Chiseling Mortise Holes (Kāi Zhù Yǎn)
To chisel a mortise hole on a beam or column for a tenon joint.
In the mortise-and-tenon joinery of traditional wooden architecture, precise holes must be chiseled at the joints between beams and columns to allow tenons to fit tightly, ensuring structural stability. The process of chiseling these 'column eyes' (zhùyǎn) is traditionally considered crucial to the overall strength and safety of the building. Therefore, an auspicious day is selected to carry out the work, seeking smooth construction and permanent durability.