Edge metal fittings

...The metal fittings on the corners and center of doors, such as the chirashikanagu (scattered metal fittings), nageshi (railed wooden beams), kayaoi (thatched backing), and gable boards, are also decorative, but among them, the corner fittings of wooden doors, the tsuji fittings of sankarado (railed wooden doors), the fastening fittings of thatch backing, and the bow fittings of gable boards were probably originally intended for reinforcement. The end fittings of rafters and corner beams are used to prevent wind erosion of the ends of wood, the eight-sole fittings of wooden doors are used to prevent the boards at the base of the axis from cracking, and the straw seat fittings that are hammered into the axis holes of doors are used to reinforce the doors and prevent wear and tear caused by opening and closing. The pull handles of sliding doors are also practical fittings that are used for decoration. ...

*Some of the terminology that refers to "edge fittings" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…扉の散金具（ちらしかなぐ）や長押，茅負（かやおい），破風板などの隅や中央に打った金具も装飾用ではあるが，そのうち板扉の隅金具，桟唐戸（さんからど）の辻金具，茅負の留金具，破風板の拝み金具などは元来は補強的な意味もあったのだろう。垂木や隅木などの木口金具は，木口の風食を防ぐため，板扉の八双金具は軸元の板の割れを防ぐため，また扉の軸穴に打つ藁座（わらざ）金具は開閉による磨滅を防ぐための補強を兼ねている。また，襖（ふすま）の引手金具は装飾を兼ねた実用の金具である。…

※「木口金具」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報