Myojin Cobalt Special COSP Santoku 180mm Ebony Handle

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.

Cobalt Special (CoSP) is Takefu's stainless blade steel for cutlery: Takefu's page describes it as super high-grade and made by a special remelting process that gives a uniform composition and finely dispersed carbides.

Takefu's table gives 1.05% carbon, 16.00% chromium, 1.50% molybdenum, 0.25% vanadium, 0.25% tungsten and 2.50% cobalt, with a hardness of HRC 60 or more. In Takefu's description, tungsten improves tempering resistance, molybdenum adds corrosion resistance, vanadium gives a finer microstructure, and cobalt strengthens the matrix and helps keep a long-lasting edge. Its 16.00% chromium is above the JSSA's 10.5% minimum for stainless, which the JSSA says strictly means rusts less; wash and dry the knife after use.

A hamaguri-ba edge, written 蛤刃, is a convex edge shape, and it is the shape the workshop 明神利器製作所 sharpens its knives to. Kochi City's craft page records that Myojin Riki learned it over several years of training in Fukui.

The same page says the workshop also takes sharpening-only orders from outside Kochi.

Yes. Kochi City's craft page for his workshop 明神利器製作所 says the work runs from forging through finishing in one continuous process, 鍛造から仕上げまで一貫して行う.

That page lists the workshop in Susaki, Kochi.