AISI 304H Stainless Steel vs. AISI 321H Stainless Steel
Both AISI 304H stainless steel and AISI 321H 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 AISI 304H stainless steel and the bottom bar is AISI 321H stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 180 | |
| 190 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 40 | |
| 40 |
| Fatigue Strength, MPa | 200 | |
| 200 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Reduction in Area, % | 51 | |
| 51 |
| Rockwell B Hardness | 79 | |
| 82 |
| Shear Modulus, GPa | 77 | |
| 77 |
| Shear Strength, MPa | 400 | |
| 400 |
| Tensile Strength: Ultimate (UTS), MPa | 580 | |
| 580 |
| Tensile Strength: Yield (Proof), MPa | 230 | |
| 230 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 290 |
| Maximum Temperature: Corrosion, °C | 420 | |
| 480 |
| Maximum Temperature: Mechanical, °C | 960 | |
| 940 |
| Melting Completion (Liquidus), °C | 1430 | |
| 1430 |
| Melting Onset (Solidus), °C | 1380 | |
| 1380 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 17 | |
| 15 |
| Thermal Expansion, µm/m-K | 16 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.4 | |
| 2.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.8 | |
| 2.7 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 15 | |
| 16 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 3.0 | |
| 3.2 |
| Embodied Energy, MJ/kg | 43 | |
| 46 |
| Embodied Water, L/kg | 150 | |
| 140 |
Common Calculations
| PREN (Pitting Resistance) | 19 | |
| 18 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 190 | |
| 190 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 130 | |
| 140 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 21 | |
| 21 |
| Strength to Weight: Bending, points | 20 | |
| 20 |
| Thermal Diffusivity, mm2/s | 4.5 | |
| 4.0 |
| Thermal Shock Resistance, points | 13 | |
| 12 |
Alloy Composition
| Carbon (C), % | 0.040 to 0.1 | |
| 0.040 to 0.1 |
| Chromium (Cr), % | 18 to 20 | |
| 17 to 19 |
| Iron (Fe), % | 66.6 to 74 | |
| 65.4 to 74 |
| Manganese (Mn), % | 0 to 2.0 | |
| 0 to 2.0 |
| Nickel (Ni), % | 8.0 to 10.5 | |
| 9.0 to 12 |
| Phosphorus (P), % | 0 to 0.045 | |
| 0 to 0.045 |
| Silicon (Si), % | 0 to 0.75 | |
| 0 to 0.75 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Titanium (Ti), % | 0 | |
| 0 to 0.7 |