Sinosword (Jkoo) T10 Dotanuki Katana (powerful cutter)

Review: Jkoo/Sinosword 29 1/4” T10 Sughua Dotanuki Katana


Above: Jkoo (Sinosword) Dotanuki Katana (a regular sized katana made extra powerful (and so extra heavy))


More pictures: Jkoo/Sinosword 29 1/4” T10 Sughua Dotanuki Katana 


Above: The Jkoo/Sinosword Dotanuki katana arrived in this tape-wrapped, styrafoam box




Above: This "off-the-shelf" Jkoo katana arrived plastic shrink-wrapped.




Above: Saya, kojiri end (shows shipping shrink wrap)



 Above: Shrink-wrapped Jkoo tsuka



Above: Jkoo Dotanuki katana in sword bag, in shipping box (sword bag is thick black cotton)



Above: Jkoo Dotanuki katana, heavier than the norm.  More powerful than the norm.  Sword bag is heavy cotton...seems quite strong with good feel to it.

Jkoo is the sword company. www.sinosword.com is its web site. Van Yang is the representative.  He does a good job of representing Jkoo/Sinosword and is also part owner of the Jkoo forge.  Jkoo makes and sells swords ranging from simple, budget backyard cutters, to their best efforts at recreating tamahagane or even fancier blades. Prices range from $99 to about $1,000 (plus shipping which for me here in California runs about $51). Their packing and shipping work has seen my seven Jkoo swords, ordered at various times and seasons, arrive just fine. Except for one katana order which arrived with about a ¼” spot of rust on the tip of the kissaki. I contacted Jkoo’s point of contact, Mr. Van Yang, about it, asking that swords have more oil/grease on the kissaki. And this latest sword seems like I was listened to.

This Jkoo (Sinosword) is a 29 ¼ inch, forged T10 mono steel, differentially hardened (sughua hamon) katana called a “dotanuki”. Jkoo is not the only sword maker/seller that offers a dotanuki model. Huawei, another Longquan sword seller I like, offers a $600 dotanuki katana I admire. This Jkoo dotanuki is more budget priced at $229. I wanted the $600 Huawei, but that was out of my price range. I was curious about dotanuki katanas though.

What is a dotanuki katana? Well, here is what I got off the www.sinosword.com site:

“This style katana design is characterized by thick and heavy blade, simplicity and durability. the sword was designed to cut off its target in a single cut. it was created by the famous swordsmith Dotanuki Kunikatsu.

Kunikatsu became know as Masakuni because Japan's most famous Generals "Kato Kiyomasa" made the sword of his choice a "Dotanuki"( Dotanuki schools style was very simple, and the reason being is the smiths would concentrate on its ability to cut, its durability and quality level), in honor of this great smithing achievement,and gave Kunikatsu part of his own name as an accolade. Thereafter, swords of the “Dotanuki Masakuni” design were forever guaranteed a place in the halls of Japan's long history.

Sword of dotanuki design was considered to be the apex of military dynamism and power. Elegant simplicity, dynamism and power are this famous weapon’s characteristic trademarks, once a favorite weapon ofJapan's feudal lords, and military commanders because of their ability to cut. when you holding the blade it is easy to understand why it was a preferred blade for generals and other high ranking individuals.”

So basically, a dotanuki katana is a simple, rugged, heavier than average and more powerful than average katana, of regular katana size. I now have a Jkoo dotanuki. So what did I receive?

Jkoo’s site, www.sinosword.com, is rather interesting in that while they do wholesale production and sales, they also offer custom orders via a rather addicting custom options menu system with many options of blade and furniture. And there is a third area to www.sinosword.com, the “already made” section. Instead of waiting about two and a half months for a custom sword, order a sword already finished and ready to be purchased. Avoid the wait. Quite a few models there, the dotanuki katana being one of the less expensive at $229, others listed that vary from predictably routine to the unusual.

IMO, the furniture offered (i.e. tsuba, fuchi, kashira, etc) are a definite step above basic stuff. For instance, the tsuba menu has sub menus for iron tsubas, brass tsubas and fancier mixed metal tsubas. Prices vary. Not handmade, but decent, detailed production furniture.

