Hamaguri and Me: The Ashi Hamono Effect —by Josh Donald

Ashi Hamono knives were among the first Japanese knives we imported directly back in 2011, when Bernal Cutlery operated out of a tiny corner of a shared small-business incubator space at 331 Cortland Ave in Bernal Heights. 

We initially got very small orders for the 90 sq ft shop, and it took years for the word to get out that these were indeed amazing knives. Back in 2011–12, cooks would mostly ask for well-known brands sold by a certain well-known New York knife shop. I got these knives in to sharpen regularly, and they were good, no doubt, but the Ashi knives were really something else. Some thought they were too light. Some just didn’t trust my word. Hey, salesmen with superlatives are everywhere. Nonetheless, Ashi’s reputation did take off here in the Bay Area, once enough cooks bought them and brought them into work. Once there, they got picked up by co-workers (hopefully only by invitation), and then it was on. Since those days, it has been harder for us to keep them in stock, and, unfortunately, a little harder for us to get in at all.

Hand-ground thin, and convex on the face, Ashi knives reminded me of the convex grind of some very lightly used fine vintage Western knives that I had come across, but cutting with an Ashi was a revelation; they just moved so effortlessly through food. This experience became my north star of what the Japanese refer to as kireage, best translated as “cutting feel”.

While the heat treatment on Ashi knives is really good, from my perspective, the real magic happens in the grinding: a thin “hamaguri” (clam-shell-shaped) convex geometry. This is not a new formula at all, but getting to experience it through the Ashi knives unlocked this understanding for me personally. Cooking with them for years and getting observations from cooks who had them in regular rotation helped me understand the importance of grind geometry in action. Once I had the opportunity to visit Sakai and see the grinding done in person with their kaiten mizu toishi literally "wheel water stone"—a large-scale Japanese grinding machine with an enormous stone wheel grinders, I had a better sense of what was involved in the convex-ground “hamaguri” geometry.

On later visits to Sakai, after bringing my more than slightly sharpened down 240 mm Ashi gyuto in to re-grind on the kaiten, I had the chance to start to understand how to use the big water-cooled “kaiten” grinding wheel that these are shaped on. While my Japanese is useless, the opportunity to grind alongside Ashi, with a small amount of translated instruction and observation, was invaluable. Before too long, after a certain amount of shadowing, the next best step was given: “go practice now”. It’s less of a ‘get out of my hair,’ and more of a “go to it”. 

Once my own kaiten wheel was set up a few years later, I really did “go to it”. I got to work with it, first refurbishing vintage Western hand-ground knives and then sharpening Japanese knives that came to our sharpening service. I started to get a feel for grinding, where the work was happening under the blade, and how it would get shaped with a certain amount of wobble. Once I started grinding our first house-made knives, the Greenfield Gyuto, and later the Fineline, I found my grinding referenced Ashi, though I wasn’t trying to duplicate it. I came in a little thinner here or a little thicker there, and the blade outline I chose was a little different, but always my reference when testing the knives was the first time I cut with an Ashi.

See knives from Ashi Hamono here.
See Elias Sideris machining the moving parts of our kaiten on IG here or on YouTube here or below.