Hand cut joinery is a rite of passage for many woodworkers. But, cutting tenons by hand is time consuming and the results are not always precise. Here is a jig to speed up your joinery and yield more consistent joints. It only takes a short while to build this jig and the time is easily paid back in one or two projects. Lowe's is happy to provide this information as a service to you.
These instructions are for a tenon-cutting jig designed to attach to your table saw's mitre gauge. This particular jig is designed to run in the left mitre gauge slot and mill 1/4" tenons in 1x (3/4") stock. You can use the principles here to cut any size tenon.
Tools & Materials
- • Table saw
- • Tape measure/steel rule
- • Drill/driver with bits
- • Clamps
- • Precut tenon
- • Dust mask
- • Goggles
- • Oak or birch faced plywood 3/4"
- • Screws
- • Wood glue
Cut the pieces, using the measurements below.
- • 1 - Mitre gauge extension - 16" wide x 12" high
- • 4 - Vertical rails - 3" wide x 12" high
- • 4 - Horizontal rails - 3" wide x 12 3/4" high
Set Up the Saw
Tenon cheeks and shoulders
Tenon length, width and thickness
The setup of your saw and the fit of the tenon you use as a gauge determine the jig's accuracy. Pay close attention as you set up the saw and take your time cutting the first tenon.
- 1. With the saw unplugged, set the blade height equal to the length of your precut tenon. Place the tenon cheek centered against the right side of the blade and slide the fence against the right side of the tenon stock.
- 2. Lock the fence in place. Ensure that the blade does not deflect (bend) when you lock the fence. The blade should rotate with the tenon as you move it along the fence, but it should not bind or grab.
- 3. Place the mitre gauge in the left slot and set the gauge to 0°.
Cut and Assemble the Pieces
The assembly is simple, but do not hurry through the process. A good jig should serve you well for several years and the time spent making it will be time saved in the future.
- 1. Cut the pieces according to the cut list.
Your completed jig should look like this. Click here for a larger, more detailed view.
- 2. Face glue and clamp the vertical and horizontal rail pieces. Allow the glue in each piece to cure according to the manufacturer's instructions before you continue working.
- 3. Rip 1/4" off each laminated face of each rail to ensure they are all flat. The rails should now be 2 1/2" wide across the factory faces and 3" wide on the laminated faces.
- 4. Stand the mitre gauge extension on its edge and butt one end against the fence. Slide the mitre gauge forward until its face is touching the back of the extension.
Drive 1" screws through the slots in the mitre gauge into the extension. Check for square between the extension and the fence.
- 5. Stand the precut tenon on end with one face against the fence and one edge against the front face of the mitre gauge extension. Butt a laminated face of the vertical rail tightly against the exposed face of the tenon stock. A factory face should be against the face of the extension. Starting 4" up from the saw table, drive 3" wood screws through the back of the extension into the vertical rail. Starting the screws at 4" up ensures that the screws are clear of the saw's maximum blade height.
- 6. Position the horizontal rail with one laminated face on the saw table, one end butted against the vertical rail and a factory face butted to the face of the extension. Drive 3" wood screws through the back of the extension into the horizontal rail.
- 7. Starting 4" up from the table, clamp your tenon stock to the right side of the vertical rail. One edge of the stock should be butted tightly to the front face of the extension. Make a test tenon. Make the cuts in the same order shown in making a mortise and tenon joint.