AISI 440A Stainless Steel vs. AISI 440B Stainless Steel
Both AISI 440A stainless steel and AISI 440B stainless steel are iron alloys. Their average alloy composition is basically identical.
For each property being compared, the top bar is AISI 440A stainless steel and the bottom bar is AISI 440B stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 5.0 to 20 | |
| 3.0 to 18 |
| Fatigue Strength, MPa | 270 to 790 | |
| 260 to 850 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 77 |
| Shear Strength, MPa | 450 to 1040 | |
| 460 to 1110 |
| Tensile Strength: Ultimate (UTS), MPa | 730 to 1790 | |
| 740 to 1930 |
| Tensile Strength: Yield (Proof), MPa | 420 to 1650 | |
| 430 to 1860 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 280 |
| Maximum Temperature: Corrosion, °C | 400 | |
| 390 |
| Maximum Temperature: Mechanical, °C | 760 | |
| 870 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1480 |
| Melting Onset (Solidus), °C | 1370 | |
| 1370 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 480 |
| Thermal Conductivity, W/m-K | 23 | |
| 23 |
| Thermal Expansion, µm/m-K | 10 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.5 | |
| 2.5 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.9 | |
| 2.9 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 9.0 | |
| 9.0 |
| Density, g/cm3 | 7.7 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 2.2 | |
| 2.2 |
| Embodied Energy, MJ/kg | 31 | |
| 31 |
| Embodied Water, L/kg | 120 | |
| 120 |
Common Calculations
| PREN (Pitting Resistance) | 18 | |
| 18 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 87 to 120 | |
| 57 to 110 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 26 to 65 | |
| 27 to 70 |
| Strength to Weight: Bending, points | 23 to 43 | |
| 24 to 45 |
| Thermal Diffusivity, mm2/s | 6.2 | |
| 6.1 |
| Thermal Shock Resistance, points | 26 to 65 | |
| 27 to 70 |
Alloy Composition
| Carbon (C), % | 0.6 to 0.75 | |
| 0.75 to 1.0 |
| Chromium (Cr), % | 16 to 18 | |
| 16 to 18 |
| Iron (Fe), % | 78.4 to 83.4 | |
| 78.2 to 83.3 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0 to 0.75 | |
| 0 to 0.75 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 to 0.015 |