Tojiro Kakugata Usuba Shirogami #1 180mm (7.1") [Buffalo]

This Kakugata Usuba is forged from Shirogami #1, one of the purest and most traditional steels used in Japanese knife manufacturing. The blade’s finish was kept within the confines of the Japanese concept of negative space (ma 間)* and given a sleek polished migaki look, and a kasumi finish on the kireha. Adorned with hand-chiseled kanji and fitted with a traditional Japanese handle made of magnolia wood topped with a buffalo horn ferrule, this minimalistic knife showcases the qualities of traditional Japanese blades we like most. 

*the Japanese concept of ma or negative space is a philosophy that guides their approach to design, as well as other, everyday things – the core belief being that absence can be just as important as presence.

BLADE SHAPE:
In Japanese, Usuba means thin, which is an appropriate description of this knife designed for preparing vegetables, where a thin blade is essential. When cutting firm vegetables such as carrots, it is important that the blade cuts instead of splitting, as can often happen with thicker knives.

Kakugata refers to the specific rectangular shape of this knife - kaku means square in Japanese. The single bevel blade enables precise chopping of vegetables on the kitchen board, and due to its height and straight edge, it can also be used for peeling larger tuberous vegetables, such as daikon, into long and thin slices. This process is called “katsuramuki” and is one of the most difficult and complex Japanese cutting techniques.

STEEL:
The core of the knife is made of Shirogami steel #1 (white steel) with the hardness 61–62 HRC. This makes the knife very sharp and easy to resharpen but a bit more demanding in terms of maintenance. Shirogami #1 is one of the purest steels, and consequently one of the easiest to sharpen. Its characteristics make Shirogami popular with traditional Japanese blacksmiths and sushi masters. The advantage of Shirogami #1 is that it has a very fine, delicate sharpness, is easy to grind, and stays sharp for a very long time. The blade will acquire a protective patina with use. Therefore, it’s recommended to wipe the blade dry between and after use and oil it regularly.

→ Learn more about knife maintenance here.

LAMINATION:
The hard core of the knife is composed of a hard core (forming the cutting edge) and a softer, external layer of soft iron, a cladding we call ni-mai lamination. The outer layer of softer steel forms a "shinogi" line along the entire edge of the blade. The shinogi line represents the border between the harder, inner steel and the outer layer of softer steel. The Ni-mai lamination method is used on single-bevel knives, where a sheet of softer metal is forge-welded onto the shinogi (front) side of the blade’s hard core. This reinforces the blade’s structural integrity and consequently makes it tougher.

GEOMETRY:
It has a single bevel blade and a flat primary angle (the surface below the shinogi line). As such, the blade and handle are not suited for left-handed people but right-handed users only. The blade has a distal taper, narrowing from the handle towards the tip.
The single bevel blade is suitable 🚨 for right-handed users only!

BLADE FINISH:
This knife has a minimalistic migaki finish, meaning the blade has been polished. The kireha, or “blade road” is adorned with a matte kasumi finish that marks the transition between the jigane (softer outer layer of steel) and hagane or the blade’s hard core.

HANDLE:
The blade extends into a traditional Japanese D-shaped Wa handle made of the most traditional wood for Japanese handles - magnolia wood - with a black water buffalo horn ferrule. Magnolia is the most popular wood type used for Japanese knife handles - and for good reason. The wood is praised as the best handle wood; it is lightweight and has antiseptic properties, and its light colour shows its cleanness, which indicates that the food being prepared is also impeccable. Magnolia also has an extremely low percentage of etheric oils or resins. Consequently, it does not leave or retain odors. This is especially important for Japanese cuisine, which focuses on fresh, delicate dishes. An additional advantage of magnolia wood handles is that they are easy and inexpensive to rehandle as there is an abundance of magnolia handles on the market.
The water buffalo horn is the most traditional choice for a Japanese handle ferrule (also known as tsunomaki). The material is made from the horns of Asian water buffalos. Its function is to keep the wood of the handle from cracking when the tang (or nakago) of the knife is heated and driven firmly into the wooden handle during the fitting process.

ABOUT THE SMITHY:
Tojiro is one of the top 5 largest Japanese kitchen knife manufacturers. They are renowned across Japan and internationally for their top-quality knives for a reasonable price. Tojiro's focus on advanced technologies, together with their insatiable dedication for constant improvements of their knives and materials, makes Tojiro's knives a must-have in any kitchen. Tojiro's main focus? Sharpness! A big bonus is their great team which we are always very eager to meet and talk to!
Take a look inside the Tojiro smithy and learn more about their master blacksmith Tomoo Matsumura in the following video: