Thermoplastic comparison
PEEK vs PETG (glycol-modified PET)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | PEEK | PETG (glycol-modified PET) | Difference |
|---|---|---|---|
| Density | 1.3 g/cm³ | 1.3 g/cm³ | identical |
| Young's modulus E | 3.6 GPa | 2.2 GPa | PEEK — 64% higher |
| Tensile strength | 100 MPa | 53 MPa | PEEK — 89% higher |
| Glass transition Tg | 143 °C | 81 °C | PEEK — 62 °C higher |
Where these numbers come from
- Callister & Rethwisch, Materials Science and Engineering, 10th ed.
- MakeItFrom.com materials database — typical grade values
Typical room-temperature values for learning and preliminary design; grades vary widely and a supplier datasheet always overrides a textbook figure. Confirm against the datasheet before design work.