The finger joint (also known as a comb joint) is a woodworking joint made by cutting a set of complementary rectangular or angular cuts in two pieces of wood, which are then glued. To visualize a finger joint simply interlock the fingers of your hands at a ninety degree angle; hence the name "finger joint." It is stronger than a butt or lap joint, and often forms part of the overall look of the piece.

The finger joint is the most common joint used to form long pieces of lumber from solid boards; the result is finger-jointed lumber.

The strength of a finger joint comes from the long-grain to long-grain contact between the fingers. It provides a solid gluing surface. The number of contact points also allows for more gluing surface as opposed to a butt joint or a rabbet joint.

The DIMAR’s DFJ Finger Joint bit is a sophisticated, yet easy to use tool. It cuts angular grooves which substantially enlarge the gluing surfaces, hence forming super strong joints. It is fully adjustable to accommodate various sizes of lumber.