Blade options are many. I have fun using the custom options menu. So many choices. I found that Jkoo gets my requests correct or nearly so and that workmanship and fit and finish have been good. Except for one area, which I am able to correct without much trouble. More on that later.

So how chose to perfection was Jkoo able to come in this $229 plus shipping Longquan katana? What did I get? The only thing I recall asking for, was for one mekugi pin instead of two, which they did.

The dotanuki katana arrived in the usual mustard-yellow tape-wrapped Styrofoam shipping box. I opened it, wiped the oil off the blade and did some air cuts. No bohi so my aging ears had trouble hearing the blade-cutting-air sound (aka “tachikaze”). Either that or my cuts weren’t very good. I let another do air cuts and he said he could hear the blade moving through the air ok. But face it, if one really wants to get serious audio feedback in cutting, have Jkoo put a bohi into the blade. All my Jkoo customs, even my Jkoo wakizashi’s have single bohi’s and I can hear them clearly. And the air travel sound tells me how my cut is. A good air cut sounds different than a bad air cut.

This sword was meant to be another “beater” sword for backyard cutting of bottles and such. Water-filled soft plastic bottle cutting is just for fun. I cut mostly one gallon and smaller, water-filled plastic milk jugs, water bottles and the waxed cardboard type half gallon milk and juice cartons. The easiest to cut are the one gallon milk jugs.

On to the sword specifications.

Sword Specifications:
Cost: $229 plus shipping ($51 for me in California)
The Sword:
Weight: sword alone: 3.02 pounds (lbs)
Weight: sword + saya: 3.71 lbs
Total Length (sword + saya) = 43.5 inches
Total sword length = 41.5 inches
Sword Point of Balance: 5 1/2 inches ahead of the tsuba.
Sori: 3/4 inches
Sword sharpness: Paper-slicing sharp, except for the first 2 inches ahead of habaki, which was deliberately kept dull to help prevent saya koguichi damage due to a bad draw or bad noto (sheathing the sword).
The Saya:


Above: Gloss black saya



Above: Koguichi (buffalo horn)




Above: Jkoo Dotanuki koguichi (no paper shim yet).



Above: Jkoo katana with card stock paper shim (glued in, to tighten up the saya's grip on the habaki. 

The Saya:
Saya length: 32 1/8 inches
Saya width (vertically) at kojiri: 1 1/2 inches
Saya width (horizontally) at kojiri: 7/8 inches
Saya width (vertically) at koguichi: 1 5/8 inches
Saya width (horizontally) at koguichi: 15/16 inches
Saya furniture (kojiri, kurigata, koguichi): black, buffalo horn, gloss finish
Saya color: gloss black
Saya shito-dome: bright gold brass 
Saya sageo: dark blue Chinese cotton 
Saya weight: 0.69 pound



Above: Dark blue sageo



Above: Gloss black saya



Above: Buffalo horn kurigata & blue sageo (cotton I think)



Above: Buffalo horn kojiri


The Blade:


Above:  Mono T10 blade with suguha (straight) hamon



Above: Jkoo offers 3 types of blade polishes:  Mirror, Cosmetic and Fingerstones (hazuya).  This is the Cosmetic polish.  



Above: Kissaki.  Geometric yokote.  Suguha boshi (hamon of kissaki)



Above: Mono T10 katana blade near habaki




Above: Shaved nakago (tang) with Smith's signature ("Mei").   I darkened the signature to make it easier to see.



Above: Middle of blade, view of suguha (straight) hamon



Above: Picture of entire nakago.  



