Jiro Nakagawa is a true one-man craftsman that works alone in the countryside. He sought out skilled craftsmen around Japan including a master sword polisher to learn the techniques of manipulating traditional materials, and have practiced the art of calligraphy for over 20 years under the master who lives in Nagano prefecture to enhance his hand-chiselling/engraving. His unique skill sets, humility, and will to improve all of his domain as a craftsman make all Jiro forged items worth treasuring for years to come.
All Jiro blades are numbered and for the one-hundredth, Jiro-san wished to imbue his maximum effort and all his knowledge to create a tool that is very different from kitchen knives. He decided to make a Kiridashi, a humble marking blade often used in woodworking.
The materials and techniques used in this project are extremely impressive and deserve the spotlights.
For the blade, he used Watetsu, a type of soft iron made from a Tatara smelter, from his personal cache. Some of the pieces date back to the 1850s: they were a part of temple door hinges, and anchors of traditional ships decommissioned at the adoption of steam engines. The Watetsu is easier and less time consuming to sharpen than modern soft iron (Gokunanko) and has rather unique aesthetic characters.
This was then layered with a small piece of hard steel, forge-welded carefully at low temperature to create 'Kitaeji', which was used as a cladding material for the Kiridashi. The Kitaeji is more sophisticated and functional than its other visually similar cousins. Because the hard steel mixed in with soft iron/Watetsu, it prevents tension warping of the blade, while being both beautiful and easy to sharpen.
Another interesting note is the usage of a labour-intensive technique called Kissaki-Kurumi. It is a traditional method used in high-quality chisel making, where a small portion of the hard steel is wrapped over the soft cladding, making it visible from the front side. To execute this, one needs to keep the welding temperature just right and be extremely vigilant through the quenching and sharpening process to not lose the hard steel portion. In the Kiridashi, you can spot this effect along the spine from the middle to the tip, where the layering is non-existent. This provides extra strength and helps prevent twisting in the blade. The usage of Kissaki-Kurumi by Jiro-san is a statement of pride and proof of his blacksmithing knowledge and skills.
The Ura of this Kiridashi has been carved out by hand using a traditional tool called a Sen, making re-sharpening and the entire blade portion have been hand polished on natural stones to bring out the folded layers. In fact, the sight of layers itself is a testament to the forging skill; using too high of a temperature or exposing it to heat for too long would cause the hard steel in the Kitaeji to lose its carbon content, preventing the pattern to show after the final polishing.
To do the blade justice, a friction-fitting, perfectly-bevelled octagonal handle was hand-carved out of a piece of Enju wood that has been dried for 50 years. This handle has a neat design element that allows the blade to be removed using the nail-like tool (also made with the special Kitaeji material) included, for full sharpening and cleaning.
This Kiridashi went to Tosho Knife Arts (Toronto, Canada) as the result of a strict lottery.