# Mortise Depth



## Bohaiboy (Jun 27, 2013)

Happy Sunday afternoon to all. M&T question. I am joining a portion of a table apron (3/4" stock) x 5" tall, to a leg that is 1 3/4×1 3/4. The apron will be set back from the edge approx 1/8". The length of the apron is approximately 20". I have attached a drawing to illustrate what I mean by a portion.

What depth should I make the mortise? I am thinking 1". And I am thinking the tenon should be 1/4" as that leaves 1/4" on either side vs making it 1/3 and only leaving 0.2083" for each shoulder. There will only be 3 1/2" of the apron against the leg.


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## Loren (May 30, 2008)

While 1" is not unheard of, since it is a handmade
piece I would recommend going to a little more
effort and making the mortises intersect. The
tenon ends can be mitered or notched out to
meet in the intersecting mortises.


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## TungOil (Jan 16, 2017)

If I were making that I would use a 3/8" x 2-1/2" tenon and go as deep as possible without interfering with the adjacent tenon from the other apron.


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## PPK (Mar 8, 2016)

I agree with Loren. The traditional method is to make the mortises intersect. 









I cheated a little and instead of mitering the tenons, I stuck one in full-length, then just chopped the other tenon to fit. It ended up a lap joint inside there. I really don't think its hugely critical.

As concerns size, I'd go with 3/8" tenon. If you're concerned with shoulder size, you could go down to 5/16". If you are using a mortising machine, anyway. Most hand chisels are not made in 5/16", so that's not a good option if you're chopping by hand. I know that the standard method is to have tenon about 1/3 of stock width, but I usually prefer them a little thicker.

The reality of the matter is, M&T joints are so strong, I think you'll be okay no matter what method you choose, as long as you take your time and make a good, snug joint and glue well.


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## runswithscissors (Nov 8, 2012)

I can't see that the shoulder width is of much significance. I use 5/16 tenons as I have a mortising machine with a 5/16" chisel, and thicker tenons are obviously stronger. Of course if you are doing them by hand, that's a different matter.


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