R30816 Cobalt vs. S17400 Stainless Steel
R30816 cobalt belongs to the cobalt alloys classification, while S17400 stainless steel belongs to the iron alloys. They have a modest 24% 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 S17400 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 280 | |
| 280 to 440 |
| Elastic (Young's, Tensile) Modulus, GPa | 210 | |
| 190 |
| Elongation at Break, % | 23 | |
| 11 to 21 |
| Fatigue Strength, MPa | 250 | |
| 380 to 670 |
| Poisson's Ratio | 0.3 | |
| 0.28 |
| Reduction in Area, % | 22 | |
| 40 to 62 |
| Shear Modulus, GPa | 81 | |
| 75 |
| Tensile Strength: Ultimate (UTS), MPa | 1020 | |
| 910 to 1390 |
| Tensile Strength: Yield (Proof), MPa | 460 | |
| 580 to 1250 |
Thermal Properties
| Latent Heat of Fusion, J/g | 300 | |
| 280 |
| Melting Completion (Liquidus), °C | 1540 | |
| 1440 |
| Melting Onset (Solidus), °C | 1460 | |
| 1400 |
| 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 | |
| 140 to 160 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 510 | |
| 880 to 4060 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 22 | |
| 25 |
| Strength to Weight: Axial, points | 31 | |
| 32 to 49 |
| Strength to Weight: Bending, points | 25 | |
| 27 to 35 |
| Thermal Diffusivity, mm2/s | 3.3 | |
| 4.5 |
| Thermal Shock Resistance, points | 28 | |
| 30 to 46 |
Alloy Composition
| Carbon (C), % | 0.32 to 0.42 | |
| 0 to 0.070 |
| Chromium (Cr), % | 19 to 21 | |
| 15 to 17 |
| Cobalt (Co), % | 40 to 49.8 | |
| 0 |
| Copper (Cu), % | 0 | |
| 3.0 to 5.0 |
| Iron (Fe), % | 0 to 5.0 | |
| 70.4 to 78.9 |
| Manganese (Mn), % | 1.0 to 2.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 3.5 to 4.5 | |
| 0 |
| Nickel (Ni), % | 19 to 21 | |
| 3.0 to 5.0 |
| 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 |