custom Jkoo/Sinosword pig iron tamahagane kobuse katana
May 13, 2020 19:16:02 GMT
Post by Robert in California on May 13, 2020 19:16:02 GMT
Sword Review: Custom JKoo/Sinosword 29” Kobuse Pig Iron Tamahagane Katana. May2020
This is a review of a Jkoo/Sinosword pig iron tamahagane katana.
above: Top sword is the Jkoo/Sinosword pig iron tamahagane katana. Below is a mono T10 wakizashi. Both with midare hamons.
Above: Jkoo pig iron tamahagane katana with Jkoo's less expensive furniture...fancier is available.
Jkoo is a small Longquan, China forge. The website, www.sinosword.com sells Chinese and Japanese swords, spears, knives and even armor. For example, a knife:
www.sinosword.com/Hand-forged-T10-steel-bowie-knife-for-hunting.html
Typical Jkoo/Sinosword Japanese swords are decent, solid, what the average, middle class samurai would carry, kind of swords. When I order a Jkoo/Sinosword, I prefer the general purpose Jkoo katana/wakizashi blade, which is a multi-role, non-specialized blade design. Custom swords are ordered via the web site. Specialized blade types are available, limited only by the customer's imagination and Jkoo's swordsmith ability to make a blade to the specifications.
Jkoo sells swords they have already finished, through the web site. Custom swords can take a couple months.
This custom Jkoo katana is a forged 29 inch, kobuse blade construction, midare hamon, pig-iron tamahagane steel, katana. Next to a Jkoo Soshu Kitae blade, this is probably the most fancy blade that Jkoo makes. The blade looks folded, but the layers of steel are finer and closer together than my folded blades. Kobuse blades have an inner softer steel body, with an outer shell of harder, higher carbon steel.
above: pic of kobuse construction
There is debate over what is tamahagane. But if Jkoo/Sinosword wants to call a blade that begins as chunks of raw iron (aka "pig iron"), instead of grains of iron-containing sand, as tamahagane , then so be it. Jkoo does not start with chunks of pig iron. The one specialty forge they use creates the raw steel and Jkoo takes it from there.
Above: chunk of pig/crude iron
What is iron sand? Ironsand, also known as iron-sand or iron sand, is a type of sand with heavy concentrations of iron. It is typically dark grey or blackish in colour. It is composed mainly of magnetite, Fe3O4, and also contains small amounts of titanium, silica, manganese, calcium and vanadium. Ironsand is found worldwide [2].
The Chinese were making pig iron by the later Zhou dynasty (which ended in 256 BC). Pig Iron is crude iron and it has extra high carbon content.
Iron sands have been used to make pig/crude iron. Crude iron has a high carbon content, around 4%, and also typically contains silica and other impurities, which makes it hard but brittle. To be further processed, eventually into sword blades, remelting and forging is done, to reduce the carbon content and convert it into steel. Starting out with pig iron instead of iron sand, saves time and effort and allows sword blades to be made at lower cost.
Where did the name "pig iron" come from? "The traditional shape of the molds used for pig iron ingots was a branching structure formed in sand, with many individual ingots at right angles to a central channel or "runner", resembling a litter of piglets being suckled by a sow. When the metal had cooled and hardened, the smaller ingots (the "pigs") were simply broken from the runner (the "sow"), hence the name "pig iron". As pig iron is intended for remelting and further processing, the uneven size of the ingots and the inclusion of small amounts of sand caused only insignificant problems considering the ease of casting and handling them. [1]
On to the sword specifications. This sword is "eye candy". It is too nice to use as a “backyard bottle cutter”. As to historical significance of this model, there is nothing unusual that I know of. It is a katana made in the Longquan area of China, by the Jkoo forge.
above: Jkoo pig iron tamahagane katana
This particular katana is slightly long and of medium weight. Nice blade with modest price furniture. Fancier furniture is available, at higher price.
JKOO / Sinosword Pig iron tamahagane katana with midare (irregular) hamon Specifications:
above: another view
The Sword:
Cost: About $500usa + $51usa shipping (China to USA)
Weight: 2.8 pounds (sword only)
Weight: 3.35 pounds (sword + saya)
Total Length (sword + saya) = 42.75 inches
Total sword length = 40.75 inches
Sword Point of Balance: 5 ½ inches ahead of the tsuba
The Blade:
above: 29 inch pig iron tamahagane blade with finger stones polish
Blade length: 29 inches
Blade construction: kobuse
Blade polish: hazuya/jizuya (finger stones)
Blade (with niku) sharpness: slices thick typing paper easily, but struggles to slice thin typing paper or flimsy newspaper.
