How to use a hole saw
The key to a creating a good, clean, large diameter hole is to use a quality hole saw.
This is not a place to skimp on tool quality because the result will be ragged, incorrectly sized holes, surface damage around the final hole and a general mess.
How to choose a hole saw
If most of your work is in wood, look for a kit that has a range of hole saws that individually mount to an arbor that has the pilot drill already inserted. The saw will mount rigidly to the arbor for an accurate, clean cut. Since most door lock hardware requires a 2⅛-inch hole, check that the kit you are considering has this size.
You’ll also use this size hole saw when running 1½-inch pipe through studs and, if it’s deep enough, through a sole plate and flooring, or through the top plate in a framed wall.
The arbor screws into the hole saw or attaches with a collar nut. A better choice is a tool system with a quick-change chuck that locks the saw quickly and correctly every time. These tool systems handle regular wood-cutting hole saws to 2½ inches.
Others systems are available to accommodate larger sized hole saws with teeth that can cut wall tile, cementboard, glass and masonry. These saws will usually have larger gullets – slots in the blade – to clear away debris from the cut. These hole saws are extremely useful for remodelers who are installing basement bathrooms, for example, working around showers and cutting out the holes required for shower hardware and plumbing.
How to use a hole saw
For the best results, you need to know how to use a hole saw. If you haven’t used a hole saw before, practice on some scrap, especially if you are working with a material you haven’t drilled before. Wear safety glasses.
With the location for the hole marked on the material, drill a ⅛-inch pilot hole in the center with a regular drill. This will guide the hole saw’s drill and help to locate the hole precisely where you want it.
With the correct hole saw selected and mounted to the arbor, slowly start the hole-saw’s guide drill into the pilot hole and bring the saw into even contact with the surface by holding the drill vertical.
As the saw engages the surface, make any adjustments necessary to how you are holding the hole saw so that you are cutting an even circle. Make the first cut about ⅛-inch deep and as accurately as you can before putting pressure on the saw.
Don’t be tempted to go too fast, either with the initial contact or with the saw speed. Remember the bigger the saw diameter, the slower the drill speed.
Don’t rush the cut. Let the saw do the work. If you see smoke, you’re going too fast, or working with a worn-out blade.
Ease back pressure on the saw from time to time to allow debris to clear the cutting edge.
If you can access the front and back sides of the job – for instance a door where you’ll be installing a lockset – watch for the projection of the arbor drill on the backside. Remove the hole saw, go to the backside and cut from the back. This will ensure a clean hole on both surfaces.
If the hole you are drilling is deeper than the hole saw, withdraw the saw at near its maximum depth and, using a chisel, break out the material from the hole. Go back in with the hole saw again and make deeper cuts until you break through.
—By Steve Sturgess, stevesturgess.com