Annealed SAE-AISI O7 vs. Annealed SAE-AISI S7
Both annealed SAE-AISI O7 and annealed SAE-AISI S7 are iron alloys. Both are furnished in the annealed condition. They have a very high 96% of their average alloy composition in common.
For each property being compared, the top bar is annealed SAE-AISI O7 and the bottom bar is annealed SAE-AISI S7.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 210 | |
| 200 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 21 | |
| 21 |
| Fatigue Strength, MPa | 290 | |
| 250 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 73 | |
| 74 |
| Shear Strength, MPa | 430 | |
| 420 |
| Tensile Strength: Ultimate (UTS), MPa | 680 | |
| 670 |
| Tensile Strength: Yield (Proof), MPa | 410 | |
| 370 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 260 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1460 |
| Melting Onset (Solidus), °C | 1430 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 41 | |
| 40 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.6 | |
| 7.8 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.7 | |
| 9.0 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 6.0 | |
| 5.0 |
| Density, g/cm3 | 7.9 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 2.3 | |
| 2.3 |
| Embodied Energy, MJ/kg | 33 | |
| 31 |
| Embodied Water, L/kg | 52 | |
| 65 |
Common Calculations
| PREN (Pitting Resistance) | 3.6 | |
| 8.4 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 120 | |
| 120 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 450 | |
| 350 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 25 |
| Strength to Weight: Axial, points | 24 | |
| 24 |
| Strength to Weight: Bending, points | 22 | |
| 22 |
| Thermal Diffusivity, mm2/s | 11 | |
| 11 |
| Thermal Shock Resistance, points | 23 | |
| 22 |
Alloy Composition
| Carbon (C), % | 1.1 to 1.3 | |
| 0.45 to 0.55 |
| Chromium (Cr), % | 0.35 to 0.85 | |
| 3.0 to 3.5 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 92.9 to 97.6 | |
| 91.6 to 94.9 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0.2 to 0.9 |
| Molybdenum (Mo), % | 0 to 0.3 | |
| 1.3 to 1.8 |
| Nickel (Ni), % | 0 to 0.3 | |
| 0 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.030 |
| Silicon (Si), % | 0 to 0.6 | |
| 0.2 to 1.0 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Tungsten (W), % | 1.0 to 2.0 | |
| 0 |
| Vanadium (V), % | 0 to 0.4 | |
| 0 to 0.3 |