At 180 mm, Jiro Nakagawa's petty sits at the upper end of the utility format: long enough for precise board work, compact enough for off-board tasks like peeling, trimming, or fine brunoise. The profile tapers toward the tip, making it well suited for detail work on fresh herbs, small vegetables, and small cuts of meat or fish.
In the countryside of Nagano, Jiro Nakagawa forges, grinds, and polishes every blade entirely on his own, using natural stones. He also practices traditional Japanese calligraphy and engraves each tang by hand in a way that is unique to each knife. The construction is warikomi sanmai: a Shirogami #1 core inserted within a soft iron cladding, finished in kasumi. Each knife is individually numbered with a certificate of authenticity.
Shirogami #1 (White Steel #1) is a pure carbon steel produced by Hitachi Metals, with no chromium or tungsten. Its high carbon content (1.25,1.35%) allows it to reach 63,65 HRC and take a very acute edge on a water stone. In return, it is reactive to moisture and acids: patina develops quickly on the hagane, and the soft iron cladding follows the same evolution. Sharpening requires more passes on the stone than alloyed steels, but the edge response is direct and precise.
Care
Wipe the blade immediately after each use. Patina on the hagane and jigane is normal and expected. Apply a thin coat of camellia oil for extended storage. Never wash in the dishwasher.
