Ari Gumi 蟻組み

Assembly insights

Ari Gumi refers to the broad family of dovetail joinery in Japanese carpentry. Ari Tsugi extends timbers end-to-end with a dovetail occupying half the thickness and a stub tenon; Katasage Ari connects corner posts to tie beams with angled slopes and locking wedges. Traditional proportional guidelines suggest the dovetail neck be one-third to one-quarter of the piece width. These joints emphasize precision layout and minimal reliance on adhesives.

Historical context

Ari (ant) describes the tapered shape of the dovetail, which resembles an ant's waist. Japanese craftsmen have used Ari Gumi for centuries in temple construction, cabinetry, and furniture. The family includes Ari Otoshi (corner dovetails), Ari Tsugi (splicing dovetails), Katasage Ari (half dovetail for beam connections), and sliding dovetails for partitions and shelves.

Construction steps

1. Lay out the dovetail; neck width typically one-third to one-quarter of piece width.
2. Cut the pin (male) or tail (female) first—many craftsmen start with the receiving half.
3. Use the first half to mark the mating piece for a precise fit.
4. Saw and chisel to the line; aim to "split the line" for minimal cleanup.
5. Assemble; the joint should tighten under load without glue.

Where to see this joint in Japan

• Temple and shrine joinery — Throughout Japan — beams and framing
• Traditional cabinetry — Kyoto workshops, furniture galleries

Variations

Ari Tsugi (splicing), Ari Otoshi (corner), Katasage Ari (half dovetail with angled mortise and wedge), Nejiri Ari Gata (twisted "impossible" dovetail). Sliding dovetails connect partitions to panels; tapered versions prevent separation over time.