Make a Quick Box Using Box Joints




I wanted to make a small box for a project and I wanted strong joints. A mitered and glued box wouldn't be strong enough for what i had in mind so I tried box joints. 

There are all kinds of commercially available jigs and tools to assist in making box joints (or dovetails) but I made my own jig quickly and easily with the router table at TechShop and some scrap wood.

Tools needed:
Router table and a 1/4" straight bit
Compound miter saw or table saw
Belt sander*
Straight file
Some clamps

3-4" wide board
Scrap board

I made it at TechShop!

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Step 1: Prepare the Sides

Plane your board to the desired thickness. I used 2.5" wide maple planed to about 3/8" thickness.

Cut four sides. Label each piece lightly in pencil: front, back, left and right. It helps to put the label at the top of each piece to aid in orientation later.

If it helps, lay them out in the way they will be assembled.

Step 2: Prepare the Jig

For this box, I wanted 1/4" fingers. I inserted a 1/4" straight bit in to the router table and set the height to be the thickness of one of my sides. A quick way to do this is to stack two piece on top of each other with one offset from the other. Raise the router bit until it just touches the offset piece on top. DO NOT CHANGE THE HEIGHT AFTER THIS STEP!

Take a piece of flat scrap wood and clamp it to your miter gauge. In my case, I needed an additional piece of scrap to provide a good clamping surface on the rear of the miter gauge. The front piece is flush with the surface of the router table, the second, clamping piece, clears the router bit.

Turn on the router and rout a rectangular hole in the front piece of scrap. This hole will hold the jig "finger".

Cut a piece of wood, perhaps from your board, just larger than your bit size, in my case 1/4" x 1/4" x ~2"

Fit the piece in to the slot you cut in the jig board. File or sand it down to a tight fit. Also, sand the bottom down so the finger is flush with the bottom of the jig board.

Now, realign the jig board on the router table, against the miter gauge. This time, however, you will clamp the board offset from the bit by EXACTLY the width of the bit (1/4"). I used a 1/4" drill bit as a spacer between the jig finger and the router bit. Clamp the jig board in to position. DO THIS STEP CAREFULLY. Be sure you are measuring against the widest part of the router bit and that the fit is as exact as you can get. This step determines how well the box will fit.

Now, with the jig board clamped in place, route a second hole in the front of the jig board. It should now look like the picture.

Step 3: Cut the Fingers on the First Piece

Now, you can start cutting fingers. It is a good idea to make some test fingers on a few pieces of scrap wood to test the alignment of the jig. If the fingers don't fit together closely, try the alignment again.

For the first cut: Align one side of the side piece with the inside edge of the jig finger. Route a hole. You should now have a piece that has a 1/4" square hole, 1/4" in from the left edge (see picture). 

For the second and following cuts: move the piece so that the slot you just cut fits over the jig finger. Route a new hole. Repeat until you run out of board. If the last hole doesn't align perfectly with the edge, don't worry, the corresponding piece will have the same amount of left over hole.

Between routing holes, especially if the jig finger is a tight fit, you may want to run a square file through the newly cut hole to adjust fit. Don't file away too much, just enough for it to fit tightly.

Step 4: Cut the Fingers on the Second Piece

The second piece is cut the same as the first piece EXCEPT: the first finger is a hole on this piece, so you have to adjust the offset of the first hole. There is an easy way to do this.

Take the corresponding piece you just cut, place the hole closest to what will be the top of the box on the jig finger. Align the back piece with the edge that will be the top of the box touching the top of the side piece (this is where the pencil marks come in handy). 

Route a hole. This will make a hole that is at the top of the edge, corresponding to the top finger of the other piece. If everything is well aligned, the router bit should not cut anything from the piece on the jig finger. 

Now proceed as before, cutting fingers by aligning the holes on the front piece on the jig finger as before.

Step 5: Test Your Fit

Dry fit your pieces. If it is too tight, try some light filing. If it is too loose - oops. try again with better measurement on the jig finger and the router bit alignment.

If the ends of the fingers are too long, that is ok since you can cut/sand them down after the box is complete. If the ends of the fingers are too short, your bit is not high enough. You might be able to file the holes slightly deeper to make a better fit.

Step 6: Make the Other Two Sides

Cut fingers on all eight sides following the same procedure as the first two sides.

