Sukenari White 2 K-tip Yanagiba 300mm, Ebony Brass Handle

Shirogami 1 (White 1) has a higher carbon content than Shirogami 2 (White 2), roughly 1.3% vs 1.1%.

White 2 (Shirogami #2) has about 1.1% carbon and, per Proterial, a hardening hardness of over 60 HRC; White 1 sits around 1.3% carbon. That 0.2% difference is the core spec gap. More carbon generally means you can push hardness higher and hold a keener edge, but it also makes the steel more brittle and less forgiving. White 2 trades a bit of that potential peak sharpness for slightly better toughness and ease of sharpening.

Shirogami 1 carries a certain prestige. Sukenari's Nobuo Hanaki once told me directly that they only use White 1 for their mizu-honyaki because it is the pure form of carbon steel, it carries that halo. Among traditional smiths, White 1 is still spoken of as the benchmark.

Sukenari's own site carries both names together, titled the official site of 株式会社スケナリ with 佑成 named as a registered trademark. 佑成 is the house mark that appears on the blades.

So one house answers to both names: Sukenari is the company, 株式会社スケナリ, working from Fuchu machi in Toyama City, and 佑成 is its mark on the steel.

Yes. Sukenari says its knives are made by craftsmen by hand, one at a time, at its workshop in Fuchu machi, Toyama City.

The Sukenari lines we stock carry the workshop name in their titles.

The workshop says the 佑 of its registered mark 佑成 (read Sukenari) is written with the person radical and 右, right, and that the character carries the wish for its tools to become the cook's indispensable right arm.

The company's own site title reads 登録商標 佑成 (registered trademark), and 佑成 is the house mark on its blades.