to 0.25 | |
| 0 |
| Residuals, % | 0 to 0.15 | |
| 0 |