5251 Aluminum vs. ASTM A302 Alloy Steel
5251 aluminum belongs to the aluminum alloys classification, while ASTM A302 alloy 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 5251 aluminum and the bottom bar is ASTM A302 alloy steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 44 to 79 | |
| 180 to 190 |
| Elastic (Young's, Tensile) Modulus, GPa | 68 | |
| 190 |
| Elongation at Break, % | 2.0 to 19 | |
| 20 to 23 |
| Fatigue Strength, MPa | 59 to 110 | |
| 250 to 280 |
| Poisson's Ratio | 0.33 | |
| 0.29 |
| Shear Modulus, GPa | 26 | |
| 73 |
| Shear Strength, MPa | 110 to 160 | |
| 370 to 390 |
| Tensile Strength: Ultimate (UTS), MPa | 180 to 280 | |
| 590 to 620 |
| Tensile Strength: Yield (Proof), MPa | 67 to 250 | |
| 350 to 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 400 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 180 | |
| 410 |
| Melting Completion (Liquidus), °C | 650 | |
| 1460 |
| Melting Onset (Solidus), °C | 610 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 900 | |
| 470 |
| Thermal Conductivity, W/m-K | 150 | |
| 39 to 51 |
| Thermal Expansion, µm/m-K | 24 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 37 | |
| 7.2 to 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 120 | |
| 8.2 to 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.5 | |
| 2.4 to 3.0 |
| Density, g/cm3 | 2.7 | |
| 7.8 to 7.9 |
| Embodied Carbon, kg CO2/kg material | 8.5 | |
| 1.5 to 1.6 |
| Embodied Energy, MJ/kg | 150 | |
| 20 to 21 |
| Embodied Water, L/kg | 1180 | |
| 48 to 50 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 5.4 to 27 | |
| 110 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 33 to 450 | |
| 330 to 410 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 50 | |
| 24 |
| Strength to Weight: Axial, points | 18 to 29 | |
| 21 to 22 |
| Strength to Weight: Bending, points | 26 to 35 | |
| 20 to 21 |
| Thermal Diffusivity, mm2/s | 61 | |
| 10 to 14 |
| Thermal Shock Resistance, points | 7.9 to 13 | |
| 17 to 18 |