A tool for soldering an electrical conductor with a connection device includes a deformation unit plastically deforming the connection device around the electrical conductor. The deformation unit has a fixed deformation module and a movable deformation module that is movable with respect to the fixed deformation module. The fixed deformation module has an anvil with an electrical contact area on which the electrical conductor and the connection device are disposed. An electric current circulates through the electrical conductor and the connection device by passing through an electrically conductive first part of the anvil that is electrically insulated from a rest of the anvil.