PURPOSE: To impart the characteristics of strength, thoughness, workability, hardness, wear resistance or the like required for a dressing tool by constituting a sintered body of certain compositional ratios of the powder of transition metallic carbides, nitrides, ferrous metals and diamond.

CONSTITUTION: The compsn. of the sintered body is constituted of, by volume, 20 to 80% carbides, nitrides, borides of any transition metals of the 4a, 5a and 6a groups in the Periodic Table or their mixture or solid solution, 2 to 30% ferrous metals and 10 to 50% diamond having ≥250μm particle size, and furthermore, in the ferrous metals constituting the sintered body or on the surface, carbon is precipitated. At the time of producing this sintered body, the mixture of the raw material is subjected to reducing treatment in an atmosphere of 500 to 900°C and is thereafter sintered at 950 to 1150°C under 1 to 30Kb. If required, the stage of the reducing treatment may be eliminated.