Introduction: 2 in 1 Cross Dowel | Barrel Nut Jig for Detachable Wooden Furniture Joints DIY

About: XDIY with Itzik

Hi all!

This Instructable started when I planned to make a bunk bed for my 2 kids.

I wanted the option to disassemble the bed in the future, like the detachable beds you buy on the stores, so I checked the optional detachable joints.

I found that one popular & strong joint between the bed frame to the legs, is done using a Cross Dowel / Barrel Nut, and additional wooden dowel, and decided to go with this option.

In the way that cross dowel works, the wood should have precise drill holes which meets in accurate position.

It's hard to make such perfect holes at home, and specially when you have many of such joints in a bed, so I decided to make a special Jig for it.

In addition, I decided to make the Jig for dual use (2 in 1), and added an option to make an additional wooden dowel connection hole, which is usually required in this cross dowel joint, and some other Bonus.

All steps are described in this Instructable but it's recommended to watch the video as well, for better undestanding of the making process and use.

You're welcome to visit my YouTube Channel, subscribe, and also watch my additional projects. Don't forget to click the 'bell' button in order to get new videos notification.
Thank you! :)



  • Small wood scap / leftover
  • Jumbo screws / anchors or metal pipes
  • Wood glue
  • Wooden dowels (10mm)
  • Strong glue (for metal + wood)
  • Cross dowel / barrel nuts + connector bolts (like these or these)

General List of tools I'm using -

Tools in this Instructable:

  • Miter Saw
  • Hex key
  • Measuring tape
  • Drill press stand
  • Drill driver
  • Hammer
  • Digital Caliper
  • Different drill bits
  • Clamps
  • Dremel with metal cutting wheel or another metal saw

Step 1: The Bed Plan - Not Final

As I mentioned, I planned to make a bunk bed. I started planning it, but didn't finish it yet.

Meantime, we got a used bed from someone, so I stopped it in the middle, but I'm sure that this Jig will be helpful in the future.

Anyway, as you can see, I marked different places in the plan, which are usually using the cross dowel joint I'm describing in this project, so you can understand it better.

Step 2: The Cross Dowel / Barrel Nut

As you can see, the cross dowel / barrel nut, is a cylindrical shaped nut. This nut should be inserted in a hole drilled in one piece of wood, and the connector bolt should pass through the nut threading in another cross hole.

You'll understand it better on the later steps.

Step 3: Barrel Nut Dimensions

There are Cross dowels / Barrel nuts, with different sizes.

I found only this size in the stores, but it's important to match the Jig holes and dimensions to the specific nuts and bolts you have, and also the wood pieces dimensions you have and you wish to connect.

In my case, the nut diameter is 10mm, height is 14mm.

Step 4: Connector Bolt Dimensions

The connector bolt length is 102mm and diameter of the screw is 6mm. It's important to know it for planning the Jig and holes distances.

Step 5: Where Will I Get Metal Pipes for This Jig???

I made this Jig in the middle of the Coronavirus lockdown and was limited with the materials I have.

Besides that, I know it's not easy to find metal pipes in different sizes which can fit well for different drill bits.

Well, I think I got lucky. I looked in all of my junk boxes and later in my screws organizers to look for metal pipes.

Finally, I saw these Jumbo screws / anchors which I had in different sizes.

I started to open each of them, and checked if the Jumbo metal 'pipe' fits the drill bits I need for this Jig and luckily it wass good enough.

I think it's a good solution for any Jig you make with drill bits, what do you think?

I needed 2 sizes of drill bits and pipes with matching inner diameter:

  1. One with diameter of 10mm, for the barrel nut, and the wooden dowel (which both have 10mm diameter)
  2. Second with diameter of 7mm, for the connector bolt, which has 6mm diameter of its screw. I needed to be a bit bigger, so the bolt will be inserted freely, but not too big.

