K&S Arare SG2 Nakiri 165mm by Iron Clad, Black Charcate 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.

SG2 (Super Gold 2, which Takefu writes as SPG2) is Takefu Special Steel's own blade steel, made by powder metallurgy. Takefu says it meets all four of what it calls the major requirements for a blade: high hardness, high toughness, good wear resistance and excellent corrosion resistance.

Takefu gives its hardness as HRC 62 or more and does not publish its composition. As of 18 October 2026, 291 of the knives we list have SG2 in their title.

Neither is objectively better, it just depends on whether you value stainless convenience or a laser-sharp carbon edge. Go with SG2 if you want a knife that holds a screaming edge without any babysitting. Choose AS if you are chasing the thinnest possible edge and don't mind wiping the blade down after every use.

SG2 is a powdered stainless steel from Takefu, rated at 62 HRC or more. It is tough and resists corrosion, which is why I reach for it when working with acidic foods. Aogami Super is high carbon, and Proterial gives it a hardening hardness of over 60 HRC. It sharpens to a hair-whittling edge that lasts slightly longer than SG2, but it will rust if you neglect it.

We can't confirm that from a steelmaker. SG2 (Super Gold 2, which Takefu writes as SPG2) is Takefu Special Steel's own blade steel, made by powder metallurgy. Takefu does not publish its composition and gives its hardness as HRC 62 or more.

As of 18 October 2026, we found no steelmaker page for a steel called R2. Some knives on our shelf are listed as SG2/R2: six as of 18 October 2026, from Kurosaki, Shiro Kamo and Yoshimi Kato.

Yes, in part. Takayuki Shibata's own page for the Koutetsu line says of those knives, "we carefully sharpen them one by one."

From our own dealings with Iron Clad, he does the sharpening himself on knives that carry his name, though probably not on each one.

Iron Clad's company page lists resharpening among its business, with the export, maintenance and making of knives.