ASTM B817 Type II vs. ASTM A387 Grade 21 Steel
ASTM B817 type II belongs to the titanium alloys classification, while ASTM A387 grade 21 steel belongs to the iron 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 B817 type II and the bottom bar is ASTM A387 grade 21 steel.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 100 | |
| 190 |
| Elongation at Break, % | 3.0 to 13 | |
| 21 |
| Fatigue Strength, MPa | 390 to 530 | |
| 160 to 250 |
| Poisson's Ratio | 0.32 | |
| 0.29 |
| Shear Modulus, GPa | 40 | |
| 74 |
| Tensile Strength: Ultimate (UTS), MPa | 900 to 960 | |
| 500 to 590 |
| Tensile Strength: Yield (Proof), MPa | 780 to 900 | |
| 230 to 350 |
Thermal Properties
| Latent Heat of Fusion, J/g | 400 | |
| 260 |
| Maximum Temperature: Mechanical, °C | 350 | |
| 480 |
| Melting Completion (Liquidus), °C | 1580 | |
| 1470 |
| Melting Onset (Solidus), °C | 1530 | |
| 1430 |
| Specific Heat Capacity, J/kg-K | 550 | |
| 470 |
| Thermal Expansion, µm/m-K | 9.9 | |
| 13 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 37 | |
| 4.1 |
| Density, g/cm3 | 4.6 | |
| 7.9 |
| Embodied Carbon, kg CO2/kg material | 40 | |
| 1.8 |
| Embodied Energy, MJ/kg | 650 | |
| 23 |
| Embodied Water, L/kg | 220 | |
| 62 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 26 to 120 | |
| 84 to 110 |
| Resilience: Unit (Modulus of Resilience), kJ/m3 | 2890 to 3890 | |
| 140 to 320 |
| Stiffness to Weight: Axial, points | 13 | |
| 13 |
| Stiffness to Weight: Bending, points | 34 | |
| 24 |
| Strength to Weight: Axial, points | 55 to 58 | |
| 18 to 21 |
| Strength to Weight: Bending, points | 45 to 47 | |
| 18 to 20 |
| Thermal Shock Resistance, points | 62 to 66 | |
| 14 to 17 |
Alloy Composition
| Aluminum (Al), % | 5.0 to 6.0 | |
| 0 |
| Carbon (C), % | 0 to 0.1 | |
| 0.050 to 0.15 |
| Chlorine (Cl), % | 0 to 0.2 | |
| 0 |
| Chromium (Cr), % | 0 | |
| 2.8 to 3.3 |
| Copper (Cu), % | 0.35 to 1.0 | |
| 0 |
| Hydrogen (H), % | 0 to 0.015 | |
| 0 |
| Iron (Fe), % | 0.35 to 1.0 | |
| 94.4 to 96 |
| Manganese (Mn), % | 0 | |
| 0.3 to 0.6 |
| Molybdenum (Mo), % | 0 | |
| 0.9 to 1.1 |
| Nitrogen (N), % | 0 to 0.040 | |
| 0 |
| Oxygen (O), % | 0 to 0.3 | |
| 0 |
| Phosphorus (P), % | 0 | |
| 0 to 0.025 |
| Silicon (Si), % | 0 to 0.1 | |
| 0 to 0.5 |
| Sodium (Na), % | 0 to 0.2 | |
| 0 |
| Sulfur (S), % | 0 | |
| 0 to 0.025 |
| Tin (Sn), % | 1.5 to 2.5 | |
| 0 |
| Titanium (Ti), % | 82.1 to 87.8 | |
| 0 |
| Vanadium (V), % | 5.0 to 6.0 | |
| 0 |
| Residuals, % | 0 to 0.4 | |
| 0 |