Step 7: Bottom and Lid

For this box, I wanted a lid that would fit loosely in to the top and a bottom I could glue in place. To do this, I took the top and bottom and routed a 3/8" rabbet around all four sides. Close measurement is helpful here. 

To do this, I set up a fence against the router bit, now a 3/8" bit, set to a height of about 1/8". The fence is just about even with the edge of the bit. Again make a test cut or two on scrap to test the fit. 

The miter gauge helps to keep the lid square when routing the short side.

Step 8: Glue and Finish

My box joint fingers were so tight that I had to use a mallet to softly bang them in to place. I probably didn't need glue. The bottom piece glued in to place easily and the lid nestles nicely in the top.

Stain or paint as you like.

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    21 Discussions


    4 years ago on Step 7

    to avoid the glitch keep the pressure on the other side higher, so start routing with higher pressure on the back end and stop routing with higher pressure on the front end


    Reply 4 years ago on Introduction

    This joint is nearly indestructible even with out glue that is why it is used in crate making.


    Reply 7 years ago on Introduction

    When I did woodwork at school we were made to do all of our joints by hand (presumably just so it took us hours rather than minutes).

    We did it by cutting several vertical lines between each finger to remove as much of the wood as possible using a backsaw then we chiseled away what was left.

    It was laborious but pretty effective and I got some very tight and accurate joints.

    Hope this could help.


    Reply 4 years ago on Introduction

    The cutting of a joint that took hours is because of your inexperience at the time. You would not have produced a better joint using a machine. Joints are only cut in "minutes" if you do not count the set up time and testing for fit time. Nevermind the learning how to use the machine time. I can cut dados by hand faster than my students can do it with a machine. Machines only save time and effort when you need many repeatable cuts and are willing to lay out a lot of money for machines. Look up Paul Sellers for someone that addresses excellent woodworking on a tiny budget.


    Reply 5 years ago on Introduction

    I use a scroll saw sometimes for this when I don"t feel like setting up the router table


    Reply 7 years ago on Introduction

    If by "old school" you mean by hand, this has never been a hand tool joint. It was developed with the advent of machinery when wood crates were used the way we use cardboard boxes today. Anyone willing to go to this much trouble would use a dovetail joint.

    The vikings and the celts used a much simplified version which only had one or two straight tongues but that is the closest you come to old school.


    Reply 7 years ago on Introduction

    On the other hand, a dovetail joint is really easy to do by hand. If you want a great example, check out the Woodwright's shop, with Roy Underhill. On several episodes he makes dovetail joints and he makes it look so easy you'll think it's magic.

    Though it is actually pretty easy to make them on your own, though you'll need practice to make it look as good as Roy.


    4 years ago on Step 8

    There is another site, with the same simple notch pin jig, that suggest to gang the two offset boards together and route both pieces at the same time. While this method is faster especially for bigger boxes, I found it created too many errors for the small boxes I was making.

    I'm glad I read your technique because doing each of the four pieces separately saved me a lot of grieve, thanks!


    7 years ago on Introduction

    Thanks for showing this technique! I'll remember it because some day I will need it!


    7 years ago on Introduction

    Try backing the project piece with some scrap to prevent the chipping on exit of the cutters.


    7 years ago on Introduction

    Router is much better for making box joints than a table saw, but only if you make a jig.


    Reply 7 years ago on Introduction

    but nice to see the same thing done on a Router - didn't even consider it, which is stupid because this looks like a nice easy way to do them. I don't have a table saw (or room for one really!) only a electric circular hand saw.


    Reply 7 years ago on Introduction

    I've cut box joints both ways. I tried a router and that was it. Since then I've gone back to doing many on a table saw. I wouldn't even consider using a router for box joints today. I guess if you're only making one box a router is OK. I make 10 at a time though. I stack all my sides for each box and cut them at once too. Zip, zip. Nothing to it!


    7 years ago on Introduction

    Excellent! I was just figuring on buying a bandsaw to do things like this, I really need to get the router I got for christmas out and have a play!


    7 years ago on Introduction

    Very nice and easy to follow structable .....very nice looking box ......last line in step 3 very good advice maybe a nice relief carving on the lid? ....ah but maple is a hard wood to carve ..did i miss a picture of it with a finish on it ?...keep up the good work