Yatoi-hozo-shachi-sen-shiguchi

Yatoi-hozo-shachi-sen-shiguchi, translated as compressed horizontal mortise tenons, is an intricate wooden joining method developed by master Japanese carpenters. With this technique, multiple short projecting tenons are cut side-by-side along the entire length of a horizontal beam end. Corresponding compressed mortises are then precisely chiseled in a continuous row along the full height of the adjoining vertical post or column. When joined, each tenon crosses the wood grain at a right angle, with opposing grains reinforcing one another. Called Yatoi-hozo-shachi-sen-shiguchi due to its horizontal compressed multipart nature, this counter-grained joinery allows rigid load-bearing structures to subtly flex and pivot at joints as needed. Found in landmark buildings like Osaka Castle, the technique's counteracting strong yet flexible reinforcement endured for centuries through multi-directional reinforcement of perpendicular wood fibers along the full height and width of joints.