Katana Thickness, How does it affect usage and performance?

[Charliebrown]

Dear Nihonto Members,

 

 

Greetings!

 

I am a new member here, and I am in the midst of finding myself a good katana for Iaido practice. Even though I am around 5.10". I am comfortable with a katana blade length of 71 -72cm.

I do know there are many factors to consider when looking for a particular katana for each purpose. Whether it's for shinken practice or just for display.

 

I came across a katana with the following specs and was wondering if it's a good fit for Iaido practice. However, when I was looking at the overall geometry of the blade, it shows a uniform thickness of 5mm from the Moto-Kasane to Saki-Kasane.

Is this normal? How does it affect the durability and cutting performance of the blade? Oh, and for reference, it also weighs around 900g with fittings on.

 

What do you guys think? Can you help a brother out as I am trying to figure and do more research before my first purchase of a modern shinken for practice.

 

Blade length(Cutting edge): 71.0cm
Curve(SORI): 1.6cm
Width at the hamachi(Moto-Haba): 3.14cm
Thickness at the Moto-Kasane: 0.50cm
Wide at the Kissaki(Saki-Haba): 2.70cm
Thickness at the Saki-Kasane: 0.50cm

Weight including handle: 900g approx*

 

 

Looking forward to your positive replies!

Many thanks!

 

Charles

[Mark S.]

I know no one likes this question… “What does your sensei recommend?”

[Charliebrown]

Hi Mark,

 

Yes, good question.

In terms of Length wise 71-72cm is recommended for me, as my sensei would suggest. My main concern is more on the geometry of the blade, as I might need some assistance and clarity on the thickness issue.

 

The thinner it is, the lighter which is logical, but what about the uniform thickness of 0.5cm? How does that affect the balance and durability of the blade?

Is it also suitable for cutting?

 

Many thanks!

 

Charles

[Scogg]

Hi Charlie,

This forum is dedicated to the study and preservation of genuine Japanese swords and fittings. For that reason, not many of us actually use our swords for martial arts.  

I am going to move your thread to the "General Nihonto related discussion" section, in hopes to get more eyes on your question, and maybe find someone with more info. 

All the best, and welcome to the forum!
Cheers,
-Sam

[Jussi Ekholm]

Do you have pictures of the sword?

 

3,15 to 2,7 cm tells that sword is still very wide at kissaki. The thickness being uniform is bit puzzling I would expect usually some taper in each plane. Also to me 900 grams in koshirae sound very light for blade with such little profile taper. Of course my view might be skewed as I am not a swordsman and I prefer very large swords.

[Nobody]

I know almost nothing about Iaido practice. And this is only a physical consideration.

Generally speaking, if its saki-kasane is thick, the blade is heavier in tip area compared with normal shape blades even if they have the same weight. So, its moment of inertia is greater than that of normal katana when you hold it by its tsuka.

That makes you feel heavier when you hold or swing the katana. But at the same time, its cutting performance may be greater.

[oli]

The best would be you fly to Japan and test some swords. Where are a lot of dealers who have Iaido ready swords.

And all swords are suitable for cutting.

[AlexiG]

Hi Charlie,

 

I find the uniform thickness at moto-kasane and saki-kasane a bit troubling. In my limited experience, have not seen a traditional katana without taper and would indicate that it is very tip heavy and potentially harder to control (but could be a beast of a cutter, as Koichi mentioned). The one detail is how is it measured. There is a design where the koshinogi widens as it meets the mune. If measured there it may appear as if there is no taper, although overall there is. I have two swords like that from Bugei (decent Chinese manufacture). Its called mune-saki (or matsuba-saki). Is the sword of interest like that? For the record the Bugei swords still taper by 1mm when measured at the widest of the saki-kasane.

 

Depending on your level of experience, 900g may be on the heavy side. Consult with your sensei.

 

Best,

Alexi

[Charliebrown]

Hi All,

 

 

First of all, thank you for all the messages. The points you all have stated are sound.

You are right, I should head over to Japan and get my hands on it and try it. 

 

Just an interesting post in regards to the thickness and the definition of kasane.

 

[ROKUJURO]

Hi Charlie,

in my experience, most IAIDO teachers will not use or even recommend sharp swords for it. Basically, it is practiced with BOKKEN, and only some advanced masters may sometimes use sharp swords in IAIDO demonstrations for show. Also, there is no cutting involved in IAIDO.

