Daimochitsugi

Daimochitsugi, known in English as through-tenon joints, is a traditional Japanese wood joining technique used to connect structural elements like beams and columns. It involves cutting a long, cylindrical tenon all the way through the end grain of each beam that will be joined to a post. Corresponding hole mortises are then chiselled through the entire width of each vertical post. When fitted together, the long tenons running through the posts lock the horizontal beams into place. Because the tenon extends through the opposing grain of the post, their fibers interlock at a perpendicular angle. This creates an incredibly strong and durable connection, as the Beam's longitudinal grain reinforces the posts' vertical grain. The layered cross-grain reinforcement gave buildings exemplary rigidity, allowing frameworks like those found in historic temples and castles to endure for centuries supporting substantial weight loads.