For all you that use a drill press, please take note from a retired 30 year machinist. #1,Install / slip a drill that just barely fits the prop hole, if the prop falls off the drill, increase the size of the drill. #2, place that drill in chuck, and tighten the chuck securley. #3, bring the table up so prop is fairly close to the drill bit. This is so you won`t run out of the throw needed for the drill to go completely threw the prop.#4, This is the important step. Somehow, I say that somehow, because most of us don`t have a true machinist drill press with all sorts of specialty clamps. Clamp the prop to the table top along with side stop, to stop the prop from spinning if it catches, generaly from hurrying the drilling prosses. Without a machinist table on your drill press you will have to become inventive in clamping the prop without damaging it. #5 Do Not hurry this drilling pocedure, gradually increase the size of the drill till you get the proper size. I personally like to have a snug fit, meaning, I have to thread/screw the prop on, instead of it falling on via it`s own weight. Pick up some junk props and experiment!