Nickel 685 vs. S21900 Stainless Steel
Nickel 685 belongs to the nickel alloys classification, while S21900 stainless steel belongs to the iron alloys. They have a modest 28% of their average alloy composition in common, which, by itself, doesn't mean much. There are 30 material properties with values for both materials. Properties with values for just one material (4, in this case) are not shown.
For each property being compared, the top bar is nickel 685 and the bottom bar is S21900 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 350 | |
| 220 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 17 | |
| 50 |
| Fatigue Strength, MPa | 470 | |
| 380 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Reduction in Area, % | 20 | |
| 57 |
| Shear Modulus, GPa | 77 | |
| 78 |
| Shear Strength, MPa | 770 | |
| 510 |
| Tensile Strength: Ultimate (UTS), MPa | 1250 | |
| 710 |
| Tensile Strength: Yield (Proof), MPa | 850 | |
| 390 |
Thermal Properties
| Latent Heat of Fusion, J/g | 320 | |
| 290 |
| Maximum Temperature: Mechanical, °C | 1000 | |
| 980 |
| Melting Completion (Liquidus), °C | 1380 | |
| 1400 |
| Melting Onset (Solidus), °C | 1330 | |
| 1350 |
| Specific Heat Capacity, J/kg-K | 460 | |
| 480 |
| Thermal Conductivity, W/m-K | 13 | |
| 14 |
| Thermal Expansion, µm/m-K | 12 | |
| 17 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 75 | |
| 15 |
| Density, g/cm3 | 8.4 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 10 | |
| 3.0 |
| Embodied Energy, MJ/kg | 140 | |
| 43 |
| Embodied Water, L/kg | 340 | |
| 160 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 | |
| 300 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1820 | |
| 380 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 23 | |
| 25 |
| Strength to Weight: Axial, points | 42 | |
| 26 |
| Strength to Weight: Bending, points | 31 | |
| 23 |
| Thermal Diffusivity, mm2/s | 3.3 | |
| 3.8 |
| Thermal Shock Resistance, points | 37 | |
| 15 |
Alloy Composition
| Aluminum (Al), % | 1.2 to 1.6 | |
| 0 |
| Boron (B), % | 0.0030 to 0.010 | |
| 0 |
| Carbon (C), % | 0.030 to 0.1 | |
| 0 to 0.080 |
| Chromium (Cr), % | 18 to 21 | |
| 19 to 21.5 |
| Cobalt (Co), % | 12 to 15 | |
| 0 |
| Copper (Cu), % | 0 to 0.5 | |
| 0 |
| Iron (Fe), % | 0 to 2.0 | |
| 59.4 to 67.4 |
| Manganese (Mn), % | 0 to 1.0 | |
| 8.0 to 10 |
| Molybdenum (Mo), % | 3.5 to 5.0 | |
| 0 |
| Nickel (Ni), % | 49.6 to 62.5 | |
| 5.5 to 7.5 |
| Nitrogen (N), % | 0 | |
| 0.15 to 0.4 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.045 |
| Silicon (Si), % | 0 to 0.75 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Titanium (Ti), % | 2.8 to 3.3 | |
| 0 |
| Zinc (Zn), % | 0.020 to 0.12 | |
| 0 |