What makes Japanese knives like the yanagiba better for cutting sashimi?
A yanagiba's single-bevel edge is ground at an acute 10–15° angle on one face only, with a concave hollow (urasuki) on the flat back that reduces drag and food-sticking. Combined with a one-stroke pulling technique (hiki-giri), this produces a cleaner cut than a symmetrical double-bevel Western knife, which tends to compress and tear delicate fish fibers when pushed or sawed. The result: a smoother, glistening cut surface that better preserves texture and moisture.
From Sword to Sashimi Knife
The story of the Japanese sashimi knife begins nowhere near a kitchen. Sakai's ironworking tradition dates to the 5th century, when blacksmiths gathered in the area to forge tools for the construction of Nintoku-tenno-ryo — at roughly 1,594 feet long, one of the largest burial mounds in the world. By the 12th century, as the samurai class rose to power during the Kamakura period, those same forging families had shifted to making swords.
The pivot to knives came from an unrelated import. In the 16th century, Portuguese traders brought tobacco and firearms to Japan. Sakai's smiths applied their sword-forging technique to a new product: exceptionally sharp knives for chopping tobacco leaves. The blades were sharper than anything else available, and during the Edo period the Tokugawa shogunate granted Sakai a formal quality seal — "Sakai Kiwame," also called Gokuin — along with a nationwide sales monopoly.
The Edo period's long peace did the rest. With demand for swords collapsing, swordsmiths increasingly turned their forges toward household and culinary blades. As Japan's urban food culture matured in cities like Edo and Osaka — and as sushi and sashimi service became genuinely specialized trades — demand grew for knives built for specific tasks rather than one general-purpose blade. The deba emerged in Sakai in the mid-Edo period, purpose-built for heavy fish butchery. The yanagiba developed separately in the Kansai region (Osaka-Kyoto), shaped specifically around the exacting requirements of slicing raw fish for sashimi and nigiri.
The final transition happened in the Meiji era, when the Sword Abolishment Edict banned the carrying of swords by ordinary citizens, ending what little sword demand remained. Generations of swordsmith families pivoted permanently to kitchen knives — carrying with them the full technical vocabulary of swordmaking: laminated construction, differential hardening, water-quenching, and the obsessive edge geometry that a katana required. That lineage is why a modern yanagiba shares construction principles with a 16th-century sword, and why Sakai knives are used today by an estimated 90–98% of professional chefs in Japan.
Why Single-Bevel Cuts Fish Cleaner
Western knives are almost universally double-beveled: sharpened symmetrically on both faces to form a "V." That geometry wedges food apart from both sides as the blade passes through — fine for chopping vegetables or portioning meat, less fine for a material as delicate as raw fish flesh.
A single-bevel Japanese blade works differently. The front face (omote) is ground to a single acute angle, typically 10–15°, forming the entire cutting edge. The back face (ura) stays essentially flat, with one exception: a shallow concave hollow called urasuki. That hollow does real mechanical work — it minimizes the blade's surface contact with the food, cutting drag and stopping the sliced fish from sticking to the steel as the blade passes through.
The mechanism
Push/Saw vs. Single-Stroke Pull
Double-bevel, pushed or sawed
A shorter, thicker Western blade often can't clear a whole fillet in one stroke. The result is a push-cut or a back-and-forth sawing motion, which compresses and crushes the fish's soft fibers — producing a ragged, torn cut surface that releases moisture and looks dull.
Single-bevel, one-stroke pull (hiki-giri)
The heel of the blade is placed at the far edge of the fillet, then drawn toward the body in one continuous motion, tip trailing last. The acute edge and the length of the stroke do the cutting — minimal downward pressure, minimal cellular compression.
Result: a mirror-smooth cut face with an intact cell structure. Fish sliced this way holds its natural moisture and translucency; fish cut with multiple strokes develops microscopic tears that dull its appearance and texture even before it reaches the plate.
The tradeoff is real, not cosmetic: because the edge is sharpened on one side only, a single-bevel knife is handed — ground specifically for a right- or left-handed user — and it requires a sharpening technique distinct from a double-bevel blade. It rewards correct technique and punishes shortcuts more than a forgiving Western chef's knife does.
The Sashimi Cutting Schools
Sashimi knife technique is its own vocabulary, codified over generations of professional training. The same piece of fish tastes and presents meaningfully differently depending on which cut is used — this is a technical decision, not a plating flourish.
Hiki-zukuri (引き造り)
The standard drawn cut
The default sashimi cut: the yanagiba is drawn smoothly from heel to tip in one motion, producing slices roughly 5–8mm thick with a slight angle off perpendicular — the characteristic lozenge cross-section seen in standard nigiri and sashimi.
