In the mid-16th century, firearms and tobacco were introduced to Japan by the Portuguese. In the latter half of the 16th century, "tobacco knives" for cutting tobacco leaves began to be made in Sakai, and the Tokugawa shogunate granted Sakai a quality certification mark called "Gokuin" and authorized a monopoly on sales, so the sharpness and reputation of Sakai cutlery spread throughout Japan.
In the mid-Edo period, the deba knife appeared, and after that, various types of knives began to be produced.

• Technology/techniques/raw materials

  Technology/techniques/raw materials

  Technology/techniques

  1. The blades of knives and scissors are shaped by heating the blade steel in a furnace and then hammering and widening it.

  2. The hardening shall be carried out using the following techniques or methods:
  (1) For fully forged knives, perform the "clay application" and then rapidly cool them.
  (2) For knives other than fully forged knives and scissors, apply a "mud coating" and then rapidly cool them.

  3. For a three-pronged forged knife, perform the "assembly" technique.

  4. Rust prevention for the blades of the scissors should be done by "smoked wood" or "coloring".

  5. "Sharpening," "sharpening," and "finishing" must be done by hand.

   

  raw materials

  1. The materials used shall be carbon steel or iron and carbon steel.

  2. The handle shall be made of wood.

• Work scene

  Work scene

  Step 1: Blade setting (steel)

  A piece of steel (blade metal) coated with a powder mixture of boric acid and other substances is placed on top of a heated base metal, and then forge-welded by applying heat of approximately 900 degrees Celsius.

  

  Process 2: Plastic surgery

  The flattened body is further heated to 600-700 degrees Celsius and flattened again to shape it into a knife.

  

  Step 3: Annealing

  To soften the blade steel and remove any internal distortions, it is heated to 700-800 degrees Celsius and then allowed to cool naturally.

  Step 4: Rough chopping

  The metal is further forged at room temperature to fill in the hammer marks and holes created during the hot forging process and to make it flat.

  Step 5: Cutting and shaping

  After sharpening the knife, trim off any excess material to match the desired shape.

  

  Step 6: Grinding

  The excess material and unwanted parts resulting from the cutting process are ground off with a grinder, and then the surface is shaped by filing.

  Step 7: Mud application

  To ensure rapid and even cooling during the hardening process, mud is applied to the knife blade and allowed to dry thoroughly using the residual heat at the back of the furnace.

  Step 8: Hardening and tempering

  To increase the hardness of the blade steel, it is heated to 750°C to 800°C and then rapidly cooled in water. Furthermore, to give the blade steel toughness and strength, it is heated to 180°C to 200°C and then allowed to cool naturally.

  

  Step 9: Sharpening (sharpening)

   

  

   

  

   

  

   

  

  Rough sharpening → polishing → straightening → flat sharpening (sharpening the knife blade to determine the thickness) → straightening → flat polishing (sharpening with a whetstone to make the grit finer) → chisel cutting (straightening the twist of the knife blade) → final sharpening (creating the cutting edge of the knife blade) → straightening → blunting (creating a temporary edge) → straightening → back sharpening (sharpening the back of the knife blade to create the correct indentation) → back buffing (making the "grain" created by sharpening with a whetstone finer) → blade sharpening Sharpening (thinning the temporarily attached blade) → Buffing (further refining the grit) → Blade coloring → Sharpening with a wooden whetstone (grinding with a wooden whetstone) → Edge sharpening (creating a bevel with oak wood) → Hand whetstone sharpening → Blurring (blurring with a rubber powder made from whetstone powder) → Blade sharpening → Back beveling → Sub-blade alignment (removing burrs, etc., and creating the final edge) → Wiping with water → Wiping with oil (rust prevention) → Straightening → Finishing
  Through these 27 sharpening steps, the knife will be finished with a sharp edge.

  
• Close-up

  Close-up

  The chef's skills are showcased in the art of fire and steel.

  I visited the workshop of Ichiro Morimoto, a traditional craftsman specializing in sharpening blades. As I opened the door, the smell of iron filings and animal glue wafted out, reminding me of the old back alleys of downtown Tokyo. He appeared, his wooden clogs clattering.

