S17700 Stainless Steel vs. R30816 Cobalt
S17700 stainless steel belongs to the iron alloys classification, while R30816 cobalt belongs to the cobalt alloys. They have a modest 28% 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 S17700 stainless steel and the bottom bar is R30816 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 180 to 430 | |
| 280 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 210 |
| Elongation at Break, % | 1.0 to 23 | |
| 23 |
| Fatigue Strength, MPa | 290 to 560 | |
| 250 |
| Poisson's Ratio | 0.28 | |
| 0.3 |
| Shear Modulus, GPa | 76 | |
| 81 |
| Tensile Strength: Ultimate (UTS), MPa | 1180 to 1650 | |
| 1020 |
| Tensile Strength: Yield (Proof), MPa | 430 to 1210 | |
| 460 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 300 |
| Melting Completion (Liquidus), °C | 1440 | |
| 1540 |
| Melting Onset (Solidus), °C | 1400 | |
| 1460 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 420 |
| Thermal Conductivity, W/m-K | 15 | |
| 13 |
| Thermal Expansion, µm/m-K | 11 | |
| 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.7 | |
| 9.1 |
| Embodied Carbon, kg CO2/kg material | 2.8 | |
| 20 |
| Embodied Energy, MJ/kg | 40 | |
| 320 |
| Embodied Water, L/kg | 150 | |
| 440 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 15 to 210 | |
| 190 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 460 to 3750 | |
| 510 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 22 |
| Strength to Weight: Axial, points | 42 to 59 | |
| 31 |
| Strength to Weight: Bending, points | 32 to 40 | |
| 25 |
| Thermal Diffusivity, mm2/s | 4.1 | |
| 3.3 |
| Thermal Shock Resistance, points | 39 to 54 | |
| 28 |
Alloy Composition
| Aluminum (Al), % | 0.75 to 1.5 | |
| 0 |
| Carbon (C), % | 0 to 0.090 | |
| 0.32 to 0.42 |
| Chromium (Cr), % | 16 to 18 | |
| 19 to 21 |
| Cobalt (Co), % | 0 | |
| 40 to 49.8 |
| Iron (Fe), % | 70.5 to 76.8 | |
| 0 to 5.0 |
| Manganese (Mn), % | 0 to 1.0 | |
| 1.0 to 2.0 |
| Molybdenum (Mo), % | 0 | |
| 3.5 to 4.5 |
| Nickel (Ni), % | 6.5 to 7.8 | |
| 19 to 21 |
| Niobium (Nb), % | 0 | |
| 3.5 to 4.5 |
| 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), % | 0 | |
| 3.5 to 4.5 |
| Tungsten (W), % | 0 | |
| 3.5 to 4.5 |