SAE-AISI 1045 Steel vs. SAE-AISI 1090 Steel
Both SAE-AISI 1045 steel and SAE-AISI 1090 steel are iron alloys. Their average alloy composition is basically identical.
For each property being compared, the top bar is SAE-AISI 1045 steel and the bottom bar is SAE-AISI 1090 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 180 to 190 | |
| 220 to 280 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 13 to 18 | |
| 11 |
| Fatigue Strength, MPa | 220 to 370 | |
| 320 to 380 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Reduction in Area, % | 40 to 51 | |
| 28 to 45 |
| Shear Modulus, GPa | 72 | |
| 72 |
| Shear Strength, MPa | 380 to 410 | |
| 470 to 570 |
| Tensile Strength: Ultimate (UTS), MPa | 620 to 680 | |
| 790 to 950 |
| Tensile Strength: Yield (Proof), MPa | 330 to 580 | |
| 520 to 610 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 240 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 400 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1450 |
| Melting Onset (Solidus), °C | 1420 | |
| 1410 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 51 | |
| 50 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.0 | |
| 7.1 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.1 | |
| 8.2 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 1.8 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 1.4 |
| Embodied Energy, MJ/kg | 18 | |
| 19 |
| Embodied Water, L/kg | 46 | |
| 46 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 84 to 93 | |
| 82 to 91 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 300 to 900 | |
| 730 to 1000 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 22 to 24 | |
| 28 to 34 |
| Strength to Weight: Bending, points | 21 to 22 | |
| 24 to 27 |
| Thermal Diffusivity, mm2/s | 14 | |
| 13 |
| Thermal Shock Resistance, points | 20 to 22 | |
| 25 to 31 |
Alloy Composition
| Carbon (C), % | 0.43 to 0.5 | |
| 0.85 to 1.0 |
| Iron (Fe), % | 98.5 to 99 | |
| 98 to 98.6 |
| Manganese (Mn), % | 0.6 to 0.9 | |
| 0.6 to 0.9 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 to 0.040 |
| Sulfur (S), % | 0 to 0.050 | |
| 0 to 0.050 |