A method for machining an enlarged profiled bore in a workpiece utilizing a numerically controlled machine and particularly a tool comprising a boring bar rotatable and axially displaceable relative to the workpiece. The milling cutter is eccentrically mounted in the boring bar thereby facilitating radial movement of the milling cutter. The milling cutter is adapted to follow a predetermined contour during removal of the boring bar from the workpiece thereby to form a correspondingly profiled bore.