SAE-AISI 8740 Steel vs. AISI 440B Stainless Steel
Both SAE-AISI 8740 steel and AISI 440B stainless steel are iron alloys. They have 83% of their average alloy composition in common. There are 29 material properties with values for both materials. Properties with values for just one material (4, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 8740 steel and the bottom bar is AISI 440B stainless steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 200 |
| Elongation at Break, % | 11 to 23 | |
| 3.0 to 18 |
| Fatigue Strength, MPa | 270 to 350 | |
| 260 to 850 |
| Poisson's Ratio | 0.29 | |
| 0.28 |
| Shear Modulus, GPa | 73 | |
| 77 |
| Shear Strength, MPa | 370 to 400 | |
| 460 to 1110 |
| Tensile Strength: Ultimate (UTS), MPa | 580 to 670 | |
| 740 to 1930 |
| Tensile Strength: Yield (Proof), MPa | 380 to 570 | |
| 430 to 1860 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 280 |
| Maximum Temperature: Mechanical, °C | 410 | |
| 870 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1480 |
| Melting Onset (Solidus), °C | 1420 | |
| 1370 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 480 |
| Thermal Conductivity, W/m-K | 39 | |
| 23 |
| Thermal Expansion, µm/m-K | 13 | |
| 10 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 2.5 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 2.9 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.6 | |
| 9.0 |
| Density, g/cm3 | 7.8 | |
| 7.7 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 2.2 |
| Embodied Energy, MJ/kg | 20 | |
| 31 |
| Embodied Water, L/kg | 50 | |
| 120 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 71 to 120 | |
| 57 to 110 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 20 to 24 | |
| 27 to 70 |
| Strength to Weight: Bending, points | 20 to 22 | |
| 24 to 45 |
| Thermal Diffusivity, mm2/s | 10 | |
| 6.1 |
| Thermal Shock Resistance, points | 17 to 20 | |
| 27 to 70 |
Alloy Composition
| Carbon (C), % | 0.38 to 0.43 | |
| 0.75 to 1.0 |
| Chromium (Cr), % | 0.4 to 0.6 | |
| 16 to 18 |
| Iron (Fe), % | 96.5 to 97.7 | |
| 78.2 to 83.3 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0 to 1.0 |
| Molybdenum (Mo), % | 0.2 to 0.3 | |
| 0 to 0.75 |
| Nickel (Ni), % | 0.4 to 0.7 | |
| 0 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.040 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0 to 1.0 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.015 |