drawboring

Drawboring is a woodworking joinery technique used to tighten joints by passing a peg or dowel through two pieces at an offset, so the act of driving the peg pulls the joint together. It is commonly applied to mortise-and-tenon joints and other pegged connections.

In a drawbore joint, holes for the dowel are drilled slightly off-center relative to the joint line. The hole on the receiving piece is positioned toward the shoulder of the tenon, so when the peg is driven in, the joint is pulled tight as the dowel sits off-center. This creates a strong, clamping effect without relying solely on glue. The pegs are typically hardwood and longer than the joint thickness, allowing a snug fit and secure pinning.

Typical procedure involves preparing the pieces, cutting the mortises and tenons, and then marking the drawboring offsets. Holes are drilled with a brace or drill press to the specified offset. The dowels are inserted and driven, often with glue used sparingly or left out in work emphasizing traditional hand methods. After driving, any protruding peg ends can be trimmed flush.

Advantages of drawboring include strong mechanical interlock, reduced visible fasteners, and the ability to tighten joints after assembly. It is favored in fine furniture and traditional cabinetry for long-lasting joints that resist pulling apart. Limitations include the need for precise measurement of offsets, potential stiffness in highly dynamic or moisture-variable environments, and the requirement for accurate alignment during assembly.

Related practices include pegged joints and other off-center pinning methods used to reinforce wood joints without relying solely on glue.