ZiLITER- Polybutylene Terephthalate (PBT) with glass filled has a very high rigidity, high mechanical strength, high creep strength and a very high dimensional stability. It is capable of meeting precision requirements for parts with tight tolerances. These material properties make this glass filled polyester suitable for use in parts which are exposed to high static loads over long periods in high temperature conditions. PBT competes with Polyethylene Terephthalate (PET) in many engineering plastics applications. Compared to PET, it has somewhat lower strength and rigidity but is more flexible and tougher (higher impact strength). It also has a slightly lower melting point and crystallizes much faster than PET. Its maximum use temperature is typically between 115-135° C (240-275° F) which is slightly lower than that of PET.