Annealed SAE-AISI A9 vs. Annealed SAE-AISI P20
Both annealed SAE-AISI A9 and annealed SAE-AISI P20 are iron alloys. Both are furnished in the annealed condition. They have a moderately high 92% of their average alloy composition in common.
For each property being compared, the top bar is annealed SAE-AISI A9 and the bottom bar is annealed SAE-AISI P20.
Metric UnitsUS Customary Units
Mechanical Properties
| Brinell Hardness | 230 | |
| 160 |
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 190 |
| Elongation at Break, % | 21 | |
| 23 |
| Fatigue Strength, MPa | 250 | |
| 210 |
| Poisson's Ratio | 0.29 | |
| 0.29 |
| Shear Modulus, GPa | 74 | |
| 73 |
| Shear Strength, MPa | 480 | |
| 340 |
| Tensile Strength: Ultimate (UTS), MPa | 770 | |
| 540 |
| Tensile Strength: Yield (Proof), MPa | 360 | |
| 290 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 260 |
| Melting Completion (Liquidus), °C | 1460 | |
| 1460 |
| Melting Onset (Solidus), °C | 1410 | |
| 1420 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 470 |
| Thermal Conductivity, W/m-K | 35 | |
| 45 |
| Thermal Expansion, µm/m-K | 12 | |
| 12 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.9 | |
| 7.4 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 9.2 | |
| 8.5 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 7.0 | |
| 2.8 |
| Density, g/cm3 | 7.8 | |
| 7.8 |
| Embodied Carbon, kg CO2/kg material | 4.7 | |
| 1.6 |
| Embodied Energy, MJ/kg | 70 | |
| 21 |
| Embodied Water, L/kg | 82 | |
| 52 |
Common Calculations
| PREN (Pitting Resistance) | 10 | |
| 2.6 |
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 130 | |
| 100 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 350 | |
| 230 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 24 |
| Strength to Weight: Axial, points | 28 | |
| 19 |
| Strength to Weight: Bending, points | 24 | |
| 19 |
| Thermal Diffusivity, mm2/s | 9.6 | |
| 12 |
| Thermal Shock Resistance, points | 25 | |
| 18 |
Alloy Composition
| Carbon (C), % | 0.45 to 0.55 | |
| 0.28 to 0.4 |
| Chromium (Cr), % | 4.8 to 5.5 | |
| 0.4 to 2.0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 to 0.25 |
| Iron (Fe), % | 87 to 90.5 | |
| 95.2 to 98.5 |
| Manganese (Mn), % | 0 to 0.5 | |
| 0.35 to 0.71 |
| Molybdenum (Mo), % | 1.3 to 1.8 | |
| 0.3 to 0.55 |
| Nickel (Ni), % | 1.3 to 1.8 | |
| 0 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 to 0.030 |
| Silicon (Si), % | 1.0 to 1.2 | |
| 0.2 to 0.8 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 to 0.030 |
| Vanadium (V), % | 0.8 to 1.4 | |
| 0 |