Translations:AY Honors/Woodworking/Answer Key/146/en
From Pathfinder Wiki
A dado and groove joint is formed by milling a slot (or dado) in one board, and inserting another board into that slot. The width of the dado should be equal to the width of the board that will be inserted into it. The dado is an excellent joint for joining plywood shelves to the upright sides of a bookcase. In this case, the dado should be cut into the side, and the shelf should be inserted into the dado. Such a shelf will support a lot of weight without relying on the strength of a mechanical fastener. A butt joint would likely fail in this situation, with the nail or screw splitting out the top of the shelf.
