SAE-AISI 8645 Steel vs. SAE-AISI 1078 Steel
Both SAE-AISI 8645 steel and SAE-AISI 1078 steel are iron alloys. They have a very high 98% of their average alloy composition in common. There are 31 material properties with values for both materials. Properties with values for just one material (1, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI 8645 steel and the bottom bar is SAE-AISI 1078 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 180 to 200 | |
| 220 to 230 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 12 to 23 | |
| 11 to 14 |
| Fatigue Strength, MPa | 280 to 350 | |
| 270 to 350 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 72 |
| Shear Strength, MPa | 380 to 400 | |
| 440 to 470 |
| Tensile Strength: Ultimate (UTS), MPa | 600 to 670 | |
| 730 to 780 |
| Tensile Strength: Yield (Proof), MPa | 390 to 560 | |
| 430 to 570 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 250 |
| Maximum Temperature: Mechanical, °C | 410 | |
| 400 |
| 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 | 39 | |
| 49 |
| Thermal Expansion, µm/m-K | 13 | |
| 11 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.3 | |
| 7.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.4 | |
| 8.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 2.6 | |
| 1.8 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 1.5 | |
| 1.4 |
| Embodied Energy, MJ/kg | 20 | |
| 18 |
| Embodied Water, L/kg | 50 | |
| 45 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 77 to 120 | |
| 77 to 90 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 420 to 840 | |
| 490 to 860 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 24 |
| Strength to Weight: Axial, points | 21 to 24 | |
| 26 to 28 |
| Strength to Weight: Bending, points | 20 to 22 | |
| 23 to 24 |
| Thermal Diffusivity, mm2/s | 10 | |
| 13 |
| Thermal Shock Resistance, points | 18 to 20 | |
| 25 to 26 |
Alloy Composition
| Carbon (C), % | 0.43 to 0.48 | |
| 0.72 to 0.85 |
| Chromium (Cr), % | 0.4 to 0.6 | |
| 0 |
| Iron (Fe), % | 96.5 to 97.7 | |
| 98.5 to 99 |
| Manganese (Mn), % | 0.75 to 1.0 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0.15 to 0.25 | |
| 0 |
| 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 |
| Sulfur (S), % | 0 to 0.040 | |
| 0 to 0.050 |