Burs are used with rotary tools, to refine and remove metal, Jewelry Tools carries over 500 styles of burs. Burs work best with a bit of lubrication, like Cut Lube, for keeping the tool cool and sharp. For stone setting you might need a set of burs, including bud, round, cone, and heart shapes. Cup burs are used on the ends of wire to smooth and refine, removing sharp edges.