There is provided a device and method for terminating a flat cable having at least one elongated substantially rectangular insulated conductor by punch and die action. The device includes opposing semi-cylinderical metallic jaws which may be attached to and aligned with one another through a tab. The curved portion of each jaw is in the form of alternating grooves and lands with the grooves of one jaw adapted to receive corresponding opposing lands of the other jaw when the cable is terminated. To terminate the cable, the insulated conductor is placed between the aligned jaws and inward force is applied on the back sides of the jaws forcing the lands into the grooves. The cable insulation is pierced and adjacent portions of the conductor are elongated and sheared by the meshing of the grooves and lands, much like a punch and die process, forming embossed strips on the conductor. Fresh metallic internal edges, preferably parallel to the longitudinal direction of the conductor, are thus formed from this shearing and electrical contact is made between the sides of the grooves and these newly formed internal edges of the conductor.