yes, the hole is bored smaller than the tube. You better make a jig to hold the bowl when boring / pressing though, or your results will be equal to my first attempts before I built the jig. Let's just put it this way - you're gonna be hunting some kind of epoxy if you don't have a jig. also, don't cut the tube once it's installed, or you'll vibrate and loosen the press fit. Also, be careful to not place the tube to deeply, or you'll obstruct the drain screw hole. HTH, Steve