TOKYO Teshigoto
2018.12.25

Tools of Beauty.

Knowing the tools


Swordsmith in the 4th Generation Mr. Muneaki (to the right), wielding the hammer, and his uncle Mr. Tadao (to the left).

The sound of the hammer, echoing through a residential area.

Tateishi, a neighbourhood in Katsushika, Tokyo, still retains the traditional Shitamachi-downtown atmosphere. In front of the Keisei Tateishi Station so-called Senbero (Sen meaning ‘1,000’ (Yen), and berobero meaning ‘drunk’ ) bars line up, and from the early evening guests form long lines to enjoy delicious and inexpensive drinks. When moving a bit past the front of the station swarming with tipsy townsfolk, a residential area rich with green appears. And then, upon entering a narrow alley following a signboard in the street, you soon hear the echoing sound of the hammer. You arrived at the Yaegashi Uchi Hamono factory. In front of the furnace, where the coke forms a red flame, two men strike pieces of heated red metal in a magnificent combination. It is the Swordsmith in the 4th Generation Mr. Muneaki, and his uncle Mr. Tadao Yaegashi. In the back of the workshop young craftsmen sharpen blades while scattering sparks.
Uchi Hamono means ‘forged bladed object’. The blacksmiths of Tokyo use two methods, the Tokyo Uchi Hamono, mainly used to manufacture scissors, and the Edo Uchi Hamono, of which the Yaegashi Uchi Hamono factory belongs to the Edo Uchi Hamono style of blacksmiths. Blades made by the Yaegashi Uchi Hamono Factory, using the traditional method of Souhi Zukuri, or ‘total fire build’, are sharp and beautiful. Hearing about the factory’s reputation, many blade manufacturing requests come in from all around the country. We asked the Yaegashi Uchi Hamono Factory, which still follows the traditional steps of sword forging, about the kinds of blade-manufacturing requests they received until now.


(Upper picture) The arc of tool bits used at factories etc., is shaped using tools made out of iron called Kanadoko. The Kanadoko are manufactured in-house as well. (Lower picture) To melt the iron paste that holds iron and steel together, temperatures near to 1000°C are necessary, which is why coke is used for the furnace.


The iron paste is made at the workshop. The crystals (left hand) emerge by simmering boric acid together with iron powder that comes as a by-product of the grinding process. These crystals are then smashed into powder form with a hammer.


In the back of the workshop young craftsmen were silently grinding knives, adding the finishing touches.


Clockwise from the upper left, in this photo you can see Kogyo Yo Hamono, or ‘Industrial Cutter’, Okeya Zuku, or ‘Cooper’s Knife’, Reed Knife, Kokusho Nomi, or ‘Calligraphy Chisel’, and Tokobashiri Hikkaki Gatana, or ‘Floor Pillar Scratcher’. All of these were order-made for professional use.

A professional’s tools, functional and beautiful.

“I’ve been helping at home since around middle school and high school.” says Mr. Muneaki, who has now been involved in crafting bladed objects for about 50 years. When Mr. Muneaki started his path, a lot of carpenter tools like chisels and hand planes were being manufactured, among which some of the chisels were apparently used in renovating the Nikko Tosho-gu Shinto Shrine and the Rinno-ji Buddhist Temple.
“Even now we mostly manufacture tools such as chisels, hand planes and Japanese knives for professional use. The tool bits we use at the factory to cut out parts account for about 30% of the total. Recently requests from private persons, to use our blades in their pastime, do increase as well.”
For example clients ordering ‘Reed Knives’, which are used to carve the reeds (mouthpieces) for woodwind instruments, will specify even blade crest, materials for the handle and weight. On one hand these designated tools heighten the efficiency of the work process, on the other hand there is the joy of owning a tool custom-made to one’s own preferences. Apparently, this feeling is not limited to professionals.


Deba Bocho, or “Pointed Carving Knife”, order-made for private persons that use them for their hobby of fishing. These knives feature modifications such as maple wood for the handle, changes possible because they are custom-made.

Manufacturing, without a blueprint.

Sometimes clients will visit the workshop, though most of the times manufacturing details are only discussed via telephone or with the help of facsimiles etc.
“For example one client ordered a Deba Bocho to cut small fishes called Sayori, or ‘Japanese Halfbeak’. Though as Sayori have very slim bodies, we decided details such as how many centimetres to use for blade length, and what thickness and kind of material for the handle would be suitable, while listening to the client’s requests. For blades that we manufacture the first time, we first create a paper template. When we manufacture the actual blade we use this template to adjust size and shape.
In the traditional manufacturing method of Souhi Zukuri, die-cutting techniques are not used, the shape of the blade is instead formed by the strikes of the hammer. There is no exact blueprint, a paper template is used to produce the form and functionality expected by the client. Also, in case of Deba Bocho, extremely soft iron and steel is used in manufacturing the blade, though depending on the purpose of usage, materials such as stainless steel, high-speed steel etc. might also be proposed.


Creations of Hisayuki Ota and his disciples, woodworkers with Asahikawa in Hokkaido as Headquarters. The disciples use tool bits made by the Yaegashi Uchi Hamono Factory.

Requests from the whole country continue.

“These are round tool bits and flat tool bits made on request of woodworkers from Hokkaido. They use our tool bits to carve 400-year-old oak tree wood from the Daisetsuzan Volcanic Group.” Stating this, Mr. Muneaki goes on to show us the creations of the woodworkers, which have smooth curves without any corners. It is fun to imagine the wood from the oak tree attached to a woodworking lathe, rotating in high speed, and the tool bits manufactured by Mr. Muneaki reflecting a bright light upon making contact with the wood, forming these smooth curves. When the blade comes in contact with the wood rotating in high speed it gets hot. When Yasuki-Steel gets hot it will become dull, which is why high-speed steel is used for this kind of usage.
Tool bits for craftsmen, tool bits for industrial use, Japanese knives for cooks, and chisels and hand planes as tools for carpenters. Mr. Muneaki, who manufactured a large variety of bladed objects, says he aims “to create tools that are beautiful, sharp, and made with attention to detail.” This does not change no matter if the client is a professional or an amateur. This is why people from all around the country frequent his workshop.


At the Yaegashi Workshop, located at a corner of a residential area with rich green, today again blades are manufactured with the Souhi Zukuri method.