Standard mortise-and-tenon joinery by hand has been addressed by many different people. It usually involves some variant of sawing the cheeks and shoulders, then cleaning up and fitting the shoulders to the face of the mating piece. Power tool aficionados have their own set routines as well. However, all of these start to break down as the stock gets smaller. If the tenon is to be almost as thick as the stock, sawing the cheeks becomes impossible. It IS possible to cut the tenons on the table saw, but I’m personally not comfortable running small thin pieces of wood over a blade with heavy carbide teeth, no matter how light the cut. Likewise, the thought of trying it on a router brings images of shattered, flying stock to my mind. A great hand tool alternative is a skewed rabbet or moving fillister plane. However, many woodworkers don’t have one of these. If, like me, the above restrictions apply to you, I have a solution.
This answer utilizes a pair of tools found in almost all shops that do any amount of hand tool joinery: A cutting gauge and a shoulder plane. I start by marking the length of the tenon with the cutting gauge. Go over the line a couple of times to ensure a deep score:
This serves the same function as the nicker on a moving fillister or skew rabbet plane, providing a clean shoulder and preventing splintering. These planes also have a fence to control the width of the cut, and we have to provide the equivalent:
Loosely clamp a straight guide block to the surface of the piece. This is then aligned with the score line through use of a wide chisel or plane iron. Place the blade in the score mark with the bevel facing toward the end of the tenon. Then position the guide block against the flat side of the blade and clamp firmly in place. I prefer something like a F-clamp to a holdfast or spring clamp because of the ease of maintaining alignment while applying clamping pressure.
Once everything is clamped in place, define the shoulder by making several strokes with the shoulder plane. Be sure to stop slightly short of final depth, and repeat the process on the other side. Once the shoulder is defined, you can dispense with the guide block and make your final passes to define the thickness of the tenon. Be careful to hold the plane body at right angles to the tenon. In the photo above, I’m using a medium shoulder plane, and it has a considerable overhang over the end of the tenon. It’s very easy to get things out of alignment, so take your time and concentrate on keeping your tenon level and centered in the stock by alternating sides as needed.
And here we have one side of a tenon after the initial cut. There is a touch of tear-out on the far end, but don’t forget the scale of this joint – everything is magnified. While there are other ways to cut a tenon, this is a good alternative when you have a limited number to do in a smaller-than-usual scale.