Sugimoto Stainless Steel Large Nakiri (Chuka) 190mm CM4030

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.

They are Sugimoto's own production numbers, original to the company, its shop says, and its cleaver categories group them by thickness: numbers 1 and 6 thin (薄口), 2, 7 and 11 medium-thick (中厚口), 3 thick (厚口) and 22 extra-thick (極厚口).

Within that numbering system, #6 is in the thin group and #7 is in the medium-thick group.