Abstract: An improvement for use with a hand operated wrench primarily intended for removing a cartridge from an opening, with such wrench having a slotted aperture at one end. This improvement comprises an elongate threaded device having a mounting shaft at one end, and tapered external threads at the other end, with an internally threaded hole extending partly along the length of the device. This mounting shaft is sized to be inserted into the apertured end of the wrench, with flattened shoulders on the shaft able to closely engage the slotted aperture of such wrench to prevent undesired rotation. The internally threaded hole is engagable by an elongate screw associated with the wrench, to prevent undesired separation during use. The external threads of the elongate device are of a diameter for tightly engaging and removing a fractured cartridge from an opening, such as in a valve body.