Step 6: The Sets of Metal Pipes With Each Drill Bit and Wooden Dowel

Step 7: Cutting the Wood Pieces

I used a wood leftover from my other Instructable(Don't miss this one :)).

The thickness of it is about 2.5cm.

I cut it to 2 pieces of 6cm. (The length is actually doesn't matter too much).

Step 8: The Drill Press

I don't have a drill press, but in order to make the Jig accurate, I needed a precise vertical drill holes.

So I was assisted by a friend's drill press stand, for making the Jig holes.

Step 9: Making the Jig Body Detachable (1)

I marked 2 places in the side of one of the pieces, which is going to be the 'horizontal' part of the Jig.

I drilled 2 10mm holes which should fit my 10mm wooden dowels.

In this case I didn't use a dowels Jig for making this Jig and it came out very good. :)

Step 10: Making the Jig Body Detachable (2)

I glued 2 wooden dowels and inserted in the holes.

Step 11: Making the Jig Body Detachable (3)

I took the previous piece, and marked the position of the dowels on the other piece, which will be the 'vertical' part of the Jig, in a position which will create a 90 degrees angle (reversed L, see later)

Step 12: Making the Jig Body Detachable (4)

I checked that the dowels are well fit, and the 2 parts are being inserted and removed easily.

The other side of the dowels shouldn't be glued of course.

Why did I make it removeable? see the different Jig uses on later steps.

Step 13: Making the Jig Body - Done

Step 14: Vertical Part - Marking the Drill Bits Holes (1)

I marked 2 places on the vertical part, 15 & 45 mm from the left edge of it.

I wanted to have 2 holes for the bolt and a wooden dowel, with distance of 30mm.

The position can be changed as you like, and according to your wood pieces you like to connect with the cross dowel joint.

Step 15: Vertical Part - Marking the Jig Drill Bits Holes (2)

Later I marked 10mm from the line of the line of the horizontal jig part position.

According to my barrel nut height (14mm) and the nut's threading hole position, I calculated that the connector bolt hole should be about 10mm from the surface of the drilled wood part, in order to meet the barrel nut in the correct position.

Step 16: Vertical Part - Drilling the Jig Drill Bits Holes

I drilled on the 2 marked positions:

One, for the connector bolt's metal pipe, which has outer diameter of ~9mm

Second, for the wooden dowel's metal pipe, which has outer diameter of ~13mm

Step 17: Vertical Part - Inserting the Metal Pipes

As I described in previous steps, I took 'metal pipes' from some Jumbo screws / anchors.

I put some strong glue on each metal pipe, and inserted in the relevant hole.

One was inserted easily and one not.

I had some luck here... I choosed a bad piece of wood with a big knot, just where I drilled the 13mm hole.

When I used a hammer to insert the pipe, it could just break apart... but it didn't :)

Step 18: Vertical Part - Cutting the Metal Pipes

Later, I cut the remaining metal pipe, using a dremel with a metal cutting disc.

I should of done it before the inserting... I would be easier. I did it later for the last metal pipe on the next steps.

Vertical part is ready.

Step 19: Horizontal Part - Marking & Drilling the Jig Drill Bits Hole

I made a mark 35mm of the edge of the 'horizontal' Jig part. (next the dowels which connects to the vertical part of the Jig). This position will be for the barrel nut drill pipe.

This position can be changed according to your needs.

In my case, I planned to use wood profile of 5.5*5.5 cm for the bed's legs, and the bolt length was 102mm, so this position (35mm) was a good for these dimesions.

Later I drilled hole for the barrel nut's metal pipe, which has outer diameter of ~13mm.

Step 20: Horizontal Part - Cutting and Inserting the Metal Pipe

I cut the metal pipe (this time before inserting it to the wood as before).

Later I glued it and inserted

Step 21: Jig Is Ready - Connected

The Jig is ready.

I filled some holes using a wood filler and sanded it a bit.

