This standard is the national method for determining the softening point of solid epoxy resins at room temperature using the ring-and-ball method. The core procedure involves placing a steel ball of specified mass on a metal ring containing the resin sample and heating it in a heating medium with a strictly controlled temperature rise rate. The temperature at which the sample softens sufficiently for the steel ball, along with the sample in the ring, to fall a specified distance is defined as the softening point. Key testing instruments include a heating bath equipped with precise programmed temperature control and stirring devices, specialized metal ring-and-ball assemblies, and a measuring instrument capable of automatically or semi-automatically detecting the ball drop and recording the final temperature. This method provides critical technical parameters and unified testing criteria for evaluating the heat resistance characteristics of epoxy resins.