Synopsis: Most common on drop-leaf tables, the rule joint looks good open or closed, and it keeps the hinges hidden. When the table leaves are down and the joint is exposed, it shows a thumbnail profile. When the leaves are up, the joint disappears. It’s not difficult to lay out and cut a rule joint accurately, but you need to understand the mechanics. Michael Zuba’s method uses two common router bits and divides construction into three distinct steps: Cut the bead, cut the matching cove, and install the hinges.

From Fine Woodworking #200

Note: The PDF was updated 8/7/2008 to fix an error. The half-round or bull nose bit was mislabeled as a 3/4-in. radius instead of a 3/8-in. radius.

Most commonly found on dropleaf tables, the rule joint allows the outside leaves to be lifted to create a large, useful surface, or folded down to save space. The beauty…