Tongue and groove router bits are often used for making doors, windowsills, or furniture panels. They’re also perfect for creating decorative edges on boards like the kind you might use to make a bookshelf.
Tongue and groove router bits are basically two different types of blades that work together to cut out the tongue (the part that fits into the groove) in your woodwork.
The first blade cuts down horizontally through your board, which leaves grooves behind it. The groove can be any width you want them to be; usually, they’re about half an inch thick so there’s plenty of room for the tongue to fit in.
The tongue router bit creates the actual tongue-shaped piece of wood for your workpieces to join together.
Tongue and Groove Router Bits are great for beginners because they’re super easy to use once you get the hang of them, but there’s also a trick or two that can make using these bits even easier (and increase their overall effectiveness). Let’s take a look at how to use tongue and groove router bits in a few different ways.
How to Cut Tongue and Groove Joints with a Router
When you’re using a router to cut your tongue and groove joints, there is a quick and easy method to achieve that. Here’s what you need to do-
1. Set the Tongue Bit in the Router
Start by setting the bit into your router. You need to adjust the bit before starting to cut with it. Make sure the bottom of the teeth goes parallel to the throat plate. This will ensure that the cut is even all around without any defect.
To ensure it’s perfectly aligned, double-check that by placing the workpiece next to the bit.
2. Align the Fence Correctly
Use a router table fence along with the bit to ensure that you get an even cut. Using this method will help you achieve both straight and clean cuts every time. The size of your router table should be on the larger side for best results as well.
Many beginners worry about cutting too much deep but you need not worry about that. Just make sure you set the fence up correctly before starting the machine.
3. Cut the Tongue Joint
Now you can start cutting. Turn on the router and let it do its job. You’ll need to make only one pass for a clean cut.
4. Setting up Groove Bit
As you are done with the tongue cut, then start by setting up the groove bit. Once you fit the bit in, take the workpiece and adjust the height of the groove bit. You need to ensure that the groove made will perfectly fit with the tongue you made already in the other workpiece.
Set the fence just like you did earlier for the tongue joint.
5. Finish it Up
Once done, simply turn on the router and let it do its job. You’ll need to repeat this step for every board you plan on joining together using tongue and groove joints.
Watch this video to understand the whole process better-
While we recommend getting a set of tongue and groove router bits for better output, you may use a one-piece bit to do the job as well. Those have a slight variation in the way they work as both groove and tongue bit are put into one setup. So, you need to be vigilant about what you are using and how you are doing stuff.
Can I make tongue and groove boards with a router?
Of course, you can. To know how to do that, you need to understand one simple fact-
You can’t use the same bit for both tongue and groove cuts. You will need two separate bits or a set of router bits with different blades in it.
Use the guide mentioned above when learning how to cut these joints using your router table. It’s not difficult at all and can be done easily at home.
How tight should the tongue and groove be?
If you want tongue and groove joints that fit together snugly, they should be as tight as possible. You can use a clamp to wring the joint tightly. However, we recommend using glue even if you don’t need it for strength; the glue adds enough extra tension on its own to make up for having no clamps or cauls in place.
The joints should be a snug fit, meaning you need to press them to join together but it shouldn’t be hard for you to join them using your own hand. At the beginner level, this may seem complicated but you’ll see that the bits are made for that. You just need to ensure that the cut is in a perfect position.
Do the tongue and groove need glue?
Yes, they do. You can use clamp to tighten them but it’s not necessary, the glue itself is more than enough for that purpose. The joint becomes strong easily with just a little bit of glue and you don’t need more or less of it regardless of how hard or easy your hand press on joining together.
Do you nail into the tongue or groove?
You can use nails on both sides of the joint. However, it’s not necessary if you are using glue. Glue makes it connect perfectly without leaving any blemishes to be seen from outside.
Are tongue and groove joints strong?
As long as you use glue, the joints are strong enough to hold together. There’s no need of worrying about them breaking out or becoming loose easily. In fact, tongue and groove joints are stronger than a usual nail or screwed joints.
What is a good depth for tongue and groove?
There isn’t any specific value that defines this depth but it should be around ¼ inch at least to ensure that they don’t become too weak after a while.
What is a good width for tongue and groove?
The joint should be at least ¼ inch in terms of thickness to ensure that it doesn’t break out easily when the glue dries up. The router bit you use will decide how much gap can come between two boards while still making them stick together properly without any hassles.
What is the difference between a dado blade vs. a dedicated tongue and groove bit?
A dado blade can be used for both purposes but it’s not as efficient or precise as using two separate bits. You will have to make multiple passes using the dado blades which are difficult at times, especially if you are a beginner in making dado cuts.
A dedicated bit is precise and easy to use as it’s made for one purpose only- cutting tongues and grooves without any hassles or difficulties whatsoever. You can cut the edges with your jointer, planer or table saw but that may take up too much time as well as effort from you!