IVY Classic 39035 1-Inch x 1/4-Inch Shank, Crimped Wire End Brush - 0.012-Inch Coarse, 1/Card For controlled removal of rust, dirt, scale, paint or welds in hard-to-reach places 1/4-inch round shank for use on drill or die grinder Tempered carbon steel bristles for long life Wire Trim Length: 1-inch, Wire Diameter: 0.012-inch Brush Diameter: 1-inch, Arbor: 1/4-inch Shank, RPM: 20,000