Japanese Knife Specs Decoded: What the Words Actually Mean

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Updated August 2026 · 10 min read · UK Japanese-steel knife specialists

You have found a knife you like, you scroll down to the specification, and it reads something like this: VG10 core, 67-layer Damascus cladding, 60±2 HRC, double bevel, 15° edge, full tang, pakkawood handle, saya included. Nine terms, and no obvious way to tell which of them should change your mind and which are there to look impressive.

This page is the decoder. It walks a typical spec list in buying order — steel, then hardness, then the edge, then the handle, then the blade-shape name, then the extras — and says plainly what each word means, what it buys you, and what it costs you. Where a term genuinely deserves a full article of its own, you get one honest paragraph here and a link to the deep dive rather than a rehash.

Every worked example below is a real listing from our own range with its real price, so you can see how the jargon reads on something you could actually buy. If you are right at the start of the process, our beginner's guide to buying Japanese chefs knives is the better first stop — come back here when you have two listings open side by side and need to break the tie.

The four specs that actually change your decision

Spec lists are written by marketing departments, so they mix the load-bearing facts in with the decorative ones and give them equal weight. Here is the honest split.

Nothing in the right-hand column is a lie. It just will not tell you whether the knife suits your hands, your board or your washing-up habits.

What "Japanese" actually refers to on a spec sheet

This is the single most misread word in the category, so let us be blunt about it.

On most listings — ours included — "Japanese" is describing the steel specification and the blade geometry, not the country the knife was assembled in. VG10 and AUS-10 are Japanese steel formulas developed by Japanese steelmakers, and a santoku or nakiri is a Japanese blade shape. That is what the word is doing there.

It is not a country-of-origin claim. Our knives are Japanese-steel knives: made to Japanese steel specifications and Japanese blade patterns, but not forged in Japan. We say "Japanese-steel" rather than the shorter phrase for exactly that reason, and we would rather you heard it from us than worked it out after the parcel arrived.

So: if made in Japan is important to you, do not accept the word "Japanese" next to a steel name as proof. Look for an explicit country-of-manufacture statement, or ask the seller directly. A shop that cannot answer that question in one sentence is telling you something.

Steel — the one spec worth reading twice

The steel at the cutting edge sets the ceiling for everything else: how sharp the knife can get, how long it stays there, how easily you can bring it back, and how forgiving it is about being left wet.

The grades you will actually meet

Grade	Roughly	What that means for you
VG10	~1% carbon, ~15% chromium, plus molybdenum, vanadium and cobalt	The default premium kitchen stainless. Takes a very keen edge and holds it well; typically hardened to about 60–61 HRC.
AUS-10	~0.95–1.1% carbon, ~13–14.5% chromium	Very close in practice. A touch softer and tougher, generally a little easier to re-sharpen, usually a little cheaper.
440C	High-carbon martensitic stainless	A long-proven Western cutlery grade that heat-treats to roughly 58–60 HRC. Not exotic, and not a warning sign — it is what sensible entry-level knives are made of.
"High-carbon stainless"	Not a grade at all	An umbrella phrase. If a listing uses it without naming an actual grade, treat the steel as unknown.

The gap between VG10 and AUS-10 is real but small, and it is smaller than the gap between a sharp knife and a blunt one. If you want the detail, we have written it up in full in our VG10 steel guide and a head-to-head on VG10 vs AUS-10.

Stainless vs carbon steel

Occasionally you will see a knife described as carbon steel or by a Japanese name like shirogami or aogami. That means non-stainless: it takes a fabulous edge and sharpens beautifully, and it will develop a patina and can rust if you leave it wet on the draining board. It is a knife for someone who enjoys the ritual. Everything we sell is stainless, because most UK home kitchens are not run that way.

"Core", "cladding" and the 67 layers

Most patterned Japanese-style blades are laminated, not solid. A hard steel core — the VG10 or AUS-10 — runs down the middle and forms the actual cutting edge. Softer stainless cladding is forge-welded to each side to support it and shrug off corrosion. The traditional three-layer version of this is called san mai.

"67 layers" is simply that sandwich with a many-layered cladding: the usual arithmetic is 33 layers of alternating stainless on each side of one core layer. Our Riku Damascus VG10 Knife is a clean worked example — VG10 core, 67 layers of high-carbon stainless cladding either side of it.

Here is the part the marketing rarely spells out: the layers are not doing the cutting. Only the core touches your onion. Going from 33 layers to 67 to 108 changes how the blade looks, not how it slices. Where cladding does earn its keep is protection — it wraps the hard, less stain-resistant core in something friendlier.

