AISI 309 Stainless Steel vs. AISI 420 Stainless Steel
Both AISI 309 stainless steel and AISI 420 stainless steel are iron alloys. They have 76% of their average alloy composition in common.
For each property being compared, the top bar is AISI 309 stainless steel and the bottom bar is AISI 420 stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 180 to 210 | |
| 190 |
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 190 |
| Elongation at Break, % | 34 to 47 | |
| 8.0 to 15 |
| Fatigue Strength, MPa | 250 to 280 | |
| 220 to 670 |
| Poisson's Ratio | 0.27 | |
| 0.28 |
| Rockwell B Hardness | 84 | |
| 84 |
| Shear Modulus, GPa | 78 | |
| 76 |
| Shear Strength, MPa | 420 to 470 | |
| 420 to 1010 |
| Tensile Strength: Ultimate (UTS), MPa | 600 to 710 | |
| 690 to 1720 |
| Tensile Strength: Yield (Proof), MPa | 260 to 350 | |
| 380 to 1310 |
Thermal Properties
| Latent Heat of Fusion, J/g | 290 | |
| 280 |
| Maximum Temperature: Corrosion, °C | 440 | |
| 390 |
| Maximum Temperature: Mechanical, °C | 980 | |
| 620 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1510 |
| Melting Onset (Solidus), °C | 1400 | |
| 1450 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 16 | |
| 27 |
| Thermal Expansion, µm/m-K | 15 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.2 | |
| 3.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.5 | |
| 3.5 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 19 | |
| 7.5 |
| Density, g/cm3 | 7.8 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 3.6 | |
| 2.0 |
| Embodied Energy, MJ/kg | 51 | |
| 28 |
| Embodied Water, L/kg | 170 | |
| 100 |
Common Calculations
| PREN (Pitting Resistance) | 23 | |
| 14 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 200 to 230 | |
| 88 to 130 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 170 to 310 | |
| 380 to 4410 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 21 to 25 | |
| 25 to 62 |
| Strength to Weight: Bending, points | 20 to 23 | |
| 22 to 41 |
| Thermal Diffusivity, mm2/s | 4.3 | |
| 7.3 |
| Thermal Shock Resistance, points | 14 to 16 | |
| 25 to 62 |
Alloy Composition
| Carbon (C), % | 0 to 0.2 | |
| 0.15 to 0.4 |
| Chromium (Cr), % | 22 to 24 | |
| 12 to 14 |
| Iron (Fe), % | 58 to 66 | |
| 82.3 to 87.9 |
| Manganese (Mn), % | 0 to 2.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 | |
| 0 to 0.5 |
| Nickel (Ni), % | 12 to 15 | |
| 0 to 0.75 |
| Phosphorus (P), % | 0 to 0.045 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 0.75 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |