There is a one-sentence test for this. It has been published in English, by a Sakai manufacturing wholesaler, since 2017. I have not found it in any of the English buying guides that rank for the question.
Here it is, in the original wording of Takahashi Kusu, a Sakai maker that produces knives for other brands:
If the edge pattern of a Japanese Knife is very straight, you can regard it as a knife made from Rikizai.
To use that sentence you need to know what rikizai is. Almost no English page will tell you, and there is a documented reason for that which I will come to: a Japanese maker states in public that the trade often chooses not to mention it.
This is the sixth piece in a series about the gap between what Japanese knives are called abroad and what they are called in Japan. The pattern has held every time: the steel grades buyers compare are shop price tiers; the three great regions are not the official list; bunka is not a blade shape; damascus is a catalogue category for pattern stock; the handle is fitted by the wholesaler at the end. This one is different in a useful way. Here the English phrase is not wrong. It is simply too coarse to answer the question buyers are asking with it.
Three Japanese words, one English phrase
Japanese knifemaking has three separate words for three separate things. English has “hand forged” for all of them.
| Japanese | What the step is | Who does it |
|---|---|---|
| 鍛接 tansetsu | Forge welding. Bonding the soft iron body to the hard steel edge at high heat | A blacksmith, or a steel mill with rollers |
| 鍛造 tanzo | Forging. Hammering the bonded billet out into a knife shape | A blacksmith, almost always with a powered hammer |
| 抜き nuki | Punching. Stamping the blade out of sheet with a die | A press |
Tojiro, in Tsubame-Sanjo, publishes both of the first two as separate stages with separate temperatures. Forge welding: the soft iron and the steel are brought together with boric acid acting as the glue, heated in the furnace to around 1,200°C until red, then hammered together. Forging: that bonded lump goes back into the furnace at 800 to 900°C and is hammered out into the shape of a knife, over and over.
Read those two definitions again and the problem with the English phrase becomes obvious. A knife can be genuinely forged and never forge welded. Nothing about the word “forged” tells you who bonded the layers, or whether anyone did.
The layers were bonded at a rolling mill, and the material has a name
Here is the Tojiro description of that material:
「利器材」は材料メーカーでハガネと異種材を熱間圧延や冷間圧延により接合したもので、鍛接を行わなくても刃物を仕上げることが出来て
Rikizai is material in which a steel maker has bonded the hard steel to a dissimilar metal by hot or cold rolling, so that a knife can be finished without doing any forge welding at all.
Tojiro then names its own lines that use it: professional western knives and stainless wa knives are made from rikizai. It is not an accusation from outside. It is a manufacturer describing its own catalogue.
Then comes the sentence that explains why you have never heard the word:
当初は「利器材」が安物の包丁に多く使用されたことから、「利器材」について良いイメージを持たないユーザーが多くなり、包丁を製造する側からも「利器材」であることをあえて表現しないことも多くなっています
Because rikizai was heavily used in cheap knives at first, many users came to hold a poor impression of it, and so knife makers themselves have often come to deliberately avoid stating that a knife is rikizai.
A Japanese knife manufacturer states in public that the industry frequently chooses not to disclose this. That single sentence explains the entire English-language vocabulary gap. The word is missing abroad because it is quietly missing at home too.
Takahashi Kusu, writing in English for foreign buyers, is blunter about the scale of it:
most double-edged knives made in Sakai are made from “Rikizai” now
And separately: in terms of single-bevel knives, most stainless ones are rikizai too. The reason it gives is practical rather than cynical. Forge welding stainless is quite difficult for blacksmiths, some pieces do not bond properly even when they try, and so it does not repay the work and the time.
Both of those are Sakai and Tsubame-Sanjo sources describing the material most of what you are shopping for is made from. Neither is a critic. One of them is a wholesaler that would benefit from you believing otherwise.
The two sides disagree in public, which is the useful part
I want to be careful not to turn rikizai into a scandal, because the Japanese trade does not treat it as one. It argues about it openly, and you want both arguments in front of you.
