R30816 Cobalt vs. AISI 305 Stainless Steel
R30816 cobalt belongs to the cobalt alloys classification, while AISI 305 stainless steel belongs to the iron alloys. They have a modest 34% of their average alloy composition in common, which, by itself, doesn't mean much. There are 26 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown.
For each property being compared, the top bar is R30816 cobalt and the bottom bar is AISI 305 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 280 | |
| 170 to 220 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 200 |
| Elongation at Break, % | 23 | |
| 34 to 45 |
| Fatigue Strength, MPa | 250 | |
| 210 to 280 |
| Poisson's Ratio | 0.3 | |
| 0.28 |
| Shear Modulus, GPa | 81 | |
| 77 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 | |
| 580 to 710 |
| Tensile Strength: Yield (Proof), MPa | 460 | |
| 230 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 290 |
| Melting Completion (Liquidus), °C | 1540 | |
| 1450 |
| Melting Onset (Solidus), °C | 1460 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 420 | |
| 480 |
| Thermal Conductivity, W/m-K | 13 | |
| 16 |
| Thermal Expansion, µm/m-K | 12 | |
| 17 |
Otherwise Unclassified Properties
| Density, g/cm3 | 9.1 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 20 | |
| 3.2 |
| Embodied Energy, MJ/kg | 320 | |
| 45 |
| Embodied Water, L/kg | 440 | |
| 150 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 | |
| 200 to 210 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 510 | |
| 130 to 320 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 22 | |
| 25 |
| Strength to Weight: Axial, points | 31 | |
| 20 to 25 |
| Strength to Weight: Bending, points | 25 | |
| 20 to 23 |
| Thermal Diffusivity, mm2/s | 3.3 | |
| 4.2 |
| Thermal Shock Resistance, points | 28 | |
| 13 to 15 |
Alloy Composition
| Carbon (C), % | 0.32 to 0.42 | |
| 0 to 0.12 |
| Chromium (Cr), % | 19 to 21 | |
| 17 to 19 |
| Cobalt (Co), % | 40 to 49.8 | |
| 0 |
| Iron (Fe), % | 0 to 5.0 | |
| 65.1 to 72.5 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 2.0 |
| Molybdenum (Mo), % | 3.5 to 4.5 | |
| 0 |
| Nickel (Ni), % | 19 to 21 | |
| 10.5 to 13 |
| Niobium (Nb), % | 3.5 to 4.5 | |
| 0 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.045 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tantalum (Ta), % | 3.5 to 4.5 | |
| 0 |
| Tungsten (W), % | 3.5 to 4.5 | |
| 0 |