Parts of a Japanese Knife
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①Tip (Kissaki 切っ先)
The tip, or Kissaki, refers to the very tip of the blade. It is often the first part used when filleting or breaking down ingredients. Therefore, it is recommended that this part be sharpened with special care. Achieving sufficient sharpness with normal sharpening methods can be difficult, so it is necessary to sharpen it at a slightly different angle. However, it is important to note that sharpening without the correct angle may result in improperly shaped blades, which can affect both efficiency and safety during use.
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②Edge (Hasaki 刃先)
The "cutting edge", located on the part of the knife from the "slide" to the chin, is the point where force is most easily applied during the butchering process. Generally, the blade is inserted into the food from the "cutting edge", and while applying force to the "cutting edge", the "sled" is used to gently remove the meat. This "cutting edge" also plays an important role in the knife slicing and pushing technique.
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③Heel (Hamoto刃元)
This refers to the part of the blade near the handle of the knife. This part is especially useful when working with hard foods and is used for tasks such as breaking bones, splitting fish heads (kabuto-splitting), or peeling vegetables. In the case of the Deba, this part is often used to process tough ingredients, making the blade susceptible to chipping and other damage.
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④Chin (Ago あご)
This is the right-angled portion located at the base of the blade line. It is mainly used for tasks such as sprouting potatoes, cutting through bones and muscles, and dividing frozen foods.
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⑤Spine (Mine 峰)
The part of the blade that is directly opposite the cutting edge and has no blade attached. This part is used for beating, scraping, and shaving hard foods during cooking. Keeping this area, which is the first thing you see when you pick up a knife, clean will help motivate you and may result in better work.
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⑥Flat (Hira 平)
It refers to the flat part of the blade surface. This part is used for crushing or pounding food.
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⑦Shinogi （しのぎ）
The Shinogi is the boundary between the flat part of the knife and the cutting edge. One of the key points to remember when sharpening is this "Shinogi." The knife should be sharpened at an angle, maintaining a clear separation between the flat and the edge. However, if sharpening is done incorrectly, the Shinogi may become smooth, resembling a clam shell. In such cases, the edge of the blade cannot be sharpened properly, and only the Shinogi stripes are emphasized, resulting in an unattractive and dysfunctional kitchen knife.
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⑧Ferrule (Kuchigane 口金)
Ferrule (Kuchigane) is located at the tip of the sword's hilt, on the blade side. The characteristic of the kuchigane is that it shrinks over time, which has the effect of making it more difficult for the sword blade to slip out of the hilt.
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⑨ Handle (E 柄)
Kitchen knife handles, especially those of Japanese kitchen knives, are mainly made of wood, and their appearance, performance, and price vary depending on the type of wood used. The most common type of Japanese kitchen knife handle on the market is the "hoku handle," made from magnolia wood. The heartwood of the magnolia tree is often used for handles because of its lightweight, splinter resistance, and water resistance. It also provides a non-slip grip, even with wet hands, ensuring safety and ease of use when cooking.
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⑩Handle end (Ejiri 柄尻)
The handle end, or handle butt, is the lowest part of the knife handle. Some knives may feature the maker's name engraved on this part. Chefs often inspect this area and may choose it to inscribe their own names as well.
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⑪Uraoshi（裏押し）
The Uraoshi is a crucial element on the backside of a Japanese knife that significantly affects its sharpness and overall performance. The Uraoshi refers to a flat, strip-like section surrounding the Urasuki, rather than the entire backside of the blade. It is located along the edge of the blade's backside, with the edge closest to the blade tip being the most important.
In terms of shape, while the Urasuki is concave, the Uraoshi is flat, serving as a reference plane that helps determine the overall blade geometry. This flat surface enhances stability when cutting, ensuring smooth and consistent performance.
Additionally, the Uraoshi plays a key role during sharpening. Since it acts as a reference point, having a well-maintained flat surface ensures easier and more accurate sharpening, helping the knife retain its sharpness over time.
In short, the Uraoshi is an essential structure that supports the knife’s functionality and requires proper maintenance and sharpening to ensure optimal performance.
