50 Piece Precision Carbide Bit Set. Used with your Dremel or Foredom, these carbide 1/8in. shank bits are rated for up to 60,000 rpm for really fine work. A must for precision work on autos, instruments, clocks, wood and more. Includes an assortment of drills, end mills, side cutting router bits, and microscribes sized #80-F/SAE and metric (.0125in./0.30mm to about 1/4in./6.35mm). Some smaller sizes are duplicated, as they're most prone to break.