I have just the boulder too Sharon.
Today was drill the drainholes day............
HaHaHaHaHa!!!! NO you do not need any drill bit even close to this size to make hole in your pots! I just happen to have this one on hand because of an old project that was only used once for drilling only 2 holes in my driveway slab. I have just used it on my hypertufa pots since as it cuts through curing cement like butter.
It makes really nice large drainholes and this is what the huge spikey pots holes look like now...
All of these pots need to be wet throughout the day here and there for another couple of days to secure they cure right.
This picture below shows a prototype for matching saucers in the works...