Hikōki kanna (飛行機鉋)

The hikōki kanna is used to plane kumiko to the required thickness. The runners on the sides are adjusted to the correct height, and a spring-loaded bamboo insert just in front of the blade cutting edge holds the kumiko down securely as it's being planed. These days this plane is very rarely used, if ever. Machinery has made this process much faster, more accurate and more efficient.

Hikōki kanna      Hikōki kanna

Maru-inrō kanna (丸印籠鉋)

The maru-inrō kanna are used to cut a rounded tongue and groove where the centre two shoji doors or screens of a four-panel set meet so there are no gaps between the two. I have the rounded version, but there is also a square angled version as well. The second photo shows the shapes of the tongue and groove. When planning the shoji, it's essential to remember that the inner stile of the door or screen that will have the tongue must be wider by that amount.

Maru-inrō kanna      Maru-inrō kanna