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⑫Urasuki (裏スキ)
The Urasuki (also called Urabiki) is one of the key features of Japanese knives. This unique concave design not only adds to the aesthetic but also enhances the knife's functionality in various ways.
First, it improves food release. When cutting ingredients, if the knife's surface has too much contact with the food, it can cause the ingredients to stick to the blade. However, the concave Urasuki creates a small gap, reducing the surface area in contact with the food, making it less likely for the food to stick. This feature is particularly beneficial for single-bevel knives, further enhancing their natural ability to release ingredients smoothly.
Second, Urasuki makes sharpening easier. Since the back of the blade is concave, when it is placed on a whetstone, the edge immediately contacts the stone. This allows for easier sharpening with less force, making it simple to remove burrs and maintain the knife's sharpness.
The Secret of Single-Edged Knives: The Backside Holds the Soul
Cheap Knives Often Lack Urasuki—What Are the Drawbacks?
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1. Reducing Friction for Smoother Cutting
Urasuki refers to a subtle concave indentation on the back of a Japanese knife. This small but essential feature reduces the contact surface between the knife and the food, thereby minimizing friction. As a result, the blade glides through ingredients with minimal resistance, allowing for a cleaner cut and a more aesthetically pleasing finish.
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4. A Design Perfectly Suited for Japanese Cuisine
The urasuki feature is not just a random addition—it has been developed to suit the unique techniques of Japanese cooking. It is especially useful for:
The Art of Japanese Knives: Mastering Tapering through Craftsmanship
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Japanese knives are primarily designed for a pulling motion rather than pushing. When slicing sashimi, for example, the cut begins at the base of the blade (near the heel) and moves smoothly toward the tip. The tapering allows for a clean, effortless cut, reducing friction and ensuring precise slicing.
The Wisdom and Functional Beauty of Japanese Knives
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One distinctive feature of Japanese knives is the “ago” (heel), located between the blade and the handle. The "ago" creates a natural gap between the cutting hand and the cutting board, preventing the hand from hitting the board during repetitive cutting tasks. This allows for efficient and comfortable movements, especially when chopping vegetables or slicing ingredients. Additionally, placing the middle finger on the "ago" enables precise control, making delicate tasks such as peeling, shaving, or slicing smoother and more effortless.
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Another defining characteristic of Japanese knives is the presence of “shinogi” (a ridge line) on the blade, commonly found in "awase-bocho" (laminated knives made of steel and soft iron). This feature plays a critical role in preparing sashimi. When slicing fish into thin, uniform pieces, the shinogi helps manage the blade's contact with the ingredient, ensuring that the fibers remain intact and the surface smooth. This not only enhances the visual appeal of the sashimi but also improves its texture on the palate.
What Are the Dimples on Japanese Knives?
Dimples on Japanese knives, known as "URASUKI," are indentations on the blade's backside that enhance the knife's sharpness and ease of use. These indentations help to reduce the blade's contact with ingredients, minimizing resistance and stickiness, especially with moist items. Dimples also lighten the blade and contribute to balance adjustments, improving maneuverability for delicate tasks and prolonged use. These features combine tradition with innovation, making dimpled Japanese knives exceptional tools for culinary precision.
Type of Handle
Japanese knife handles are often made from materials such as ebony, rosewood, and magnolia, each of which brings its own unique characteristics to the knife's balance, feel, and durability.
Why are Kitchen Knives Sharp?
A kitchen knife's sharpness hinges on the blade's edge and overall design, enabling it to cut efficiently. The edge needs to be sharp for initial contact, while the blade's angle and surface features facilitate smooth cutting. Techniques like pushing or pulling enhance cutting efficiency. Understanding these elements can make cooking more enjoyable and improve food presentation.
KIREAJI's Three Promises to You
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1. Exceptional Japanese Knives
Our knives, crafted by Sakai City's master artisans, combine traditional techniques with carefully selected materials, delivering unrivaled sharpness and durability.
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2. Genuine Sharpness
We offer free Honbazuke sharpening performed by skilled craftsmen, ensuring that you experience the authentic sharpness of a true Sakai knife.
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3. Lifetime Knife Use
Each knife comes with a free Saya (protective sheath) for added durability. We also offer after-sales service through a trusted Sakai City workshop to maintain your knife's performance.
