Demonstrating a sliding dovetail joint fitting into groove

For the woodworker building furniture and cabinets, the sliding dovetail is a joint well worth mastering.

Strong and versatile, the sliding dovetail joint has many applications, from case construction to leg-and-rail joinery. You've probably seen a drawing of the sliding dovetail joint. It's a hybrid of the dado and the dovetail, with a groove in one part, a tongue on the other. Because both the groove walls and the tongue sides are angled like a dovetail, the joint has to be assembled by sliding the tongue into the groove from one end.

Close look at the groove walls around dovetail key
The inward-slanting walls of the dovetail groove prevent the tail from pulling straight out. To assemble the joint, you slide the tail into the groove from the end.

Those canted walls give the sliding dovetail joint a decided strength advantage over a dado. The joint mechanically resists tension, meaning that the tailboard can't pull away from the grooved board. Even without glue, the parts stay linked together. The wood must crush or break before the two parts separate.

Using a rubber mallet to pound dovetails into place
The mechanical lock of the sliding dovetail joint makes it easy to assemble, because the parts won't fall apart while you look for clamps. You only need two hands. What a concept!

This characteristic of the joint simplifies assembly routines. You won't have parts collapse while you're fumbling with clamps. Two hands usually are sufficient for assembling even multi-part casework, like a chest of drawers. Slightly bowed panels sometimes can be pulled into line without elaborate clamping configurations.

Breadboard end of a chest lid fit onto the panel with sliding dovetail
A chest lid's breadboard end, joined to the main panel with a sliding dovetail and glued only at the front, directs the panel's seasonal movement to the rear and keeps the panel flat to boot.

Other applications of the sliding dovetail abound:

Wall shelf built with a sliding dovetail base
Joined to the underside of a tabletop with an unglued sliding dovetail, a batten keeps the top flat while allowing it to expand and contract seasonally.

  • Build drawers, joining the sides to the front and the back to the sides.
  • Join aprons to table legs, and even rails to stiles, in frame-and-panel constructions.
  • Mount moldings and case tops with dovetail keys or butterfly keys, holding them tight to the structure but allowing the wood to move.

  • Basic bookshelf built with sliding dovetail framework
    Even without a back, bookshelves constructed with tight sliding dovetails are free of wobbling or leaning out of square.

  • Join shelves to bookcase sides.
  • Mount battens to tabletops, lids, and doors to prevent them from bowing, doing this in the same way you'd mount a breadboard end.
  • Make drawer runners and guides.
  • Construct extension-table slides.