How to Cut & Chisel a Mortise & Tenon Joint for Woodworking

Learn how to make mortise and tenon joints from Makeville Studio in this Howcast woodworking video, part 2 of a 2-part series.

Okay. We’re at the drill press, and we’re getting ready to remove the material for our mortise. We’ve marked it out. And, the one thing you want to set here is, first get our Fortstner bit in here. A Forstner bit is a drill that creates a flat-bottom straight-side hole, and that’s perfect for making mortises. We’ve got that in, it’s a half inch bit. The other thing we’re going to want to set is a depth stop, so we only go down as far as we need to, and on a drill press you usually have a way to force the drill press to stop at a certain point, and that’s what this is. So, I’ve set these nuts so that they’re going to stop right on the line down here that I’ve marked, that represents the depth of our tenon, and how far it’s going to go down.

Now, one thing with mortises and tenons – you want to leave a little extra room at the bottom for the glue to collect, so we’ll be doing that as well. We’ll be going a little deeper than the tenon’s actual length. But that should cover us with the depth. Now we’re ready to drill. When you’re drilling out a mortise on the drill press, one of the things you always going to want to do is to…you’re drilling holes like this in succession – drill one at the end, at one end, and one at the other end, first, and then you hollow out the middle parts, as necessary. The rest of this extra stuff we’re going to chisel out.

All right, so first cut. We want to get it set on the end of the line here, and I’ve got my Fence already set up so that I’m going to keep parallel, so I’m ready to drill. Forstner bits – you want to just take a little material at each pass, until you get down to your bottom. There we go. That’s one side. Now we’ll do the other.

Okay. Now I can get the rest of this out, just by going through the middle. There we go. There’s not much to grab onto, so the drill press and the bit are going to move around a little bit. That’s okay. Okay. We’ve roughed it out, and that’s what we have to work with. So, now we can square this out using the chisels. Now we’re making the tenon, and we’re using the table saw, with a set of Dado Blades. Dado Blades are a set of blades that you stack up in to make a very thick cutting blade that removes a lot of material at once, and it makes the table saw capable of doing all kinds of different joinery, including, making tenons very easily.

There’s a couple steps to setting this up. The first one is we’ve gotta get the saw blade at the right height. Now, we’re going to be passing this piece of wood over the top of the Dado Blades, like that, so that means we have to set our blade height such that we capture the height of the tenon. With table saw blades you have to be careful…you want to be at the maximum height of that arc, when you’re checking. I’m just lowering the blade now. A little bit of eyeballing here, and one of the things when you do eyeball measurements like this, you should always run a piece of scrap through first, and check your set up, before you work on your actual pieces.

We’ve got the height set. Now, our other set up, is…what we’re going to want to do, is make our first cut along the shoulder of the tenon. That’s the lower limit of the tenon as it comes down into the piece of wood. That shoulder has to be even all the way around, evenly cut all the way around on this piece of wood, and so, we’re going to have to find a way to make that cut in the same place every single time. We’re doing this cut four times on this piece of wood. So, the way to do that in woodworking on a table saw, is to use a stop block. A stop block is just basically a piece of wood that you push up against every time you make a cut, so that you’re in the same place, and if I rotate it around, I can bump up against it again, and make the same cut. I’m lining up that pencil line with the outside edge of the blade. Just looking down on top of it, getting it set up. It’s right up against there.

Okay. With that in place, I’m going to hold that, I’m going to bring the Fence over, top it up against there, with the block in place. The block’s not going to be here, but I’m just setting the Fence with it there. Now I’ll lock the Fence down. Now I can take out the block, and put it back here somewhere in a safe place. I’m going to clamp the block to the Fence back here, so now when I bump up against that block, I’ll be in the right place to make the cut.

And there’s our tenon. And I’ll just chop these out real quick, using a couple of bench chisels. So, we have to go down the whole depth of the mortise, but it’s not really a good idea to go all the way down with these bench chisels. They don’t have enough thickness, like a real mortising chisel would, to get the whole depth out at once. We’re just going to go gradually, and get the material removed.

All right. We’re almost down to the bottom. Get the waste out, and, a little more clean up, and we’ll be done. There we go. Okay. Got all the chips out, and we’ll fit the mortise in. Nice, tight fit. It fits nice and square and snug, pulling those two pieces together.