Tojiro defends rikizai and names the criticism directly:
一部の包丁製造の現場からは、「利器材」を製造する上での圧延時の熱加工が刃物の性能を下げるなどの、解説をされている場合がありますが、これは間違いです
Some in knife manufacturing explain that the heat working during rolling lowers the performance of the blade. This is wrong.
Its argument is consistency. Forge welding also needs high heat, and the result varies with the season, the conditions and the skill of the individual smith. A steel maker controls temperature precisely, so every piece of rikizai comes out the same, with no unit-to-unit variation and no bad ones. Tojiro also makes an economic argument that I think is the honest core of it: rather than asking a customer to pay for something that depends on the luck of one smith on one day, put the money into a stage where it reliably buys something.
Takahashi Kusu argues the other way, and it is the maker of both that says it:
“Sanmaiuchi” knives are much sharper because the number of hammering material to make “Sanmaiuchi” is much larger
Sanmaiuchi is the hand forge welded three-layer construction. The same page concedes that rikizai is rational from a cost-effectiveness point of view and that material makers have improved it steadily through trial and error, and then says that because Sakai is a historical production area it ought to cherish and improve the forge welding skill anyway.
Two Japanese houses disagree about the merits, in public, in writing, and each one tells you which method it uses. The English listing tells you neither. That is the actual failure here, and it is not a failure of manufacturing.
Why the straight line works
Now the test makes sense. Rikizai is bonded by rollers, so the boundary between the soft body and the hard steel runs as straight as the mill that made it. Forge welded by hand, that boundary wanders, because a person put the steel on the iron and beat it out.
And Japanese knives are deliberately finished to show you that boundary. Look at what the sixth sharpening stage of the official Sakai process actually is:
砥石の粉をねって泥状になったものをゴム片につけて切刃の部分をこする。これにより軟鉄の部分がくもり、刃金部分は、さらにつやが出て刃紋がくっきり浮き出る
Whetstone powder is worked into a paste, applied on a piece of rubber and rubbed over the bevel. The soft iron clouds over, the hard steel takes on more gloss, and the hamon, the boundary line, stands out sharply.
That is the kasumi finish I wrote about in the first piece in this series. It is a required element of the national designation for Sakai. The trade goes to a specific extra step to make the line visible, and the line is the tell.
Three limits, because a test you cannot break is a test you should not trust:
- It does not work on a damascus blade. A patterned cladding hides the boundary entirely, which is one more reason the layer count on those listings tells you so little.
- It does not work on a mirror-polished western-style knife, where the whole flat is buffed to one finish.
- It does not work on honyaki, which is one single steel throughout and therefore has no boundary to look at.
And a straight line is evidence, not proof. What it earns you is the right to ask a specific question instead of a vague one.
The national designation says hammer, not hand
This is the part I found hardest to believe until I read the text.
Japan has one place where “what counts as a forged blade” is written down as law rather than as marketing: the traditional craft designations administered under the national scheme, the same system I used to establish the official list of knife regions. Here is requirement one for Sakai forged blades, in full:
包丁及び鋏の穂の成形は、刃物鋼を炉で熱し、鎚打ちによる打ち延ばし及び打ち広げをすることにより行うこと
Forming of the blade body shall be carried out by heating the blade steel in a furnace and drawing it out and spreading it by hammer blows.
Echizen carries the same wording, with the two-piece stacking method added.
Nowhere does it say by hand. It says heated in a furnace and hammered. And the industry publishes exactly which hammers, on its own websites, in Japanese, for anyone to read:
- The Sakai Cutlery Commercial and Industrial Association describes stage two of the smithing process as shaping the heated material while striking it with a 動力ハンマー, a power hammer, and stage five, the rough beating, with a power hammer again. Stage nine notes that machine tempering with controlled temperature at 160 to 180°C has become widespread.
