Cobra Carbide 10639 Micro Grain Solid Carbide Regular Length Burr with Ball End, Single Cut, Shape D SD-7, 1/4" Shank Diameter, 3/4" Head Diameter, 11/16" Cutting Length (Pack of 1) Solid carbide tools offer long tool life and faster cutting speeds than other substrates, but are more brittle and must be used with rigid toolholding systems Designed for rapid stock removal and excellent surface finishes Round shanks allow use with a wide variety of toolholding systems Single-cut style has rows of teeth cut in a single direction for slower material removal and smoother finishes High stock removal and excellent surface finish on relatively hard materials