IRWIN Hex Bolt Auger Bits feature an innovative 2-in-1 design that allows professional tradesmen to counterbore the hex bolt and washer for deck building with one bit. The full screw point tip and auger flute design of these wood drilling bolt bits make through-hole drilling easy for holes up to 9" deep. These bits avoid the hassles of using separate auger and spade bits when putting in hex bolts.