This standard specifies the test method for the determination of high-temperature modulus of rupture, which is applicable to both shaped and unshaped refractory materials. The principle involves heating the specimen and maintaining it at the specified test temperature, followed by applying a constant rate of bending stress until the specimen fractures. This allows for the measurement of the material's ability to resist bending moments at elevated temperatures. The core testing instrument for performing this test is the high-temperature modulus of rupture testing machine. This type of equipment can provide a testing environment with temperatures up to 1600°C and precisely control both temperature and applied load. Depending on the material properties, a sagger containing graphite powder may sometimes be placed inside the furnace to protect oxidation-prone specimens.