AISI 304 Stainless Steel vs. AISI 321 Stainless Steel
Both AISI 304 stainless steel and AISI 321 stainless steel are iron alloys. They have a very high 98% of their average alloy composition in common. There are 33 material properties with values for both materials. Properties with values for just one material (1, in this case) are not shown.
For each property being compared, the top bar is AISI 304 stainless steel and the bottom bar is AISI 321 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 170 to 360 | |
| 170 to 210 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 8.0 to 43 | |
| 34 to 50 |
| Fatigue Strength, MPa | 210 to 440 | |
| 220 to 270 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 77 |
| Shear Strength, MPa | 400 to 690 | |
| 420 to 460 |
| Tensile Strength: Ultimate (UTS), MPa | 580 to 1180 | |
| 590 to 690 |
| Tensile Strength: Yield (Proof), MPa | 230 to 860 | |
| 220 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 290 |
| Maximum Temperature: Corrosion, °C | 420 | |
| 480 |
| Maximum Temperature: Mechanical, °C | 710 | |
| 870 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1430 |
| Melting Onset (Solidus), °C | 1400 | |
| 1400 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 16 | |
| 16 |
| Thermal Expansion, µm/m-K | 17 | |
| 17 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.4 | |
| 2.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.7 | |
| 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 | |
| 45 |
| Embodied Water, L/kg | 150 | |
| 140 |
Common Calculations
| PREN (Pitting Resistance) | 20 | |
| 19 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 86 to 250 | |
| 190 to 230 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 140 to 1870 | |
| 130 to 310 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 21 to 42 | |
| 21 to 25 |
| Strength to Weight: Bending, points | 20 to 32 | |
| 20 to 22 |
| Thermal Diffusivity, mm2/s | 4.2 | |
| 4.1 |
| Thermal Shock Resistance, points | 12 to 25 | |
| 13 to 15 |
Alloy Composition
| Carbon (C), % | 0 to 0.080 | |
| 0 to 0.080 |
| Chromium (Cr), % | 18 to 20 | |
| 17 to 19 |
| Iron (Fe), % | 66.5 to 74 | |
| 65.3 to 74 |
| Manganese (Mn), % | 0 to 2.0 | |
| 0 to 2.0 |
| Nickel (Ni), % | 8.0 to 10.5 | |
| 9.0 to 12 |
| Nitrogen (N), % | 0 to 0.1 | |
| 0 to 0.1 |
| 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 |