Abstract: A grounding rod or other article is manually driven into the ground by an impact tool including an elongated guide shaft or rod having a center axis and upper and lower end portions. The lower end portion of the rod is secured by a cross pin to a coupler including a cylindrical body of electrical insulating material. The body defines a cavity extending downwardly from a metal anvil pad embedded within the body, and the cavity is formed by angularly related wedge surfaces extending from a slot. The slot opposes a threaded fastener extending radially through a flanged nut also embedded within the body. A cylindrical metal weight or hammer is slidable on the guide rod for impacting the coupler, and the hammer carries a pair of freely rotatable knobs disposed circumferentially at an angle less than 180.degree..