Dog Hole Bushing for 20 mm Holes
These 20 mm hardened steel bushings help you make an accurate dog-hole drilling guide using any 38 mm (1-1/2 inch) thick board.
Knurling on the bushing provides a mechanical lock when installed in a 25 mm hole, and a projecting rim ensures that it rests perpendicular to the jig's surface.
If you don't already have a bit in the required size, we offer a 25 mm forstner bit that is 90 mm long overall.
For drilling the dog holes, we offer 20 mm drill bits that are 200 mm long overall, enough to go through the jig and a thick bench top. The lipped brad-point style scores the perimeter of the hole for clean entry and smooth sidewalls.