Kanna (planer)

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Japanese plain planer (Hira-Kanna)

Kanna ( Jap. 鉋 ) is the Japanese word for planing , in the narrow sense traditional Japanese planes thus are meant.

Woodwork in Japan is mostly natural and its surfaces are planed. The Kanna is therefore an important tool for the Japanese carpenter and the last tool for the completion of a workpiece. For the final processing, Kanna planes so smooth that sanding is no longer necessary, chips up to approx. 3/100 mm thick can be removed. There are around 300 different Kanna, many of which are special tools.

In contrast to European planers, Kanna is used for planing on pull. The Japanese carpenter often uses a downward sloping "planing beam" as a support for the workpiece, on which the workpiece is only held by an iron nail.

Adjustment mechanisms (as in some European planes) are deliberately avoided. The iron is fitted very precisely into the cuboid wooden body of the plane and only clamped in the mouth by the friction of the iron. The planer is adjusted by the craftsman according to his own preferences, so there are usually no ready-made Kanna to buy.

The iron is adjusted with short blows of a hammer, either on the end of the iron to increase the chip thickness or on the rear upper edge of the plane to reduce the chip thickness.

The blades of the Japanese planes are slightly conical and very thick, so that vibrations are well damped. They are made of high quality, hard carbon steels . Therefore, the cutting edge may only be ground wet.

Classic Kanna, consisting of a wooden body, chip breaker and plane iron
Modern Kanna with interchangeable HSS blade

There are also modern versions with interchangeable blades, which however have little more in common with the actual Kanna than the external shape.

Types and special forms

Examples:

  • Ara-Shiko (finishing plane)
  • Ari-Sakuri-Kanna (dovetail joint plane)
  • Jo-Shiko (smoothing plane)
  • Kiwa-Kanna (rabbet plane)
  • Maru-Kanna (round planer)
  • Naga-Dai-Kanna (Raubank)
  • Tachi-Ba-Kanna (standing-bladed scraper)
  • Yari-Kanna (freehand guided planer forerunner)

further reading

  • Toshio Odate: Japanese Woodworking Tools: Their Tradition, Spirit, and Use ; Linden Publishing Co Inc., US, ISBN 0941936465