Chouna - Japanese Adze

The ideal Adze handle chosen by professional carpenters

First: Choose a wooden handle with a curved end instead of a straight one.

The curved wooden handle is more comfortable and stable to hold.

In addition, the downward bend at the end of the wooden handle makes the center of gravity of the entire adz lower. When using the adz, the kinetic energy generated by swinging the axe is applied closer to the edge of the blade.

In reality, there are very few adze that come with ideal wooden handles. The picture above shows a chouna used by a retired temple carpenter. He told me that it took him several months to find the near-perfect wooden handle.

Currently, most wooden handles for adz on the market have a straight end. Some of them are decorative or ceremonial adzes; some are also practical tools, but since they are rarely used nowadays, some carpenters naturally do not have such high requirements for their wooden handles.

Second: Try to find a wooden handle that fits your height.

Since the adze is a tool used while standing, finding a wooden handle that fits your height will make your work less tiring.

The length of the hypotenuse in the figure below is called "Obake" by Japanese carpenters. With your arm straight, "Obake" length should be approximately equal to the length from your armpit to the middle of your palm.

The length of the Japanese adze handle "obake". The length of the "obake" of this adze from a retired Japanese temple carpenter is about 540mm. It fits me just fine and I'm 165cm tall.

Third: The size setting that needs to be paid attention to when installing the axe handle.

The width of the "こごみ具合/Kogomi Guai" shown in the figure below is determined by "山の高さ/Yama no Takasa".

Mr. Tsuchida's data mentions two sizes:

「七寸山の四分こごみ」, meaning that if "Yamano Takasa" is 210mm, the width of the "Kogomi" should be set to 12mm.

「八寸山の五分こごみ」, meaning that if "Yamano Takasa" is 240mm, the width of the "Kogomi" should be set to 15mm.

Pictures from Tsuchida Noboru, 「Shape of Carpentry Tools - About Chouna」, Knife Magazine No. 8, 2011.

The adze from a retired temple carpenter in the picture above has a "Yamano Takasa" of 170mm and a "Kogomi" width of 12mm. This means that when the height of "Yamano Takasa" is less than 210mm, the width of "Kogomi" is still 12mm. Whether this is a rule remains to be verified.

※ Today (June 27, 2025) I asked Mr. Tsuchida Noboru about the above question. He told me that 「七寸山の四分こごみ」 and 「八寸山の五分こごみ」are just two common standards. In actual situations, the "Yama no Takasa" with a lower height is easier to use. So we can assume that when “Yama no Takasa" is equal to or less than 210mm, the width of "Kogomi" should be set to 12mm.