Introduction: How to Make a Simple Table Leg Assembly Using Mortise and Tenon Joinery

Picture of How to Make a Simple Table Leg Assembly Using Mortise and Tenon Joinery

One of the simplest traditional joinery methods is the mortise and tenon. This is a fantastic join for table legs, and with a few tools it can be extremely strong.

This is the method that I use to create table-leg bases, but there are of course lots of other ways around it.

Click here to watch the YouTube video where I make this table: https://youtu.be/faPzXCdEwCw

Step 1: Milling and Marking

Picture of Milling and Marking

The first step is to get your stock for the job. The more square and stable the wood, the better it'll work. If the wood is only recently dried try to leave a day between each milling step. This will allow the wood to move as the stresses are released.

Once your stock is cut square and to size it's time to mark out for the mortise, the holes in the legs. In this case the rail will be the tenon, so it's important that all the rails are the same size.

Using a combination square mark out the front facing edge, the face that you'll see when looking at the table. Make this the same all the way around the table on each leg. This line will be cut first because it's what people will see, any adjustments will be made on the line facing inwards.

Now draw the line on the other side to represent the width of the rail, and finally, cut along the lines with a marking knife. I can't stress how important this part is, especially if you're using a hardwood. A lot of hardwoods splinter easily so breaking the wood fibres along the line means you'll have cleaner lines.

Step 2: Removing Material From the Leg

Picture of Removing Material From the Leg

Now that you've marked out the leg you need to remove the material. I like to use a drill press to get rid of the majority of it because it's quicker, but also because the router should be under as little stress as possible to ensure a clean cut.

Drill a series of holes using a depth stop, leaving a couple of millimetres before the line.

Now setup a stop block for the router, so you don't accidentally cut too far, and start removing along the cut line.

Setup the fence on the router so you're cutting on the line of the outside face of the rail/leg (again, start with the outside face and any mistakes can be fixed on the inside face). Do all the legs with this setting on the fence so they're all the same. Be careful cutting in both directions as the router will react differently to the feed direction. This highlights the need to remove as much material as possible using the drill press.

Once you've done all the legs with the fence in one setting, move it to cut along the other line and repeat. At this stage the rails should either be a snug fit, or not be able to fit. I would rather cut the mortises undersize and sand the rails down to fit. Cutting the mortise too big is a deal breaker.

Step 3: Cut Shoulder Into Rail

Picture of Cut Shoulder Into Rail

I like to cut the mortise into the leg slightly shorter than the height of the rail. This means you can cover the curved corners left by the router with a shoulder on the rail. You could square up the corners of the mortise but this is quicker and the net result is almost the same.

Cut a small notch out of the bottom of the rail in each corner, enough so that the corner sits flush against the leg and the top of the rail is flush with the top of the leg. The sharper this cut is, the better it will look, so take you time and cut all your lines with a marking knife.

Step 4: Glue Up

Picture of Glue Up

Now that you have a snug fit you can glue the parts together. Use a ratchet strap of clamps to pull the legs into the rail. I like to do this glue up in 2 stages so I have time to make sure that the rail is 90 degrees to the leg.

The best way to improve is by practicing and learning form mistakes. My first leg assembly was horrible, but after a lot of mistakes I'm finally at a point where I'm happy with the end product. It just takes practice.

Comments

danthemakerman (author)2017-11-21

Jarrah is such a beautiful wood, great work!

emason (author)2017-11-20

That's a beautiful table, demonstrating careful yet confident work. It is simple and elegant. I must say, your pictures illustrate it wonderfully, and your video is as carefully crafted as the table itself!

Robin Lewis (author)emason2017-11-20

Thank you very much for the kind words! Glad you liked the post

rafaelnfs (author)2017-11-18

fantastico gracias por el conocimiento.
No sabia como se llamaban esas uniones. :)

nex_otaku (author)2017-11-18

It's just beautiful! Loved it.

Wish to make this, it's so great.

zuipschuit (author)2017-11-18

nice job! i love it, using reclaimed wood.

It is sometimes like people. The looks on the outside is not always nice but the real treasure can be found on the inside. It is up to you to make something beautifull!! ;-)

mscullin (author)2017-11-17

To check for squareness of the subassembly, measure the diagonals and adjust until they are equal. Use a framing square or a right-angle template you make to ensure the legs are square to the aprons.

Oldchugger (author)2017-11-16

Nice job, I especially like the shoulder you cut on the rails it's going to really tidy up my joints.

Did you use these figure 8 brackets for ease of use or because you want to be able to remove the top for maintenance etc? I always try to use dowels but find it really difficult lining everything up.

Again great job
,

Robin Lewis (author)Oldchugger2017-11-16

Thanks very much!
You basically answered the figure 8 question for me; it's the easiest method I know. I've seen people use all kinds of crazy (but awesome) joins when it comes to table tops but this is the simplest one I can think of.

It give the top the ability to move with the seasons, although because of how dense this wood is I don't think it'll move much, and all it requires is a tiny notch on the rails. Then when it comes time to line up the rails you can adjust as much as you like until you're happy, then drill holes into the top. It's hard to mess it up.

TwelveFoot (author)2017-11-16

Notching the rail instead of squaring the mortise is brilliant.

Neil2009 (author)2017-11-14

Man, I'm jealous. What a great little treasure find on the old jarrah. I would have been afraid to take a router to those mortises and wound have chiseled for fear of blowing it. Elegant little table there mate, you ought to be happy with that one, although I weeded a little when I realized it wasn't going to get a French polish.

Robin Lewis (author)Neil20092017-11-14

Thanks very much! It's funny, I didn't use a chisel to square up the mortises because I didn't want to split the leg; the router was a safer option for me!

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