Honyaki knives are most appealing to experienced users and professionals that demand the very best knives available. As we shall explain below, Honyaki knives are also the most challenging knives for forge-smiths and craftsmen to produce.
The ‘one-piece’ blade construction of the Honayki knife is handcrafted using processes which are similar to those used in Japanese sword making, such as the Tsuchi-Oki process. This method involves heating the blade to around 800 °C and then quenching it in water to increase its hardness and placing it in rice-straw ash to slowly cool down to room temperature; This detail is important since it helps to prevent uneven tension from developing in the blade. A skilled craftsman then carefully applies a special mixture of semi-liquid clay (Which typically includes clay, water, and pulverized charcoal, powdered stone and other secret ingredients) to the blade, using a thin layer of clay on the cutting edge and a thicker layer along the Shinogi-ji and the spine. By varying the thickness of the clay, the craftsman can control the speed at which the steel cools when it is quenched during the tempering process and thus manipulate the hardness of individual parts of the blade (Differential tempering). Skilled artisans can also use this technique to create a variety of beautiful Hamon patterns in the steel of the blade.
Because of the difficulty of controlling the large number of variables involved in this heat-treatment method, it is common for blades to develop small cracks or distort severely. Consequently, the production of Honyaki knives is expensive and time-consuming. Indeed, there are currently only a few companies who have craftsmen skilled enough to make true Honyaki knives. Master Nagao (President of Hiromoto Company and Master Bladesmith) once explained that Sukenari produces some of the best Honyaki knives he had ever seen and, after visiting Sukenari’s workshop and witnessing their fine craftsmanship for ourselves, we understood why he respects them so much.
Sukenari uses high quality Hitachi Shirogami #1 (White Steel No.1) for their Honyaki knives (HRc. 64). When we saw their Shirogami #1 Honyaki knives for the first time, we anticipated how much extra expense and difficulty using this great Japanese high carbon steel must add to the Honyaki knife making process; Many other knife makers will only use steel with a lower carbon content, such as White No.2 steel or Blue No.2 steel.
Sukenari have used their rich experience and knowledge to determine what methods work the best when making Honyaki knives and have also managed to develop a keen sense for what variables are important: The traditional hammer forging techniques used to shape the blade; the special ingredients for the Tsuchi-Oki (Clay mixture) and its application to the blade; carefully managing the temperature of the blade during the water-quenching process. Every step of production is perfectly demonstrated by Sukenari’s Master forge-smith and faithfully passed on to the next generation.
Each one of Sukenari’s Shirogami #1 Honyaki knives is beautifully mirror-polished and has an impressive wavy Hamon pattern. They are fitted with a traditional octagonal magnolia wood handle that has a water buffalo horn ferrule. A matching magnolia wood Saya (Sheath) is also supplied for safekeeping.
Please note that whilst Honyaki knives offer truly remarkable hardness, edge sharpness and edge retention, this also means that they are difficult to sharpen and can be easily damaged by incorrect use. In Japan, they are normally only used by very experienced top-star Chefs, and similarly, we only recommend them for people who have extensive experience with traditional Japanese knives, or to knife collectors.