Gripe: Sword sharpness tests that aren't any good

[SimonM]

I was wandering around the web and I came to a website of a guy who tested out the sharpness of a Hanwei Katana by cutting a free-standing cardboard box in half. This was the only test he did but he made it sound like a big deal. So I decided to replicate the test. First I took my box and I got out a Longquan Bao Jian... a pretty sharp sword. I attacked the box on the same angle this man had (just a bit level of 45 degrees) and cut it right in half. OK

So I picked up a rusty old Katana I mainly bought because I liked the Laquerwork on the scabbard and proceeded to cut the box again. Once more the cut was straight through and actually a bit cleaner (I used two hands with the katana and only one with the Jian).

What does this prove?


Cutting a box in half is not an effective method of testing the sharpness of a sword.

So what is?

[Kristoffer]

cutting wood, like bamboo. only if you are no good at cutting the result of the test might delude you.

[green_willow]

I was wandering around the web and I came to a website of a guy who tested out the sharpness of a Hanwei Katana by cutting a free-standing cardboard box in half. This was the only test he did but he made it sound like a big deal. So I decided to replicate the test. First I took my box and I got out a Longquan Bao Jian... a pretty sharp sword. I attacked the box on the same angle this man had (just a bit level of 45 degrees) and cut it right in half. OK

So I picked up a rusty old Katana I mainly bought because I liked the Laquerwork on the scabbard and proceeded to cut the box again. Once more the cut was straight through and actually a bit cleaner (I used two hands with the katana and only one with the Jian).

What does this prove?


Cutting a box in half is not an effective method of testing the sharpness of a sword.

So what is?

Makes perfect sense. the japanese make their houses out of paper and wood. Hence they invented the katana to cut through defensive structures.

[Sekabin]

I thought they invented the katana to cut through people?

[EarthDragon]

as kristofer said a better test is bamboo. However you must realize that the cut of a katana is different type of cut. The proper technique is the thrust after the balde has made contact, Not before if you are swinging the blade evenly to cut through the object this is not a proper cut. also bound hay is much more denser, and easier to come across than a bamboo tree

[SimonM]

I thought they invented the katana to cut through people?

Mostly the Chinese and the Koreans invented the Katana. The Japanese just made it better.

[Jun Fan]

The only way to truely test a blade's sharpness is to run somebody through.

I suggest you try it on someone that nobody will miss. Like an IRS agent or an attorney.

[SimonM]

as kristofer said a better test is bamboo. However you must realize that the cut of a katana is different type of cut. The proper technique is the thrust after the balde has made contact, Not before if you are swinging the blade evenly to cut through the object this is not a proper cut. also bound hay is much more denser, and easier to come across than a bamboo tree

Especially in Lishi. Bamboo does not like the cold Shanxi winters.

I did cut an inch and a half into green willow with the Spring Autumn Pear Wood Sword though. Can't really replicate the test though because I don't want to accidentally chop down any ten year old willow trees while figuring out which of my swords is the sharpest.

[Sekabin]

Plenty of bamboo round here. Send the sword over and we'll check it out for you

[YMC]

Never done any real test cutting myself, but as a caveat, I'm told that one should generally avoid cutting dry bamboo versus green.

Have you considered using tatami like the JSA people?

Makes perfect sense. the japanese make their houses out of paper and wood. Hence they invented the katana to cut through defensive structures.

No. Though I'm not a Japanese sword arts practioner, I can safely say that almost no sword was designed to do this; it's all about cross section and edge geometery. There are better tools to cut down thick bits of wood, (e.g. axe).

[Judge Pen]

The only way to truely test a blade's sharpness is to run somebody through.

I suggest you try it on someone that nobody will miss. Like an IRS agent or an attorney.

Tell me that wehn you get sued and I'm the only thing between you and a judgment for damages.

But, come to think of it, there are a few attorneys that I would like to cut in half with a katana.

[GeneChing]

It's easy to cut cardboard. You don't even need a sharp blade, just a good stroke. Traditional Japanese cutting practice (batto-jitsu) uses bamboo wrapped in grass and soaked in brine - it's supposed to simulate a human body - those Japanese think of everything. I dabbled in batto-jitsu - we did a similar process using bamboo and pampas grass. It worthy of note that there is a wide range of bamboo, not just thickness and dryness, but many different types. If memory serves, we used bisetti and goldenrod bamboo, a few springs bound together.

Some blade makers still use rather rigorous tests, but cardboard certainly isn't one of them. At Shaolin, they cut nails.

[SimonM]

I was more testing the test than testing the blade. Like I said this made a rusty pseudo-antique katana look like it was hella-sharp.

[green_willow]

It's easy to cut cardboard. You don't even need a sharp blade, just a good stroke. Traditional Japanese cutting practice (batto-jitsu) uses bamboo wrapped in grass and soaked in brine - it's supposed to simulate a human body - those Japanese think of everything. I dabbled in batto-jitsu - we did a similar process using bamboo and pampas grass. It worthy of note that there is a wide range of bamboo, not just thickness and dryness, but many different types. If memory serves, we used bisetti and goldenrod bamboo, a few springs bound together.

Some blade makers still use rather rigorous tests, but cardboard certainly isn't one of them. At Shaolin, they cut nails.

Ha you can talk. you can't tear your weay outta wet paper bag.

[GeneChing]

Oh yeah? You can't spell your weay out of a wet post.
No weay!
Weay!