Starrett A19 Oops Arbor 14-140mm

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