. The 1/2" spiral portion of the drill stayed sharp for the 80+" Cherry wood I drilled. But because it has such a small flex shaft I would only use it to widen the smaller straight hole pilot, otherwise it will follow the grain of the wood and deviate. If you have a situation that doesn't require a straight hole, that's fine. If you want a straight hole, I would look for a long drill bit with the shank slightly smaller than the twist bit portion.