I have written several prior articles about milling cutters, and today it’s time for another. We’re going to look at a specialized cutter for making dovetails. Once again, the person who named these didn’t waste much time on the task. They’re called dovetail cutters.

Two examples of a dovetail cutter
The one on the left makes a 45 degree angle. The one on the right makes a 60 degree angle.

What shape does a dovetail cutter make?

A dovetailed item, showing the shape made by the cutter.
The indicator holder on the left has a dovetail made with a 60 degree dovetail cutter.

Consider the shape of the indicator holder pictured above. You couldn’t make the dovetail with a regular straight end mill, no matter what angle you hold the work. But a milling cutter makes it easy.

But why are dovetails important? The answer is simply repeatability. The male dovetail mates with a female dovetail on my lathe tool post. The tool post can clamp onto the male dovetail, creating a very solid connection. Even more important, if I remove the male dovetail and then reinstall it, it will go back to the exact same place every time. Since the measuring tool measures to 0.001″, that repeatability is critical.

The indicator holder goes in place of the tool holder. The picture was recycled from this post.