ASTM B685 Alloy vs. S21904 Stainless Steel
ASTM B685 alloy belongs to the otherwise unclassified metals classification, while S21904 stainless steel belongs to the iron alloys. There are 17 material properties with values for both materials. Properties with values for just one material (16, in this case) are not shown.
For each property being compared, the top bar is ASTM B685 alloy and the bottom bar is S21904 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 120 | |
| 200 |
| Poisson's Ratio | 0.37 | |
| 0.28 |
| Shear Modulus, GPa | 43 | |
| 78 |
| Tensile Strength: Ultimate (UTS), MPa | 660 to 1060 | |
| 700 to 1000 |
Thermal Properties
| Latent Heat of Fusion, J/g | 180 | |
| 290 |
| Melting Completion (Liquidus), °C | 1230 | |
| 1400 |
| Melting Onset (Solidus), °C | 1200 | |
| 1350 |
| Specific Heat Capacity, J/kg-K | 300 | |
| 480 |
| Thermal Expansion, µm/m-K | 14 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 5.0 | |
| 2.5 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 4.1 | |
| 2.9 |
Otherwise Unclassified Properties
| Density, g/cm3 | 11 | |
| 7.7 |
Common Calculations
| Stiffness to Weight: Axial, points | 6.1 | |
| 14 |
| Stiffness to Weight: Bending, points | 15 | |
| 25 |
| Strength to Weight: Axial, points | 17 to 27 | |
| 25 to 36 |
| Strength to Weight: Bending, points | 16 to 21 | |
| 23 to 29 |
| Thermal Shock Resistance, points | 28 to 46 | |
| 15 to 21 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.0050 | |
| 0 |
| Cadmium (Cd), % | 0 to 0.050 | |
| 0 |
| Carbon (C), % | 0 | |
| 0 to 0.040 |
| Chromium (Cr), % | 0 | |
| 19 to 21.5 |
| Copper (Cu), % | 39.5 to 40.5 | |
| 0 |
| Iron (Fe), % | 0 to 0.050 | |
| 59.5 to 67.4 |
| Lead (Pb), % | 0 to 0.030 | |
| 0 |
| Manganese (Mn), % | 0 | |
| 8.0 to 10 |
| Nickel (Ni), % | 0 | |
| 5.5 to 7.5 |
| Nitrogen (N), % | 0 | |
| 0.15 to 0.4 |
| Palladium (Pd), % | 59 to 60.5 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.045 |
| Silicon (Si), % | 0 | |
| 0 to 1.0 |
| Silver (Ag), % | 0 to 0.1 | |
| 0 |
| Sulfur (S), % | 0 | |
| 0 to 0.030 |
| Zinc (Zn), % | 0 to 0.060 | |
| 0 |
| Residuals, % | 0 to 0.2 | |
| 0 |