And "Damascus"?

Modern Damascus is pattern-welded steel: layers of two contrasting alloys forge-welded together, then acid-etched so the alloys darken at different rates and the pattern appears. The original Damascus — properly wootz, a crucible steel from India and the Middle East — has not been produced commercially for centuries, and nobody is making kitchen knives from it today. That is not a scandal, it is just what the word means now. A "feather" pattern and a "raindrop" pattern with the same core steel will cut identically. Full explanation in what is Damascus steel, and a straight comparison in Damascus vs stainless steel.

HRC — what the hardness number buys you

HRC is the Rockwell C hardness scale. Kitchen knives sit in a narrow band, so small differences carry more weight than they look like they should: a typical mass-market European knife lands around 55–58 HRC, and Japanese-steel kitchen knives usually land around 58–61.

Read it as a trade, not a score:

• Harder (60–61) — takes a finer edge and keeps it for longer. In exchange it is more brittle, so it chips if you twist it through a squash or hit a bone, and it takes more work on a stone to bring back.
• Softer (56–58) — rolls rather than chips, forgives clumsiness, and comes back to sharp quickly. It just will not stay screamingly sharp as long.

When you see 60±2 HRC, the ± is a manufacturing tolerance, not a menu — it is the maker telling you what the batch can vary by. Our Minato series and our entry-level Haru set are both specified at 60±2 HRC, from completely different steels and at completely different prices, which tells you how much of the story hardness alone is.

If a listing does not state HRC at all, that is worth noticing but is not automatically a red flag — plenty of good knives simply do not publish it. The full explainer lives in what is the Rockwell hardness scale.

Bevels and angles — and why left-handers should read this bit

The bevel is the ground wedge that forms the cutting edge.

Double bevel means ground on both sides, like a V. It steers straight, works identically in either hand, and is what almost every everyday knife is — santoku, gyuto, nakiri, petty. Single bevel means ground on one side only, with the other side flat or slightly hollowed. Traditional single-bevel knives — the yanagiba, usuba and deba — are specialist tools, and this is the crucial part: they are made handed. A standard single-bevel knife is ground for a right-handed user, and in a left hand it steers away from the cut and leaves a ragged face. Left-handed versions exist, but they are made to order and cost more.

If you are left-handed, that one distinction answers most of the question: every knife in our range is double bevel, so handedness simply is not a factor.

The angle is how acute that wedge is, quoted per side. Japanese-style double bevels are commonly ground to around 15° per side, against roughly 20° on a classic Western knife. Fewer degrees means a thinner, keener edge that parts food with less force — and a slightly more fragile one. It also means you need to hold that same angle when you sharpen: our guide to the correct Japanese knife sharpening angle covers how to find and keep it.

Two related words worth knowing. Blade thickness at the spine — usually quoted in mm, 2.0–2.5mm on most of our knives — tells you how much the blade has to shove aside as it descends; thinner wedges less. And full flat grind or convex grind describe how the blade tapers from spine to edge, which matters mainly for whether food releases or sticks.

For where the spine, choil, heel and bolster actually are on a blade, we have a dedicated page: the anatomy of a chef knife.

Handle words — wa, yo, pakkawood, G-10, full tang

The handle is the spec that most changes how a knife feels, and the one buyers most often ignore because it does not sound technical.

• Wa handle — the Japanese style. No bolster, no visible rivets, usually octagonal, D-shaped or oval, fitted onto a narrower partial tang. Lighter, which shifts the balance forward towards the blade. Favoured for precision work and a pinch grip.
• Yo handle — the Western style. Bolster, rivets, a contoured full tang, heavier, balance sitting further back in the hand. More familiar if you have only ever used European knives.
• Full tang — the steel runs the whole length and width of the handle, sandwiched between two scales and pinned. It adds rear weight and durability. A partial or hidden tang is not a defect, though: traditional wa handles are built that way on purpose, and can be replaced when they wear.
• Pakkawood — hardwood veneers impregnated with resin under heat and pressure, roughly seventy per cent wood to thirty per cent resin. It looks and feels like wood but will not swell, warp or split the way untreated timber does in a wet kitchen. Detail in what is pakkawood.
• Stabilised wood and resin — real wood, often burl, infused with resin and set solid. The Aiko series uses exactly this, which is why no two handles are quite identical.
• G-10 / Garolite — a fibreglass-and-epoxy laminate, as used on the Riku. Grippier than wood when wet, effectively waterproof, and close to indestructible. Less warm to look at.
• Ebony and rosewood — genuine dense hardwoods, sealed. Beautiful, and the one handle family that genuinely benefits from being kept out of the sink and re-oiled occasionally.

