Hatsukokoro Hayabusa ZDP-189 Santoku 180mm

Both are all-purpose Japanese knives, and for most home cooks either will handle the bulk of daily prep. The choice comes down to length, blade shape, and how you like to cut.

A gyuto is the Japanese chef's knife, with a gently curved edge that lets you rock and slide through cuts as well as chop. Tojiro's guide to Western knife shapes gives 150 to 210mm as the household size for a gyuto and up to 360mm for professional use. The extra length and pointed tip give you reach and versatility, from proteins to large produce.

Tojiro's guide to Japanese knife shapes gives 165 to 170mm as the household size for a santoku, which has a flatter profile and a rounded sheep's-foot tip. It rewards a straight up-and-down push cut, feels nimble in smaller hands or tight kitchens, and is the classic Japanese household knife.

Rule of thumb: choose a gyuto if you want one do-everything knife with more reach, or a santoku if you prefer a compact, easy-to-control blade. Plenty of our customers end up owning both.

Match the shape to your stroke. Rock chopping keeps the tip on the board and rolls the curved belly through the food, so a gyuto or a Western chef's knife suits it, and Japanese knives rock fine as long as you rock gently.

Up-and-down chopping, the Chinese style, wants a straight run of edge, so a nakiri, usuba, santoku or bunka suits it better; a curved edge chopped straight down easily leaves pieces joined. Neither shape is better; it depends on how you cut.

A Japanese dictionary explains the name of the santoku (三徳包丁) as coming from the three things it handles: meat, fish and vegetables. The same dictionary entry points from the santoku to the bunka (文化包丁), treating the two as one knife.

One Japanese knife maker guide distinguishes the two by the tip. It says that in the Showa era the bunka was made with its tip cut at an angle, and the santoku came after it by rounding that tip.

ZDP-189 holds an edge longer than any other steel we sell. The price is a blade that chips more easily, takes a long time to sharpen and is only modestly rust resistant. It's a specialist's steel, and we wouldn't make it your first Japanese knife, or your second.

The good:

• Edge life. In Knife Steel Nerds' CATRA testing it lasted about 162% as long as 440C, well past SG2. On a board full of meat and tendon it keeps cutting long after most stainless knives have gone dull.
• Hardness. Proterial gives a hardening hardness of over 65 HRC, so it takes and holds a very fine edge.
• Bite. Roughly 30% of the steel is chromium carbide, more of it and coarser than in SG2, and you can feel the edge grip fibrous protein.

The bad:

• Chipping. At that hardness it won't forgive bone, frozen food, a twist in the cut or a glass board.
• Sharpening. We find it slow on most waterstones, with vague feedback, and much happier on a diamond plate. Given the choice, we'd rather not sharpen it at all.
• Rust. The spec sheet says about 20% chromium, but the 3% carbon ties most of that up in carbides. Larrin Thomas's modelling puts the chromium left in the steel near 6.5%, and in his water test a ZDP-189 sample rusted inside eight hours while SG2 and VG10 stayed clean. Treat it as stainless, not stainproof, and dry it straight after use.

It suits a cook who already sharpens on stones, cuts a lot of protein and treats knives gently. For most people SG2 is the better buy. We call SG2 the goldilocks of high-performance cutlery steels: a little softer than ZDP-189, but tougher, more stainless and far easier to keep sharp. Our SG2 vs ZDP-189 page has the full comparison.

ZDP-189 comes and goes in our range. When it's in, it's Hatsukokoro's Hayabusa line and Sukenari's Hairline line.

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.

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.