Kei Kobayashi SG2 Nakiri 165mm

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 is my go-to recommendation for anyone who wants a stainless knife that performs like carbon steel without the fuss. At 62 HRC or more (Takefu's figure), it takes a screaming edge and holds it far longer than VG-10 or AEB-L, all while being rust-resistant. You get the best of both worlds: no patina worry, but real cutting performance.

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.

Yes, R2 and SG2 are the same steel — R2 is the name used by Kobelco Steel, and SG2 (Super Gold 2) is the name used by Takefu Special Steel for the identical powdered metallurgy formula. SG2 / R2 is a powder (PM) steel from Takefu Special Steel, Japan, with a composition of 1.25% carbon, 14.0% chromium, 1.8% vanadium, 2.3% molybdenum, and a hardness range of 62–64 HRC. So if you see a knife labeled R2 or SG2, you are getting the exact same material.