This part of ISO 2507 specifies a general method for determining the Vicat softening temperature of thermoplastics pipes and fittings. lt includes the adaptation of method B of ISO 306:1994, using a forte of 50 N. This method is applicable only to thermoplastics materials for which it is possible to measure the temperature at which their rate of softening becomes rapid. lt is not applicable to crystalline or semi-crystalline polymers.