Tenoning Jig

A tenon is the male portion of a mortise and tenon joint. The mortise is the hole in the workpiece, usualy cut with a mortising machine, but a traditional drill press will also work.  The tenon is the tab that is inserted into the mortice to secure two workpieces together.  Tenons can be cut on the table saw using a jig. They can be cut free hand, but it is extremely difficult to be accurate, and can also be dangerous becase the workpiece can slip out of your hand, and be kicked back by the blade.

You can purchase a tenoning jig, but I find it much more cost effective to make one. I have also found that my design seems to be rather unique in that it rides over the eip fence, rather than in the miter groove as many manufactured jigs do. but you can decide for yourself.

The jig pictured top right is a simple design that can be assembled in a short time using the table saw and a screwdriver or cordless drill/driver.  I used some scrap wood, and a piece of Melamime coated particle board.

You may use what materials you like, but I prefer a hard wood like Red Oak. It's sturdy, and not too expensive for the small amount needed here. I also used a melamine coated particle board I got in the scrap bin at the Depot. I used this for the face of the jig because it is perfectly straight and flat so the workpiece will always be at a correct angle..

Using the tenoning jig it very simple. The only difference is that you will have to mark your workpiece, and adjust manually for your cuts, rather than using the precision adjustments and gadgets that come with manufactured jigs. Here are some easy steps for getting accurate results. cut the shoulders first, using your miter

1. Adjust your saw blade height to 1/2 the width of your workpiece, plus an additional 1/2 the width of the tenon (EXAMPLE: If your workpiece is 2 inches thick, adjust your saw blade height to 1 inch, then, if you want a 1/2 inch thick tenon, lower your saw blade another 1/4 inch to 3/4"
   
2. After making your shoulder cuts, find the center line of your workpiece and mark it with a pencil line.
   
3. Lock the workpiece into the jug, and align with the table saw blade so the line is dead center in the blade.
   
4. Divide the desired width of your tenon in half, (if you were making a 1/2 inch tenon, you want to make a 1/4 inch adjustment.)
   
5. With the workpiece locked to the jig, and the jig mounted on the fence, adjust the fence away from the blade 1/2 the desired tenon thickness, PLUS 1/16 inch to alow for half the typical blade width.
   
6. Adjust the blade height so the blade will penetrate about 1/16 into the shoulder cut
   
7. Make your side leg cut, then, rotate the piece the piece around and make your opposite side leg cut.
   
8. go back to step 2, and repeat the process for the end leg cuts.

NOTE: The width of your tenon should be constant and match the width of your mortise for a snug fit.(you want it to be tight enough that you need to whack it with a mallet a few times to get it all the way in.) The length of your tenon is up to you, just make sure it also matches your mortise length, and is centered on the workpiece.

 Budget Woodworking.