Knife Forging of Tottori Prefecture

Tottori Prefectural Government

Traditional techniques and new challenges

The blacksmiths of Inaba
Since ancient times, iron forging has prospered in Western Honshū thanks to the high-quality iron-sand available there. Today, in a region formerly known as Inaba, there are still blacksmiths using long-established traditional techniques.
The mountains of Chizu
Charcoal, indispensable for forging iron, is abundantly available in the mountains of Tottori Prefecture. Forestry in this region also utilized iron tools, so the blacksmiths’ work was closely entwined with local people’s daily lives.
Ōtsuka knife forging
Ōtsuka knife forgingThe Ōtsuka Knife Workshop is located in a residential area. Here third-generation blacksmith, Yoshifumi Ōtsuka, continues to make knives.   In the past many smithies could be seen around Tottori Prefecture but now only two, including Mr. Ōtsuka’s, remain.
The forging process
The construction of a knife
A knife blade is made from two materials: steel and ferrite. Sandwiching hard steel between soft ferrite ensures a knife that is tough yet soft.
Basic shaping
The steel and ferrite are softened by heating on a coal fire, and then beaten flat using a mechanical electric hammer to make them easily workable.
Heat is used to cut a deep groove in a piece of ferrite; a pre-shaped piece of steel is slotted into this groove. Iron sand is used to adhere the two metals. 
The combined piece is heated and lengthened into a knife form by beating with a hammer. The welding process hones the cutting edge and the spine to a degree invisible to the eye. Beating the metal reduces the size of the particles, which enhances the toughness of the knife.
The beaten metal is cut to the desired knife shape using a template. Then the handle is made.
In order to harden the steel, the knife is placed into water after it has been heated to 800℃ to rapidly cool it down to 250℃. This vital heat treatment will determine how well the knife can cut. 
Straightening and tempering
Immediately after the quenching is complete, the knife is left in 100℃ water, before it then gets pounded to straighten the surface using a hammer.   Next, the straightened knife in its hard and brittle state is left in oil heated to 180℃. After that it is slightly heated once more to give the steel flexibility. 
This is the sharpening process. Various grinders are used to gradually finish the cutting edge.
Introducing Ōtsuka knives
Ōtsuka’s knives are made with meticulous attention to detail so they are easy to hold, make the right sound when cutting food, and even produce a nice texture of cut.   These knives can be enjoyed using all five senses.  
The all-purpose knife
Knives are made according to the type of ingredients they are intended for – meat, fish or vegetables. The all-purpose knife is made to incorporate the advantages of various different knives to suit a wide range of purposes. It is frequently used in the home.  
The vegetable knife
This knife, featuring a rectangular, straight-edged blade, is most common in the Kantō region. It is ideal for fine cutting or chopping of food, so ideal for preparing vegetables.  
The Yamame knife
This small knife with a sharp point is designed for cutting and trimming small river fish. The handle is made from a cherry branch, which gives it durability and a rustic beauty. Users enjoy seeing the knife change over the years.
The Yamagoya knife
This knife can be used to cut wild boar meat or venison. It is popular with outdoor enthusiasts.  
Rigging knife
This type of knife has a very sharp tip and is used to kill fish to preserve it fresh. Being made from steel sandwiched between two stainless steel sides, this type of knife is resistant to rust.
The Fisherman’s knife 
This is a multi-purpose knife made for fishermen to use onboard a boat. Also known as a ‘sea knife’ it can be used to cut and trim fish, for example to prepare sashimi.  
Mr. Ōtsuka has a high reputation for his outstanding skills and adherence to traditional techniques. He continues to preserve these traditions, whilst also experimenting with new products and sales strategies.   
Until recently it was difficult to get hold of Mr. Ōtsuka’s knives, but in the last few years he started selling them at the local deluxe-shop COCOROSTORE, increasing awareness and interest.
Tottori Prefecture
Credits: Story

Supported by:

Movie by:
Takayama Kengo, A-PROJECTS

English translation by:
Eddy Y. L. Chang
Martie Jelinek

Text and Exhibition created by:
Aoi yukari, Kyoto Women's University
Ishida ayaka, Kyoto Women's University
Miyagawa yuka, Kyoto Women's University

Project Directer:
Dr Maezaki Shinya, Kyoto Women's University

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.