Vitrified superabrasive tool and method of manufacture

A method of making a bonded abrasive tool, comprising the steps of:

• a) combining a superabrasive grain component, present in an amount of at least about 5 percent by volume, a filler component having hollow bodies and present in an amount of at least about 10 percent by volume, and a vitreous bond component that includes zinc oxide and at least two alkali metal oxides in an amount in a range of between about five percent by weight and about fifteen percent by weight, the vitreous bond component present in an amount less than about 28 percent by volume;
• b) molding the combined components at pressure effective to avoid crushing more than about 10% by weight of the hollow bodies;
• and
• c) firing the combined components at a temperature in a range of between about 600° C. and about 850° C., for a period of time sufficient to form a bonded abrasive tool having a porosity of at least about 15 percent by volume.