Abstract: The present invention is an expansion tool device for pliers or machine for producing sockets at the ends of pipes made out of plastic or composite material, used in the field of plumbing. The device includes a cylindrically-shaped ferrule formed by the tightening of several sector-shaped chucks. The chucks are movable in the radial direction under the action of the insertion between them of a tapered needle movable in axial translation through the actuation of the pliers or machine. The chucks are allowed to pass from a tightened position to a separated position. In an integrated way or in a unit designed capable of being intercalated between the ferrule and the pliers or machine, there is an automatic driver for the ferrule, when the ferrule passes from the separated position to the tightened position, directly or indirectly, in axial swiveling according to a portion of a turn.