SAE-AISI A8 Steel vs. Grade 21 Titanium
SAE-AISI A8 steel belongs to the iron alloys classification, while grade 21 titanium belongs to the titanium alloys. There are 21 material properties with values for both materials. Properties with values for just one material (11, in this case) are not shown.
For each property being compared, the top bar is SAE-AISI A8 steel and the bottom bar is grade 21 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 140 |
| Poisson's Ratio | 0.29 | |
| 0.32 |
| Shear Modulus, GPa | 74 | |
| 51 |
| Tensile Strength: Ultimate (UTS), MPa | 700 to 1920 | |
| 890 to 1340 |
Thermal Properties
| Latent Heat of Fusion, J/g | 270 | |
| 410 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1740 |
| Melting Onset (Solidus), °C | 1430 | |
| 1690 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 500 |
| Thermal Conductivity, W/m-K | 37 | |
| 7.5 |
| Thermal Expansion, µm/m-K | 12 | |
| 7.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 8.5 | |
| 60 |
| Density, g/cm3 | 7.9 | |
| 5.4 |
| Embodied Carbon, kg CO2/kg material | 2.3 | |
| 32 |
| Embodied Energy, MJ/kg | 31 | |
| 490 |
| Embodied Water, L/kg | 73 | |
| 180 |
Common Calculations
| Stiffness to Weight: Axial, points | 14 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 32 |
| Strength to Weight: Axial, points | 25 to 68 | |
| 46 to 69 |
| Strength to Weight: Bending, points | 22 to 44 | |
| 38 to 50 |
| Thermal Diffusivity, mm2/s | 9.9 | |
| 2.8 |
| Thermal Shock Resistance, points | 22 to 62 | |
| 66 to 100 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 2.5 to 3.5 |
| Carbon (C), % | 0.5 to 0.6 | |
| 0 to 0.050 |
| Chromium (Cr), % | 4.8 to 5.5 | |
| 0 |
| Copper (Cu), % | 0 to 0.25 | |
| 0 |
| Hydrogen (H), % | 0 | |
| 0 to 0.015 |
| Iron (Fe), % | 88.5 to 91.9 | |
| 0 to 0.4 |
| Manganese (Mn), % | 0 to 0.5 | |
| 0 |
| Molybdenum (Mo), % | 1.2 to 1.7 | |
| 14 to 16 |
| Nickel (Ni), % | 0 to 0.3 | |
| 0 |
| Niobium (Nb), % | 0 | |
| 2.2 to 3.2 |
| Nitrogen (N), % | 0 | |
| 0 to 0.030 |
| Oxygen (O), % | 0 | |
| 0 to 0.17 |
| Phosphorus (P), % | 0 to 0.030 | |
| 0 |
| Silicon (Si), % | 0.75 to 1.1 | |
| 0.15 to 0.25 |
| Sulfur (S), % | 0 to 0.030 | |
| 0 |
| Titanium (Ti), % | 0 | |
| 76 to 81.2 |
| Tungsten (W), % | 1.0 to 1.5 | |
| 0 |
| Residuals, % | 0 | |
| 0 to 0.4 |