823 At Ural Research Institute of Abrasives and Grind� ing, theoretical and experimental data have been gath� ered regarding the operational properties of grinding wheels produced by AO Chelyabinskii Abrazivnyi Zavod. On that basis, a set of operational parameters for grinding wheels has been formulated; methods of deriving these parameters have been developed; and a method has been outlined for expressing these param� eters in the technological rating of the grinding wheel, a document that contains information regarding the operating properties (capabilities) of the grinding wheel in machining different materials. The rating includes a title page; a set of test charts for the grinding wheel; and instructions for use. The test charts consist of a table presenting the test condi� tions and a set of graphs of the grinding parameters: the radial Py and tangential Pz components of the cut� ting force; the roughness R a of the ground surface obtained in constant cutting conditions and the roughness Rab at the dwelling stage; and the volume Wi of metal removed from the blank during the wheel life and the volume Wa of the worn wheel section in the same period, as a function of the actual cutting depth tac. The graphs show the test results for the grinding wheel. In the tests, a blank (sample) made of material from one of seven grindability groups is ground, and the parameters are measured. The tests are conducted on a special bench based on a numerically controlled machine tool equipped with grinding wheels and instruments for measuring the radial and tangential components of the cutting force, as well as a unit for measuring the radial wear of the wheel and a vibrome� ter. Detailed information regarding the test method and the formulation of the test charts may be found in [1]. In the figure and in Table 1, as an example, we present the test chart for a wheel obtained in grinding a steel 45 sample, which corresponds to the first grind� ability group.