Edge Sharpness Vs. Application

This Forum is a place for students of swordsmanship to ask advice from moderators Paul Champagne & Scott M. Rodell on how to practice test cutting in a manner consistent with how swords were historically used in combat. Readers use this Forum at their own risk.

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Edge Sharpness Vs. Application

Post by Scott M. Rodell » Fri Sep 22, 2006 8:58 am

Paul, in the thread: Making a cutting stand (http://www.grtc.org/forum/viewtopic.php ... ight=#1125) you wrote:



"The ?not so sharp? blade will still cut pretty well on most soft test materials ? but the problem is it wont have any ? bite? what I mean by this is that it wont want to stay on its cut line once it impacts the surface of the target. This causes sloppy cuts, poor penetration and frustration. In a competitive situation, where maximizing cut length, speed, accurate tracking through the cut etc etc is most important your sword will have to be quite sharp to stand a chance of doing well.



In summary if we look at sharpness on a scale from 1-10, 10 being hair popping and scary sharp, 1 being basically a blunt theatrical sword, anything in the 3-10 range will work. 3-8 range for combat and everyday work, and 9-10 for competition. So you see there is quite a range of ?sharp? that will cut/work in combat. It depends upon your situation. "



Given the range of degrees of sharpness that a sword blade might be at, at any given time, could you address what degree of sharpness is best for which situations?



For example, we have discussed a "duller" edge being better for combat facing hard armor to prevent the edge from rolling or chipping from impact with the duifang's armor. What historical situation do you feel a very sharp edge would be most useful? What about other degrees of sharpness?



Thanks...

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Post by J HepworthYoung » Sat Sep 30, 2006 8:19 pm

I have experimented with edges a great deal, being an edge weapon collector and a hobby wood carver for many year. With a good edge it seems a slow cut can be very effective, and thus it is easier to present the edge to the target in a precise manner. One can hold a sharp blade to their side and cut soft targest by running, but of course the blade must stay level and move forward, not up and down.



I find that the edges which cut cardboard well, cut flesh well (deer flesh) and cut 2 inch thick green hardwood branches well; were all a bit different. I wonder about differential sharpening and how it might relate to the intended target of the blade.

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Post by PaulC » Mon Oct 09, 2006 7:10 pm

Hi Scott,

A very sharp edge, say in the 8-10 range, is best toward the tip of a sword, or on a low mass type of weapon.



The tip, being the thinnest part of most swords, lends itself to being sharpened with a finer edge. Striking with the tip will not be used for penetrating cuts on hard targets, thus avoiding the chance of damaging a thinner sharper edge here. As I know you are aware, There is no reason that the entire edge of a sword has to be shaped or sharpened in the same way. I have seen this done on historical swords from different cultures and times. (For the record each edge on a double edged sword does not have to be sharpened in the same way)



On the same sword we could easily have a strong well supported edge near the guard (2-5), a sharp but not frail edge we can cut armored/unarmored targets with (6-8 ) and a sharper thiner area at the tip perfect for well aimed quick cuts against exposed areas ( 9-10).

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Blunt Sword Cutting

Post by Scott M. Rodell » Wed Nov 29, 2006 11:12 am

"... next time you see katana cutting bamboo, don't be so impressed."

- John Clements



http://www.youtube.com/watch?v=fFQ4aanm ... ed&search=



Nice control at the end of the cut.

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Re: Edge Sharpness Vs. Application

Post by B.Ko » Wed Jul 15, 2009 9:00 am

I have noticed in some of my antiques that some larger later Jian (late Qing / Ching) seem to have very thin and somewhat wider blades than earlier ones. Also the late jian seem to be quite long compared to earlier ones. The edge damage on such examples seem to be much worse...includes stress fractures, rollover of the edge...than thicker, narrower blades (usually just nicks)


What were the evolutionary forces towards such characteristics???

Was it due to the advent of the firearm??? We all know at some point swords became Sword Like Objects with little practical combat value...was this happening in late Qing/early Republic era???

Or was there some purpose to combat in the wider, thinner, and much longer blade???

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Re: Edge Sharpness Vs. Application

Post by Scott M. Rodell » Wed Jul 15, 2009 9:35 am

B.Ko wrote:... noticed ... some ... some larger later Jian (late Qing...) .. have very thin ... wider blades than earlier ones. Also the late jian seem to be quite long compared to earlier ones...

What were the evolutionary forces towards such characteristics???
My "educated" guess is that two factors are at work here:
One is that with less armor in use, & none of it being the dingjia type, those defending themselves during the tumultuous late QIng era were more concerned with cutting thru fabric than edge durability cutting tougher targets.
The second is that, as part of the "strengthen the nation" movement, there was a surge in interest in martial arts, & that springier longer blades are some what interesting to practice with as they give a better & more visible feed back during power training. So as weapons training became more a supplemental strength training practice than a practical, battlefield prep one, lighter springier blades become more desirable.
B.Ko wrote:... due to the advent of the firearm??? We all know at some point swords became Sword Like Objects with little practical combat value...was this happening in late Qing/early Republic era???
In some ways, yes, but it doesn't appear that this transition to whippy non-functional blades occurred until after the Republic.
B.Ko wrote:.. some purpose to combat in the wider, thinner, and much longer blade???
The short answer is more reach is more reach, if one doesn't need the weight in the blade to hurt the duifang thru armor, than a longer lighter blade can be employed.

