3 Ways to Cut a Square Hole in Thick Wood

Drilling holes into a wood blank is relatively easy, especially if you have power tools at your disposal. These tools make quick work of even thicker pieces of wood. However, the challenge comes when you want to drill a hole to shape, rather than just drilling a round hole right through the wood – for example, when you want to drill a square hole, which is a key part in creating many wooden joints.

To cut a square hole in a thick piece of wood, you’ll first need to draw the shape of the hole on your piece of wood. It should, of course, be square-shaped and should be the size you want the final hole to be. Then, use the tools of your choice – you can use power tools such as a drill, hand tools like a chisel and sledgehammer, and even specialized tools like a jigsaw.

Drawing the shape of the square on your wood blank is the easy part – the challenge comes when you move on to actually cutting the hole. Not only do you need to know how to use your tools, but you’ll also need to be careful that you stick to the lines and don’t overshoot and oversize or undersize your hole. If you’re looking for more help on cutting a square hole in wood, keep reading.

How to Cut a Square Hole With Hand Tools

Most woodworkers start with using hand tools before they progress on to power tools. While hand tools can be time-consuming to work with, they help you get a clear foundation in woodworking that will serve you well in the future

When cutting a square hole with hand tools, you’ll need:

  • A chisel
  • A framing square
  • A sledgehammer
  • Sandpaper

Here’s what you’ll need to do:

  • Use the framing square to draw the shape of the square onto your wood blank. If you don’t own a framing square or only need to make a small square hole, you can also use a ruler or another straight edge for this task.
  • Position the chisel on one of the corners of your square, with the tip touching the piece of wood.
  • Tap on the chisel with the sledgehammer. You don’t have to be gentle when you do so – putting force into your actions will make the process go faster.
  • Keep tapping the chisel until you cut through the wood.
  • Repeat the steps above for the rest of the side. Then, do the same for the other three sides of the square
  • Gently nudge out the square piece of wood from the hole.
  • Sandpaper the edges to make them smooth

How to Cut a Square Hole With a Drill

Using a drill or other power tools is undoubtedly a quicker way of cutting wood (and carving in general) than using hand tools. However, these tools are not always available, which is why it’s best to know how to use both hand and power tools.

That said, if you have access to a drill, you should definitely consider using it instead of a chisel when cutting out square holes. It’s much more convenient and definitely much easier when you’re working with thick wood

If you’re worried about affordability, take a breath – it is possible to buy high-quality power tools on a budget, so you don’t have to worry about blowing your yearly tool budget on just one tool. 

Here are a few affordable drills and circular saws that I love. All of them are available on Amazon. This means you can get them delivered to your home so that you can get started on your project as soon as possible.


Circular Saws:

These options are all cordless, so you don’t have to worry about a ton of wires tripping you up when you try to maneuver around your workshop.

Here are the tools you’ll need:

  • A drill and suitable drill bits
  • Sandpaper
  • A framing square
  • A chisel 
  • A circular saw

There are two ways in which you can use your drill to cut a square hole in your wood blank. Which way you should opt for depends on the size of the square hole you’re looking to make. 

For smaller square holes, you should:

  • Draw the square on the piece of wood with a framing square or another square edge
  • Use the drill to drill a hole in the center of the square
  • Make more drill holes on each side of the square depending on the size of your shape
  • Use your chisel to remove the wood by cutting across the lines that you drew in the first step
  • Smooth your edges with sandpaper

This video will give you an idea of how to create a square hole with a drill bit and a chisel. While the hole made in the video is rectangular shaped, you can use the same technique when making a square hole:

The main difference between a square hole and the mortise in this video is that you’ll be drilling through the wood instead of creating a hollow with some material left over at the end.