Usu-zukuri (薄造り)
The thin cut
Used for firm, delicately flavored white fish — flounder, sea bass, fugu — where a thick slice would overwhelm the flavor. Cut at a steep angle into nearly translucent 1–2mm slices, maximizing surface area for seasoning and arranged in overlapping, flower-like presentations.
Kaku-zukuri (角造り)
The square cut
A straight, downward cut reserved for dense, fatty fish like tuna, yellowtail, or swordfish. It produces neat, uniform cubes that emphasize the flesh's density and concentrate flavor in every bite — the opposite instinct from usu-zukuri's thin, delicate slices.
A related variation, ito-zukuri ("thread cut"), produces a fine julienne from squid, cuttlefish, and other fine-textured seafood where delicacy of presentation matters as much as flavor.
The Steel Guide — Material Science
Japanese knife steels split broadly into two families: traditional high-carbon "Hagane" steels (Shirogami and Aogami, produced by Hitachi/Yasugi Specialty Steel), and modern stainless or powder-metallurgy steels (VG-10, SG2/R2). The tradeoffs are consistent across both families: higher carbon and more alloying generally mean higher hardness and longer edge retention, at the cost of being harder to sharpen and, for carbon steels, more reactive to moisture.
Most Western knives sit around 56–58 HRC on the Rockwell hardness scale. Japanese knife steels typically run 60–67+ HRC — one of the reasons they can hold the acute edge angles a single-bevel blade requires.
| Steel | Type | Carbon % | HRC | Edge retention | Corrosion resistance |
|---|---|---|---|---|---|
| Shirogami #1 (White #1) | Carbon | 1.25–1.35% | 64–67 | Good — sharpens fast, refreshed often | None — dries and oils daily |
| Shirogami #2 (White #2) | Carbon | 1.05–1.15% | 62–65 | Good; most popular carbon steel | None |
| Shirogami #3 (White #3) | Carbon | 0.80–0.90% | 60–63 | Moderate; most forgiving/tough | None |
| Aogami #1 (Blue #1) | Carbon + W, Cr | 1.25–1.35% | 64–67 | Excellent | Very low |
| Aogami #2 (Blue #2) | Carbon + W, Cr | 1.05–1.15% | 63–66 | Excellent; most popular blue steel | Very low |
| Aogami Super | Carbon + W, Cr, V | 1.40–1.50% | 65–68 | Best of any carbon steel | Very low |
| VG-10 | Stainless (Cr, Mo, V, Co alloyed) | Not specified by mfr. | 60–62 | Very good; industry standard | High |
| SG2 / R2 | Powder-metallurgy stainless | Highly alloyed | 63–65 | Exceptional; rivals carbon steel | High |
For a yanagiba, Shirogami #1 or #2 is often considered the benchmark — it takes the finest, most refined edge, which matters more on a slicing knife than on almost any other blade in the kitchen. High-volume sushi counters, where stopping mid-shift to resharpen is impractical, often favor Aogami instead. For a deba, toughness matters more than ultimate hardness, since the blade is meant to contact bone — Shirogami #2 or Aogami #2 balance edge quality against chip resistance better than the harder, more brittle Shirogami #1 or extreme-hardness powder steels.
Construction: San Mai, Honyaki & Kasumi
How a blade's steel is assembled matters as much as which steel is used. Three construction terms come up constantly in any serious knife discussion.
San mai — the laminated core
San mai (三枚, "three layers") is a laminated construction that dates back roughly 2,000 years to jacketed-lamination sword techniques in ancient China. A hard steel core (hagane), typically 60–65 HRC, is sandwiched between two layers of softer steel or iron (jigane), typically 40–55 HRC. The hard core supplies the sharp, long-lasting cutting edge; the softer cladding absorbs impact and stress that would otherwise propagate through the blade and cause chipping — and it makes the knife considerably easier to thin and resharpen over its working life than a knife forged from a single piece of hard steel.
Honyaki vs. kasumi
Traditional single-bevel knives fall into two forging categories. Honyaki ("true forge") knives are made from a single piece of high-carbon steel using techniques nearly identical to traditional Japanese swordmaking — differential heat treatment, water-quenching, extensive hand-hammering. The result holds an edge exceptionally well but is hard, brittle, difficult to sharpen, and cannot be mass-produced, which makes honyaki knives expensive, rare, and generally reserved for top-tier professional chefs.
Kasumi ("mist," for the hazy appearance of the soft iron body against the glossy steel edge) knives forge-weld a hard carbon-steel cutting edge to a softer iron body — the same underlying idea as san mai construction. This makes kasumi knives significantly easier to sharpen and less prone to chipping, which is why kasumi is the standard construction for daily professional use, with a premium sub-grade, hongasumi, using higher-quality steel and more refined construction.
