I have some self-tapping bits, but I needed short ones for hard-to-reach places. Even a new (sharp) 3/4" drill bit was hard to get through the pine posts with a powerful cordless drill! My guess is that the thread is too long and biting off too much at once. I'm not sure that's helpful considering the number of times I've had to stop, back up to get a punch out, and start all over again. I suppose I could use this as an excuse to buy a more powerful drill, but then it might not fit in the space and I'm back to square one!