What is a dado joint and where would you use it in a cabinet?

• A. A through or stopped groove to accept a shelf or divider; used for fixed shelves or cabinet back attachments.
• B. A joint used for connecting two boards at 45 degrees.
• C. A type of rabbeting joint used on doors.
• D. A metal fastener used to join two pieces end to end.

Answer: (A)

A dado joint is a groove cut across the grain in one piece to accept another piece, creating a strong, right-angle connection. In cabinetmaking, that groove is typically cut into the sides or shelves so a shelf or divider can slide into and sit flush with the faces. Because the shelf or divider fits into the groove, it’s well aligned and supported along its full width, which makes the joint very sturdy for fixed shelves. Dadoes can be cut all the way through (through dado) or stop short of the far edge (stopped dado) to hide the end of the groove for a cleaner look. This method is especially useful for installing fixed shelves or for attaching a back panel into a recess, providing stability beyond what a simple butt joint would offer. It’s not used for corner joints at 45 degrees, not the same as a rabbeting joint used on doors, and not a metal fastener.