PEEK vs. PES
Both PEEK and PES are thermoplastics. There are 24 material properties with values for both materials. Properties with values for just one material (12, in this case) are not shown.
For each property being compared, the top bar is PEEK and the bottom bar is PES.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 4.0 to 24 | |
| 2.6 |
| Elongation at Break, % | 1.6 to 43 | |
| 65 |
| Flexural Modulus, GPa | 3.8 to 19 | |
| 2.6 |
| Flexural Strength, MPa | 150 to 330 | |
| 130 |
| Impact Strength: Notched Izod, J/m | 78 to 120 | |
| 91 |
| Tensile Strength: Ultimate (UTS), MPa | 97 to 200 | |
| 87 |
Thermal Properties
| Glass Transition Temperature, °C | 240 | |
| 220 |
| Heat Deflection Temperature At 1.82 MPa (264 psi), °C | 160 to 300 | |
| 200 |
| Maximum Temperature: Autoignition, °C | 600 | |
| 500 |
| Maximum Temperature: Decomposition, °C | 570 | |
| 540 |
| Maximum Temperature: Mechanical, °C | 330 | |
| 200 |
| Specific Heat Capacity, J/kg-K | 1390 to 1700 | |
| 1100 |
| Thermal Conductivity, W/m-K | 0.25 to 0.93 | |
| 0.18 |
| Thermal Expansion, µm/m-K | 15 to 52 | |
| 53 |
Electrical Properties
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 3.0 to 14 | |
| 15 |
Otherwise Unclassified Properties
| Density, g/cm3 | 1.3 to 1.5 | |
| 1.4 |
| Limiting Oxygen Index (LOI), % | 38 | |
| 36 |
| Water Absorption After 24 Hours, % | 0.060 to 0.3 | |
| 0.34 |
Common Calculations
| Stiffness to Weight: Axial, points | 1.5 to 10 | |
| 1.1 |
| Stiffness to Weight: Bending, points | 36 to 73 | |
| 33 |
| Strength to Weight: Axial, points | 20 to 41 | |
| 18 |
| Strength to Weight: Bending, points | 36 to 55 | |
| 32 |
| Thermal Diffusivity, mm2/s | 0.1 to 0.51 | |
| 0.12 |
| Thermal Shock Resistance, points | 34 to 57 | |
| 45 |