Above:  Mekugi ana (hole for mekugi is drilled through the nakago)




Above: Ha-Machi and Mune-Machi  (shows where the blade ends and the nakago starts)



Above: Brass habaki


Blade Specifications:

Blade length: 29 1/4 inches without habaki
Blade construction: forged mono T10
Blade polish: “cosmetic” (beautiful polish, looks like a jizuya/hazuya polish)
Blade (with niku) sharpness: slices paper except near the habaki
Blade sori: 3/4 inches
Blade thickness at yokote: 3/16 inches
Blade thickness ½ way down blade: 3.5/16 inches
Blade thickness at habaki: 4/16 inches
Blade width (ha to mune) at yokote: 1 inch
Blade width (ha to mune) ½ way down: 1 3/16 inches
Blade width (ha to mune) at habaki: 1 1/4 inches
Blade bohi width: (no bohi)
Blade kissaki length: 1 1/2 inches (chu (medium) length kissaki)
Blade hamon: sughua (straight) (3/16” to 5/16” wide averaging ¼” wide)
Blade boshi: suguha (boshi is the hamon of the kissaki) (1/4” wide with slight curve back, at tip of kissaki.


Above: production Brass habaki, simple, strong


The Habaki:


Above: Brass habaki, factory made, not a custom fit to this nakago.  I asked for filed/shaved nakago.



Above: Brass habaki, rear view (before I reduced the habaki opening size with JBWeld)



Above: Brass habaki, after I used steel-impregnated Auto engine repair grade JBWeld to better fit the undersized nakago to the oversized habaki interior.  My requesting a filed/shaved nakago took steel off the nakago and made the nakago more undersized.  I was dumb.


Habaki: dulled gold color, brushed brass.

Habaki length: 1 inch

Habaki fit to blade: perfectly placed when sword is assembled. That is, the top of habaki was flush with top of blade (shinogi-ji), as it should be. Unassembled though, the habaki was loose on the bare blade. Since I had the sword apart anyway and it was an easy job, I fixed the habaki with a small amount of steel-impregnated, auto engine repair, JBWeld.


Above: Brass habaki tight and perfectly placed when sword assembled.   Loose when sword disassembled.  


The Tsuba:


Above: Iron tsuba (both sides looked the same)



Above: The other side of the unsigned iron tsuba


Tsuba: dark, blackened iron, rounded edges, circular with random threads design.
Tsuba thickness: 3/16”
Tsuba length (ha to mune direction): 3 1/4 inches
Tsuba width side to side): 3 inches


Above: Tsuka with black cotton ito and full rayskin wrap


The Tsuka:


Above: Tsuka, good ito wrap job.  Even, tight.   As good as my Huawei wraps.



Above: Tsuka ito wrap is tight, even.  Well done.  Samegawa (ray skin) is full wrap of basic ray skin (small nodules).  Looks blue but that is due to the odd lighting.  Actually is black Chinese cotton.


Tsuka length: 11 ¼ inches
Tsuka: wood with full wrap of raw, white, small nodules ray skin
Tsuka ito: dark blue Chinese cotton
Tsuka ito wrap: traditional “criss-cross”. Very tight. Diamonds even.
Every bit as good as on my Huawei’s.
Tsuka Mekugi: one bamboo mekugi
Tsuka width (ha to mune) at fuchi: 1 1/2 inches (with ito)
Tsuka width (halfway between fuchi & kashira): 1 5/16” inches (with ito)
Tsuka width (ha to mune) at kashira: 1 5/16” inches (with ito)
Tsuka thickness (side to side) at fuchi: 1 inch (with ito)
Tsuka thickness (side to side) at kashira: 1 inch (with ito)


Above: Iron fuchi, simple, classic


The Fuchi:

Fuchi: lacquered, blackened iron, oval with a small character design on sides.
Fuchi length: 1 ½ inches
Fuchi width: 7/8 inches



Above: Iron kashira


The Kashira:

Kashira: lacquered, blackened iron, oval with small character design on sides.
Kashira length: 1 5/16 inches
Kashira width: 3/4 inches


Above: Iron menuki of an interesting but unknown design


The Menuki:


Above: iron menuki of mystery design (rolled up scroll maybe?)


Menuki: Interesting, dark brown, probably iron of a design hard to identify. Rolled up scroll? Strange fish shape? Hard to tell, partly covered by the ito wrap.


