4 Inch Hole Saw

[deltaenterprizes]

I need to cut a hole in a wall for a dryer vent using 4 inch ductwork.
The question I have is the hole saw OD 4 inches or is the ID 4 inches?
I would like a 4-1/8 inch finished hole for a little clearance.

[mattthemuppet]

size refers to the OD. I used a 4" holesaw to install a 4" ceiling light can to hang a fan. It was a pretty close fit, so you may need to up the size if you need a 4 1/8" hole. Or wiggle the holesaw around a bit so it cuts oversize (1/16" each side isn't much).

[Corbettprime]

All of mine are OD, but holes are always a little oversized. Why not just take a tape measure to Lowes or HD and check?

[BCRider]

How often do you make holes like this? If you're like me it's once a decade. It doesn't justify buying a 4" hole saw. There's lots of ways to make a hole other than a hole saw. Even if it's in a spot you can't swing a jig or saber saw you could still mark it out, chain drill, bust out the plug then clean up a little with any number of sanding drums, coarse files or rasps or even just smooth it out with piece of smaller tubing wrapped with coarse sandpaper. And it would be all done in less time than it takes to drive to the store and buy a hole saw. And best of all you can have any size you want.