ASTM A387 Grade 21 Steel vs. Grade 20 Titanium
ASTM A387 grade 21 steel belongs to the iron alloys classification, while grade 20 titanium belongs to the titanium alloys. There are 25 material properties with values for both materials. Properties with values for just one material (8, 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 20 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 120 |
| Elongation at Break, % | 21 | |
| 5.7 to 17 |
| Fatigue Strength, MPa | 160 to 250 | |
| 550 to 630 |
| Poisson's Ratio | 0.29 | |
| 0.32 |
| Shear Modulus, GPa | 74 | |
| 47 |
| Shear Strength, MPa | 310 to 370 | |
| 560 to 740 |
| Tensile Strength: Ultimate (UTS), MPa | 500 to 590 | |
| 900 to 1270 |
| Tensile Strength: Yield (Proof), MPa | 230 to 350 | |
| 850 to 1190 |
Thermal Properties
| Latent Heat of Fusion, J/g | 260 | |
| 400 |
| Maximum Temperature: Mechanical, °C | 480 | |
| 370 |
| Melting Completion (Liquidus), °C | 1470 | |
| 1660 |
| Melting Onset (Solidus), °C | 1430 | |
| 1600 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 520 |
| Thermal Expansion, µm/m-K | 13 | |
| 9.6 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.9 | |
| 5.0 |
| Embodied Carbon, kg CO2/kg material | 1.8 | |
| 52 |
| Embodied Energy, MJ/kg | 23 | |
| 860 |
| Embodied Water, L/kg | 62 | |
| 350 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 84 to 110 | |
| 71 to 150 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 140 to 320 | |
| 2940 to 5760 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 33 |
| Strength to Weight: Axial, points | 18 to 21 | |
| 50 to 70 |
| Strength to Weight: Bending, points | 18 to 20 | |
| 41 to 52 |
| Thermal Shock Resistance, points | 14 to 17 | |
| 55 to 77 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 3.0 to 4.0 |
| Carbon (C), % | 0.050 to 0.15 | |
| 0 to 0.050 |
| Chromium (Cr), % | 2.8 to 3.3 | |
| 5.5 to 6.5 |
| Hydrogen (H), % | 0 | |
| 0 to 0.020 |
| Iron (Fe), % | 94.4 to 96 | |
| 0 to 0.3 |
| Manganese (Mn), % | 0.3 to 0.6 | |
| 0 |
| Molybdenum (Mo), % | 0.9 to 1.1 | |
| 3.5 to 4.5 |
| Nitrogen (N), % | 0 | |
| 0 to 0.030 |
| Oxygen (O), % | 0 | |
| 0 to 0.12 |
| Palladium (Pd), % | 0 | |
| 0.040 to 0.080 |
| Phosphorus (P), % | 0 to 0.025 | |
| 0 |
| Silicon (Si), % | 0 to 0.5 | |
| 0 |
| Sulfur (S), % | 0 to 0.025 | |
| 0 |
| Titanium (Ti), % | 0 | |
| 71 to 77 |
| Vanadium (V), % | 0 | |
| 7.5 to 8.5 |
| Zirconium (Zr), % | 0 | |
| 3.5 to 4.5 |
| Residuals, % | 0 | |
| 0 to 0.4 |