Above: Brass seppa and bamboo mekugi



Above: closeup of brass seppa



Above: closeup of bamboo mekugi


Tsuka Ito observations:


Above: Chinese cotton, softer, most comfortable



Above: Chinese silk



Above: synthetic silk

I have Jkoo/Sinosword swords with synthetic silk, Chinese cotton and Chinese silk. The synthetic silk has a slicker and harder feel. The cotton is less shiny, more soft, warmer and comfortable. The Chinese silk feels about halfway between synthetic silk and cotton.


My Thoughts:

With my Jkoo/Sinosword katanas, a 29 inch blade feels good. The 28 inch Jkoo katana I had felt slightly too short for my liking. I have not tried a 30 inch blade. I am 6 feet 2 inches tall.

I have a 29 inch Jkoo katana with a 10 ½ inch tsuka but it feels a little short for my large hands. My Jkoo katanas with a 11 or 11 ¼ inch tsuka feel better. Maybe I’d like a 12 inch tsuka, but I have not tried one. I also have found that a rounded kashira (tsuka end cap) is more comfortable than a kashira with a flat top and resulting edges.

Sword weights:

My four Jkoo katanas are very close to being the same length (nagasas of 29 inches, plus or minus ¼ inch). Heaviest (no bohi) was the dotanuki at 3.02 pounds. The (pig iron) tamahagane was 2.52 pounds. The mono T10 katana was 2.45 pounds. One mono 1095 katana was 2.60 pounds. The other mono 1095 katana was 2.68 pounds. These weights are sword with furniture (tsuka & habaki), without the saya. All but the dotanuki katana have single bohi’s.


Above: Blade has niku but still sliced paper, both before and after bottle cutting session.



Above: Another view, no problem slicing paper



Above: The water-filled bottle cutting session....lots of fun!



Above: Soft plastic water-filled milk bottles and juice cartons are good targets that minimally scratch the softer parts of the blade.


Summary and nit picking:

Overall, this Jkoo dotanuki katana feels powerful. It feels like it could cleave hard targets easily. This dotanuki katana also feels noticeably heavier than my other Jkoo katanas. It is a noticeable weight in my obi. If I was a daimyo of old, I would have an assistant carry it on long hikes. If I was an ordinary samurai, who had to walk or run long distances, I would choose a lighter, if less powerful sword, one less tiring to carry (and wield). The down side of a lighter samurai sword is that there is less available power for the cut. More speed, but less power. No free lunch.

The Good:

Good: For $229 dollars one gets a balanced, well crafted, powerful cutter with good looks and an excellent tsuka-ito wrap. Polish is Jkoo’s “cosmetic”, which is a very attractive polish, much better than a mirror polish and shows features better too.

The Bad: Dotanuki’s are heavier than average, so sustained use will tire the user faster than the average katana. On the other hand, for hard targets…..I would choose this sword. This is not what I would recommend for my small, petite, Chinese wife (though she wielded it quite well during our bottle cutting).

Bad: The only real complaint I have is that the perfect habaki-to-blade fit, was only perfect when the sword was assembled. When the tsuka was on, the habaki-to-blade fit was perfect. When the tsuka was off, the habaki was loose on the nakago, only tightening up when the sword was fully assembled. Happily it was an easy fix by degreasing the habaki, putting JBWeld (stick version) inside the habaki, and positioning it back on the (well-greased) nakago until firm, removing and letting the JBWeld cure for a day. I realize at this price, Jkoo has to use factory habaki’s and Jkoo tries to custom fit their nakago’s to the factory habaki’s. Could Jkoo make a custom fit habaki? I did not think to ask.  That said, some of the "habaki is loose on the bare blade" issue is my fault.  I asked to have the nakago shaved and smoothed.  The fit was probably better prior to the steel being taken off the nakago.   

Bad: Unlike most all my custom menu Jkoo swords, this dotanuki katana would slide out of the saya by its own (heavy) weight if I turned it upside down. So I cut a rectangle out of a sheet of cardstock (heavy paper) and wood glued it in the koguichi.

Robert Hamilton, California December 2019