Soda-lime Glass vs. Synthetic Sapphire
Soda-lime glass belongs to the glass and glass-ceramics classification, while synthetic sapphire belongs to the oxide-based engineering ceramics. There are 20 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 soda-lime glass and the bottom bar is synthetic sapphire.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 70 to 71 | |
| 450 |
| Knoop Hardness | 570 | |
| 1860 |
| Poisson's Ratio | 0.23 | |
| 0.28 |
| Shear Modulus, GPa | 29 | |
| 150 |
| Tensile Strength: Ultimate (UTS), MPa | 41 to 180 | |
| 2470 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 300 | |
| 2000 |
| Specific Heat Capacity, J/kg-K | 720 to 800 | |
| 760 |
| Thermal Conductivity, W/m-K | 1.0 to 1.1 | |
| 30 |
| Thermal Expansion, µm/m-K | 8.8 to 9.0 | |
| 5.3 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 7.3 to 7.4 | |
| 10 |
| Dielectric Strength (Breakdown Potential), kV/mm | 13 | |
| 9.9 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.4 | |
| 4.0 |
| Light Transmission Range, µm | 0.35 to 2.5 | |
| 0.17 to 5.5 |
| Refractive Index | 1.5 | |
| 1.8 |
Common Calculations
| Stiffness to Weight: Axial, points | 16 | |
| 63 |
| Stiffness to Weight: Bending, points | 56 | |
| 64 |
| Strength to Weight: Axial, points | 4.6 to 20 | |
| 170 |
| Strength to Weight: Bending, points | 11 to 28 | |
| 100 |
| Thermal Diffusivity, mm2/s | 0.51 to 0.6 | |
| 9.9 |
| Thermal Shock Resistance, points | 4.7 to 20 | |
| 74 |