AISI 440A Stainless Steel vs. Grade 18 Titanium
AISI 440A stainless steel belongs to the iron alloys classification, while grade 18 titanium belongs to the titanium alloys. There are 28 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 AISI 440A stainless steel and the bottom bar is grade 18 titanium.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 200 | |
| 110 |
| Elongation at Break, % | 5.0 to 20 | |
| 11 to 17 |
| Fatigue Strength, MPa | 270 to 790 | |
| 330 to 480 |
| Poisson's Ratio | 0.28 | |
| 0.32 |
| Shear Modulus, GPa | 77 | |
| 40 |
| Shear Strength, MPa | 450 to 1040 | |
| 420 to 590 |
| Tensile Strength: Ultimate (UTS), MPa | 730 to 1790 | |
| 690 to 980 |
| Tensile Strength: Yield (Proof), MPa | 420 to 1650 | |
| 540 to 810 |
Thermal Properties
| Latent Heat of Fusion, J/g | 280 | |
| 410 |
| Maximum Temperature: Mechanical, °C | 760 | |
| 330 |
| Melting Completion (Liquidus), °C | 1480 | |
| 1640 |
| Melting Onset (Solidus), °C | 1370 | |
| 1590 |
| Specific Heat Capacity, J/kg-K | 480 | |
| 550 |
| Thermal Conductivity, W/m-K | 23 | |
| 8.3 |
| Thermal Expansion, µm/m-K | 10 | |
| 9.9 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 2.5 | |
| 1.3 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 2.9 | |
| 2.7 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.7 | |
| 4.5 |
| Embodied Carbon, kg CO2/kg material | 2.2 | |
| 41 |
| Embodied Energy, MJ/kg | 31 | |
| 670 |
| Embodied Water, L/kg | 120 | |
| 270 |
Common Calculations
| Resilience: Ultimate (Unit Rupture Work), MJ/m3 | 87 to 120 | |
| 87 to 110 |
| Stiffness to Weight: Axial, points | 14 | |
| 13 |
| Stiffness to Weight: Bending, points | 25 | |
| 35 |
| Strength to Weight: Axial, points | 26 to 65 | |
| 43 to 61 |
| Strength to Weight: Bending, points | 23 to 43 | |
| 39 to 49 |
| Thermal Diffusivity, mm2/s | 6.2 | |
| 3.4 |
| Thermal Shock Resistance, points | 26 to 65 | |
| 47 to 67 |
Alloy Composition
| Aluminum (Al), % | 0 | |
| 2.5 to 3.5 |
| Carbon (C), % | 0.6 to 0.75 | |
| 0 to 0.080 |
| Chromium (Cr), % | 16 to 18 | |
| 0 |
| Hydrogen (H), % | 0 | |
| 0 to 0.015 |
| Iron (Fe), % | 78.4 to 83.4 | |
| 0 to 0.25 |
| Manganese (Mn), % | 0 to 1.0 | |
| 0 |
| Molybdenum (Mo), % | 0 to 0.75 | |
| 0 |
| Nitrogen (N), % | 0 | |
| 0 to 0.030 |
| Oxygen (O), % | 0 | |
| 0 to 0.15 |
| Palladium (Pd), % | 0 | |
| 0.040 to 0.080 |
| Phosphorus (P), % | 0 to 0.040 | |
| 0 |
| Silicon (Si), % | 0 to 1.0 | |
| 0 |
| Sulfur (S), % | 0 to 0.015 | |
| 0 |
| Titanium (Ti), % | 0 | |
| 92.5 to 95.5 |
| Vanadium (V), % | 0 | |
| 2.0 to 3.0 |
| Residuals, % | 0 | |
| 0 to 0.4 |