Hole saw heaven

[Rob]

I get this questions alot: What size hole saw do I want to use for a <blank> fan?

Here's what I use:

80mm fan: 3" (76mm) holesaw
120mm fan: 4-1/4" (108mm) holesaw

The general idea here is: it's a lot easier to enlarge your hole slightly than to shrink it.

Also, if you aren't using a drill press, your hole will be a bit oversized due to changes in your hand position.

Furthermore: hole saws don't usually come with an arbor (the part in the center that you put in your drill chuck). When you shop for a big hole saw, make sure you get an arbor that your drill chuck can handle. But then you can use that arbor on all your hole saws.