2018 Aluminum vs. ASTM A225 Steel
2018 aluminum belongs to the aluminum alloys classification, while ASTM A225 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 2018 aluminum and the bottom bar is ASTM A225 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 120 | |
| 190 to 250 |
| Elastic (Young's, Tensile) Modulus, GPa | 73 | |
| 190 |
| Elongation at Break, % | 9.6 | |
| 21 to 23 |
| Fatigue Strength, MPa | 120 | |
| 330 to 390 |
| Poisson's Ratio | 0.33 | |
| 0.29 |
| Shear Modulus, GPa | 27 | |
| 73 |
| Shear Strength, MPa | 270 | |
| 390 to 520 |
| Tensile Strength: Ultimate (UTS), MPa | 420 | |
| 620 to 830 |
| Tensile Strength: Yield (Proof), MPa | 310 | |
| 460 to 550 |
Thermal Properties
| Latent Heat of Fusion, J/g | 390 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 220 | |
| 400 |
| 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 | 150 | |
| 52 |
| Thermal Expansion, µm/m-K | 22 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 40 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 120 | |
| 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 | 8.1 | |
| 1.8 |
| Embodied Energy, MJ/kg | 150 | |
| 24 to 25 |
| Embodied Water, L/kg | 1130 | |
| 48 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 37 | |
| 120 to 170 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 670 | |
| 580 to 820 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 45 | |
| 24 |
| Strength to Weight: Axial, points | 38 | |
| 22 to 29 |
| Strength to Weight: Bending, points | 41 | |
| 21 to 25 |
| Thermal Diffusivity, mm2/s | 57 | |
| 14 |
| Thermal Shock Resistance, points | 19 | |
| 18 to 24 |