- Tojiro writes that the smith works without a die, using a 機械式のスプリングハンマー, a mechanical spring hammer, and a hand hammer, switching between them as needed.
- Masahiro in Seki describes heating the steel and working it with a ハンマープレス機, a hammer press.
So the knives that carry the national traditional designation, made in the town that is the reason the word Sakai means anything to you, are shaped with a power hammer. If “hand forged” meant a human arm swinging a hammer, the most traditional knives in Japan would fail the test.
There is a reason for this that has nothing to do with cutting corners. Both Tojiro and Masahiro state that the point of forging is not the shape. Tojiro: beyond making the form, forging has the important role of conditioning the material, which binds it densely so it finishes harder and more supple. Masahiro is even more direct, saying the purpose of forging is less about changing the shape than about working the metal into a good grain structure. A power hammer delivers consistent blows for as long as the piece is hot. A human arm gets tired. The machine is not a substitute for the craft here. It is the better tool for the specific metallurgical job.
What the law does reserve for human hands
The same designation, the same document, requirement five, identical in Sakai and Echizen:
「刃付け」、「研ぎ」及び「仕上げ」は、手作業によること
Edge-setting, sharpening and finishing shall be done by hand.
That is the one place the state puts a person in the loop. And it is not a small carve-out. The official Sakai process description lists what sits inside that single requirement, one named step after another: rough grinding, flat grinding, distortion correction, flat polishing, chisel work, main grinding, edge drawing, back grinding, back buffing, edge grinding, buff finishing, colour raising, wood-wheel work, shinogi lining, the kasumi blurring, back pressing, final edge matching, water wiping, oil wiping, distortion correction, finished. The page closes the list with a count:
以上27行程の研ぎの作業により、切れ味の良い包丁に仕上がります
By the above 27 stages of sharpening work, the knife is finished with a good edge.
Twenty-seven. The forging side of the same document runs to ten.
Then the fact that settles the argument, and it comes from the press-punched side of the business. This is Tojiro describing stage eleven of its mass-produced, die-cut, machine-made line:
最新技術の導入に積極的な私たち藤次郎株式会社でも、自動機械などは全く使用せず、全て職人の手作業にこだわっています
Even at Tojiro, a company that actively adopts the latest technology, we use no automatic machinery whatsoever here, and insist on doing all of it by the hands of craftspeople.
On the knives that buyers are warned away from as machine made, the sharpening is one hundred per cent hand work with no automation at all. The company says so about its own budget line.
And on the same page, describing the grinding stage:
包丁の値段に影響する工程の一つで、高い包丁ほどこの工程が非常に多くなります
This is one of the stages that affects the price of a knife, and the more expensive the knife, the far greater the number of these stages.
The maker is telling you where the money goes. It goes into grinding passes. Buyers are shopping for the hammer.
One honest correction to my own point
Hand work does not mean unpowered. The Sakai sharpening description involves rotating grinding wheels, buffing wheels and grinders throughout. The craft profile of Ichiro Morimoto, a designated master craftsman in knife sharpening, describes five powered grinding machines in his workshop with wheels over 90cm across.
So requirement five is not a rule against electricity. It is a rule that every pass is set up, judged and corrected by a person rather than run through a program. That reading cuts against a romantic picture of the sharpener as much as it cuts against the romantic picture of the smith, and it is the reading the documents support.
Punched blades are not what you think either
While we are dismantling things, the bottom of the range deserves accuracy too.
Tojiro states plainly that the punched-blade method exists because rikizai exists: improvements in modern material production gave rise to rikizai, and rikizai made mass production possible. Sheet material comes in, a die punches out the profile. Its published sequence runs to twelve stages: press, roller straightening, hardening, tempering at 180 to 200°C for an hour and a half to two hours, grinding, bolster welding, polishing, washing, marking, handle fitting, sharpening by hand, inspection.
