Needed to drill 3 holes through concrete block wall for mini split installation. One of the holes turned out to be solid. Drill worked much better than I expected, being a dry bit. I suggest forgetting about the pilot bit, and saving it for other uses. The bit is too long to center properly, and will not guide the blade to the center anyway. Not the fault of the hole saw, it is just long. Instead, I drilled a 2.5 inch hole in a 2x4, then mounted it on the wall with Tapcons, and used it as a guidSee full review