Abstract: This improved rotary-type, super-abrasive grinding tool is designed to cope with a longstanding problem heretofore encountered when subjecting such tools to periodic dressing operations. The improved tool comprises an annular hub having a periphery or rim with a generally U-shaped slot therein, and a generally annularly-configured super-abrasive matrix supported in said slot and having an outer peripheral, configured working surface. The axially opposed walls of the slot buttress and support the sides of the super-abrasive matrix. Each of the walls have a plurality of peripherally-exposed, radially-disposed recesses therein containing a super-abrasive medium, preferably having the same composition and integral with the super-abrasive matrix. The exposed periphery of the super-abrasive medium protects peripherally-aligned portions of the rim from excessive wear when improperly contacted with the dressing medium.