7021 Aluminum vs. ACI-ASTM CB7Cu-1 Steel
7021 aluminum belongs to the aluminum alloys classification, while ACI-ASTM CB7Cu-1 steel belongs to the iron alloys. There are 28 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown. 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 7021 aluminum and the bottom bar is ACI-ASTM CB7Cu-1 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 69 | |
| 190 |
| Elongation at Break, % | 9.4 | |
| 5.7 to 11 |
| Fatigue Strength, MPa | 150 | |
| 420 to 590 |
| Poisson's Ratio | 0.32 | |
| 0.28 |
| Shear Modulus, GPa | 26 | |
| 76 |
| Tensile Strength: Ultimate (UTS), MPa | 460 | |
| 960 to 1350 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 760 to 1180 |
Thermal Properties
| Latent Heat of Fusion, J/g | 380 | |
| 280 |
| Melting Completion (Liquidus), °C | 630 | |
| 1430 |
| Melting Onset (Solidus), °C | 510 | |
| 1500 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 480 |
| Thermal Conductivity, W/m-K | 150 | |
| 17 |
| Thermal Expansion, µm/m-K | 24 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 38 | |
| 2.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 120 | |
| 2.3 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.5 | |
| 13 |
| Density, g/cm3 | 2.9 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 8.3 | |
| 2.6 |
| Embodied Energy, MJ/kg | 150 | |
| 38 |
| Embodied Water, L/kg | 1140 | |
| 130 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 41 | |
| 71 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1110 | |
| 1500 to 3590 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 47 | |
| 25 |
| Strength to Weight: Axial, points | 44 | |
| 34 to 48 |
| Strength to Weight: Bending, points | 45 | |
| 28 to 35 |
| Thermal Diffusivity, mm2/s | 59 | |
| 4.6 |
| Thermal Shock Resistance, points | 20 | |
| 32 to 45 |
Alloy Composition
| Aluminum (Al), % | 90.7 to 93.7 | |
| 0 |
| Carbon (C), % | 0 | |
| 0 to 0.070 |
| Chromium (Cr), % | 0 to 0.050 | |
| 15.5 to 17.7 |
| Copper (Cu), % | 0 to 0.25 | |
| 2.5 to 3.2 |
| Iron (Fe), % | 0 to 0.4 | |
| 72.3 to 78.4 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 0 |
| Manganese (Mn), % | 0 to 0.1 | |
| 0 to 0.7 |
| Nickel (Ni), % | 0 | |
| 3.6 to 4.6 |
| Niobium (Nb), % | 0 | |
| 0 to 0.35 |
| Nitrogen (N), % | 0 | |
| 0 to 0.050 |
| Phosphorus (P), % | 0 | |
| 0 to 0.035 |
| Silicon (Si), % | 0 to 0.25 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Titanium (Ti), % | 0 to 0.1 | |
| 0 |
| Zinc (Zn), % | 5.0 to 6.0 | |
| 0 |
| Zirconium (Zr), % | 0.080 to 0.18 | |
| 0 |
| Residuals, % | 0 to 0.15 | |
| 0 |