Annealed SAE-AISI A7 vs. Annealed R30008 Cobalt
Annealed SAE-AISI A7 belongs to the iron alloys classification, while annealed R30008 cobalt belongs to the cobalt alloys. They have a modest 21% of their average alloy composition in common, which, by itself, doesn't mean much. There are 19 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.
For each property being compared, the top bar is annealed SAE-AISI A7 and the bottom bar is annealed R30008 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 210 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 72 | |
| 83 |
| Tensile Strength: Ultimate (UTS), MPa | 800 | |
| 950 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 320 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1400 |
| Melting Onset (Solidus), °C | 1430 | |
| 1330 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 450 |
| Thermal Expansion, µm/m-K | 12 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 10 | |
| 95 |
| Density, g/cm3 | 7.7 | |
| 8.4 |
| Embodied Carbon, kg CO2/kg material | 13 | |
| 8.1 |
| Embodied Energy, MJ/kg | 200 | |
| 110 |
| Embodied Water, L/kg | 100 | |
| 400 |
Common Calculations
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 29 | |
| 31 |
| Strength to Weight: Bending, points | 25 | |
| 25 |
| Thermal Shock Resistance, points | 27 | |
| 25 |
Alloy Composition
| Boron (B), % | 0 | |
| 0 to 0.0010 |
| Carbon (C), % | 2.0 to 2.9 | |
| 0 to 0.15 |
| Chromium (Cr), % | 5.0 to 5.8 | |
| 18.5 to 21.5 |
| Cobalt (Co), % | 0 | |
| 39 to 42 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 |
| Iron (Fe), % | 81.4 to 87.7 | |
| 7.6 to 20 |
| Manganese (Mn), % | 0 to 0.8 | |
| 1.0 to 2.0 |
| Molybdenum (Mo), % | 0.9 to 1.4 | |
| 6.5 to 7.5 |
| Nickel (Ni), % | 0 to 0.3 | |
| 15 to 18 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.015 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 to 1.2 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.015 |
| Tungsten (W), % | 0.5 to 1.5 | |
| 0 |
| Vanadium (V), % | 3.9 to 5.2 | |
| 0 |