PTFE vs. Machinable Glass-ceramic
PTFE and machinable glass-ceramic belong to fundamentally different material chemistries. PTFE is a polymeric material, while machinable glass-ceramic is ceramic. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 12 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 PTFE and the bottom bar is machinable glass-ceramic.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 6.9 to 24 | |
| 310 |
| Flexural Strength, MPa | 13 to 50 | |
| 96 |
| Tensile Strength: Ultimate (UTS), MPa | 13 to 25 | |
| 84 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 260 to 270 | |
| 760 |
| Thermal Conductivity, W/m-K | 0.24 to 0.65 | |
| 1.2 |
| Thermal Expansion, µm/m-K | 110 to 120 | |
| 21 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 2.1 to 2.4 | |
| 6.4 |
| Electrical Dissipation At 1 MHz | 0.00017 to 0.050 | |
| 0.0050 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 2.0 to 18 | |
| 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.1 to 2.3 | |
| 2.7 |
Common Calculations
| Strength to Weight: Axial, points | 1.7 to 3.2 | |
| 8.8 |
| Strength to Weight: Bending, points | 5.7 to 8.7 | |
| 16 |