Tetsujin Ginsan Ukiba Nakiri 180mm Ebony Handle

Part of the edge never reaches the board, so the cut never finishes. At our counter we put it simply: there is not enough flat at the heel. A knife with a long curve is built for rock chopping, not for the Chinese or Eastern up-and-down chop.

A straight edge, like a nakiri's, meets the board along its whole length and finishes the cut. On any knife, a dip worn near the heel or a dull section can cause the same thing.

The bevel. A Japanese dictionary describes the nakiri (菜切包丁) as shaped like an usuba but double-bevel and relatively easy to handle; the Sakai cutlery association describes the usuba (薄刃包丁) as an acute, wide knife for vegetables, in a square Kanto type and a kamagata Kansai type.

The names overlap, since another dictionary records the usuba as also called nakiri, so check the bevel rather than the name.

Ginsan, also known as Silver 3, is a stainless steel from Proterial, the Yasugi Specialty Steel division. Proterial describes it as a stainless steel which has hardness and sharpness comparable to carbon steel, and lists its uses as kitchen knives and scissors.

Knife makers use it when they want the corrosion resistance of a stainless together with the hardness and sharpness that Proterial compares to carbon steel. The steel maker lists 59 HRC or over after hardening, but that is a heat treatment figure, not a finished knife figure.

Dry it after use, like any stainless knife. Its performance depends on the heat treatment and construction of the specific knife, not the steel name alone.

Yes. Proterial lists the steel as GIN 3 with 13.00 to 14.50% chromium, above the Japan Stainless Steel Association's 10.5% minimum for stainless steel.

Proterial describes it as a stainless steel with hardness and sharpness comparable to carbon steel, used in various kitchen knives and scissors, and the association notes that stainless, strictly, means it rusts less. Wash the knife and dry it after use.

Tetsujin Ginsan Ukiba combines Toru Tamura's forging with Naohito Myojin's sharpening. It has a stainless-clad sanmai blade and an Ukiba finish. K&S recommends the line for first-time buyers, students and professional cooks.

A hamaguri-ba edge, written 蛤刃, is a convex edge shape, and it is the shape the workshop 明神利器製作所 sharpens its knives to. Kochi City's craft page records that the workshop's second generation, whose name the page gives as 直人, learned it over several years of training in Fukui.

The same page says the workshop also takes sharpening-only orders from outside Kochi.

Yes. Kochi City's craft page for his workshop 明神利器製作所 says the work runs from forging through finishing in one continuous process, 鍛造から仕上げまで一貫して行う.

That page lists the workshop in Susaki, Kochi.