Champion Cutting Tool SN51 Tin Coated Miniature Bur, Inverted Cone Shape Solid Carbide, 1/4-Inch Cutter Diameter 1/4-Inch Cutter Diameter Inverted Cone Shape Edge machining from the rear in hard to reach areas 1/8-Inch Shank Used in mold and pattern making, die sinking, tool making and maintenance, burs reach into small intricate areas Burring cast iron, steels, titanium, brass, bronze, copper