The chuck of a drill press wears over time due to drill bits slipping and the pressure required to drill through tough metals, such as stainless steel. When a chuck is worn, a secured drill bit will wobble and wander across the surface of the material you are drilling. You need a special tool–a drift key–to remove the chuck from a drill press.  The chuck drift is for knocking loose a drill or drill socket from a receiving member.  It's also known as a steel wedge used to to remove tapered shank tools from spindles, sockets, and sleeves.