Enlarging a hole can present a tricky problem, whether it’s an existing hole that needs enlarging, or somebody made an “oops” and used the wrong size hole saw. How do you center the hole saw at the same location and keep it from wandering? This question drove the engineers at Starrett to develop the Oops Arbor.
As long as the new hole is 3/16″ larger than the old hole, you can use the Oops Arbor to pilot the larger hole saw with a second hole saw the size of the original hole. The Oops Arbor’s 1/4″ shank replaces the normal pilot bit for most hole saw mandrels and accepts both 1/2″ and 5/8″ threaded cutters.
You can get the Oops Arbor for as little as $6. What’s it worth to be the hero next time somebody makes an Oops?