7021 Aluminum vs. AISI 420 Stainless Steel
7021 aluminum belongs to the aluminum alloys classification, while AISI 420 stainless steel belongs to the iron alloys. There are 30 material properties with values for both materials. Properties with values for just one material (4, 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 AISI 420 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 69 | |
| 190 |
| Elongation at Break, % | 9.4 | |
| 8.0 to 15 |
| Fatigue Strength, MPa | 150 | |
| 220 to 670 |
| Poisson's Ratio | 0.32 | |
| 0.28 |
| Shear Modulus, GPa | 26 | |
| 76 |
| Shear Strength, MPa | 270 | |
| 420 to 1010 |
| Tensile Strength: Ultimate (UTS), MPa | 460 | |
| 690 to 1720 |
| Tensile Strength: Yield (Proof), MPa | 390 | |
| 380 to 1310 |
Thermal Properties
| Latent Heat of Fusion, J/g | 380 | |
| 280 |
| Maximum Temperature: Mechanical, °C | 200 | |
| 620 |
| Melting Completion (Liquidus), °C | 630 | |
| 1510 |
| Melting Onset (Solidus), °C | 510 | |
| 1450 |
| Specific Heat Capacity, J/kg-K | 870 | |
| 480 |
| Thermal Conductivity, W/m-K | 150 | |
| 27 |
| Thermal Expansion, µm/m-K | 24 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 38 | |
| 3.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 120 | |
| 3.5 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.5 | |
| 7.5 |
| Density, g/cm3 | 2.9 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 8.3 | |
| 2.0 |
| Embodied Energy, MJ/kg | 150 | |
| 28 |
| Embodied Water, L/kg | 1140 | |
| 100 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 41 | |
| 88 to 130 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1110 | |
| 380 to 4410 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 47 | |
| 25 |
| Strength to Weight: Axial, points | 44 | |
| 25 to 62 |
| Strength to Weight: Bending, points | 45 | |
| 22 to 41 |
| Thermal Diffusivity, mm2/s | 59 | |
| 7.3 |
| Thermal Shock Resistance, points | 20 | |
| 25 to 62 |
Alloy Composition
| Aluminum (Al), % | 90.7 to 93.7 | |
| 0 |
| Carbon (C), % | 0 | |
| 0.15 to 0.4 |
| Chromium (Cr), % | 0 to 0.050 | |
| 12 to 14 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 |
| Iron (Fe), % | 0 to 0.4 | |
| 82.3 to 87.9 |
| Magnesium (Mg), % | 1.2 to 1.8 | |
| 0 |
| Manganese (Mn), % | 0 to 0.1 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 | |
| 0 to 0.5 |
| Nickel (Ni), % | 0 | |
| 0 to 0.75 |
| Phosphorus (P), % | 0 | |
| 0 to 0.040 |
| 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 |