Also called die grinder bits, rotary burrs and rotray files, these burrs are designed for cleaning out material in a wide-range of products including wood, plastics, stainless steel and other metals such as nickel, iron, steel, tool steel and titanium Trade number SD-51 with a Ball End Miniature shape Double-cut style has rows of cutting teeth cut in two intersecting directions for fast material removal and a rougher finish 1/4" Head Diameter with 7/32" Head Length and 1-23/32" Overall Length 1/8" round shank allow use with a wide variety of toolholding systems