Sakai: 600 Years of Division of Labor
What sets Sakai apart isn't just craft history — it's structure. A single Sakai knife passes through three (traditionally four) distinct specialist workshops: a blacksmith forges the blade from iron and carbon steel; a dedicated sharpener refines the edge geometry, a step that in Sakai's tradition includes a fine chisel-work pass unique to the region; and a handle-maker fits a bespoke handle, often magnolia wood, water buffalo horn, or ebony. Historically a fourth company — the wholesaler — attached the handle, engraved the brand, and distributed the finished knife.
This division of labor, unchanged for centuries, is why quality stays consistent across roughly 75 knife-making companies still operating in Sakai. Hand-forged Sakai knives are designated a traditional craft by Japan's Ministry of Economy, Trade and Industry, and the domestic share of professional chefs using Sakai-forged blades is estimated at 90–98%.
How to Choose
The right knife depends on the task, not on chasing the highest HRC number available.
- Slicing sashimi at home or plating for guests: a yanagiba. Its length is what makes the one-stroke pull cut possible — a shorter knife, even a very sharp one, forces you into a push-cut or a saw, which is the exact motion a yanagiba is designed to avoid.
- Breaking down a whole fish — heads, bones, filleting: a deba. Its thickness and weight supply the leverage a thin slicing blade can't, without risking a chip on bone.
- Want the sharpest possible edge and don't mind daily maintenance: Shirogami (white steel). Dry it after every use and oil it before storage — carbon steel rusts within minutes if left wet.
- Want long edge retention for frequent use: Aogami (blue steel) or a powder-metallurgy steel like SG2/R2.
- Want low-maintenance, rust-resistant performance: VG-10 or another quality stainless. It won't take quite as fine an edge as top-tier carbon steel, but it's a legitimate, practical choice — not a compromise to be embarrassed about.
Care, Sharpening & Sashimi DC's Classes
A single-bevel knife is only as good as its edge, and maintaining that edge is a different skill from sharpening a double-bevel Western knife — the flat back (ura) is never ground the same way as the beveled front (omote). Carbon steel blades additionally demand daily discipline: wipe dry immediately after use, wash by hand (never a dishwasher or abrasive scrubber), and apply a thin coat of food-safe oil before any extended storage.
Sashimi DC sharpens knives in-store for customers who purchase fish — ask at the counter. We also run a hands-on Knife Sharpening and Sashimi Slicing Class: bring your own kitchen knife, restore its edge on whetstones alongside Keita, then put it to work slicing sashimi-grade fish while covering muscle structure and how to read the grain. Participants leave with a sharpened knife, a technique they can repeat at home, and fresh-sliced fish to take with them.
Upcoming dates and tickets for the Knife Sharpening and Sashimi Slicing Class are posted at sashimidc.com/events. The same page also lists our sushi-making and negitoro-making classes.
Sources
- Association for the Promotion of Traditional Craft Industries. (n.d.). Sakai Uchihamono (Forged Blades). Traditional Crafts Aoyama Square. https://kougeihin.jp/en/craft/0605/ — Official traditional-crafts overview of Sakai's forging process, division of labor, and 16th-century tobacco-knife origin.
- Axminster Tools. (n.d.). Japanese White & Blue Steels [Technical guide]. https://www.axminstertools.com/blogs/knowledge-hub/japanese-white-and-blue-steels — Explains the metallurgical relationship between White Paper and Blue Paper steel grades and their Western-steel equivalents.
- Chubo Knives. (n.d.). What Is a Deba Knife? Guide to Uses, Care, & Techniques. https://chuboknives.com/blogs/knowledge/deba-knife-guide — Deba anatomy, common steels (Shirogami, Aogami Super, Blue #2), and why carbon steel is preferred over stainless for single-bevel debas.
- Dream of Japan. (n.d.). The History of Japanese Knives: From Samurai to Precision Craftsmanship. https://dreamofjapan.com/blogs/japanese-knife-stories/history-of-japanese-knives — Traces the direct lineage from Kamakura-period swordsmithing through the Meiji Sword Abolishment Edict to the modern kitchen-knife industry.
- Hasu-Seizo. (n.d.). Single Bevel Knives vs Double Bevel Knives. https://hasu-seizo.com/blogs/news/single-bevel-vs-double-bevel-knives — Edge-geometry comparison explaining the chisel-shaped bevel and why single-bevel blades favor precision cuts on fish and produce.
- Hitachi Metals, Ltd. (2006). 高級刃物鋼 [High-Class Cutlery Steels] (Catalog No. HY-B10-D) [Technical catalog]. Special Steel Company. — Manufacturer catalog documenting Shirogami and Aogami chemical composition and heat-treatment hardness ranges. Text source
- Hocho Knife (Japanese Chef Knife) Official Blog. (n.d.). Honyaki and Kasumi Knives — Two Basic Categories of Japanese Wa-Bocho. http://www.hocho-knife.com/honyaki-and-kasumi-knives/ — Primary source distinguishing honyaki (mono-steel) from kasumi (laminated) construction, including the hongasumi premium grade.
