uses matching profiles to fit a table top together with a folding leaf. The resulting shapes fit together perfectly and allow the table panel to offer support to the leaf along the edge, something a hinged butt joint cannot do. The rule joint gets its name from folding rulers that used a similar interlocking shape and were commonly used by carpenters. Traditionally, this joint was cut with specialty planes that created the mating shapes. Today, we can speed up the process by using carbide-tipped router bits. The bits are a matched set, so they both have the same radius and appropriate bearing size for this type of work. Although these bits are
