ASTM A227 Spring Steel vs. Grade 21 Titanium
ASTM A227 spring steel belongs to the iron alloys classification, while grade 21 titanium belongs to the titanium alloys. There are 27 material properties with values for both materials. Properties with values for just one material (5, in this case) are not shown.
For each property being compared, the top bar is ASTM A227 spring steel and the bottom bar is grade 21 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 190 | |
| 140 |
| Elongation at Break, % | 12 | |
| 9.0 to 17 |
| Fatigue Strength, MPa | 900 to 1160 | |
| 550 to 660 |
| Poisson's Ratio | 0.29 | |
| 0.32 |
| Shear Modulus, GPa | 72 | |
| 51 |
| Shear Strength, MPa | 1030 to 1330 | |
| 550 to 790 |
| Tensile Strength: Ultimate (UTS), MPa | 1720 to 2220 | |
| 890 to 1340 |
| Tensile Strength: Yield (Proof), MPa | 1430 to 1850 | |
| 870 to 1170 |
Thermal Properties
| Latent Heat of Fusion, J/g | 250 | |
| 410 |
| Maximum Temperature: Mechanical, °C | 400 | |
| 310 |
| Melting Completion (Liquidus), °C | 1450 | |
| 1740 |
| Melting Onset (Solidus), °C | 1410 | |
| 1690 |
| Specific Heat Capacity, J/kg-K | 470 | |
| 500 |
| Thermal Conductivity, W/m-K | 52 | |
| 7.5 |
| Thermal Expansion, µm/m-K | 12 | |
| 7.1 |
Otherwise Unclassified Properties
| Base Metal Price, % relative | 1.8 | |
| 60 |
| Density, g/cm3 | 7.8 | |
| 5.4 |
| Embodied Carbon, kg CO2/kg material | 1.4 | |
| 32 |
| Embodied Energy, MJ/kg | 19 | |
| 490 |
| Embodied Water, L/kg | 46 | |
| 180 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 200 to 260 | |
| 110 to 180 |
| Stiffness to Weight: Axial, points | 13 | |
| 14 |
| Stiffness to Weight: Bending, points | 24 | |
| 32 |
| Strength to Weight: Axial, points | 61 to 79 | |
| 46 to 69 |
| Strength to Weight: Bending, points | 41 to 48 | |
| 38 to 50 |
| Thermal Diffusivity, mm2/s | 14 | |
| 2.8 |
| Thermal Shock Resistance, points | 55 to 71 | |
| 66 to 100 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 2.5 to 3.5 |
| Carbon (C), % | 0.45 to 0.85 | |
| 0 to 0.050 |
| Hydrogen (H), % | 0 | |
| 0 to 0.015 |
| Iron (Fe), % | 97.4 to 99.1 | |
| 0 to 0.4 |
| Manganese (Mn), % | 0.3 to 1.3 | |
| 0 |
| Molybdenum (Mo), % | 0 | |
| 14 to 16 |
| 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 0.040 | |
| 0 |
| Silicon (Si), % | 0.15 to 0.35 | |
| 0.15 to 0.25 |
| Sulfur (S), % | 0 to 0.050 | |
| 0 |
| Titanium (Ti), % | 0 | |
| 76 to 81.2 |
| Residuals, % | 0 | |
| 0 to 0.4 |