The Ha index tester standard grindability coal sample is mainly used for instrument calibration, inspection, and result calculation in coal grindability index testers. The standard coal sample was measured by the Beijing Institute of Coal Chemistry, China Coal Science Research Institute, using an imported American Hastelloy apparatus. After statistical processing of the test data, the standard value was determined, and the results were accurate and reliable. Each set of standard samples includes four types of coal samples, with the following standard values: