GENERAL MACHINE PRODUCTS 67970 LEAD DRILL CORING TOOL, REPAIRED These drills let you ake clean cable holes for placing flanges in 1 inch diameter or larger paper or pulp insulated lead or plastic sheath cable. Available with a 0.221 inch diameter shank. The double- ended hollow bit is secure to the shank of the knurled, aluminum-alloy handle with a steel nut. To bore a hole, just twist the drill into the cable until the drill turns freely , you can then remove the slug with the spring loaded ejection-pin built into the handle.