   

  Operating a high-speed rotating sharpener

  "These paulownia wood clogs keep my feet warm. In my work, water is always involved with the whetstones. The floor is always wet, so this height is just right." Five sharpening machines, including those for rough sharpening and fine sharpening, are lined up in Mr. Morimoto's workshop. A large electric sharpening machine, over 90 centimeters in diameter, rotates with a loud noise. He sharpens the blades, cradling the whetstone in his arms. As the process progresses, an even higher-pitched metallic sound is added. Water is placed beneath the sharpening machine to dissipate the heat generated by friction. The meaning of Mr. Morimoto's clogs becomes clear. The metal, the height of the ceiling, and the water on the floor make his feet cold. A drum of hot water is placed on top of a kerosene stove. Mr. Morimoto quickly washes his hands, which have become cold from being wet with rust-preventive liquid, in the hot water and moves on to the next step. Random scratches have been made on the sharpening machine. "Without these scratches, the friction would be too strong, causing the blade to stick and becoming dangerous. I even consulted with a blacksmith to have a machete specially made to create these scratches." The scratches, which appear to be made randomly, are actually difficult to create without experience.

  

  The geta sandals on her feet are unique.

  A kitchen knife imbued with the passion of a chef and a cutlery craftsman.

  Just as every human face is unique, every handmade knife is different. For sashimi knives used by professional chefs, only about 20 can be sharpened per day. Western cuisine utilizes many different types of knives. However, there are fewer types of Japanese knives compared to Western knives. This is because Japanese people are dexterous and can perform various intricate techniques with a single knife. Consequently, the requests from chefs are often meticulous and subtle. The chef's desire to create a knife exactly as they envision it, and the desire to fulfill that vision, combine to create a single, artistically crafted knife.
  In the final stage, he puts his hands directly into cold water and sharpens the knife with a whetstone. "This level of cold is nothing. Back in our day, ice would form on the surface." Shak, shak, shak... The knife makes a distinctive sound and begins to shine. This is the final stage of sharpening. Mr. Morimoto's expression becomes serious. In the flickering light of the incandescent lamp, the knife shines even brighter.

  

  The sharpening machine has a handle on top to allow for stable sharpening.

  A knife is not a weapon.

  "Recently, there have been some unfortunate incidents involving knives, which is regrettable. But knives themselves aren't inherently dangerous. It's just that if used incorrectly, they can become incredibly deadly weapons. So it's sad to see kitchen knives simply equated with danger." Not so long ago, schools tried to keep dangerous things away from children, even prohibiting them from carrying utility knives. But recently, the policy has finally shifted to encouraging children to learn about the dangers and uses of knives before trying them out. "Elementary school students have started visiting this workshop as part of their field trips to local industries. I try to let them experience as much as possible. There's an innate 'intuition' to be found, but the younger a person is, the greater their ability to learn new things. So, if they can feel it with their bodies rather than just understanding it intellectually, then their visit here will have been worthwhile. I also hope that by experiencing and learning about Sakai's history, they will become interested in traditional industries. I would be happy if this leads to the emergence of more successors."

  

  Mr. Morimoto, who knows everything there is to know about blades, stands before the finishing whetstone.

  A single knife embodies the souls of many craftsmen.

  Each stage of the process, from forging to sharpening, is handled by specialized craftsmen, resulting in a knife crafted with unique attention to detail. I felt that it was far too profound to simply dismiss it as a cutting tool. "Lately, I've started spending a little more time in the kitchen. When I actually use the knives, I can better understand the demands that chefs have for them. I've tried filleting fish, cutting vegetables neatly... When I say cooking, I mean, of course, it's just to try out the knives. So I can't guarantee the taste," he said, smiling a little shyly.

  

  He tests the sharpness of a kitchen knife by holding it against his own hair.

   

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    An axe used to create friction scratches on a sharpening machine.

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    There are various sizes of sharpening machines.