Drill America DWRRB Series Hex Shank Bridge/Construction Reamers are used to align existing holes prior to bolt or rivet installation. The short length facilitates use in areas with limited access. They have a a tapered point to permit entry into overlapping holes. Three symmetrically places flats on shank provide positive grip in portable electric and pneumatic tools. Hex shanks have six flats on their sides to reduce slippage when working in high-torque applications. This heavy-duty hex shank designed for portable pneumatic tools. For additional safety magnet inside the shank of reamer to secure in socket 5" Flute Length, 6-7/8" Overall Length