S81921 Stainless Steel vs. S82121 Stainless Steel
Both S81921 stainless steel and S82121 stainless steel are iron alloys. Both are furnished in the annealed condition. They have a very high 98% of their average alloy composition in common.
For each property being compared, the top bar is S81921 stainless steel and the bottom bar is S82121 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 260 | |
| 250 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 29 | |
| 28 |
| Fatigue Strength, MPa | 370 | |
| 370 |
| Poisson's Ratio | 0.28 | |
| 0.27 |
| Rockwell C Hardness | 27 | |
| 26 |
| Shear Modulus, GPa | 79 | |
| 78 |
| Shear Strength, MPa | 460 | |
| 470 |
| Tensile Strength: Ultimate (UTS), MPa | 710 | |
| 730 |
| Tensile Strength: Yield (Proof), MPa | 500 | |
| 510 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 290 |
| Maximum Temperature: Corrosion, °C | 430 | |
| 430 |
| Maximum Temperature: Mechanical, °C | 990 | |
| 1020 |
| Melting Completion (Liquidus), °C | 1430 | |
| 1430 |
| Melting Onset (Solidus), °C | 1390 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 15 | |
| 15 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.2 | |
| 2.2 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.5 | |
| 2.5 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 14 | |
| 14 |
| Density, g/cm3 | 7.7 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 2.9 | |
| 2.8 |
| Embodied Energy, MJ/kg | 41 | |
| 40 |
| Embodied Water, L/kg | 150 | |
| 150 |
Common Calculations
| PREN (Pitting Resistance) | 28 | |
| 28 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 180 | |
| 180 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 630 | |
| 660 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 25 | |
| 26 |
| Strength to Weight: Bending, points | 23 | |
| 23 |
| Thermal Diffusivity, mm2/s | 4.0 | |
| 4.0 |
| Thermal Shock Resistance, points | 20 | |
| 20 |
Alloy Composition
| Carbon (C), % | 0 to 0.030 | |
| 0 to 0.035 |
| Chromium (Cr), % | 19 to 22 | |
| 21 to 23 |
| Copper (Cu), % | 0 | |
| 0.2 to 1.2 |
| Iron (Fe), % | 66.7 to 75.9 | |
| 66.7 to 75.4 |
| Manganese (Mn), % | 2.0 to 4.0 | |
| 1.0 to 2.5 |
| Molybdenum (Mo), % | 1.0 to 2.0 | |
| 0.3 to 1.3 |
| Nickel (Ni), % | 2.0 to 4.0 | |
| 2.0 to 4.0 |
| Nitrogen (N), % | 0.14 to 0.2 | |
| 0.15 to 0.25 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.010 |