By Christopher Schwarz
Woodworking Magazine, Autumn 2005, pages 12-15
Drawboring is one of the simple reasons that so much antique furniture survives today, some of it as sound as the day it was made.
What is drawboring? It’s a technique that greatly strengthens a mortise-and-tenon joint, transforming it from a joint that relies on glue adhesion into a joint that has a permanent and mechanical interlock. In essence, you bore a hole through both walls of your mortise. Then you bore a separate hole through the tenon, but this hole is closer to the shoulder of the tenon. Then you assemble the joint and drive a stout peg through the offset holes. The peg draws the joint tight.
Drawboring offers several advantages compared to a standard glued mortise and tenon:
■ The joint will remain tight. A common problem with mortise-and-tenon joints is that the joint can open up and develop an ugly gap at the shoulder.