The 3/4" fine bit from Aanraku fits most glass grinders and is perfect for cleaning up your work prior to a final firing and the smaller radius lets you get into tight spots. This grit eliminates the chipping caused by rougher grits. Twofers Grinder Bits offer superior quality at a low-cost. The diamond abrasive grinding surface is double plated for strength, durability and long life. It's large 18mm bit height gives you a larger grinding surface, designed to maximize bite and allows for the uniform grinding.