ASTM A387 Grade 21 Steel vs. Grade 5 Titanium
ASTM A387 grade 21 steel belongs to the iron alloys classification, while grade 5 titanium belongs to the titanium alloys. There are 30 material properties with values for both materials. Properties with values for just one material (4, 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 5 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 110 |
| Elongation at Break, % | 21 | |
| 8.6 to 11 |
| Fatigue Strength, MPa | 160 to 250 | |
| 530 to 630 |
| Poisson's Ratio | 0.29 | |
| 0.32 |
| Shear Modulus, GPa | 74 | |
| 40 |
| Shear Strength, MPa | 310 to 370 | |
| 600 to 710 |
| Tensile Strength: Ultimate (UTS), MPa | 500 to 590 | |
| 1000 to 1190 |
| Tensile Strength: Yield (Proof), MPa | 230 to 350 | |
| 910 to 1110 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 410 |
| Maximum Temperature: Mechanical, °C | 480 | |
| 330 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1610 |
| Melting Onset (Solidus), °C | 1430 | |
| 1650 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 560 |
| Thermal Conductivity, W/m-K | 41 | |
| 6.8 |
| Thermal Expansion, µm/m-K | 13 | |
| 8.9 |
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 | |
| 4.4 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 38 |
| Embodied Energy, MJ/kg | 23 | |
| 610 |
| Embodied Water, L/kg | 62 | |
| 200 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 84 to 110 | |
| 100 to 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 140 to 320 | |
| 3980 to 5880 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 24 | |
| 35 |
| Strength to Weight: Axial, points | 18 to 21 | |
| 62 to 75 |
| Strength to Weight: Bending, points | 18 to 20 | |
| 50 to 56 |
| Thermal Diffusivity, mm2/s | 11 | |
| 2.7 |
| Thermal Shock Resistance, points | 14 to 17 | |
| 76 to 91 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 5.5 to 6.8 |
| 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 0.4 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0 |
| Molybdenum (Mo), % | 0.9 to 1.1 | |
| 0 |
| Nitrogen (N), % | 0 | |
| 0 to 0.050 |
| Oxygen (O), % | 0 | |
| 0 to 0.2 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 |
| Titanium (Ti), % | 0 | |
| 87.4 to 91 |
| Vanadium (V), % | 0 | |
| 3.5 to 4.5 |
| Yttrium (Y), % | 0 | |
| 0 to 0.0050 |
| Residuals, % | 0 | |
| 0 to 0.4 |