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: 5/16 inches
Blade width (ha to mune) at yokote: 15/16 inches
Blade width (ha to mune) ½ way down: 1 1/16 inches
Blade width (ha to mune) at habaki: 1 1/4 inches
Bohi width: 1/4 inch
Kissaki length: 1 1/2 inches (medium kissaki)
Blade hamon: midare (irregular, averaging 7/16 inches wide)
Blade boshi (hamon of kissaki): suguha (straight, 1/4 inch wide)
above: raw blade blank from the specialty forge. Jkoo takes it from there (forging/heating/hamon/polishing)
above: finished blade, pig iron tamahagane blade, kissaki. Folding on this kobuse blade is visible.
above: geometric kissaki option
above: another view of the geometric kissaki
above: now for some blade pics..
above: pics of different parts of the blade
above: blade showing single, general bohi
above: blade near habaki
above: other side
above: signed nakago (smith name)
above: better view of smith signature
above: ha-machi & muni-machi
above: mekugi ana
above: other side of the nakago
The Habaki:
Habaki: dulled gold color brass with diagonal file scratches
Habaki length = 1 inch
Habaki fit: perfect when the sword is assembled. With tsuka off and only the habaki on the bladed, there was about 1/2 mm (0.02 inches) of vertical looseness. So though unnecessary, but being the detail obsessive kind of guy that I am, I degreased the habaki and put a very thin thread of automobile engine repair grade (steel impregnated) JBWeld to make the habaki a perfect fit to the nakago, even unassembled. Not needed, but I did it anyway, being a kind of a nit picky perfectionist. Jkoo has been improving in this area, if for no other reason that Van Yang seeks product improvement. Some sellers are receptive to feedback and suggestions. Some are not. Van Yang is. His customer service is also excellent.
above: brass habaki
above: top view
above: bottom view
above: habaki on the blade
The Tsuba:
Tsuba: dark, blackened iron, rounded edges, circular with raised waves.
Tsuba thickness: 3/16”
Tsuba length (ha to mune direction): 3 inches
Tsuba width side to side): 2 3/4 inches
above: blackened iron tsuba
above: closer view
The Tsuka:
Tsuka length: 10 1/2 inches
Tsuka: full wrap of raw, white, small nodules ray skin
Tsuka ito: black, silk (real silk)
Tsuka ito wrap: traditional “criss-cross”. Very tight. Diamonds even.
Every bit as good a wrap as the tsukaito wraps of my Huawei's.
Tsuka Mekugi: one bamboo mekugi
Tsuka width (ha to mune) at fuchi: 1 5/8 inches (with ito)
Tsuka width (half way between fuchi & kashira): 1 4/8 inches (with ito)
Tsuka width (ha to mune) at kashira: 1 3/8” 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: Jkoo/Sinosword tsukas: katana on top, Jkoo wakizashi on the bottom, iron furniture
above: kashira end of the tsuka
above: another view
above: black silk ito on tsuka
above: full tsuka wrap of small nodule rayskin (samegawa)
above: the mekugi ana (hole for bamboo mekugi peg)
The Fuchi:
Fuchi: blackened iron with waves design
Fuchi length: 1 5/8 inches
Fuchi width: 7/8 inches
above: fuchi, blackened iron, waves design
above: fuchi, another view
above: tsuka under the fuchi
above: full wrap of small nodules rayskin for the tsuka, stronger than panels and more traditional.
The Kashira:
Kashira: blackened iron, rounded oval shape with waves design on sides and top.
Kashira length: 1 5/16 inches
Kashira width: ¾ inches
above: kashira, blackened iron
above: another view
The Menuki:
Menuki: dull brass, eagle in flight, one of multiple menuki available
above: menuki, brass, flying eagle
The Saya:
Saya length: 32 inches
Saya width at kojiri: 1 1/2 inches
Saya thickness at kojiri: 7/8 inches
Saya width at koguichi: 1 5/8 inches
Saya thickness at koguichi: 15/16 inches
Saya furniture (kojiri, kurigata, koguichi): buffalo horn, black
Saya color: gloss black
Saya shito-done: brass (gold)
Saya sageo: black & white braided, Chinese cotton
Saya weight: .65 pound
above: sayas, gloss black
above: saya, black buffalo horn kojiri
above: closeup black enameled (laquered?) buffalo horn kojiri
above: sageo
above: sageo
above: koguichi, buffalo horn
above: another view, koguichi, slight gape.
