Abrasive rotary tool with abrasive agglomerates

An abrasive rotary tool comprising:

• a tool shank defining an axis of rotation for the rotary tool;
• and
• an abrasive external working surface coupled to the tool shank, wherein the abrasive external working surface comprises:
• a resin;
• and
• a plurality of porous ceramic abrasive composites dispersed in the resin, the porous ceramic abrasive composites comprising individual abrasive particles dispersed in a porous ceramic matrix, material, wherein at least a portion of the porous ceramic matrix comprises glassy ceramic wherein a ratio of the average porous ceramic abrasive composite size to the average individual abrasive particle size is no greater than 15 to 1;
• wherein the abrasive external working surface forms an arrangement of precisely shaped abrasive agglomerates, each precisely shaped abrasive agglomerate being tapered with diminishing width toward its distal end.