Hatsukokoro ZDP-189 Migaki Petty 150mm

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.

ZDP-189 is a powder metallurgy steel. Proterial lists the carbon at 3.00% and the chromium at 20.00%, and does not list the other elements. Proterial gives a hardening hardness of over 65 HRC.

Knife Steel Nerds' testing puts roughly 30% of the steel as carbide. In Knife Steel Nerds' CATRA test it scored 162% against 440C, where 440C is 100%, but it stayed below S90V, which Larrin Thomas attributes to chromium carbides adding less to edge retention than vanadium carbides. In Knife Steel Nerds' water-spray test the steel rusted, and Larrin Thomas judged that it does not qualify as stainless. He notes that Hitachi's own corrosion data looked better than his result.

It suits a cook who already sharpens on stones and treats knives gently. We would not make it your first Japanese knife. Our SG2 vs ZDP-189 page has the full comparison.

On Proterial's own figures, ZDP-189 carries 3.00% carbon and 20.00% chromium, with the molybdenum, tungsten, vanadium and cobalt figures kept closed.

Proterial describes it as a stainless blade steel made by a powder metallurgy process, lists its hardening hardness as over 65 HRC, and gives it for custom knives and high-quality cutlery tools.

They come from different steelmakers, and both are made by powder metallurgy. Takefu lists SG2 as a blade steel created by powder metallurgy, with its composition not disclosed; SG2 runs 61 to 65 HRC depending on the maker.

Proterial describes ZDP-189 as a stainless blade steel made by powder metallurgy, lists 3.00% carbon and 20.00% chromium with its other elements not published, and gives a hardening hardness of over 65 HRC.

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.