Consider the thermal requirements of your application using both typical and extreme conditions.
A material's heat resistance is characterized by both its heat deflection temperature (HDT) andcontinuous service temperature. HDT is an indication of a material's softening temperature and is generally accepted as a maximum temperature limit for moderately to highly stressed, unconstrained components. Continuous service temperature is generally reported as the temperature above which significant, permanent physical property degradation occurs after long term exposure. This guideline is not to be confused with continuous operation or use temperatures reported by regulatory agencies such as Underwriters Laboratories UL.
The melting point of crystalline materials and glass transition temperature of amorphous materials are the short-term temperature extremes to which form stability is maintained. For most engineering plastic materials, using them at or above these temperatures should be avoided.