Drilling out a 1-1/2 inch deadbolt hole to a new 2-1/8 inch hole
I recently had to install a new 21/8 deadbolt in an old 11/2 inch hole. I was going to cut a plug with my 11/2 inch saw but I realized it would be sloppy in the hole. Instead, I just screwed my 11/2 inch saw onto the mandrel inside my 21/8 inch saw and used the smaller saw as a guide for the larger hole saw. It worked perfectly!