A method of driving a rod into the ground comprises coupling an impact portion of an attachment to a powered hammer, positioning the rod between a first jaw of the attachment and a second jaw of the attachment, activating a first motor to move the first jaw toward the second jaw, such that the rod is clamped between the two jaws, and activating a second motor to drive an axial impact mechanism of the powered hammer to deliver repeated axial impacts to the impact portion of the attachment.