An apparatus is configured for use with an electrode and a CNC machine tool. The apparatus includes a holder configured to hold the electrode in a position projecting outward from the holder, and a pull stud configured to mount the holder on the CNC machine tool. The apparatus further includes a driving mechanism that is operative to provide a motive force, and a coupling configured to couple the holder with the driving mechanism when the holder is not mounted on the CNC machine tool. The holder is configured to transmit the motive force from the coupling to the electrode in the holder to move the electrode outward of the holder.