1 5/8" holesaw good quality like a lenox on a drill press with the bit removed may get you a 1.5" circle although it may burnish the sides a bit. Measure the set of the teeth. Or 2" sanded to fit? Yeah, my original post was dumb as a 1.5" holesaw will get you a 1.5" hole not a 1.5" plug. Doh!