2218 Aluminum vs. SAE-AISI 6150 Steel
2218 aluminum belongs to the aluminum alloys classification, while SAE-AISI 6150 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 6150 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 95 to 110 | |
| 200 to 350 |
| Elastic (Young's, Tensile) Modulus, GPa | 73 | |
| 190 |
| Elongation at Break, % | 6.8 to 10 | |
| 15 to 23 |
| Fatigue Strength, MPa | 110 | |
| 300 to 750 |
| Poisson's Ratio | 0.33 | |
| 0.29 |
| Shear Modulus, GPa | 27 | |
| 73 |
| Shear Strength, MPa | 210 to 250 | |
| 400 to 730 |
| Tensile Strength: Ultimate (UTS), MPa | 330 to 430 | |
| 630 to 1200 |
| Tensile Strength: Yield (Proof), MPa | 260 to 310 | |
| 420 to 1160 |
Thermal Properties
| Latent Heat of Fusion, J/g | 390 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 220 | |
| 420 |
| Melting Completion (Liquidus), °C | 640 | |
| 1460 |
| Melting Onset (Solidus), °C | 510 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 470 |
| Thermal Conductivity, W/m-K | 140 | |
| 46 |
| Thermal Expansion, µm/m-K | 22 | |
| 12 to 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 37 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 110 | |
| 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 11 | |
| 2.3 |
| Density, g/cm3 | 3.1 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.2 | |
| 2.0 |
| Embodied Energy, MJ/kg | 150 | |
| 28 |
| Embodied Water, L/kg | 1130 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 27 to 31 | |
| 130 to 180 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 450 to 650 | |
| 460 to 3590 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 45 | |
| 24 |
| Strength to Weight: Axial, points | 30 to 39 | |
| 22 to 43 |
| Strength to Weight: Bending, points | 34 to 41 | |
| 21 to 32 |
| Thermal Diffusivity, mm2/s | 52 | |
| 13 |
| Thermal Shock Resistance, points | 15 to 19 | |
| 20 to 38 |
Alloy Composition
| Aluminum (Al), % | 88.8 to 93.6 | |
| 0 |
| Carbon (C), % | 0 | |
| 0.48 to 0.53 |
| Chromium (Cr), % | 0 to 0.1 | |
| 0.8 to 1.1 |
| Copper (Cu), % | 3.5 to 4.5 | |
| 0 |
| Iron (Fe), % | 0 to 1.0 | |
| 96.7 to 97.7 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 0 |
| Manganese (Mn), % | 0 to 0.2 | |
| 0.7 to 0.9 |
| Nickel (Ni), % | 1.7 to 2.3 | |
| 0 |
| 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 |
| Vanadium (V), % | 0 | |
| 0.15 to 0.3 |
| Zinc (Zn), % | 0 to 0.25 | |
| 0 |
| Residuals, % | 0 to 0.15 | |
| 0 |