The Seppa:
Seppa: brass, yellow gold color
above: brass seppa
My Thoughts:
On tsuka length:
This sword has a 10 1/2 inch tsuka. Trying it, I find I like a slightly longer tsuka better, 11 to 12 inches. Nothing wrong with a 10 1/2 inch tsuka. It is just that I am 6'2" tall and have big hands.
On kashira shapes:
Jkoo/Sinosword has a decent number of fuchi/kashiras to choose from on a custom order. This rounded kashira is a favorite because when I lean on the sword like a walking stick, the kashira is more comfortable than a kashira with more of a flat end and thus edges. Of course, a katana is not a walking stick.
Summary and nit picking:
Observations: This $500usd katana has a handsome blade with a good feel to it. A tamahagane blade that starts out as a bucket of raw iron sand would be beyond my budget, due to the extra processing iron sands require. For instance, here is a sword seller who offers tamahagane katanas produced from iron sands and a tatara, not chunks of crude (pig) iron but asks about $3,700usd. [3]
That is a high retail price, maybe too high, but still it points out that there is a big time and labor difference between starting with iron sand and starting with pig iron. And China, in the ancient days, had more iron resources and used a more productive method than did old Japan's tatara (sort of a labor intensive, disposeable smelter) [2].
Jkoo/Sino do not make perfect swords for $300. Is it reasonable to expect perfection for about $300usd? Of course not, but Jkoo does make good, solid, workingman's swords. When good, pre-shipping q.c. is done, there is no or minimal saya rattle; outstanding tsukaito wrap; good blades, with a wide variety of available furniture options (which I normally go with the lower priced choices because I care most about function and workmanship.) And when they do mess up a sword, they have been good about making things right.
Yes, I like the swords JKOO makes. I have enough of them, more than I need, that when asked how many, I have to stop and think a bit. Unlike other makes I have bought, there is something about Jkoo swords that makes me want yet another...maybe the overall quality, the many options, the lower than I would expect prices, maybe the feel, maybe how no two of my midare hamon Jkoo/Sino blades look quite the same...the individualism, and the step above "blah" tsuba/fuchi/kashira/etc choices. Choices that are fairly detailed castings and look authentic.
All my JKOO’s have single bohi’s. Why? Because my hearing is not as good as when I was young, and in air cuts especially, the sound the blade makes tells me how my cut is. And I like the looks of a bohi blade.
The Good:
Good:
Attractive blade and furniture. Good workmanship. First class tsuka ito wraps. Good feel in the hands. Perfect saya fit. Zero "blade in saya rattle". Koguichi fit holds the sword in the saya with the sword upside down, but releases smoothly with a kind of pulling a stick out of jello feel. Not all at once, but gradually. Nice.
The Bad:
above: blade is sharp but slightly dull in yokote area. Can cut school binder paper, except right at the yokote.
Bad:
Sharpness. While the blade slices heavy typing paper, I have trouble slicing thin paper, like newspaper. True, the blade is "sharp with niku", but so are my other Jkoo/Sinoswords and they slice thin paper ok.
Habaki. Almost perfect, but I want perfect. Though the habaki fit to blade is perfect and unmoving on the assembled sword, when I put the habaki on the bare blade alone, I can wiggle the habaki about 1/2 mm vertically. I know I am being really picky but for any Jkoo/Sinosword in the neighborhood of $300usd or so, I expect perfect habaki fit. I know I'm being unreasonable on this but my nature is to want a Mercedes for a Ford price. I think it is something Jkoo can fix. My guess would be that the nakago be made very slightly too big for the habaki and then careful hand fileing/shapeing to a perfect fit.
Thoughts:
Keep custom orders from being unusually complex. Perhaps one reason I have been happy and successful with the blades Jkoo/Sinosword makes is that when I give blade specifications for a custom order, I only request blade steel and construction type, polish type, length, kissaki, bohi and hamon details. I don't get more detailed than that. The way I figure, right or wrong, is that a forge does best, what it does most.
Jkoo/Sinosword can and has been able to meet detailed and unusual specifications, but I'm not the one who asks for such. Their standard blades feel good to me and to me, that is good enough.
