How to Cut Tenons With a Table Saw

Measure the width of the wood that will receive a tenon. Calculate two-thirds the width and round that result to the nearest 1/8 inch. The general rule of thumb is that the tenon width should be two-thirds the width of the stock. Measure the thickness of the wood. The thickness of the tenon should be about one-third the thickness of the workpiece, also rounded to the nearest 1/8 inch. The length of the tenon depends on the width of the wood being mortised to accept the tenon, but the general concept is that tenon length should be at least five times tenon width. The tenon should end up being centered on the end of the workpiece.

Mark reference lines on the wood to indicate where cuts will be made. Adjust the table saw's fence to the length of the tenon minus the thickness of the blade.

Adjust the height of the table saw blade to match the depth of the shoulder cut to be made. Don safety glasses and place the wood on its edge against the table saw's miter gauge in the slot left of the saw blade. Butt the wood up against the fence.

Pull the gauge and wood back away from the blade, turn on the saw and make a single pass. Turn off the blade and let it stop before pulling the gauge and wood back. You've just completed the first shoulder cut. Flip the wood onto the opposite edge, turn the saw back on and make the second shoulder cut. Turn the saw off.

Adjust the blade height (if necessary) to cut the two shoulders that are perpendicular to the edges. This adjustment may be needed in order to accommodate the tenon width calculations you made earlier. Adjust the blade as needed and make these two shoulder cuts.

Since the wood can be held safely against the miter gauge as it passes through the blade, you can make the edge cheek cuts by "nibbling" away a little wood at a time. Move the wood away from the fence a saw blade thickness each time and make a pass through the saw until the edge cheeks are formed.

Remove the miter gauge and place a tenoning jig in the miter gauge slot. Lock the wood into place by turning the locking mechanism adjustment on the jig. The tenon end of the wood should be touching the table saw surface with the wood held upright in the jig. With the saw still off, adjust the jig so it will be the correct distance from the blade to make the cheek cut you need.

Pull the jig back, turn on the saw and make a single pass to cut the first cheek cut. Turn the saw off, pull the jig back, readjust the wood and make additional cheek cuts as needed to complete the tenon.