Have you ever destroyed the wood surface around a countersunk #4 or #6 screw? The body of our standard Power Driver bits is sometimes too large to fit into a 1/4 diameter countersunk hole to drive a recessed screw, as shown in the illustration. When that happens, the driver bit body makes a mess of the wood surrounding the hole. The solution is quite simple - use a driver bit with a reduced shank. That way the bit tip can reach the screw without creating an unsightly mess. One-piece bits are usually a disappointing compromise between the need for a hardened tip and a durable body. A special Iso-Temp heat treating process makes these the toughest one piece bits available though and their reduced shank nose can reach just a little farther into a countersunk screw hole without damaging the wood. Normally this is only a problem when using a 1/4 diameter countersink with #4 and #6 screws.