Abstract: The combination with a machining tool for machining boles, of a clamping and feeding device for feeding the boles to the machining tool. The clamping and feeding device comprises a slide on which the bole rests during machining. The slide has mounted thereon a pivotable device that directly supports the bole, this pivotable device being elongated and extending lengthwise of the bole and being pivotally connected at one end to the slide. A power jack changes the elevation of the other end of the elongated pivotal device thereby to permit positioning the bole with its heart zone parallel to the direction of movement of the slide. In another embodiment, a lifting device is carried by the slide for lifting one end of the bole relative to the other end of the bole, the lifting device comprising at least one cam supported eccentrically on the slide, and a power jack to rotate the at least one cam to lift the one end of the bole.