ASTM A387 Grade 21 Steel vs. Grade 29 Titanium
ASTM A387 grade 21 steel belongs to the iron alloys classification, while grade 29 titanium belongs to the titanium alloys. There are 30 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.
For each property being compared, the top bar is ASTM A387 grade 21 steel and the bottom bar is grade 29 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 110 |
| Elongation at Break, % | 21 | |
| 6.8 to 11 |
| Fatigue Strength, MPa | 160 to 250 | |
| 460 to 510 |
| Poisson's Ratio | 0.29 | |
| 0.32 |
| Shear Modulus, GPa | 74 | |
| 40 |
| Shear Strength, MPa | 310 to 370 | |
| 550 to 560 |
| Tensile Strength: Ultimate (UTS), MPa | 500 to 590 | |
| 930 to 940 |
| Tensile Strength: Yield (Proof), MPa | 230 to 350 | |
| 850 to 870 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 410 |
| Maximum Temperature: Mechanical, °C | 480 | |
| 340 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1610 |
| Melting Onset (Solidus), °C | 1430 | |
| 1560 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 560 |
| Thermal Conductivity, W/m-K | 41 | |
| 7.3 |
| Thermal Expansion, µm/m-K | 13 | |
| 9.3 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 7.6 | |
| 1.0 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 8.8 | |
| 2.0 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 4.1 | |
| 36 |
| Density, g/cm3 | 7.9 | |
| 4.5 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 39 |
| Embodied Energy, MJ/kg | 23 | |
| 640 |
| Embodied Water, L/kg | 62 | |
| 410 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 84 to 110 | |
| 62 to 100 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 140 to 320 | |
| 3420 to 3540 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 35 |
| Strength to Weight: Axial, points | 18 to 21 | |
| 58 to 59 |
| Strength to Weight: Bending, points | 18 to 20 | |
| 47 to 48 |
| Thermal Diffusivity, mm2/s | 11 | |
| 2.9 |
| Thermal Shock Resistance, points | 14 to 17 | |
| 68 to 69 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 5.5 to 6.5 |
| Carbon (C), % | 0.050 to 0.15 | |
| 0 to 0.080 |
| Chromium (Cr), % | 2.8 to 3.3 | |
| 0 |
| Hydrogen (H), % | 0 | |
| 0 to 0.015 |
| Iron (Fe), % | 94.4 to 96 | |
| 0 to 0.25 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0 |
| Molybdenum (Mo), % | 0.9 to 1.1 | |
| 0 |
| Nitrogen (N), % | 0 | |
| 0 to 0.030 |
| Oxygen (O), % | 0 | |
| 0 to 0.13 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 |
| Ruthenium (Ru), % | 0 | |
| 0.080 to 0.14 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 |
| Titanium (Ti), % | 0 | |
| 88 to 90.9 |
| Vanadium (V), % | 0 | |
| 3.5 to 4.5 |
| Residuals, % | 0 | |
| 0 to 0.4 |