Joints #2: How to shorten timber using a tenoning Jig

  • Advertise with us
Blog entry by robscastle posted 09-24-2014 04:33 AM 2337 reads 0 times favorited 7 comments Add to Favorites Watch
« Part 1: SPalm and SMaloof Joint work Part 2 of Joints series Part 3: Woodsmith Tip Rabbeted Miter Joint test »

I was reading a post by Partickhosey showing a joint he made and the associated comments regarding its strength and durability.

The joint looked like one I could try, if only to work out how to make it.

I started off with some rubbish timber jointed it square and set to work

Its obviously a half lap joint so I cut them in with the table saw

With that done marked out where the four tenons would fit.

Returned to the table saw and cut the four entry points in

This is what they look like finished.

I did some finishing sanding and fitted them together, they all fitted up OK so I started on the four tenons.

Cutting them in presented no problems at all.

So I fitted everything together.

Oh not so good very sloppy work.

Dismantling them I was about to huck them in the bin and go do something constructive when I took a look at the tenons and noticed that they had a taper down to the points.

Ah ha I thought the Tenoning Jig is out, so I checked it, sure enough it was not set at exaclty 90 deg, and along with the saw blade it was out as well.

Note: should have done this check first !!

Adjusted everything to their correct positions and cut the tenons off and tried again.

This time the result was almost the same but no taper this time.

So it was off with the tenons again and reset the jig a fraction.

I made the third tenon cut and fitted them up again.

This time a better result was achieved but was not as good as I could do so chopped off No 3 and went again.

Some more fine tuning could be done but I was running out of timber.

That was enough to satisfy my curiosity about the joint

Will it work, I beleive it will, there must have been a use for it in furniture making even if adding four reinforcing wedges to the base and sides for added strength.

Its a bit short for a table now so I am not sure if I would even bother to glue it up and destroy it just to find out the answer as to how strong it is.

I certainly agree you have a mixture of edge and end grain to contend with leading to a “weaker” joint

Tools used:

Table saw, Tenoning Jig and some sandpaper, however there is no reason it could not be cut with just a tenon saw.

And thats how you shorten timber using a Tenoning Jig!!

Update Feb 2016:
Some interesting information I found.
This joint is called an Interlocking Tenon Joint, its heritage from what I have found is from Japan.

A series of Time life Books
The Art of Woodworking series
Handbook of Joinery
and within there is a section Japanese Jionery from page 136 to 139.

You may find a complete downloadable PDF version of the publication On

-- Regards Rob

7 comments so far

View kaerlighedsbamsen's profile


1362 posts in 2799 days

#1 posted 09-24-2014 07:25 AM

Interesting joint. Newer seen that one before.
Looks like the piezes that cross are weakened quite a bit though..
Have you tried glueing it up and test the strength?

Thanks for sharing!

-- "Do or Do not. There is no try." - Yoda

View stefang's profile


17040 posts in 4420 days

#2 posted 09-24-2014 08:20 AM

Very interesting joint Robert. I could see it being very useful in some situations, and if it is a tight fit I think it would be strong enough, depending somewhat on how it’s being used. I can see that the layout and cutting has to be very precise to get a tight joint and that is not easy with so many cuts in one joint even using a tenon jig. Regardless, you were pretty close on that last one. One more and you would have aced it.

-- Mike, an American living in Norway.

View degoose's profile


7281 posts in 4440 days

#3 posted 09-24-2014 10:16 AM

Neat… by the time you finished it …

-- Don't drink and use power tools @

View David Dean's profile

David Dean

608 posts in 3984 days

#4 posted 09-24-2014 09:58 PM

Now that was a diffent. nice work

View Joe Lyddon's profile

Joe Lyddon

10963 posts in 5138 days

#5 posted 09-25-2014 03:25 AM

COOL combination of slick Half-lap joints!

COOL layout / design…

Love it!

Thank you!

-- Have Fun! Joe Lyddon - Alta Loma, CA USA - Home: ... My Small Gallery:

View Roger's profile


21054 posts in 3889 days

#6 posted 09-25-2014 10:48 AM

This is different.

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed. [email protected]

View Patrick's profile


41 posts in 2428 days

#7 posted 10-04-2014 11:55 PM

I know this seems backwards but try cutting the tenons first. Once the tenons are all cut, you can set them inside the half-lap joint and trace where they go. Then the only tricky part is getting the height of your tablesaw blade correct. Cut just inside of your lines and your golden. This was made way easier because I used a dado sled. Very awesome. I have a tight fitted joint and I don’t think it’s weak at all. In fact I bet it’s a lot stronger than people might think.

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics