[2025] What Is a Jointer & How to Use It?

When visiting a woodworking shop, you may see a jointer and wonder what it is. Jointer is a powerful woodworking machine to flatten and square faces, edges on the bowed, cupped, crooked, and twisted boards. Moreover, a jointer with stand can create rabbets for jointing two boards.

In this comprehensive guide, we will show you what a jointer is, how it works, and how to use it effectively and safely for your woodworking projects. Just read on to get the information you want.

What Is a Woodworking Jointer?

A jointer is an efficient machine that can quickly produce flat surface and straight, smooth edges in woodworking projects. It generally comes in sizes from 6'' to 18'', with the most common sizes being 6'', 8'', 10'', 12'', 16''.

There are generally two types of jointers: jointer with stand (sit on the ground) and benchtop jointer (sit on the workbench).

• A jointer with stand is big, heavy, and built to sit on the floor. It is ideal for big workshops and is available to process large wood projects. It can create flat, straight surfaces and smooth edges with high accuracy. But mention that it is expensive and difficult to move.
• A benchtop jointer is compact, smaller than a jointer with stand, and built to sit on a workbench. It is suitable for smaller workshops and is powerful for processing most home woodworking projects. It is affordable and portable.

The common sizes of a benchtop jointer are usually 6'' and 8'', less commonly 10'' and 12''. In contrast, the jointer with stand covers almost all the sizes in the range. Moreover, it's worth noting that the jointer with stand can cut rabbets, but the benchtop jointer can not.

Parts of a Jointer

Common jointers consist of an infeed table, an outfeed table, a guard, a cutter head, a fence, and two table height adjustments.

• Infeed table: The right bed of a jointer that feeds the workpiece into the machine.
• Outfeed table: The left bed of a jointer, which is the height reference table.
• Cutter head: It is fixed to the base casting and rotates by means of bearings, typically driven by an electric motor. There are three styles: straight, spiral and helical.
• Guard: It covers the cutter head when a workpiece is not present, minimizing the posibility of cutter head contact with the operator's hand.
• Fence: It keeps the workpiece in position as it is fed through the jointer.
• Table height adjustments: There are two table height adjustments, one is for the infeed table, and another is for the outfeed table.
• Rabbeting ledge: It's always on a jointer with stand for cutting rabbets.

How Does a Jointer Work?

You already know what a jointer is and its powerful function, now we will show you how it does that. This performance is due to the cutterhead, the infeed table, and the outfeed table. They work in harmony enabling the jointer to create a flat and smooth board.

As the wood piece is fed into the motorized, high-speed rotating cutterhead, it automatically cuts the surface. Then the wood is fed from the outfeed table with a flat surface. In most cases, you need to take several passes on the jointer, but with each case, the side of the board will become flatter and flatter.

You can control how deeply the blade cuts into the wood by adjusting the height difference between the infeed and outfeed tables. However, one important thing is that the blades at the top center on the cutter head are dead-flush with the outfeed table.

This makes you use it with less effort and more efficiency than using a hand jointer. A jointer is usually used to handle large pieces of wood, such as wooden floors. It has the advantage of being easy, fast, and efficient to operate, making it ideal for jobs that require a lot of wood processing. However, you must pay attention to safety when using it to avoid hand injuries or wood kickback.

How to Use a Jointer?

At the very beginning of this post, you know that a jointer can not only square and flatten faces and edges, but also create rabbet cuts. You may be curious about how to achieve both outcomes. Therefore, in this section, we will show you how.

For Flattening and Squaring Faces and Edges

1. Make sure your jointer is correctly set up.
2. Wear an eye-protection.
3. Decide which face or edge of a board to flatten or square.
4. Adjust the height of the infeed table to control the depth of cut.
5. Turn on the jointer and feed the board through. Remember to use a push block.
6. Take several passes through the jointer until the face or edge is smooth and flat.
7. Power off the jointer.

For Cutting Rabbets on a Jointer with Stand

1. Remove the blade guard.
2. Adjust the jointer fence to control the width of the rabbet.
3. Adjust the height of the infeed table to control the depth of the rabbet.
4. Hold the workpiece tight against the fence and feed it through the jointer.
5. If the board is thin and you want to make a rabbet on a face rather than an edge, use a push block to ensure it maintains firm contact with the table.

（image source: Woodsmith）

Safety Tips for Using a Jointer

As we mentioned before, during the operation, the most essential thing is to pay attention to safety. Here are some rules you must follow to minimize the risk of injury from the blade and wood kickback.

• Adjust the correct cutting depth. Taking small bites is an essential factor to keep safe and get a good result. Cut no more than 1/16” at a time. 1/32” is probably best. If the cut is too deep, the workpiece is difficult to pass through the cutter head. This means a greater possibility of kickback and tear-out, not to mention the excessive strain on the motor.
• Always use the blade guard and push blocks. The guard prevents overexposure of the cutter head. You can remove it only when using a jointer for rabbeting or jointing boards wider than the cutterhead capacity. The push blocks keep your hands as far away from the blade as possible.
• Before jointing, check the workpiece for knots and nails. And apply even pressure to the surface of the wood to prevent its end from denting.
• Don't joint the wood that is too short or too thin. Typically, the minimum length of the jointing wood is 300mm, and the minimum thickness is 10mm. If the wood is too short or too thin passing through the jointer can easily cause the wood to bounce or break, and you will get hurt.
• Joint the wood with its grain. If you want to joint the hardwood or joint against the grain, you need to slow down the feeding speed.

Final Thoughts

If you have a jointer, you might be worried about what to do if the cutter head is dull or ineffective. Our FindBuyTool will give you a solution: an alternative cutterhead. Those high-precision cutterheads with top-quality tungsten carbide insert knives mounted, can produce a better finish, reduced sound, smaller shavings, and save maintenance costs.

FAQ About Jointer

1. What does a jointer do?

A jointer creates flat, straight faces and square, smooth edges on the bowed, cupped, twisted, and crooked boards. Moreover, it can cut rabbets on a workpiece.

2. What is the difference between a jointer and a planer?

The differences between a jointer and a planer are as follows:

• The cutterhead of a jointer is mounted underneath the wood boards, while the planer's cutterhead is mounted above the boards.
• A jointer flattens one face or edge  of a board, but a planer makes both faces of a board parallel and creates a consistent thickness.
• In woodworking projects, a jointer is always used first to create a flat surface and square up one edge on the board, and then a planer makes two surfaces parallel.

3. Do I need a jointer if I have a planer?

The answer is actually optional. That depends on the types of woodworking you do and the materials you use.

• Yes, you need a jointer if you require high precision and frequently mill rough or uneven boards.
• No, you don't need a jointer if the wood is already milled to surfaced three sides. Then only a planer may suffice. Or, you can use a hand plane as an alternative to the jointer for small projects (though it may be slower and less precise).

Also read:

Planer and Jointer: What They Are and What They Do?

What is a Thickness Planer Used For?