Description of π οΈ Starrett KA19 N OOPS Arbor Enlargement Tool
"Oops" Arbor, Hole Enlargement Arbor. Replaces the pilot drill in any Starrett A1, A2 or A10 type arbors. Replacing the pilot drill, the KA19 allows diameters to be enlarged by attaching a saw of the same size to that of the existing hole. This saw then acts as the pilot for the larger diameter saw that is attached to the arbor in the normal way.
We need to make a larger hole for the lock in our metal front door. My set of hole saws did not match the two needed. That made it very easy. I'm not sure I'll ever need it again, but I hope I will.
Great hole reamer except you have to use a smaller one with a big one. If you are trying to upsize a smaller hole, you may run into problems because smaller holes use a smaller adapter than a larger one. As long as you use a different size adapter it should be fine.
Starrett KA19 expanding mandrel 1/4β shank flattened like most hole saws. It is 1-11/16" long so it sinks deep into the hole saw arbor. The holding end of the hole saw is threaded for standard large (5/8") and small (1/2") hole saws, just like regular mandrels. It can be held using a large mandrel and a small or large hole saw as a hole guide, and it replaces the 1/4" center drill bit. To clarify another point, this doesn't offset the center from the first hole drilled, it only does enlargedβ¦