A petty knife is a small Japanese utility knife, typically with a blade between 120mm and 180mm, designed for precision tasks like peeling, trimming, and slicing fruits and vegetables. You need one when your main chef’s knife feels too large for detail work, think deveining shrimp, cutting garnishes, or any in-hand peeling where a bigger blade gets in the way. Its slightly longer and slimmer profile than a Western paring knife gives you more control for intricate cuts without sacrificing the nimble feel you want for small jobs. If you regularly find yourself reaching for a smaller blade for finishing work, a petty fills that gap cleanly.

A petty is not a replacement for a gyuto or santoku. It lacks the blade length and belly for efficient chopping, rocking, or breaking down larger proteins. If your work is mostly bulk prep, like dicing onions or slicing roasts, a petty will feel slow and underpowered. It also won’t handle heavy tasks like splitting bones or prying, so treat it as a precision tool, not an all-rounder.

The petty’s role in a Japanese kitchen is as the smaller counterpart to the gyuto, built for tasks where a full-size blade is clumsy. At Knives and Stones, the petty category covers a range of steels including VG10, White#2, Swedish Steel, VG5, SG2, and MV, from makers like Sakai Takayuki, Masamoto Sohonten, Ryusen, Nigara, Hatsukokoro, and Sentan. Most are double-beveled, and the blade length runs from 120mm to 180mm, which is what gives it that balance of reach and precision. For more on how this fits into your knife kit, see the Knives and Stones Education Centre.

SG2 is my go-to recommendation for anyone who wants a stainless knife that performs like carbon steel without the fuss. At 1.25% carbon and HRC 62-64, it takes a screaming edge and holds it far longer than VG-10 or AEB-L, all while being fully 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, usually sitting around 62-64 HRC. It is tough and resists corrosion, which is why I reach for it when working with acidic foods. Aogami Super is high carbon and typically harder at 64-66 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.

Yes, Yu Kurosaki is widely regarded as one of the leading Japanese knife makers of his generation, known for combining exceptional cutting performance with artistic, hand-forged designs. Based in Takefu, he established his own workshop in 2014 after a twelve-year apprenticeship under Hiroshi Kato, and he has since earned recognition from the Japanese government as a “master blacksmith”, notably the youngest to receive that title. His knives are built around thin geometry and advanced steels like SG2 and Blue Super, which contribute to strong edge retention and precise cutting. He is also celebrated for innovative finishes such as Tsuchime and Suminagashi, which set his work apart visually while maintaining traditional craftsmanship.

That said, "good" depends on what you're after. Kurosaki's blades are designed for extreme performance and artistic flair, not for heavy-duty or rough everyday use. The thin geometry that makes them cut so well also means they require careful handling and a proper cutting board, they are not the right choice if you're looking for a workhorse knife to abuse in a busy commercial kitchen. If you prioritise durability and forgiving edge stability over razor-sharp precision and visual uniqueness, a more robust, thicker-ground knife would serve you better.

Kurosaki's reputation is built on a clear philosophy: aiming for the ultimate knife. His journey from teenage apprentice to master blacksmith reflects a deep commitment to both function and form. He is known for his use of SG2 and Blue Super steels, paired with distinctive hammered and layered finishes, which together deliver a balance of strength, edge retention, and aesthetic originality. For a closer look at his work and approach, you can explore the Yu Kurosaki maker page on the Knives and Stones site.