PURPOSE: To heighten porosity while preventing the dispersion of grinding quality and the increase of abrasive grain falling frequency so as to obtain desirable chip discharging performance and cooling performance.

CONSTITUTION: A metal plating layer 11 is formed on the surface of abrasive grain 10 to form plated abrasive grain 12. This plated abrasive grain 12 is mixed with metal binding powder 13 smaller in average grain diameter than the plated abrasive grain 12. Pressure rolling motion is applied thereto, and the metal powder 13 is pressure-bonded onto the metal plating layer 11 by mechanical friction pressure contact action to form a pressure-bonded coating layer 14. The obtained metal covered abrasive grain is then formed into a green compact, and hot hydrostatic pressing is applied to the obtained green compact. A porous abrasive grain layer of 3-40% in porosity is thereby formed.