Hatsukokoro Kurokaze White 2 Kurouchi Petty 150mm Stainless Clad

A petty is a small utility knife, from the French petit. It is commonly shaped like a small gyuto and runs from 120 to 150 mm, up to 180 mm. Its clearest role is detailed work where a larger knife feels cumbersome: fruit peeling, garnish work, condiments, and small board work beside a gyuto or santoku.

A knife maker, Tojiro, frames the petty as a useful second knife, not an automatic necessity, and recommends santoku plus petty or gyuto plus petty combinations. It is not a replacement for a full size chef's knife; it lacks the blade length and belly for efficient chopping, rocking, or breaking down larger proteins. Treat it as a precision tool, not an all-rounder.

Petty knife lengths vary by maker: KAI's guide defines a petty (ペティナイフ) as a small knife with a narrow blade measuring 150 mm or under. Its table gives 90 to 150 mm, and it describes the shape as a smaller gyuto with a pointed tip.

We list petty knives from 70 mm to 165 mm, including lengths above the limit used in KAI's guide.

Shirogami 1 (White 1) has more carbon than Shirogami 2 (White 2): Proterial lists 1.25 to 1.35% carbon for Shirogami 1 and 1.05 to 1.15% for Shirogami 2, with the same silicon (0.10 to 0.20%) and manganese (0.20 to 0.30%) ranges for both.

Proterial describes both as carbon steel with minimum impurities, Shirogami 1 with the highest hardness and Shirogami 2 with high hardness, and gives a hardening hardness of over 60 HRC for both. It lists Shirogami 1 for the highest quality tipped tools, planes, chisels and razors, and Shirogami 2 for high quality tipped tools, chisels, razors, sickles, axes and gravers.

White 1, White 2 and White 3 are Proterial's Shirogami 1, Shirogami 2 and Shirogami 3. Proterial lists carbon at 1.25 to 1.35% for Shirogami 1, 1.05 to 1.15% for Shirogami 2 and 0.80 to 0.90% for Shirogami 3, with the same silicon and manganese ranges for all three and no chromium listed.

Proterial describes all three as carbon steel with minimum impurities, at highest, high and middle hardness in that order, and gives a hardening hardness of over 60 HRC for each.

Proterial lists 1.05 to 1.15% carbon for both steels; its Blue 2 table lists 0.20 to 0.50% chromium and 1.00 to 1.50% tungsten, while its White 2 table lists neither.

Proterial describes White 2 as a carbon steel with minimum impurities and high hardness, and Blue 2 as an alloy steel with tungsten and chromium to improve heat-treatment properties and wear resistance, with a hardening hardness of over 60 HRC for both. In its Japanese materials, Proterial calls its Aogami (青紙) steels high-carbon steel (高炭素鋼). Neither steel is close to the JSSA's 10.5% minimum for stainless.

Hatsukokoro (初心) is a brand, not a forge. H&K, a company founded in 2013 and based in Amagasaki, Hyogo, created it in 2019.

H&K names the producer for some lines, for example Shinkiro by Takahiro Nihei in Fukushima, Ginyou by Yoshihiro Yauji in Echizen and Kurosagi by Motokyuichi Hamono in Nagasaki, and keeps others confidential. Some knives we stock carry the maker in the title, such as Hatsukokoro x Yoshikane SKD Nashiji.

The name comes from the Japanese proverb 初心忘るべからず, which means don't forget your original intention. The company read it gently as hatsukokoro rather than shoshin.

H&K created the brand in 2019, six years after the company was founded, and chose the name for its knife line.

Pick by how much care you want to give. The carbon lines, Blue 1, Blue 2 and AS kurouchi, need drying and a little oil after use. The SG2, HAP40, Ginsan and VG10 lines are low maintenance, so they suit a busy kitchen or someone who just wants to cook.

Neither is better; it depends on your routine. If you will dry and oil the blade after each use, a carbon line can suit you, and if you want the least fuss, a stainless line is the easier choice.