The same forged-blade specialist writes this about its own punched line:
近年では材料の性質も格段に上がり、包丁の性能としても打ち刃物と遜色の無い、切れ味に優れる包丁の製造が可能になっています
In recent years the properties of the materials have improved dramatically, and it has become possible to make knives with excellent sharpness that are in no way inferior in performance to forged blades.
One detail from that list is worth pulling out, because it closes a loop from the first piece in this series. Stage nine is marking: the name goes onto the blade by press stamp, by electrochemical etching, by silk-screened ink, by hand chisel, or now by computer-controlled laser. The name on the blade is applied near the end of the process, by whichever method the line uses. It is a label, not a signature, exactly as the wholesaler process showed. A Sakai wholesaler will in fact piece on blade shapes that the cutting board is what should decide your blade length. It turns out the cutting board is also the one of the two that has to tell you what it is made of.
Three questions to send a shop
This is what I would send instead of asking whether a knife is hand forged. Copy the Japanese if the shop is in Japan. Any real knife shop can answer all three in one line each.
- 鍛接ですか、利器材ですか — Was the steel forge welded by a smith, or is it rikizai? A shop that answers “rikizai” immediately and without embarrassment is a shop that knows its stock and is not hiding it. That answer should raise your confidence, not lower it.
- 刃付けは誰がしましたか。手研ぎですか — Who did the edge work, and was it hand sharpened? This is the only stage the national designation reserves for a person, and the maker of the cheapest knives on the shelf says it is where the price lives.
- 打刃物ですか、抜きですか — Was the shape hammered out, or punched from sheet?
“Hand forged” answers none of the three. That is not a translation problem. There is no English sentence of that length that can carry three answers.
And before you write to anyone, look at the picture. If the boundary line between the cloudy body and the bright steel is dead straight along the whole blade, you already have the answer to question one.
What I would buy
Top pick: a rikizai three-layer stainless santoku at 170 to 180mm. On the shelf I am partnered with, that is the Sakai Takayuki INOX PRO Santoku 180mm at $108.99. I want to be explicit, because the whole article has been building to it: this is a rikizai knife and I am recommending it on purpose. It is the construction Tojiro says gives no unit-to-unit variation, in the size the Echizen catalogue overwhelmingly uses for home kitchens, at a price where the money went into grinding rather than into a story. The other standard answer at this size is the Tojiro DP three-layer, which I earn nothing from, and which is made by the company whose published documents are the backbone of this article.
If you are spending $300 or more, buy a person rather than a process. Takeshi Saji gyuto knives at 210mm start at about $417.99. Saji is a designated master craftsman in Echizen, which is the one credential in this whole trade that attaches to an individual, is examined, and expires unless renewed. That is what the regions piece established as the only verified thing you can buy.
Now the part a seller would leave out. Those Saji knives are VG10 and R2 damascus, which means they are rikizai. The certification covers forging and finishing, not rolling. Being a designated master craftsman and working from mill-bonded material is not a contradiction, and anyone who tells you it is has not read the requirements. You are paying for the hands at the forging and the sharpening, which is exactly what the designation says those hands are certified for.
If what you actually want is the hand forge welded thing, it is expensive and nobody should pretend otherwise. The Hinoura Ajikataya white steel no. 2 kurouchi tsuchime gyuto 210mm is $1,599.99. That is more than fourteen times the top pick. What you get for it, in the words of a Sakai maker rather than mine, is a blade that took far more hammering and is sharper for it, in carbon steel that will rust if you let it, which is full affiliate disclosure is here.
Sources used here, all free and all checkable: Tojiro for the forged, rikizai and punched-blade process pages; Takahashi Kusu for the rikizai explanation and the straight-line test, which it publishes in English; the Sakai Cutlery Commercial and Industrial Association for the smithing and sharpening stages; the national traditional craft records for the Sakai and Echizen designation requirements and the 27-stage sharpening list; Masahiro for the forging purpose; and the Consumer Affairs Agency schedules for what a cutting board must declare and a knife need not.