S81921 Stainless Steel vs. Type 4 Niobium
S81921 stainless steel belongs to the iron alloys classification, while Type 4 niobium belongs to the otherwise unclassified metals. There are 21 material properties with values for both materials. Properties with values for just one material (13, in this case) are not shown.
For each property being compared, the top bar is S81921 stainless steel and the bottom bar is Type 4 niobium.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 260 | |
| 120 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 110 |
| Elongation at Break, % | 29 | |
| 23 |
| Poisson's Ratio | 0.28 | |
| 0.4 |
| Shear Modulus, GPa | 79 | |
| 38 |
| Tensile Strength: Ultimate (UTS), MPa | 710 | |
| 220 |
| Tensile Strength: Yield (Proof), MPa | 500 | |
| 140 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 310 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 270 |
| Thermal Conductivity, W/m-K | 15 | |
| 42 |
| Thermal Expansion, µm/m-K | 13 | |
| 7.3 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.7 | |
| 8.6 |
| Embodied Water, L/kg | 150 | |
| 160 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 180 | |
| 44 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 630 | |
| 93 |
| Stiffness to Weight: Axial, points | 14 | |
| 6.8 |
| Stiffness to Weight: Bending, points | 25 | |
| 18 |
| Strength to Weight: Axial, points | 25 | |
| 7.2 |
| Strength to Weight: Bending, points | 23 | |
| 9.5 |
| Thermal Diffusivity, mm2/s | 4.0 | |
| 18 |
| Thermal Shock Resistance, points | 20 | |
| 21 |
Alloy Composition
| Carbon (C), % | 0 to 0.030 | |
| 0 to 0.010 |
| Chromium (Cr), % | 19 to 22 | |
| 0 |
| Hafnium (Hf), % | 0 | |
| 0 to 0.020 |
| Hydrogen (H), % | 0 | |
| 0 to 0.0015 |
| Iron (Fe), % | 66.7 to 75.9 | |
| 0 to 0.010 |
| Manganese (Mn), % | 2.0 to 4.0 | |
| 0 |
| Molybdenum (Mo), % | 1.0 to 2.0 | |
| 0 to 0.050 |
| Nickel (Ni), % | 2.0 to 4.0 | |
| 0 to 0.0050 |
| Niobium (Nb), % | 0 | |
| 98.1 to 99.2 |
| Nitrogen (N), % | 0.14 to 0.2 | |
| 0 to 0.010 |
| Oxygen (O), % | 0 | |
| 0 to 0.025 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 0.0050 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |
| Tantalum (Ta), % | 0 | |
| 0 to 0.5 |
| Titanium (Ti), % | 0 | |
| 0 to 0.020 |
| Tungsten (W), % | 0 | |
| 0 to 0.050 |
| Zirconium (Zr), % | 0 | |
| 0.8 to 1.2 |