S21904 Stainless Steel vs. Type 2 Niobium
S21904 stainless steel belongs to the iron alloys classification, while Type 2 niobium belongs to the otherwise unclassified metals. There are 21 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 S21904 stainless steel and the bottom bar is Type 2 niobium.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 210 to 300 | |
| 110 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 110 |
| Elongation at Break, % | 17 to 51 | |
| 29 |
| Poisson's Ratio | 0.28 | |
| 0.4 |
| Shear Modulus, GPa | 78 | |
| 38 |
| Tensile Strength: Ultimate (UTS), MPa | 700 to 1000 | |
| 140 |
| Tensile Strength: Yield (Proof), MPa | 390 to 910 | |
| 82 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 320 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 270 |
| Thermal Conductivity, W/m-K | 14 | |
| 52 |
| Thermal Expansion, µm/m-K | 17 | |
| 7.3 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.7 | |
| 8.6 |
| Embodied Water, L/kg | 160 | |
| 160 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 160 to 310 | |
| 35 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 380 to 2070 | |
| 32 |
| Stiffness to Weight: Axial, points | 14 | |
| 6.8 |
| Stiffness to Weight: Bending, points | 25 | |
| 18 |
| Strength to Weight: Axial, points | 25 to 36 | |
| 4.6 |
| Strength to Weight: Bending, points | 23 to 29 | |
| 7.1 |
| Thermal Diffusivity, mm2/s | 3.8 | |
| 23 |
| Thermal Shock Resistance, points | 15 to 21 | |
| 13 |
Alloy Composition
| Carbon (C), % | 0 to 0.040 | |
| 0 to 0.010 |
| Chromium (Cr), % | 19 to 21.5 | |
| 0 |
| Hafnium (Hf), % | 0 | |
| 0 to 0.020 |
| Hydrogen (H), % | 0 | |
| 0 to 0.0015 |
| Iron (Fe), % | 59.5 to 67.4 | |
| 0 to 0.010 |
| Manganese (Mn), % | 8.0 to 10 | |
| 0 |
| Molybdenum (Mo), % | 0 | |
| 0 to 0.020 |
| Nickel (Ni), % | 5.5 to 7.5 | |
| 0 to 0.0050 |
| Niobium (Nb), % | 0 | |
| 99.5 to 100 |
| Nitrogen (N), % | 0.15 to 0.4 | |
| 0 to 0.010 |
| Oxygen (O), % | 0 | |
| 0 to 0.025 |
| Phosphorus (P), % | 0 to 0.045 | |
| 0 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.0050 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |
| Tantalum (Ta), % | 0 | |
| 0 to 0.3 |
| Titanium (Ti), % | 0 | |
| 0 to 0.030 |
| Tungsten (W), % | 0 | |
| 0 to 0.050 |
| Zirconium (Zr), % | 0 | |
| 0 to 0.020 |