R30816 Cobalt vs. S15500 Stainless Steel
R30816 cobalt belongs to the cobalt alloys classification, while S15500 stainless steel belongs to the iron alloys. They have a modest 23% of their average alloy composition in common, which, by itself, doesn't mean much. There are 27 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 S15500 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 280 | |
| 290 to 430 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 23 | |
| 6.8 to 16 |
| Fatigue Strength, MPa | 250 | |
| 350 to 650 |
| Poisson's Ratio | 0.3 | |
| 0.28 |
| Reduction in Area, % | 22 | |
| 17 to 40 |
| Shear Modulus, GPa | 81 | |
| 75 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 | |
| 890 to 1490 |
| Tensile Strength: Yield (Proof), MPa | 460 | |
| 590 to 1310 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 280 |
| Melting Completion (Liquidus), °C | 1540 | |
| 1430 |
| Melting Onset (Solidus), °C | 1460 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 420 | |
| 480 |
| Thermal Conductivity, W/m-K | 13 | |
| 17 |
| Thermal Expansion, µm/m-K | 12 | |
| 11 |
Otherwise Unclassified Properties
| Density, g/cm3 | 9.1 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 20 | |
| 2.7 |
| Embodied Energy, MJ/kg | 320 | |
| 39 |
| Embodied Water, L/kg | 440 | |
| 130 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 | |
| 98 to 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 510 | |
| 890 to 4460 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 22 | |
| 25 |
| Strength to Weight: Axial, points | 31 | |
| 32 to 53 |
| Strength to Weight: Bending, points | 25 | |
| 26 to 37 |
| Thermal Diffusivity, mm2/s | 3.3 | |
| 4.6 |
| Thermal Shock Resistance, points | 28 | |
| 30 to 50 |
Alloy Composition
| Carbon (C), % | 0.32 to 0.42 | |
| 0 to 0.070 |
| Chromium (Cr), % | 19 to 21 | |
| 14 to 15.5 |
| Cobalt (Co), % | 40 to 49.8 | |
| 0 |
| Copper (Cu), % | 0 | |
| 2.5 to 4.5 |
| Iron (Fe), % | 0 to 5.0 | |
| 71.9 to 79.9 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 3.5 to 4.5 | |
| 0 |
| Nickel (Ni), % | 19 to 21 | |
| 3.5 to 5.5 |
| Niobium (Nb), % | 3.5 to 4.5 | |
| 0.15 to 0.45 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| 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 |