A center tool with a shank receivable in a sleeve carried by a body of a holder which may have cutters on a work surface disposed outward of the sleeve. A hydraulic actuator forces the sleeve radially inward to grip, releasably retain and center the shank of the center tool to permit rapid removal and replacement of the center tool. The actuation may also react radially outwardly to move the body and cutters radially outward to vary and adjust the diameter of the bore machined by the cutters on work surfaces. Preferably, the tool holder has a shank received in a chuck with the holder or chuck having a hydraulically actuated sleeve to retain the tool holder in the chuck.