It's not mandatory for such project, but it was very dirty from the metal cutting and glue... so I felt it's required :)

Step 22: Jig Is Ready - Disconnected

Disconnected state of the Jig.

You'll soon uderstand why I made it detachable.

Step 23: Using the Jig - (1/2) One Use

The first use of the Jig, as expected, is making the barrel nut and connector bolt accurate drilling positions.

As you saw, I also combined on the Jig, a position for a dowel, which usually goes together with a cross dowel joint.

For these drillings, I used the Jig in it's 'connected' state (2 parts of the Jig are connected - 'reversed L').

I connected the Jig to the wood piece using a clamp, and drilled 3 holes:

  1. 1 hole on the top of the Jig, using a 10mm drill bit, for the barrel nut. I limited the drill height with a stopper on the drill bit, so the drill bit will drill about 15mm after the thickness of the Jig itself, and the barrel nut will be inserted well (I remind that my barrel nut has 14mm height)
  2. 2 holes on the side of the Jig. First on the left, using a 10mm drill bit, for the wooden dowel position. Second on the right, using a 7mm drill bit, for the connector bolt position.

Note that for this demonstraiton, I used some wood leftovers and not parts for a real bed or other furniture project.

Step 24: Using the Jig - (1/2) One Use - Result

This is the result of the 3 drilled holes. You can watch the video to see additional views.

Step 25: Inserting the Barrel Nut

I inserted the barrel nut into the top hole and turned it so its threading hole will be towards the connector bolt hole.

If the position nut's hole isn't good, you can turn it using a flat screwdriver.

Step 26: Using the Jig - (2/2) Second Use

The second use of the Jig. I call it a Bonus use. :)

Since that I combined in this Jig, also a pipe for drilling hole for a wooden dowel, together with the connector bolt on the same side, I thought how can I make the same accurate position, on the second wooden piece which should be connected, without making another Jig.

If ths Jig was only for a cross dowel, I could just drill a hole for the connector bolt, on the second wood, without the Jig.

But, in my case, I decided to make the Jig detachable, in order to use its 'vertical' part for drilling the same holes positions on the other wood, easily.

So for these drillings, I used the Jig in it's 'disconnected' state and used only the vertical part.

I connected the vertical Jig part, to the wood piece using a clamp, and drilled 2 holes:

  1. One using a 10mm drill bit, for the wooden dowel position.
  2. Second using a 7mm drill bit, for the connector bolt position.

Step 27: Using the Jig - (2/2) Second Use - Result

This is the result of the 2 drilled holes.

Step 28: Drilling the Bolt Head Countersink

I used a 16mm drill bit, to enlarge the top of the bolt hole, in order to create a countersink, so the bolt can be inserted flush with the surface.

This drill bit is pretty bad, there was a lot of smoke during the drilling :)

Step 29: Inserting the Connector Bolt

I checked that the connector bolt is being inserted freely and also aligned well with the wood surface.

Step 30: Connecting the Wooden Parts

I inserted a wooden dowel into it's hole on one of the parts and then connected both parts with the dowel.

No glue is required, since it should be removeable later!

Step 31: Tightening the Connector Bolt

I inserted the connector bolt into its hole. It was perfectly met the nut's threading hole.

Finally, I tightened using a hex key.

Step 32: Done!

I checked the strength of the connection and it was very good.

Later I removed the connector bolt and checked that the parts holded by the dowel, can be removed easily.

The joint I demonstrated, shows a common connection between a leg of a bed, to a frame of the bed.

The sizes of the wood pieces may be different from the ones I used, accoriding the the bed or other furniture you plan.

Step 33: Closeup Photos

Step 34: The Video

Thank you for reading! I hope you like my Instructable, let me know what do you think, in the comments.

It's recommended to watch the video as well, for better undestanding of the making process and use.

You're welcome to visit my YouTube Channel, subscribe, and also watch my additional projects. Don't forget to click the 'bell' button in order to get new videos notification.
Thank you!

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