- Carpenter's tools used for tsugite
This article introduces the roles of the saw (nokogiri), chisel (nomi), plane (kanna), ink pot (sumitsubo) and carpenter's square (kanejaku) in making tsugite and shiguchi, together with the names and history that dictionaries and commentaries can confirm. It does not cover how to use the tools or how to cut joints.
- Where a joint stops working when its dimensions change
Taking the places where the Japanese wood joints site judges "These dimensions do not work" as a starting point, this article sorts out the key features of the form: the neck and head of a dovetail, the peg and the mechigai, the ago, and the wood left beside a hole. The judgment is a check on the 3D shape, not on the strength of a real joint.
- Why joints loosen and split
Based on strength-test reports, this article sorts the failure modes of tsugite into shear, embedment, peg failure, splitting and bending fracture, and shows that the mode that appears depends on the shape and dimensions of the joint.
- Seeing tsugite in old buildings
Once assembled, tsugite and shiguchi lock together inside the members and are often invisible from outside. This article sets out places and occasions where the frame can be seen, such as folk house museums, open days at restoration sites and carpentry tool museums, to the extent official information could confirm.
- Timber drying, shrinkage and joints
Timber shrinks by different amounts in different directions as its moisture content falls, causing cracks and distortion. This article sets out how that works, how it relates to loosening and cracking in tsugite and shiguchi, and what references say about limiting loosening, to the extent they could be confirmed.
- Where the names of joints come from
Names such as ari, kama, koshikake, ago, mechigai, shachi, daimochi, okkake and kanawa refer to a shape, a part, an attached piece, or a place of use. This article sorts them using dictionaries and explanations, and notes where an origin could not be confirmed.
- Pegs, wedges and shachi
How timber joints are held without nails or metal fittings, using wooden pegs, wedges and shachi. Pegs stop pulling out, wedges lock by being driven in, and shachi are driven at a slant to draw members together.
- Dovetail (ari) and gooseneck (kama)
Dovetail and gooseneck shapes both fit a protrusion with a narrow neck into a socket to resist pulling apart. Their forms and relative strength, where they are used, why a koshikake is added, and their names, based on published references.
- Kanawa-tsugi and okkake-daisen-tsugi
Two splices of similar shape compared in published references: the mechigai and how they are assembled, the number of pegs and the direction they are driven, where each is used, and the strengths obtained in tests.
- Tsugite and shiguchi
Tsugite join members running in the same direction; shiguchi join members that meet at an angle. Where each is used in a Japanese timber frame, and how the types are chosen, based on published references.
