Tsunehisa Kiritsuke Aogami Super Kuro-uchi 210mm (8.3") [Walnut] is a great multi-purpose knife with a black Kuro-uchi protective patina and hammer dents. The kiritsuke blade shape is a multifunctional Japanese kitchen knife, suitable for everyday use since 210mm (8.3") blade length is an optimal size for chopping vegetables as well as cutting larger pieces of meat and fish. The Kuro-uchi (black) patina on the upper part of the knife gives it a unique and rustic appearance.

BLADE SHAPE:

Kiritsuke knives are double-bevel hybrids between the traditional Japanese knife yanagiba (slicer knife, mostly used for sushi) and the usuba (knife specialized to cut vegetables). This means kiritsuke knives can be used for all sorts of tasks in the kitchen, from making sashimi, slicing through ribeye, to chopping veggies. Traditionally, kiritsuke knives were only allowed to be used by the Executive Chef of the restaurant, but we'll look away if you're not (yet) the head chef.

STEEL:

The core of this knife is Hitachi's Super Blue Steel (Aogami Super), which is the very top quality of traditional Japanese steels. This knife was heat-treated to around 63 HRC. It is a very hard steel, meaning that it will retain a super-fine sharpness for a long time. In addition, due to the high carbon content (1.4-1.5%), the knife is very easy to sharpen. Among the high carbon steels, Aogami Super is also the least sensitive to rust. It also contains 0.4% vanadium as an admixture for micronized metal grains, which gives the steel more toughness. Aogami Super is rated as the most advanced carbon steel. The outer layers are of softer, stainless steel, giving the knife extra rust protection.

LAMINATION:

A high hardness of around 63 HRC means that the blade won’t be very tough, so the blade’s core was laminated using the san-mai method to improve its structural integrity and subsequent ability to withstand impacts and prevent chipping. San-mai translates to “three layers” in Japanese, referring to a blade that is composed of a primary, inner layer of harder steel (hagane) and of two secondary, outer layers of softer steel (jigane) that protect the prior.

BLADE FINISH:

Kuro-uchi finish, the unprocessed (black) part on the top side of the blade has already developed a dark patina, which protects the blade and gives it a traditional Japanese look. The knife bears visible impressions of the hand-forging process (round hammer dents on the blade), which gives it a beautiful finish and also prevents food from sticking to the blade.

HANDLE:

The traditional Japanese Wa handle is oval and smooth, with no discernible transition between the walnut and maple wood. It’s suitable for both left- and right-handed users.

BLACKSMITH:

Tsunehisa is a curated brand that brings together high-quality knives from Japan’s top smithing regions—Tosa, Seki, and Sakai. Each area specializes in distinct steels and techniques: Tosa is known for Ginsanko and AUS-8; Seki for the V-Gold series; and Sakai for its traditional single-bevel Honyaki knives.