ASTM B685 Alloy vs. R31538 Cobalt
ASTM B685 alloy belongs to the otherwise unclassified metals classification, while R31538 cobalt belongs to the cobalt alloys. There are 17 material properties with values for both materials. Properties with values for just one material (12, in this case) are not shown.
For each property being compared, the top bar is ASTM B685 alloy and the bottom bar is R31538 cobalt.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 120 | |
| 220 |
| Poisson's Ratio | 0.37 | |
| 0.29 |
| Shear Modulus, GPa | 43 | |
| 86 |
| Tensile Strength: Ultimate (UTS), MPa | 660 to 1060 | |
| 1020 to 1360 |
Thermal Properties
| Latent Heat of Fusion, J/g | 180 | |
| 320 |
| Melting Completion (Liquidus), °C | 1230 | |
| 1360 |
| Melting Onset (Solidus), °C | 1200 | |
| 1290 |
| Specific Heat Capacity, J/kg-K | 300 | |
| 450 |
| Thermal Expansion, µm/m-K | 14 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 5.0 | |
| 2.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 4.1 | |
| 2.1 |
Otherwise Unclassified Properties
| Density, g/cm3 | 11 | |
| 8.4 |
Common Calculations
| Stiffness to Weight: Axial, points | 6.1 | |
| 15 |
| Stiffness to Weight: Bending, points | 15 | |
| 24 |
| Strength to Weight: Axial, points | 17 to 27 | |
| 34 to 45 |
| Strength to Weight: Bending, points | 16 to 21 | |
| 27 to 32 |
| Thermal Shock Resistance, points | 28 to 46 | |
| 25 to 33 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.0050 | |
| 0 |
| Cadmium (Cd), % | 0 to 0.050 | |
| 0 |
| Carbon (C), % | 0 | |
| 0.15 to 0.35 |
| Chromium (Cr), % | 0 | |
| 26 to 30 |
| Cobalt (Co), % | 0 | |
| 58.7 to 68.9 |
| Copper (Cu), % | 39.5 to 40.5 | |
| 0 |
| Iron (Fe), % | 0 to 0.050 | |
| 0 to 0.75 |
| Lead (Pb), % | 0 to 0.030 | |
| 0 |
| Manganese (Mn), % | 0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 | |
| 5.0 to 7.0 |
| Nickel (Ni), % | 0 | |
| 0 to 1.0 |
| Nitrogen (N), % | 0 | |
| 0 to 0.25 |
| Palladium (Pd), % | 59 to 60.5 | |
| 0 |
| Silicon (Si), % | 0 | |
| 0 to 1.0 |
| Silver (Ag), % | 0 to 0.1 | |
| 0 |
| Zinc (Zn), % | 0 to 0.060 | |
| 0 |
| Residuals, % | 0 to 0.2 | |
| 0 |