Robert Hamilton aka "RinC", California May 2020
[1] en.wikipedia.org/wiki/Pig_iron
[2] en.wikipedia.org/wiki/Ironsand
[3] www.swordsofnorthshire.com/tamahagane
This is a review of a Jkoo/Sinosword pig iron tamahagane katana.
above: Top sword is the Jkoo/Sinosword pig iron tamahagane katana. Below is a mono T10 wakizashi. Both with midare hamons.
Above: Jkoo pig iron tamahagane katana with Jkoo's less expensive furniture...fancier is available.
Jkoo is a small Longquan, China forge. The website, www.sinosword.com sells Chinese and Japanese swords, spears, knives and even armor. For example, a knife:
www.sinosword.com/Hand-forged-T10-steel-bowie-knife-for-hunting.html
Typical Jkoo/Sinosword Japanese swords are decent, solid, what the average, middle class samurai would carry, kind of swords. When I order a Jkoo/Sinosword, I prefer the general purpose Jkoo katana/wakizashi blade, which is a multi-role, non-specialized blade design. Custom swords are ordered via the web site. Specialized blade types are available, limited only by the customer's imagination and Jkoo's swordsmith ability to make a blade to the specifications.
Jkoo sells swords they have already finished, through the web site. Custom swords can take a couple months.
This custom Jkoo katana is a forged 29 inch, kobuse blade construction, midare hamon, pig-iron tamahagane steel, katana. Next to a Jkoo Soshu Kitae blade, this is probably the most fancy blade that Jkoo makes. The blade looks folded, but the layers of steel are finer and closer together than my folded blades. Kobuse blades have an inner softer steel body, with an outer shell of harder, higher carbon steel.
above: pic of kobuse construction
There is debate over what is tamahagane. But if Jkoo/Sinosword wants to call a blade that begins as chunks of raw iron (aka "pig iron"), instead of grains of iron-containing sand, as tamahagane , then so be it. Jkoo does not start with chunks of pig iron. The one specialty forge they use creates the raw steel and Jkoo takes it from there.
Above: chunk of pig/crude iron
What is iron sand? Ironsand, also known as iron-sand or iron sand, is a type of sand with heavy concentrations of iron. It is typically dark grey or blackish in colour. It is composed mainly of magnetite, Fe3O4, and also contains small amounts of titanium, silica, manganese, calcium and vanadium. Ironsand is found worldwide [2].
The Chinese were making pig iron by the later Zhou dynasty (which ended in 256 BC). Pig Iron is crude iron and it has extra high carbon content.
Iron sands have been used to make pig/crude iron. Crude iron has a high carbon content, around 4%, and also typically contains silica and other impurities, which makes it hard but brittle. To be further processed, eventually into sword blades, remelting and forging is done, to reduce the carbon content and convert it into steel. Starting out with pig iron instead of iron sand, saves time and effort and allows sword blades to be made at lower cost.
Where did the name "pig iron" come from? "The traditional shape of the molds used for pig iron ingots was a branching structure formed in sand, with many individual ingots at right angles to a central channel or "runner", resembling a litter of piglets being suckled by a sow. When the metal had cooled and hardened, the smaller ingots (the "pigs") were simply broken from the runner (the "sow"), hence the name "pig iron". As pig iron is intended for remelting and further processing, the uneven size of the ingots and the inclusion of small amounts of sand caused only insignificant problems considering the ease of casting and handling them. [1]
On to the sword specifications. This sword is "eye candy". It is too nice to use as a “backyard bottle cutter”. As to historical significance of this model, there is nothing unusual that I know of. It is a katana made in the Longquan area of China, by the Jkoo forge.
above: Jkoo pig iron tamahagane katana
This particular katana is slightly long and of medium weight. Nice blade with modest price furniture. Fancier furniture is available, at higher price.
JKOO / Sinosword Pig iron tamahagane katana with midare (irregular) hamon Specifications:
above: another view
The Sword:
Cost: About $500usa + $51usa shipping (China to USA)
Weight: 2.8 pounds (sword only)
Weight: 3.35 pounds (sword + saya)
Total Length (sword + saya) = 42.75 inches
Total sword length = 40.75 inches
Sword Point of Balance: 5 ½ inches ahead of the tsuba
The Blade:
above: 29 inch pig iron tamahagane blade with finger stones polish
Blade length: 29 inches
Blade construction: kobuse
Blade polish: hazuya/jizuya (finger stones)
Blade (with niku) sharpness: slices thick typing paper easily, but struggles to slice thin typing paper or flimsy newspaper.
