Thermoplastic comparison
PBT (polybutylene terephthalate) vs POM (acetal)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | PBT (polybutylene terephthalate) | POM (acetal) | Difference |
|---|---|---|---|
| Density | 1.31 g/cm³ | 1.41 g/cm³ | POM (acetal) — 8% higher |
| Young's modulus E | 2.6 GPa | 3.1 GPa | POM (acetal) — 19% higher |
| Tensile strength | 55 MPa | 65 MPa | POM (acetal) — 18% higher |
| Glass transition Tg | 45 °C | -60 °C | PBT (polybutylene terephthalate) — 105 °C higher |
| Melting point Tm | 225 °C | 175 °C | PBT (polybutylene terephthalate) — 50 °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.