The CTA Manufacturing E-Z Chamfer Tool, No. 3838, is designed for quick and clean deburring. The five-point cutting design efficiently removes burrs and ridges from bolts, pipes, threaded rods, bars, and dowels. It's ideal for starting a nut on a bolt or threaded bar, a button die or die nut on rod and a leading edge on timber dowel. The single-piece, tungsten-molybdenum HSS construction, provides durability and accuracy. For best results, use a slow drill speed with medium pressure on most materials. Harder materials will require a higher feed pressure, the company says. The E-Z Chamber has a range of 5/16 to 7/8".