Sakai’s kitchen knives account for about 7% of the national market share, but more than 90% of professional kitchen knives, and are known among chefs as “Sakai for kitchen knives. Incidentally, another famous kitchen knife production area in Japan is Seki City in Gifu Prefecture (Seki kitchen knives). Sakai’s kitchen knives are characterized by the division of labor, with the “hizukuri forging,” “bladesetting,” and “handle setting” processes being completed by a number of specialized craftsmen. This system promoted friendly rivalry among the craftsmen, resulting in the creation of excellent kitchen knives. The traditional “wakashi-tsuke” technique, which is said to be a Sakai specialty, involves heating the metal to over 1,000 degrees Celsius and laminating the steel with boric acid, borax, iron oxide, and other materials.

Sakai Uchihamono(knives) is characterized by the sharpness produced by its single-edged blade structure. The blade is sharp and the sharpness is brilliant. There are more than 40 different types of knives such as a willow blade knife (for sashimi or Sushi), a thin blade knife (for vegetables), a deba knife (for slicing fish and meat), and so on.

An important point in choosing a Sakai Uchihamono knife is whether to choose a single-edge or double-edge blade. The single-edged blade was developed in Sakai in the middle of the Edo period (1603-1868), and is still the mainstay of Sakai-daibu knives today. Single-edged and double-edged blades each have their own merits and demerits, but single-edged blades have the following merits.

Single-edged knives are positioned as knives designed for the characteristics of Japanese cuisine, and match delicate Japanese food preparation. It is rather suitable for restaurants and professional cooks.

• Excellent sharpness and quick cutting when cooking vegetables, such as peeling and chopping.
• When cooking fish, you can cut off the part closest to the bone.
• The cross section of the cut is beautiful.

On the other hand, double-edged knives have both sides of the blade sharpened, and are common in Western-style kitchen knives that came to Japan after the Meiji period, such as Santoku knives and Gyuto knives. Since the blade is sharpened on both sides, it is characterized by its ability to cut as desired when viewed from directly above.

Steel material is also an important point in choosing a kitchen knife. Depending on what kind of material the knife is made of, the sharpness of the knife, how long the sharpness lasts, how easy it is to resharpen, and how resistant to rust it is. Sakai Uchihamono uses carbon steel to achieve sharpness, but there are many different types and combinations of steels. Some knives are made of stainless steel, which is rust-resistant and easy to handle. Choose a knife made of the material that best suits your tastes and preferences.

The production of knives in Sakai, which has a history of 600 years, began in the 15th century when a group of knife smiths, whose ancestors were swordsmiths, moved to Sakai from Kaga Province (present Ishikawa Prefecture). However, the foundation was laid far back in the 5th century with the construction of the Nintoku Emperor’s Tomb. A group of craftsmen who made iron tools such as hoes and plows settled in Sakai and developed blacksmithing techniques.

The opportunity to expand production came in the 16th century. When guns and tobacco were brought to Japan from Portugal, the production of guns and tobacco blades that chop tobacco leaves using the knife smithing technique became popular in Sakai. Especially, tobacco knives with sharp cutting ability were allowed to sell by the Edo Shogunate with a seal of “Sakai-kyoku” (Sakai pole), and they became prosperous. In the Genroku era (1688-1704), the single-edged blade type, which is the characteristic of Sakai kitchen knives, was born in Sakai. The tradition has been inherited down to the present day, and we continue to boast 98% share of the domestic market for kitchen knives for professional chefs.

The red-hot base metal (soft iron) and the blade metal (steel) coated with boric acid, borax, iron oxide, or other powders are placed in a furnace and heated to about 900°C to soften them. The two metals are then tapped with a hammer to bond them together to make the steel plate that forms the basis of the blade.

The iron plate is heated again in the furnace to 600 to 700 degrees Celsius to stretch it out. The entire surface is beaten with a hammer to make it thinner, and the base metal and blade metal are blended together to form the approximate shape of the knife. Unnecessary parts are trimmed off, and the part to be inserted into the handle is also shaped.

The shaped knife is placed in straw and allowed to cool naturally. By cooling it gradually in the process of turning it into ash, the strain inside is removed.

The surface of the knife, which has cooled to room temperature, is struck with a hammer in order to flatten the hammer marks and sticky holes that were made during the process. Rough hammering removes unnecessary components and forges the knives. Also, strain and distortion are removed and the thickness becomes uniform.

The excess portion of the knife is cut off to fit the mold.

After adjusting for distortion and strain, the back is engraved. After shaving off the excess and unnecessary parts, the entire piece is finished with a grinder (a machine for grinding and sharpening). The entire piece is then finished with a grinder (a machine for grinding and shaving), and any kinks are corrected by tapping it with a hammer.

Mud is applied to the work during the hardening process in order to reduce unevenness in the hardening process and to cool the work quickly and evenly. Before applying mud, remove oil and dirt from the knife, and dry the knife well in the residual heat of the furnace.

The composition of the blade metal is changed by cooling it down rapidly, and it becomes harder. In quenching, the temper is heated to 750 to 800 degrees Celsius and then cooled in water all at once to increase the hardness of the blade. After quenching, the tempering process is repeated at 180 to 200 degrees Celsius, and the knife is allowed to cool naturally. This is a process that requires skill and experience, as the temperature is measured by dropping a drop of water on the knife and checking how it runs, but this process makes the blade metal sticky and creates a blade that is strong and resistant to chipping.

Rough sharpening, hon(main) sharping, back sharpening, blurring, and finishing are done in this order.

1. Rough sharpening is an important process that determines the angle of the knife blade. The knife is then sharpened to a fine point, checking frequently to make sure it is not warped by the sharpening process.
2. Hon(main) Sharpening: This is the process of sharpening the blade in earnest. The thickness of the knife blade is also adjusted. The thickness of the blade is also adjusted.
3. Back sharping: The back of the blade is also lightly sharpened. The back of the blade is also lightly sharpened. The sharpening grind is made a little finer to remove scratches and check for any distortion.
4. Blurring: The blade is then rubbed with a mixture of whetstone powder on the blade. The base metal is dulled and the blade shines, and the boundary between the base metal and the blade iron becomes clear and beautiful to the eye.
5. Finishing: The blade is then carefully sharpened using a very fine grindstone to complete the sharpness of the knife.

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