Most Efficient Tenon Fitting - Hybrid technique

[YSU65]

Actually what this does is effectively reduce the thickness (and therefore strength) of the tenon by 1/16".

But you would have to apply a bending moment exactly at that junction.  I would assume that most fails, if they ever occur, would be due to a shrinkage or glue failure, not fracture of the tenon. and that is not appreciably affected.    If you have worries about shrinkage failures, just cut your tenons a bit oversize, then dry then in your oven for a short while, then pare them to the final dimension.  Wait until your wife is out....

[ez-duzit]

Just like when you score glass or laminate, that creates a stress riser and the piece breaks precisely along that line. Such is with the tenon; it will be weakened precisely where the extreme fibers have been cut. And the tenon's strength will be governed by its thickness at the root of the groove.

[Jim Waldron]

If you're making Mission furniture, you're most likely working in oak.

With good attention to detail, I've found it productive to cut shoulders first (I use a carcass saw; table saw is good too, of course, if you must).

Then I split something like half off the cheek with a wide chisel to see how the grain runs, then allowing for the grain, split as close as possible to the line of the cheek cut, then trim faces of the cheeks with a paring action with the chisel cross grain. A router plane at the finish is a good thing in some cases. For very large tenons, after splitting off as much as possible, I finish the cheeks with a No. 10 1/2 router plane or - if I'm working on a bench size piece, raising a barn or building a boat - a No. 10 router plane.

It is quicker to do it than to describe it. Good with oak, pine and other straight grain wood that splits decently well. A trial with a scrap of your stock is prudent before you use the technique on expensive wood.

[Strokes77]

Update with Pictures:

Finished the 22 mortises for the back rail of the cabinet.  Gang marked them with pencil.  Went over to the PM701.  10 minutes and they were done.

https://ibb.co/hvcjfa

Marked out the tenons, setup my sled with stop block and gang cut the shoulders.  Nibbled the waste.

https://ibb.co/n3LsYv

Went back to the bench and fit them cutting the width with a tenon saw, and thickness with the router plane.  Other than a problem with the router blade slipping it's setting, didn't take too long to fit. The top of the slats you can see what I'm left with after the table saw. The shoulders are perfect, most of the thickness is gone, they are ready for about a 2-3 minutes process on each one to fit perfect.

https://ibb.co/cbnZfa