Also called hassō kanamono 八双金物; sakawa kanagu 逆輪金具 or saba-no-o 鯖の尾. Lit. twin eights metalwork. A long, narrow decorative metal work fitting *kazarikanagu 飾金具 that is bent around the hinged edge of a door leaf in such a way that the forked design appears on both sides of the door. Generally, the metalwork is gilt bronze and is nailed down top and bottom near the edges with about one third exposed on either side of the door. Aside from being decorative, it is practical. It strengthens the pivot hinge *jikuzuri 軸釣 and prevents separation from the door leaf. The name is derived from the identical forked design on each side of the door leaf (as sō 双 means 'both'), and the forked part resembling the character 八 hachi, meaning eight. Many hassō kanagu are decorated with embossed patterns on a thin metal sheet. From the Momoyama period and into the Edo period, some were made with brilliant relief patterns on thick metal plates. An example can be found on the plank doors *itakarado 板唐戸 of the Guest Hall, Kyakuden 客殿 at Daikakuji 大覚寺 in Kyoto. In this case, the ends are not forked but protrude. Patterns with protruding ends in the shape of a flower are called dehassō 出八双. These are the standard types of decorative metal-work on doors. Prior to the Heian period dehassō were used exclusively and continued to be used even after the introduction of the popular hassō kanagu in the Kamakura period. The type of hassō kanagu that attached only around the front stiles and top and bottom rails of a door as pure ornamentation is called chirashihassō 散八双. A hassō kanagu in a forked fish-tail inlet is called *irihassō 入八双.
