How I Put A Square Peg in a Round Hole

Two-step stepstool with handle

When it comes to woodworking, chances are you’re going to drill a hole and drive a screw at some point in almost every project.

If that connection point is going to be visible on the face of the project, then the hole will need to be filled.

Square wooden peg, prepped to fit into a round hole

For painted projects, you can usually fill the hole with some type of wood putty. But if the project is going to be stained or finished with a clear coat, you’ll probably want to plug the hole with wood instead.

The obvious choice is to use a plug cutter. A plug cutter creates a tapered round plug that fits snugly into the countersunk hole you’ve drilled.

But there’s another option: a square peg.

Hammering the square peg into the round hole

A little backstory…

Back in 1985, I started working at a woodworking shop called The Woodworker in Wayne, New Jersey. That’s where I learned many of the skills I still use today from my boss at the time, Bob Waltsack. In fact, Bob and I are still friends to this day.

Back then, we built a lot of furniture out of knotty pine.

We would build the face frames and then attach the cabinet sides by driving screws directly through the front of the cabinet. To hide those screw holes, we used square pegs.

Cutting the peg flush with the surface

To make the pegs, we’d rip long sticks to roughly 5/16” square. Then we’d whittle one end—not to a sharp point, but just enough to break the corners. We’d add a dab of glue to the end and drive it into the round hole with a hammer.

The result was a strong plug that looked like a traditional pegged joint.

Applying finish to the finished stepstool

I used this same method on one of my projects a few years ago: the Shaker-Inspired Two-Step Stool with Handle.

I’m happy to say that the project became very popular. Woodworkers from all over the world have built it, and I often receive emails specifically about the square-peg-in-a-round-hole technique. There seems to be something especially satisfying about tapping that peg into place and then trimming it flush with a flush-cut saw.

Close-up detail of the square pegs

It’s probably not the right choice for every project, but on the right piece, I think it adds character and a handcrafted look that’s hard to duplicate with a standard round plug.

Two Step Shaker Step Stool

Download Plans

If you’d like to see the technique in action, check out the project video and plans linked below.

And if you use this method on one of your own projects, post it on Instagram and tag me—I’d love to see what you build.

Shaker-inspired two-step stepstool with handle

Thanks for reading, and I’ll see you in the next one.

Happy woodworking!