What Is a Thickness Planer and When Is It Used?

What Is a Thickness Planer and When Is It Used?

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If you are just getting into the world of woodworking, and you are gathering all of the tools and machines for your woodshop, one of the machines that you need to look into is the thickness planer. This an invaluable tool that every carpenter will eventually require, and it can serve a few different purposes.

So, what is a thickness planer, what can it do, and for what purposes might you use it?

What Is a Thickness Planer?

A thickness planer is also known simply as a planer in North America, or as a thicknesser in the UK and Australia. This is a special kind of woodworking or carpentry machine that is designed to cut or trim boards down to specific thicknesses along both lengths. It is not the hand tool that most imagine when hearing the word “planer.” For the differences between the two, check this article.

A thickness planer consists of four main parts including:

  • A motor that provides the necessary power
  • Cutting knives that do the trimming
  • Rollers that pull the wood through the cutting knives
  • A table on which the wood sits and which can be adjustable relative to the cutter head in order to adjust the amount of wood being trimmed off

There are different sizes of thickness planers out there. You have your regular thickness planers that are found in woodworking shops and ones used by contractors, and you also have industrial-sized thickness planers that are designed for large scale use, with the ability to accept very large pieces of wood.

Keep in mind that thickness planers cut the wood from above.

Thickness Planer

Are Thickness Planer and Jointer the Same Tool?

Although thickness planers and jointers do look somewhat similar, and although their functions may appear to be nearly identical to one another, they are different woodworking tools with different purposes.

To be clear, a thickness planer is used to trim down pieces of wood, usually long boards, in order to create uniform thickness, or in other words, to make the board the same thickness from one end to the other. A thickness planer can be used on both the wide length and the narrow length of a board to make it straight, flat, and even.

Remember that thickness planers kind of resemble X-ray machines in airports, kind of like a little square tunnel that boards pass through, with cutting knives located on top.

JointerOn the other hand, you have the jointer, with one of the major differences being that jointers have their cutting heads located on the bottom, so in other words, they cut wood from the bottom instead of from the top like thickness planers. Moreover, jointers usually do not have rollers that pull the wood into the blades, as thickness planers do. Jointers generally require the user to push the wood through the machine manually.

Let’s talk about some of the other major differences.

For one, while thickness planers are used to create uniform thickness in boards, but jointers are more precise in the sense that they are used to perfectly square and flatten a single wooden surface, so on just one side of a board. On the other hand, whereas thickness planers ensure uniform thickness, jointers can only be used to produce roughly the same thickness throughout the whole piece, with roughly being the operational term. Also, planers tend to be a bit more expensive than jointers.

For a more detailed comparison of the two, read this article. For more on how to use a jointer, click here.

What Is a Thickness Planer Used For?

As we have established by now, thickness planers are used to trim down boards along all four sides of their length, in order to create a uniformly thick board. Remember, when you are building something, unless specifically stated so, your boards should have the same thickness from one end to the other. Let’s take an exact look at the three specific things that a thickness planer can do:

  • Make one side of a board parallel to the other
  • Smooth out stock that is rough
  • Reduce the thickness of wood stock down to the required size

In terms of practical uses of a thickness planer, let’s take a look at a few examples, some of the actual purposes that this woodworking tool can be used for.

First of all, a thickness planer can be used to repurpose scrap wood. Instead of throwing out old wood, you can get it looking like new and cut it down to size for other purposes. Also, if you are making anything where various blocks are glued together, such as a kitchen counter, no matter what you do, those blocks never line up perfectly. Once the glue is dry, you can then push the whole block through the planer to even it all out. Finally, you can use it to straighten up warped and uneven boards from reclaimed wood.

All in all, no matter what you are doing, building something out of wood that is not straight, parallel, and of uniform thickness is not going to go well. Planer helps solve all those issues.

Thickness Planer in Use

Do You Need a Thickness Planer?

If you are just doing some small projects here and there, then no, you might not need a thickness planer.

That said, if you are serious about woodworking and you plan on building a lot of things out of longer boards, things that require those boards to be of a certain thickness, even, and parallel from one side to the other, then you will need a planer. This is especially the case if you are working with scrap or reclaimed wood.

It’s really the only tool that effectively accomplishes these tasks. Sure, you don’t have to get a planer, but if you don’t you won’t have any good way to make your boards thinner and even. The simple fact of the matter is that wood needs to be straight and even, and the planer is the only tool for this task.

As such, every pro woodworker will tell you that for the best results, realistically, you want both a thickness planer and a jointer.


The bottom line here is that if you plan on being a professional woodworker or carpenter, and you need to build things fast and with ultimate accuracy, then a wood thickness planer is a must-have machine for any woodworking shop.

In all reality, you won’t be able to get by without one. Once you get yours, read this article to learn how to use a thickness planer. First, though, check my benchtop planer recommendations.