"If you ever buy a hole saw just make sure you buy a whole hole saw, no one wants a whole hole in their hole saw only to find it cant saw whole holes!"
You will need to have the drill bit, unless you purchase the fancy hole saw with the outer extended handle that attaches to the electric drill. Without the drill bit, there is a hole in the hole saw.
The complete hole saw usually consists of shank, the exchangeable center drill and the round saw blades.
Growing up we would replace house doors and purchase doors with no holes for door locks, so we would purchase a door kit that consisted of different sizes of hole saws.
Sincerely, Monica Andrews, Editor-in-chief, #FreePeoplesFreePress News