Abstract: The chuck includes a structure supporting a table provided with first sliding seats and with second sliding seats which extend radially from the center of the table and respectively accommodate means for centering the workpiece and means for locking the workpiece; the centering means are controllably movable towards or away from the center of the table, while the locking means are controllably movable from a first position spaced from the workpiece to a second position proximate to the workpiece and are also controllably movable in a direction substantially perpendicular to the face of the table directed towards the workpiece from a release position, in which the locking means are disengaged with the workpiece, to an engagement position, in which the locking means are engaged from the workpiece. The chuck also includes control means which act on the centering means and on the locking means; means are furthermore provided for the connection of the control means to the locking means in the second position.