AISI 440B Stainless Steel vs. AISI 440A Stainless Steel
Both AISI 440B stainless steel and AISI 440A stainless steel are iron alloys. Their average alloy composition is basically identical.
For each property being compared, the top bar is AISI 440B stainless steel and the bottom bar is AISI 440A stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 200 |
| Elongation at Break, % | 3.0 to 18 | |
| 5.0 to 20 |
| Fatigue Strength, MPa | 260 to 850 | |
| 270 to 790 |
| Poisson's Ratio | 0.28 | |
| 0.28 |
| Shear Modulus, GPa | 77 | |
| 77 |
| Shear Strength, MPa | 460 to 1110 | |
| 450 to 1040 |
| Tensile Strength: Ultimate (UTS), MPa | 740 to 1930 | |
| 730 to 1790 |
| Tensile Strength: Yield (Proof), MPa | 430 to 1860 | |
| 420 to 1650 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 280 |
| Maximum Temperature: Corrosion, °C | 390 | |
| 400 |
| Maximum Temperature: Mechanical, °C | 870 | |
| 760 |
| 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 | 57 to 110 | |
| 87 to 120 |
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 25 | |
| 25 |
| Strength to Weight: Axial, points | 27 to 70 | |
| 26 to 65 |
| Strength to Weight: Bending, points | 24 to 45 | |
| 23 to 43 |
| Thermal Diffusivity, mm2/s | 6.1 | |
| 6.2 |
| Thermal Shock Resistance, points | 27 to 70 | |
| 26 to 65 |
Alloy Composition
| Carbon (C), % | 0.75 to 1.0 | |
| 0.6 to 0.75 |
| Chromium (Cr), % | 16 to 18 | |
| 16 to 18 |
| Iron (Fe), % | 78.2 to 83.3 | |
| 78.4 to 83.4 |
| 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 |