This standard specifies the test method for determining the softening deformation temperature of shaped refractory materials under constant load using the differential heating method, which is used to evaluate the high-temperature load-bearing capacity of the materials. During testing, the sample and the differential temperature measuring cone are placed together in a specialized high-temperature differential-load softening test furnace, and a constant pressure is applied to the top of the sample. By continuously measuring and comparing the temperature changes of the sample and the differential temperature measuring cone, this method accurately determines characteristic temperature points such as the onset of softening and deformation. The maximum test temperature can reach 1700 degrees Celsius.