Annealed SAE-AISI 4140 vs. SAE-AISI 4145 Steel
Both annealed SAE-AISI 4140 and SAE-AISI 4145 steel are iron alloys. Both are furnished in the annealed condition. Their average alloy composition is basically identical. There are 31 material properties with values for both materials. Properties with values for just one material (2, in this case) are not shown.
For each property being compared, the top bar is annealed SAE-AISI 4140 and the bottom bar is SAE-AISI 4145 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 200 | |
| 310 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 26 | |
| 16 |
| Fatigue Strength, MPa | 480 | |
| 240 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 73 |
| Shear Strength, MPa | 470 | |
| 360 |
| Tensile Strength: Ultimate (UTS), MPa | 740 | |
| 580 |
| Tensile Strength: Yield (Proof), MPa | 660 | |
| 360 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 420 | |
| 420 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1460 |
| Melting Onset (Solidus), °C | 1420 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 43 | |
| 42 |
| Thermal Expansion, µm/m-K | 13 | |
| 13 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 7.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 8.4 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.4 | |
| 2.4 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 1.5 |
| Embodied Energy, MJ/kg | 20 | |
| 20 |
| Embodied Water, L/kg | 51 | |
| 51 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 180 | |
| 80 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 1140 | |
| 350 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 26 | |
| 21 |
| Strength to Weight: Bending, points | 23 | |
| 20 |
| Thermal Diffusivity, mm2/s | 12 | |
| 11 |
| Thermal Shock Resistance, points | 22 | |
| 17 |
Alloy Composition
| Carbon (C), % | 0.38 to 0.43 | |
| 0.43 to 0.48 |
| Chromium (Cr), % | 0.8 to 1.1 | |
| 0.8 to 1.1 |
| Iron (Fe), % | 96.8 to 97.8 | |
| 96.7 to 97.7 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0.75 to 1.0 |
| Molybdenum (Mo), % | 0.15 to 0.25 | |
| 0.15 to 0.25 |
| Phosphorus (P), % | 0 to 0.035 | |
| 0 to 0.035 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0.15 to 0.35 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.040 |