AISI 304 Stainless Steel vs. R30816 Cobalt
AISI 304 stainless steel belongs to the iron alloys classification, while R30816 cobalt belongs to the cobalt alloys. They have a modest 32% 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 AISI 304 stainless steel and the bottom bar is R30816 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 170 to 360 | |
| 280 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 210 |
| Elongation at Break, % | 8.0 to 43 | |
| 23 |
| Fatigue Strength, MPa | 210 to 440 | |
| 250 |
| Poisson's Ratio | 0.28 | |
| 0.3 |
| Shear Modulus, GPa | 77 | |
| 81 |
| Tensile Strength: Ultimate (UTS), MPa | 580 to 1180 | |
| 1020 |
| Tensile Strength: Yield (Proof), MPa | 230 to 860 | |
| 460 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 300 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1540 |
| Melting Onset (Solidus), °C | 1400 | |
| 1460 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 420 |
| Thermal Conductivity, W/m-K | 16 | |
| 13 |
| Thermal Expansion, µm/m-K | 17 | |
| 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.8 | |
| 9.1 |
| Embodied Carbon, kg CO2/kg material | 3.0 | |
| 20 |
| Embodied Energy, MJ/kg | 43 | |
| 320 |
| Embodied Water, L/kg | 150 | |
| 440 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 86 to 250 | |
| 190 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 140 to 1870 | |
| 510 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 22 |
| Strength to Weight: Axial, points | 21 to 42 | |
| 31 |
| Strength to Weight: Bending, points | 20 to 32 | |
| 25 |
| Thermal Diffusivity, mm2/s | 4.2 | |
| 3.3 |
| Thermal Shock Resistance, points | 12 to 25 | |
| 28 |
Alloy Composition
| Carbon (C), % | 0 to 0.080 | |
| 0.32 to 0.42 |
| Chromium (Cr), % | 18 to 20 | |
| 19 to 21 |
| Cobalt (Co), % | 0 | |
| 40 to 49.8 |
| Iron (Fe), % | 66.5 to 74 | |
| 0 to 5.0 |
| Manganese (Mn), % | 0 to 2.0 | |
| 1.0 to 2.0 |
| Molybdenum (Mo), % | 0 | |
| 3.5 to 4.5 |
| Nickel (Ni), % | 8.0 to 10.5 | |
| 19 to 21 |
| Niobium (Nb), % | 0 | |
| 3.5 to 4.5 |
| Nitrogen (N), % | 0 to 0.1 | |
| 0 |
| Phosphorus (P), % | 0 to 0.045 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 0.75 | |
| 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 |