Abstract: A tool for enlarging pipe ends includes a toolholder body containing an axially movable mandrel having a tapering end and capable of being displaced by an externally applied force. A toolhead is exchangeably attached to the toolholder body coaxially with the mandrel and contains a plurality of expanding members in the form of cylindrical segments radially displaceable by the axial displacement of the mandrel and mounted so that they project axially from the toolhead. The edges of the segments facing the mandrel form a recess corresponding to the mandrel taper. An adapter is interposed between the toolholder body and the toolhead and has a body containing an axially displaceable supplementary mandrel having an elongated tapering end for cooperating with the exchangeable toolhead. The other end of the supplementary mandrel contains a recess shaped to receive the tapering end of the mandrel mounted in the toolholder body.