The A19 'Oops' Arbor is for use in conjunction with either the A1, A2 or A10 type hole saw arbors (e.g.  A1-1, XA2, A1E etc).  Replacing the pilot drill, the 'Oops' Arbor allows diameters to be enlarged by attaching a saw of the same size to that of the existing hole. thereby acting as a pilot for the larger diameter saw.  Minimum hole enlargement is 4.7mm (3/16") between the pilot saw diameter and the cutting saw diameter.

The A19 ‘Oops’ Arbor works with the following holesaws because they all have the same screw threads (1/2”-20 & 5/8”-18):

  • (SH) Constant Pitch HSS Bi Metal Holesaws
  • (DH) Dual Pitch HSS Bi Metal Holesaws
  • (MPH) TCT Multi Purpose Holesaws
  • (CT) Carbide Tipped Holesaws
  • (D) Diamond Grit Holesaws

Please note: Hole Saws and Arbor sold separately.


"A not often used tool but indispensable when needed"

"I had the advantage of seeing this tool in use years before needing it. As brief as possible, the home I was renovating used undersized locksets. In order to standardize door hardware, I had to enlarge the lockset holes on a dozen doors. A jig and router would have done the job but at the cost of far too much time and the creation of a mess. This brilliant but simple tool saved me untold hours of work.
It's definitely a quality tool of hardened steel. Whether you have one mistake to correct or a situation similar to mine, the tool will help you and on that you may rely."

14 Dec 2010 By Fixitmister