- International Journal of Food Studies. Effects of Knife Edge Angle and Speed on Peak Force and Specific Energy When Cutting Vegetables of Diverse Texture. https://www.iufost.org/ijfs — Peer-reviewed study quantifying how edge angle and cutting speed affect force and tissue damage — the mechanical basis for why an acute single-bevel edge cuts with less compression.
- Japanese Knife Lab. (n.d.). Japanese Steel Types Explained: White, Blue, VG-10, SG2 & More. https://japaneseknifelab.com/blogs/guides/japanese-steel-types — Comparative hardness, sharpness, edge-retention, and price ratings across the full range of traditional and modern Japanese knife steels.
- Japanese Knife Lab. (n.d.). Yanagiba Knife: The Japanese Sashimi Knife Guide. https://japaneseknifelab.com/blogs/guides/yanagiba-knife-guide — Detailed yanagiba anatomy (omote, ura, urasuki, shinogi-suji), Edo-period Kansai origin, and hiki-giri technique instructions used as the primary source for the cutting-mechanics section of this guide.
- Jikko Japanese Knives. (n.d.). Single-Bevel vs. Double-Bevel Knives: Which Knife Cuts Better? https://jikko.jp/en/blogs/knowledge/single-bevel-vs-double-bevel — Sakai maker's own hands-on cutting comparison between single- and double-bevel knives across multiple ingredients.
- Kasumi Japan. (n.d.). What Is San Mai Steel? Complete Guide to Structure, Benefits, and Uses. https://kasumijapan.com/blogs/guides/san-mai-steel — Explains san mai's hard-core/soft-cladding structure, typical HRC ranges for each layer, and how to visually identify genuine san mai lamination.
- Lyons, S. (2020). Technological Choice in a Medieval Japanese Sword. Materials Science Forum, 983, 41–46. https://doi.org/10.4028/www.scientific.net/MSF.983.41 — Metallurgical case study of medieval Japanese sword construction, providing the historical materials-science link between swordmaking and later knife steel choices.
- Notis, M. R., et al. (2020). Japanese Sword Studies Using Neutron Bragg-Edge Transmission and Computed Tomography. Quantum Beam Science, 9(4), 33. https://doi.org/10.3390/qubs9040033 — Non-destructive imaging analysis of internal steel structure in Japanese swords, illustrating the layered/laminated construction later inherited by kitchen knives.
- Proterial, Ltd. (n.d.). Shirogami 1, 2, 3 and Aogami 1, 2, Super — Chemical Composition and Heat Treatment Specifications [Technical data sheets]. Yasugi Specialty Steel. — Manufacturer specification sheets for all six Hagane grades, the primary source for the carbon-percentage and hardness figures in the steel comparison table. Text source
- Provenance Technique Library. (n.d.). Japanese Sashimi Knife Technique: The Hiki-Zukuri, Usu-Zukuri, and Kaku-Zukuri Cutting Schools. — Codified reference on the three primary sashimi cutting techniques, their textural and visual effects, and the ito-zukuri variation. Text source
- Sakai City Government. (n.d.). 堺打刃物 [Sakai Forged Blades]. https://www.city.sakai.lg.jp/ — Municipal source on Sakai Uchihamono's designation as a nationally registered traditional craft and regional trademark.
- Sakai Tourism & Convention Bureau. (n.d.). Appeal of World Renowned Sakai Knives. Sakai NAVI. https://www.sakai-tcb.or.jp/en/feature/appeal-of-world-renowned-sakai-knives/ — Regional tourism-board overview of Sakai's 5th-century origins and the 98% professional-chef market share figure cited in this guide.
- SAKAI DENSHOKAN. (n.d.). Knife. https://www.sakaidenshokan.jp/en/craft/knife/ — Sakai heritage museum's account of the tobacco-knife origin story and the "Sakai Kiwame" Tokugawa-era quality seal.
- Toishi.info. (n.d.). 青鋼と白鋼：刃物用に開発された合金鋼 [Blue Steel and White Steel: Alloy Steels Developed for Cutlery]. https://toishi.info/ — Japanese-language technical resource with detailed alloy composition tables for the Shirogami and Aogami steel series.
- Turrell, C. (n.d.). The Japanese City Known for Making Knives That Are a Cut Above. BBC Travel. https://www.bbc.com/travel — Profile of a fifth-generation Sakai knife sharpener, including firsthand detail on the modern division-of-labor production process.
- Yakushi Knives. (n.d.). History of the Yanagiba Knife: From Tradition to Modern Sushi. https://yakushiknives.com/blogs/journal/history-of-the-yanagiba-knife — Regional development history distinguishing the Kansai yanagiba from the related Kanto takobiki, and the knife's role in the maturation of Edo-period sushi culture.