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: 5/16 inches
Blade width (ha to mune) at yokote: 15/16 inches
Blade width (ha to mune) ½ way down: 1 1/16 inches
Blade width (ha to mune) at habaki: 1 1/4 inches
Bohi width: 1/4 inch
Kissaki length: 1 1/2 inches (medium kissaki)
Blade hamon: midare (irregular, averaging 7/16 inches wide)
Blade boshi (hamon of kissaki): suguha (straight, 1/4 inch wide)
above: raw blade blank from the specialty forge. Jkoo takes it from there (forging/heating/hamon/polishing)
above: finished blade, pig iron tamahagane blade, kissaki. Folding on this kobuse blade is visible.
above: geometric kissaki option
above: another view of the geometric kissaki
above: now for some blade pics..
above: pics of different parts of the blade
above: blade showing single, general bohi
above: blade near habaki
above: other side
above: signed nakago (smith name)
above: better view of smith signature
above: ha-machi & muni-machi
above: mekugi ana
above: other side of the nakago
The Habaki:
Habaki: dulled gold color brass with diagonal file scratches
Habaki length = 1 inch
Habaki fit: perfect when the sword is assembled. With tsuka off and only the habaki on the bladed, there was about 1/2 mm (0.02 inches) of vertical looseness. So though unnecessary, but being the detail obsessive kind of guy that I am, I degreased the habaki and put a very thin thread of automobile engine repair grade (steel impregnated) JBWeld to make the habaki a perfect fit to the nakago, even unassembled. Not needed, but I did it anyway, being a kind of a nit picky perfectionist. Jkoo has been improving in this area, if for no other reason that Van Yang seeks product improvement. Some sellers are receptive to feedback and suggestions. Some are not. Van Yang is. His customer service is also excellent.
above: brass habaki
above: top view
above: bottom view
above: habaki on the blade
The Tsuba:
Tsuba: dark, blackened iron, rounded edges, circular with raised waves.
Tsuba thickness: 3/16”
Tsuba length (ha to mune direction): 3 inches
Tsuba width side to side): 2 3/4 inches
above: blackened iron tsuba
above: closer view
The Tsuka:
Tsuka length: 10 1/2 inches
Tsuka: full wrap of raw, white, small nodules ray skin
Tsuka ito: black, silk (real silk)
Tsuka ito wrap: traditional “criss-cross”. Very tight. Diamonds even.
Every bit as good a wrap as the tsukaito wraps of my Huawei's.
Tsuka Mekugi: one bamboo mekugi
Tsuka width (ha to mune) at fuchi: 1 5/8 inches (with ito)
Tsuka width (half way between fuchi & kashira): 1 4/8 inches (with ito)
Tsuka width (ha to mune) at kashira: 1 3/8” 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: Jkoo/Sinosword tsukas: katana on top, Jkoo wakizashi on the bottom, iron furniture
above: kashira end of the tsuka
above: another view
above: black silk ito on tsuka
above: full tsuka wrap of small nodule rayskin (samegawa)
above: the mekugi ana (hole for bamboo mekugi peg)
The Fuchi:
Fuchi: blackened iron with waves design
Fuchi length: 1 5/8 inches
Fuchi width: 7/8 inches
above: fuchi, blackened iron, waves design
above: fuchi, another view
above: tsuka under the fuchi
above: full wrap of small nodules rayskin for the tsuka, stronger than panels and more traditional.
The Kashira:
Kashira: blackened iron, rounded oval shape with waves design on sides and top.
Kashira length: 1 5/16 inches
Kashira width: ¾ inches
above: kashira, blackened iron
above: another view
The Menuki:
Menuki: dull brass, eagle in flight, one of multiple menuki available
above: menuki, brass, flying eagle
The Saya:
Saya length: 32 inches
Saya width at kojiri: 1 1/2 inches
Saya thickness at kojiri: 7/8 inches
Saya width at koguichi: 1 5/8 inches
Saya thickness at koguichi: 15/16 inches
Saya furniture (kojiri, kurigata, koguichi): buffalo horn, black
Saya color: gloss black
Saya shito-done: brass (gold)
Saya sageo: black & white braided, Chinese cotton
Saya weight: .65 pound
above: sayas, gloss black
above: saya, black buffalo horn kojiri
above: closeup black enameled (laquered?) buffalo horn kojiri
above: sageo
above: sageo
above: koguichi, buffalo horn
above: another view, koguichi, slight gape.