A blade without much taper in the KASANE will have a tendency to wobble when a stroke is stopped mid-air. 

TAMESHIGIRI is another thing, and there, wide heavy blades are used by some experts. 

[Katsujinken]

Hi Charlie,

 

If you are set on buying a shinken I recommend you read this article: https://www.brooklynbattodo.com/reading/5-6-2021/how-to-buy-a-real-sword

 

Beyond that, I would suggest with respect that if you are asking these questions you probably should not be buying a shinken just yet, and certainly not a Japanese blade you’ve never held. 
 

What style / school do you practice? What is the nature of your tameshigiri curriculum? What kind of targets are you using? What is your plan for sharpening? These questions can have a big impact on what kind of sword is appropriate to buy — in terms of both the materials and the geometry. 
 

As for the blade you’ve described: the lack of taper in the kasane is curious and has a significant impact on balance. I would not buy a sword like this sight unseen if I were asking the same questions you are. My guess is this sword will be tip heavy, which is not ideal for real use. 900 grams is also quite light for a sword you want to cut with as Jussi mentioned. 1000-1200 grams is a more appropriate weight for a shinken of that length. You also didn’t mention if it has a bohi or not. At that weight I would expect the sword to bend easily, especially if it has a bohi. 
 

In my experience, most practitioners unfortunately end up using blades that are not ideal for one reason or another, so I urge you to take it one step at a time. I’d be happy to answer more questions after you read the article. 

[Tohagi]

With a very humble opinion on this topic, If you will only pratice iaï, you should choose a lite sword with good balance (some funbari and 7mm at the moto-kasane vs 4.5mm saki-kasane) à bohi will give a lite, fast, and whistleling blade.

 

For tameshigiri you will probably search for speed at the mono-uchi. A heavy blade is hell for the shoulders after some years of pratice...

 

A Japanese shinken is an expensive choice... 

[OceanoNox]

In iaido, shinken is recommended eventually. It may implicit, but for 5th dan onward, shinken is practically mandatory for testing and taikai. If you go to a dojo with high ranking practitioners, there are no mogito, only shinken being swung around.

 

900g is fine for a iai shinken. If it has a bohi, like most swords for iaido to avoid tennis elbow and such repetitive joint injury, it is not recommended for cutting, especially if you are a beginner, since it is a bit easier to bend.

Weight distribution rather than total weight is more important for iai, but you need to swing the sword (single-handed) to check if the sword fits you. The sori and kissaki shape are also very important (I know a person with a sori almost like a tachi, but he is an exception).

 

N.B.: For comparison, my own shinken for iai (I do ZNKR iai and muso shinden ryu) is 79.6 cm long (sori is 2.0 cm) and about 970g. The blade tapers towards the tip, and it feels like a feather compared to my mogito.

[Charliebrown]

Hi All,

 

Many thanks for the respectful guide and insights for my Shinken purchase. I respectfully agree with all of your points.

I am here to learn, so I apologize beforehand if I seem a little amateur asking silly questions

 

My school is the Toyama-Ryu school, where I practice. So, technically, we have an Iaito for Kata practice and a cutting sword for Tameshigiri Tatami Cutting (without bamboo core).. I do see my seniors practicing with their Shinken swords though.

The sword I was concerned of had a Bo-Hi on it. As for sharpening, I ALWAYS and will ONLY send it to a professional in Japan for it. Even if it costs $$$$, oh, and yes, it costs a lot to maintain a blade nicely. I do not encourage people to sharpen their swords without the proper training and knowledge! (Replying to Michael)

 

I understand that the price is a factor, and I also respect the culture and traditions. My sensei encourages me to practice with a Shinken eventually.

 

As for timing, I am trying to learn more before my purchase and would love a visit to Japan just to do so (AND the best food haha).

I have a few blades in my collection, so from a collector's point of view, I would love to learn more about blade geometry, performance, and its practical usages.

 

Thanks for all the insights!

 

Charles

[moriarty]

3 hours ago, Charliebrown said:

Hi All,

 

Many thanks for the respectful guide and insights for my Shinken purchase. I respectfully agree with all of your points.

I am here to learn, so I apologize beforehand if I seem a little amateur asking silly questions

 

My school is the Toyama-Ryu school, where I practice. So, technically, we have an Iaito for Kata practice and a cutting sword for Tameshigiri Tatami Cutting (without bamboo core).. I do see my seniors practicing with their Shinken swords though.