None of these makes a knife cut better. They decide whether it stays comfortable at minute twenty of prep, and whether it still looks good in five years. Fuller treatment in Japanese knife handles explained.

Blade-shape names, one line each

Product titles use these names as if everyone knows them. Here is the one-line version of each, with a link if you want the full profile.

• Santoku — "three virtues" (meat, fish, vegetables). Around 165–180mm with a flat profile and a dropped tip; suits push-and-slice cutting and smaller hands.
• Gyuto — the Japanese take on the chef's knife, usually 200–240mm with more belly curve. The right default if you rock-chop or cook in volume.
• Nakiri — straight, rectangular vegetable knife. The edge meets the board along its whole length, so nothing stays joined at the end of the cut.
• Kiritsuke — long blade with a dramatic angled tip; a slicer-and-chef's-knife hybrid. Looks the part, demands better knife skills than a gyuto.
• Petty / utility — roughly 90–150mm. Bigger than a paring knife, smaller than a chef's; the one you reach for without thinking, for shallots, herbs and citrus.
• Deba — thick, heavy, single-bevel fish-butchery knife. Built for taking a whole fish apart, not for daily prep, and not something to buy as a first knife.

If you only ever own one, it is a santoku or a gyuto, and the choice between them is genuinely down to grip and cutting style — we settle it in santoku vs gyuto, with sizing advice in what size chef knife to buy first. For the wider family, see our guide to the types of Japanese kitchen knives.

The extras — saya, tsuchime, dimples, racks and blocks

• Saya — a wooden sheath, the same word used for a sword scabbard. Genuinely useful if the knife lives in a drawer or travels; irrelevant if it lives on a magnetic rack. Our Haruta 10-piece set ships with one per knife.
• Tsuchime — the hammered dimpling you see on the cladding. It breaks up the flat face of the blade so wet slices release instead of clinging, and it looks handsome. It is a finish, not a grind, and it does not touch the edge.
• Granton edge / kullenschliff — the row of oval scallops on some blades, doing the same anti-stick job by trapping air. Worth having only if they sit close to the edge; high up the blade they are decoration.
• Magnetic rack vs knife block — a rack keeps edges apart and dries them; a block is tidier and hides the blades. Both beat a drawer. We compare them properly in knife rack vs knife block and cover the alternatives in three methods for Japanese knife storage. If you want the simple answer, a magnetic wooden wall rack from £39.99 does the job.
• Nitrogen-cooled / cryo-treated — a sub-zero step after hardening that helps the steel finish transforming. It is a real process and a sign of a proper heat treatment, but it is standard practice at this level rather than a reason to pick one knife over another.

The spec list, translated

Keep this open next to the listing you are reading.

What the listing says	What it means	Changes how it cuts?
VG10 core	Japanese stainless formula forming the hard cutting layer down the middle of the blade	Yes
AUS-10	Similar Japanese stainless, marginally softer and tougher, usually cheaper	Yes
440C	High-carbon stainless, hardens to roughly 58–60 HRC; the sensible entry-level choice	Yes
"High-carbon stainless"	An umbrella phrase, not a grade — look for the grade name beside it	Only if a grade is named
67-layer Damascus cladding	33 stainless layers each side of the core, acid-etched to reveal the pattern	No — looks and corrosion protection
Feather / raindrop pattern	The shape of the etched pattern in the cladding	No
60±2 HRC	Rockwell hardness with the batch tolerance; higher holds longer but chips more easily	Yes
Double bevel	Ground on both sides; works the same in either hand	Yes
15° edge	The angle of each side of the edge — keener than a 20° Western edge, a little more delicate	Yes
Blade thickness 2.5mm	Thickness at the spine — thinner blades wedge less through dense veg	Yes
Full tang	Steel runs the full length and width of the handle, usually riveted	Balance and durability
Wa / octagonal handle	Japanese-style handle: no bolster, lighter, blade-forward balance	How it feels, yes
Pakkawood / G-10	Resin-impregnated wood, or fibreglass laminate — both water-resistant and stable	No — durability and grip
Tsuchime / hammered	Dimpled finish on the cladding that helps wet slices release	Marginally
Saya included	A wooden sheath for storage and transport	No

Four real spec lists, decoded

These are not a "best of" list — they are four knives from our own Damascus range chosen because their spec sheets read very differently from one another. Read them as worked examples of everything above. Prices and ratings are live as at August 2026.

