This part of GB/T 5169 describes the method for evaluating the resistance to abnormal heat of polymeric materials and components used in electrical and electronic products, that is, the softening temperature and material fluidity under load are determined by the ball pressure test. This standard applies to electrical and electronic equipment, assemblies and parts, and solid electrical insulating materials other than ceramics. This part is intended for product standards committees to prepare standards according to the principles specified in IEC Guide 104 and ISO/IEC Guide 51. One of the tasks of the Product Standards Committee is to use this series of standards wherever applicable when writing its own standards. Unless specifically mentioned or listed in the relevant standard, the requirements, test methods or test conditions of this section will not apply.