The sword I was concerned of had a Bo-Hi on it. As for sharpening, I ALWAYS and will ONLY send it to a professional in Japan for it. Even if it costs $$$$, oh, and yes, it costs a lot to maintain a blade nicely. I do not encourage people to sharpen their swords without the proper training and knowledge! (Replying to Michael)

 

I understand that the price is a factor, and I also respect the culture and traditions. My sensei encourages me to practice with a Shinken eventually.

 

As for timing, I am trying to learn more before my purchase and would love a visit to Japan just to do so (AND the best food haha).

I have a few blades in my collection, so from a collector's point of view, I would love to learn more about blade geometry, performance, and its practical usages.

 

Thanks for all the insights!

 

Charles

Greetings Charles,

 

As a fellow martial artist, my sole recommendation is that you don't consider making an expensive purchase due to pressure, even for tameshigiri, most live blades outside of Japan will render a similar performance. As for blade geometry, not much deviates from common sense, thicker blades can make cutting straw easier, but will enfeeble your batto/notto. Blades with bo-hi produce tachi-kaze (blade wind) with most correct cutting motions, those without it often produce a lesser sound and have different balancing. Some degree of curvature is helpful towards notto, but excessive examples take nuanced handling.

 

I wish you continuous luck in your efforts, and don't be afraid to ask questions, we get bored without them! 

[jeremy]

4 hours ago, OceanoNox said:

In iaido, shinken is recommended eventually. It may implicit, but for 5th dan onward, shinken is practically mandatory for testing and taikai. If you go to a dojo with high ranking practitioners, there are no mogito, only shinken being swung around.

 

900g is fine for a iai shinken. If it has a bohi, like most swords for iaido to avoid tennis elbow and such repetitive joint injury, it is not recommended for cutting, especially if you are a beginner, since it is a bit easier to bend.

Weight distribution rather than total weight is more important for iai, but you need to swing the sword (single-handed) to check if the sword fits you. The sori and kissaki shape are also very important (I know a person with a sori almost like a tachi, but he is an exception).

 

N.B.: For comparison, my own shinken for iai (I do ZNKR iai and muso shinden ryu) is 79.6 cm long (sori is 2.0 cm) and about 970g. The blade tapers towards the tip, and it feels like a feather compared to my mogito.

That's a big blade! How tall are you using a blade of that length, if you don't mind me asking ?

[OceanoNox]

6 hours ago, jeremy said:

That's a big blade! How tall are you using a blade of that length, if you don't mind me asking ?

I am 1m88 tall. My sensei had seen a few nice blades and had them sent to the dojo for us to try (another dojo member was also looking for a shinken). That blade simply fit me.

[Jacques]

I'd say if you're a beginner an iaito is sufficient and as they're not steel they're light. 

[Katsujinken]

Charlie, where do you train?

 

I am a godan in Toyama Ryu Battodo and am the chief instructor at a dojo here in New York City (same website as the article I shared). 
 

If you want to PM me I would be happy to help answer some more questions. I may even know your teacher. 

[Charliebrown]

3 hours ago, Katsujinken said:

Charlie, where do you train?

 

I am a godan in Toyama Ryu Battodo and am the chief instructor at a dojo here in New York City (same website as the article I shared). 
 

If you want to PM me I would be happy to help answer some more questions. I may even know your teacher. 

Hi Michael,

 

 

Greetings! Please to meet you.

I train at the Toyama-Ryu Iaido Association in Hong Kong, the Hong Kong branch of Zen Nihon Toyama Ryu Remei.

 

Would be happy to link up with you in the future!

 

Charles

[OceanoNox]

15 hours ago, Jacques said:

I'd say if you're a beginner an iaito is sufficient and as they're not steel they're light. 

I will caveat that by saying that some iaito have very poor balance. Case in point, my shinken is about the same weight as my iaito, but it feels much lighter than the iaito.

There are some iaito made especially light and thin to avoid injuries in beginners or people with less muscular strength.

[Katsujinken]

22 hours ago, Charliebrown said:

Hi Michael,

 

 

Greetings! Please to meet you.

I train at the Toyama-Ryu Iaido Association in Hong Kong, the Hong Kong branch of Zen Nihon Toyama Ryu Remei.

 

Would be happy to link up with you in the future!

 

Charles

Excellent. My dojo is also part of ZNTIR, and I had a great time with some of your colleagues in Japan last May. Ping me anytime.