Range	Core steel	Stated hardness	Handle	From
Riku — best value	VG10, 67-layer cladding	Not stated	G-10 Garolite	£49.99
Aiko Black	VG10, 67-layer cladding	Not stated	Stabilised burl wood and resin	£64.99
Haru	440C, solid	60±2 HRC	Ebony	£29.99
Minato	AUS-10, three-layer	60±2 HRC	Rosewood, acacia block included	£379.99
Haruta 10-piece	VG10, 67-layer cladding	Not stated	Wood, with saya per knife	£499.99

Worth saying plainly: three of those five listings do not publish an HRC figure, including two of our own premium lines. We would rather show you that in a table than quietly leave the column out. [OWNER INPUT: if we have tested or supplier-certified HRC figures for the Aiko, Riku and Haruta lines, send them over and we will publish them here.]

The specs that are mostly marketing

We sell these knives, so treat this section as us marking our own homework in public.

• Layer count. 67 sounds better than 33 and costs more to make, but the core steel does the cutting. If two knives share a core and differ only in layers, buy the cheaper one.
• Pattern names. Feather, raindrop, twist — etched cosmetics. Choose the one you like looking at.
• "Professional", "chef-grade", "restaurant quality". No standard sits behind any of these words.
• "Hand-forged", "hand-polished". Almost always describes one finishing stage in an otherwise machine process. It is not dishonest, it is just not the whole story.
• Bonus honing steels and gift boxes. Nice, but a honing rod realigns an edge rather than sharpening it — you will still want a stone eventually.
• "Lifetime warranty". Only as good as what it excludes. Chipping from bones and frozen food is normally excluded, and that is what actually breaks knives.

And the honest counterpart: the spec that changes your life with a knife is not on the listing at all. It is whether you sharpen it. A £29.99 set kept sharp will out-cut a £400 set that has never seen a stone. If you buy nothing else alongside your knife, buy a stone — our Whetstone Sharpening Stones 400/1000 3000/8000 are £59.99 and rated 4.87 from 119 reviews, and what grade of whetstone should I buy explains which grits you need.

New to stones? Start with how to sharpen a knife using a whetstone, then keep the rest right with our complete Japanese knife care guide.

Frequently asked questions

What does "67-layer Damascus" actually mean?

It means the blade is laminated: a single hard core steel down the middle, with 33 alternating layers of softer stainless forge-welded onto each side, then acid-etched so the pattern shows. Only the core forms the cutting edge, so the layer count affects how the knife looks and how well the core is protected from corrosion, not how it cuts.

Is VG10 better than AUS-10?

Slightly, on paper. VG10 carries a little more chromium plus vanadium and cobalt, and is usually hardened a point or so higher, so it holds a fine edge marginally longer. AUS-10 is a touch tougher and generally easier to bring back on a stone. For home cooking the difference between the two is much smaller than the difference between a sharp knife and a blunt one.

What HRC should I look for in a kitchen knife?

Around 58 to 61 HRC suits most home kitchens. Towards 61 you get longer edge retention but a more brittle edge that chips if you twist it or hit a bone. Towards 58 the edge rolls instead of chipping and comes back quickly on a stone. A figure written as 60±2 HRC is a manufacturing tolerance for the batch, not a choice you are being offered.

Do these knives work if I am left-handed?

Yes. Every knife we sell is double bevel, meaning it is ground on both sides and behaves identically in either hand. The handedness problem only arises with traditional single-bevel knives such as the yanagiba, usuba and deba, which are ground for right-handed users unless a left-handed version is specifically ordered.

Does "Japanese steel" mean the knife was made in Japan?

No. It describes the steel specification. VG10 and AUS-10 are Japanese steel formulas, and santoku, gyuto and nakiri are Japanese blade shapes, but neither tells you where a knife was manufactured. Our knives are Japanese-steel knives made to those specifications and patterns; they are not made in Japan. If country of manufacture matters to you, look for an explicit statement rather than the word Japanese beside a steel name.

What does "full tang" mean, and does it matter?

A full tang is a blade whose steel runs the entire length and width of the handle, sandwiched between two scales and usually pinned with visible rivets. It adds weight at the rear, which shifts the balance back towards your hand, and it is very durable. A partial or hidden tang is not a fault: traditional Japanese wa handles are built that way deliberately, which keeps the knife light and blade-forward and lets the handle be replaced later.

Do I need a saya, or is a magnetic rack enough?

One or the other, not both. A saya is a wooden sheath that protects the edge in a drawer or in transit, so it earns its place if your knives live in a drawer or travel with you. If they hang on a magnetic rack or sit in a block, the edges are already protected and drying properly, and a saya adds nothing. The thing to avoid is loose knives rattling around a drawer with no protection at all.

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