The Seppa:
Seppa: brass, yellow gold color
above: brass seppa
My Thoughts:
On tsuka length:
This sword has a 10 1/2 inch tsuka. Trying it, I find I like a slightly longer tsuka better, 11 to 12 inches. Nothing wrong with a 10 1/2 inch tsuka. It is just that I am 6'2" tall and have big hands.
On kashira shapes:
Jkoo/Sinosword has a decent number of fuchi/kashiras to choose from on a custom order. This rounded kashira is a favorite because when I lean on the sword like a walking stick, the kashira is more comfortable than a kashira with more of a flat end and thus edges. Of course, a katana is not a walking stick.
Summary and nit picking:
Observations: This $500usd katana has a handsome blade with a good feel to it. A tamahagane blade that starts out as a bucket of raw iron sand would be beyond my budget, due to the extra processing iron sands require. For instance, here is a sword seller who offers tamahagane katanas produced from iron sands and a tatara, not chunks of crude (pig) iron but asks about $3,700usd. [3]
That is a high retail price, maybe too high, but still it points out that there is a big time and labor difference between starting with iron sand and starting with pig iron. And China, in the ancient days, had more iron resources and used a more productive method than did old Japan's tatara (sort of a labor intensive, disposeable smelter) [2].
Jkoo/Sino do not make perfect swords for $300. Is it reasonable to expect perfection for about $300usd? Of course not, but Jkoo does make good, solid, workingman's swords. When good, pre-shipping q.c. is done, there is no or minimal saya rattle; outstanding tsukaito wrap; good blades, with a wide variety of available furniture options (which I normally go with the lower priced choices because I care most about function and workmanship.) And when they do mess up a sword, they have been good about making things right.
Yes, I like the swords JKOO makes. I have enough of them, more than I need, that when asked how many, I have to stop and think a bit. Unlike other makes I have bought, there is something about Jkoo swords that makes me want yet another...maybe the overall quality, the many options, the lower than I would expect prices, maybe the feel, maybe how no two of my midare hamon Jkoo/Sino blades look quite the same...the individualism, and the step above "blah" tsuba/fuchi/kashira/etc choices. Choices that are fairly detailed castings and look authentic.
All my JKOO’s have single bohi’s. Why? Because my hearing is not as good as when I was young, and in air cuts especially, the sound the blade makes tells me how my cut is. And I like the looks of a bohi blade.
The Good:
Good:
Attractive blade and furniture. Good workmanship. First class tsuka ito wraps. Good feel in the hands. Perfect saya fit. Zero "blade in saya rattle". Koguichi fit holds the sword in the saya with the sword upside down, but releases smoothly with a kind of pulling a stick out of jello feel. Not all at once, but gradually. Nice.
The Bad:
above: blade is sharp but slightly dull in yokote area. Can cut school binder paper, except right at the yokote.
Bad:
Sharpness. While the blade slices heavy typing paper, I have trouble slicing thin paper, like newspaper. True, the blade is "sharp with niku", but so are my other Jkoo/Sinoswords and they slice thin paper ok.
Habaki. Almost perfect, but I want perfect. Though the habaki fit to blade is perfect and unmoving on the assembled sword, when I put the habaki on the bare blade alone, I can wiggle the habaki about 1/2 mm vertically. I know I am being really picky but for any Jkoo/Sinosword in the neighborhood of $300usd or so, I expect perfect habaki fit. I know I'm being unreasonable on this but my nature is to want a Mercedes for a Ford price. I think it is something Jkoo can fix. My guess would be that the nakago be made very slightly too big for the habaki and then careful hand fileing/shapeing to a perfect fit.
Thoughts:
Keep custom orders from being unusually complex. Perhaps one reason I have been happy and successful with the blades Jkoo/Sinosword makes is that when I give blade specifications for a custom order, I only request blade steel and construction type, polish type, length, kissaki, bohi and hamon details. I don't get more detailed than that. The way I figure, right or wrong, is that a forge does best, what it does most.
Jkoo/Sinosword can and has been able to meet detailed and unusual specifications, but I'm not the one who asks for such. Their standard blades feel good to me and to me, that is good enough.
Robert Hamilton aka "RinC", California May 2020
[1] en.wikipedia.org/wiki/Pig_iron
[2] en.wikipedia.org/wiki/Ironsand
[3] www.swordsofnorthshire.com/tamahagane