For larger square holes, you’ll need to:

  • Draw the square to size
  • Use the drill to drill through one side of the square. Unlike the above method, you do not need to drill through the center of the shape first.
  • Repeat on the other four sides
  • The holes you’ve just made will serve as the starting point for your circular saw. Use the saw to cut through the sides of the square and remove the square from the wood blank.
  • Smooth the sides of the hole with sandpaper

How to Cut a Square Hole Without a Jigsaw

While using a chisel or a drill are both effective ways of cutting a square hole in a thick piece of wood, the most common option is undoubtedly to use a jigsaw. It makes cutting a perfect square a job that will barely take you minutes.

However, not everyone has a jigsaw handy. Additionally, some people may not like the feel of using a jigsaw or may want a faster option

If you’re in the last camp, you’re in luck – while using a jigsaw is the most common option for square holes, it’s neither the fastest nor the most professional

If you’re looking to make your square holes look truly perfect, what you’ll need is a mortising machine

These machines are a bit expensive, and you’ll also need to invest in a mortising chisel set when you buy them. However, the first time you use your new purchase, you’re sure to fall in love.

So, what is a mortising machine? It’s essentially a machine that combines an auger drill bit within a square chisel. Together, these tools ensure you have perfectly square holes every time you use the machine. 

Here’s what you’ll need for this option:

  • A mortising machine
  • A mortising chisel set. Two options I love are the SaferCCTV Mortising Chisel Set and the Woodstock D2845 Mortising Chisel Set, both of which are available on Amazon and are extremely effective. While the SaferCCTV set is the better option based on quality, there’s not much of a quality difference between the two, and the Woodstock set is more affordable. However, the SaferCCTV set comes with 7 chisels, while the Woodstock set only has 4.
  • A framing square

To use this machine, you’ll need to:

  • Draw the shape of the square on your wood blank
  • Insert the chisel and the drill bit into the machine. You’ll have to make sure that the tip of the auger bit leads the chisel.
  • Ensure the wood is held in place and that it won’t move when you start the machine
  • Start using the machine. If the square shape you want is bigger than the chisel, you’ll have to drill multiple holes. When you position the chisel, make sure that there is wood on all four sides of the chisel, or only on two sides. For safety reasons, it should never have wood on three sides and one side bare.
  • Smooth the edges with sandpaper

If you’re unsure about how to set up the machine and use it, you can refer to this YouTube video:

5 Pro Tips to Cut a Square Hole Easier

If you’re looking for more help with cutting a square hole through a thick piece of wood, here are some tips that will help!

  1. When using power tools to cut a square hole, make sure to use a bit that is at least as long as the wood is thick. If your bit is shorter than the thickness of the wood, it won’t be able to drill all the way through. Instead, you’ll need to turn your piece of wood around and repeat the drilling process from the back.
  2. Wear protective gear, especially if you’re working with power tools. While a chisel doesn’t produce much sawdust, this isn’t the case with drills and mortising machines. Breathing in sawdust can be dangerous, so make sure you’re wearing a face mask at least. Additionally, eye protection is key so that you can avoid dust flying into your eyes and damaging them.
  3. If you’ve never used a particular power tool before, practice and look up precise guidelines before you use it on wood. This ensures you know what you’re doing and helps you achieve a better finish.
  4. Make sure all your tools are sharp so that you don’t get tripped up by blunt edges.

Additionally, when working with hand tools, make sure you choose a chisel that is long enough to meet your needs. If the cutting edge of your chisel isn’t long enough, pushing it to the other end of a piece of wood will pose a challenge

Final Thoughts

Knowing how to cut a square hole in thick wood can come in handy for a number of different projects, including everything from creating wood joints to making a frame for a square window

The process is relatively easy, and you can use either hand or power tools to do the job. Power tools are faster. However, knowing how to reach your objective using only a chisel and sledgehammer will ensure that you’ll never be caught off guard and find yourself unable to complete a project due to power loss or a lack of access to power tools.

Martin Swizz

Hi! This is Martin, I like to research, experiment, and learn new things related to wood carving and other kinds of woodworking.

Recent Posts