A Female For The Dovetail Plane

In a sliding dovetail joint, the two elements, male and female, slide into one another. The resulting joint is very strong and is most often used when vertical and horizontal parts must resist pulling forces (for example, shelves in a bookcase).

The traditional way to make this joint requires three tools: a saw, a chisel, and a router plane. Another option is to use dedicated planes, but while there are many choices for the male element, specialized planes for the female part of the joint are rare. Japanese tools, however, include the Ari-Kake-Shakuri-Kanna for this purpose, a grooving plane that requires a separate angled fence.

Since this joint is usually cut across the grain, it is necessary to score the wood fibers beforehand. The plane used for cutting the female element is similar to a dado plane, but with an angled sole and a skewed blade.

Finally, I decided to make one myself, and here is the result:

FDT stands for “Female Dovetail,” and 6 refers to the blade width (6 mm). The blade is skewed at 20°, and the sole is inclined at 78°, the same as the male cutting plane. The blade is bedded at 50°. It has an adjustable depth stop and a double spur for cross-grain cuts. The body is made of beech, with mahogany used for the sole and wedges.

The body construction is quite simple. I cut a rabbet for the 6 mm bottom section, then cut recesses for the blade and wedges, and glued a piece of mahogany to the bottom.

I planed the sole to 78°, ensuring it matched the male element.

The most critical part of the work is achieving the exact alignment between the angled sole, the skewed blade, and the wedge. For the blade, I used an old plane iron; for the nickers, I used a 10 mm spade bit, ground to shape.

Finally, the side is closed with a piece of beech, which forms the slots for the blade and wedges. The finish is shellac and wax.

The plane is able to cut grooves whose minimum width must be larger than the blade width; in practice, however, it is better if this difference is at least 3–4 mm.

The cut is made in two passes (or more, if the dovetail is larger), with the final pass made in the opposite direction.

Here is the test in action:

First, cut the male part and mark two parallel lines at a distance corresponding to the narrow end of the dovetail. This is the only marking required.

The angled fence keeps the plane in the correct position:

The cut begins:

  A couple of minutes are enough for the first groove.

The second cut is made in the opposite direction. The depth stop brings the plane to the desired depth.

 

At this point, the router plane has very little work left to do.

Here is the completed groove...

 ....and the finished joint!

In this case, I used beech wood; it will be interesting to see how the plane performs on harder woods. The tool can certainly be improved with a higher-quality blade. I have made only a few cuts so far, but I have learned that it is better to keep the groove slightly narrower (about 1 mm less) and then fine-tune the fit by taking a few more passes on the male part—plane passes, of course!