PEEK vs. Fused Silica
PEEK and fused silica belong to fundamentally different material chemistries. PEEK is a polymeric material, while fused silica is ceramic. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 18 material properties with values for both materials. Properties with values for just one material (19, in this case) are not shown.
For each property being compared, the top bar is PEEK and the bottom bar is fused silica.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 120 to 300 | |
| 1100 |
| Elastic (Young's, Tensile) Modulus, GPa | 4.0 to 24 | |
| 73 |
| Flexural Strength, MPa | 150 to 330 | |
| 67 |
| Tensile Strength: Ultimate (UTS), MPa | 97 to 200 | |
| 50 |
Thermal Properties
| Maximum Temperature: Decomposition, °C | 570 | |
| 1100 |
| Maximum Temperature: Mechanical, °C | 330 | |
| 1080 |
| Melting Onset (Solidus), °C | 340 | |
| 1900 |
| Specific Heat Capacity, J/kg-K | 1390 to 1700 | |
| 720 |
| Thermal Conductivity, W/m-K | 0.25 to 0.93 | |
| 1.4 |
| Thermal Expansion, µm/m-K | 15 to 52 | |
| 0.5 |
Electrical Properties
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 3.0 to 14 | |
| 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 1.3 to 1.5 | |
| 2.2 |
Common Calculations
| Stiffness to Weight: Axial, points | 1.5 to 10 | |
| 18 |
| Stiffness to Weight: Bending, points | 36 to 73 | |
| 63 |
| Strength to Weight: Axial, points | 20 to 41 | |
| 6.3 |
| Strength to Weight: Bending, points | 36 to 55 | |
| 14 |
| Thermal Diffusivity, mm2/s | 0.1 to 0.51 | |
| 0.85 |
| Thermal Shock Resistance, points | 34 to 57 | |
| 97 |