Powder steel knives are next level and we have something limited and rare on deck. Introducing the HAP-40 Bunka Black Ebony Blond Buffalo 190mm (7.5″). This limited edition Bunka is made from premium powder steel, HAP-40, and features a traditional octagonal ebony wood handle. Limited stock!
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HAP-40 Bunka Black embodies the best characteristics we could possibly expect from a kitchen knife:
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BLADE SHAPE:
With its typical functionality, Bunka design is intended for versatile use in Western cuisine. It has a flexible profile that is wide enough at the handle, a gently designed belly of the blade suitable for making either long or short cuts, a flat back side of the blade, and a thin tip for precise work with food.
STEEL:
The secret of this knife lies in extremely (68 HRC!) hard core made of a somewhat exotic and currently one of the most mysterious and attractive steels produced in Japan (at least as far as kitchen knives are concerned): Hitachi’s HAP-40 steel that fits into the category of modern and technologically advanced steels. HAP-40 is fine-grained enough to sharpen very well, and knives from this steel keep their sharpness 3-5 times longer than traditional knives. An interesting fact is that, considering it is a powder steel, it has an extremely small content of chromium (around 4%) and can react as a high-carbon steel in specific circumstances.
This steel is heat-treated to an incredible 68 HRC, yet it can still be relatively easily sharpened on whetstones. It is extremely tough, and so not as likely to chip along the edge as the steel used in traditional knives.
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COMPOSITION: 1.27–1.37% carbon (C), 3.70–4.70% chromium (Cr), 5.60–6.40% tungsten (W), 4.60–5.40% molybdenum (Mo), 2.80–3.30% vanadium (V) and 7.50–8.50% cobalt (Co). |
LAMINATION:
Osamu-san chose a warikomi (also called “split and insert”) method. A glowing hot piece of iron is split and a piece of steel is inserted. The new material is now forged into one piece composed of a very hard steel core in a jacket of two external layers of softer, stainless steel. This creates a highly durable kitchen knife with a slightly more pliable core. The main advantage of these knives is that they are thin, sharp and retain their edge very well.
GEOMETRY:
It has a double bevel (symmetrical) blade.
BLADE FINISH:
The blade has a dark finish which is the reason why this look is also called kuro-uchi – the word “kuro” means black. This look is traditional and robust, with an unprocessed top part of the blade that has already developed a dark patina.
HANDLE:
This limited edition HAP-40 Gyuto Black Ebony Blond Buffalo 210mm (8.3″) features a traditional octagonal Japanese handle made from ebony wood, paired with a blonde buffalo horn ferrule. Designed for both left- and right-handed users, it offers a balanced and comfortable grip. Ebony is renowned for its exceptional hardness and density, which makes it one of the most durable and resistant woods. It is polished to a high gloss, creating a luxurious and elegant appearance and smooth feel that fits into the hand seamlessly. The octagon shape of the handle provides a comfortable and secure grip, allowing for precise control during use.
ABOUT THE BLACKSMITH:
The knife is manufactured at the smithy of Yoshida Hamono in Japan, a family company with an age-long tradition in manufacturing state-of-the-art tools and Japanese swords, i.e., katanas, by hand. Yoshida Hamono has a great deal of experience forging ZDP-189 steel in the traditional manner.


















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