Thermoplastic comparison
Polyamide 66 (PA66, Nylon 66) vs PEI (Ultem)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | Polyamide 66 (PA66, Nylon 66) | PEI (Ultem) | Difference |
|---|---|---|---|
| Density | 1.14 g/cm³ | 1.27 g/cm³ | PEI (Ultem) — 11% higher |
| Young's modulus E | 3.2 GPa | 3.2 GPa | identical |
| Tensile strength | 83 MPa | 105 MPa | PEI (Ultem) — 27% higher |
| Glass transition Tg | 60 °C | 217 °C | PEI (Ultem) — 157 °C higher |
Where these numbers come from
- CAMPUS plastics database — typical grade datasheet values (campusplastics.com)
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.