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Historically Accurate Edge Sharpness

Post by Scott M. Rodell » Wed Jul 15, 2009 9:54 am

Over the years, as I've done more & more cutting with different blades, & discussed the results with people like Paul Champagne, I've questioned many of the things that were taken as gospel concerning the sharpness of Chinese swords, especially jian. In short, I don't think they need to be as sharp as we always assumed they were, to be effective. And as B. Ko's post above suggestions, there is some danger of potential to damage a blade if the edge is too thin & sharp. Also there has been a tendency in the Chinese martial arts world to over simply, that is, to go for the one answer fits all approach. IN other words, jian were sharp as "X." As I examine antique jian with edge geometry in mind, I find that there is quite a scale of different edge sharpness, from the very tough, that barely slices at all, to the quite thin, very sharp. Clearly these are different tools to do different jobs, so there wasn't a one solution fits all.

Recently I've been testing the prototype of the Cutting Jian I designed for Hanwei. It has historically accurate edges that are not razor sharp like the swords Huanuo produces. However, this edge is just sharp enough to cut paper, though not with a nice clean slice, but with a slight "tearing." When I tested this less sharp edge on white & clear plastic bottles (i.e. very soft targets), it cut then quite easily. Likewise, as you can see in the photo below, this edge slices thru mats as effortlessly as the sharper edges. So clearly, an edge does not have to be razor sharp to cut thru soft targets, however, the question remains, is there a difference when it comes to cutting thru a soft target covered with cloth? I plan to answer this question with test cutting in the near future.
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Re: Edge Sharpness Vs. Application

Post by J HepworthYoung » Wed Jul 15, 2009 10:22 am

I have a Chinese made katana with an edge that is not razor sharp, I thought for a time that it needed sharpening.
It didn't, I needed to learn how to cut with it. Now I can cut better with it that with my sharper machetes.

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historical perspective

Post by Philip Tom » Wed Jul 15, 2009 4:17 pm

The use of jian in a military context faded away during the Ming Dynasty. This weapon was supplanted by single-edged weapons (dao), in various configurations so that by the mid-18th cent., jian were not listed in the Qing regulations governing standard patterns of hilt weapons. Furthermore, the use of metal armor in China declined beginning in the 18th cent. and all but disappeared by the 19th. The Qing campaign in Tibet against the Ghurkas and the resultant incursion into Nepal at the close of the 18th cent. was perhaps the last time that Chinese forces had to deal with armored opponents. The increasing use of firearms even in culturally conservative Central Asia by the 19th cent. ensured that significant use of armor had also waned in that area by this time.

Thus, it is not understandable that the jian, now relegated to the world of civilian martial arts and being deployed mostly for dueling and as an apparatus of "physical culture", changed its blade configuration. By the 19th cent. we see the thinner, wider blades with more acute edge geometry that are the subject of this thread. The reasons for the change in proportions suggested by other forum members are all valid.

I'm looking forward to Scott's tests of jian on cloth-covered cutting dummies. (Hey, it's summer and time to make shorts out of your old pairs of jeans!).

I notice something similar in the evolution of the Turkish saber called "kilij" which remained in use for almost four centuries but by the late 18th cent. had likewise become lighter with a very thin edge (achieved mainly by forging the blade with a x-section in the form of an elongated letter T). A friend has done cutting tests with these (on large leftover Holloween pumpkins!), comparing them against the typical Turco-Persian saber "shamshir" whose blade is of wedge-shaped section and relatively stiff like a katana. He found the shamshirs to be incomparable for deep, clean cuts -- even a small example of one of these can cut a pumpkin clean through and it's perhaps no wonder why these weapons are still used for capital punishment in the Arabian peninsula. The late Ottoman kilij with its thin blade cannot cut as deeply because of the T shaped cross section, but when well-sharpened, it's like slashing with a giant straight-razor. Against a foe who is wearing cloth, it will disable or kill if it contacts the right target.

Likewise in the Middle East, metal armor began to fade from the scene by the 18th cent., and due to the area's proximity to Europe, the advancement in firearms was more marked than in the case of the Far East.
Phil

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Re: Edge Sharpness Vs. Application

Post by B.Ko » Wed Jul 15, 2009 7:15 pm

Granted a thinner blade was ok for attacking nonarmored foes. However, I'm curious why the tougher profile didn't continue for reasons of parrying. Granted one used the flat, but in the heat of combat, the edge may hit another edge even at an angle, wouldn't the beefing edge have withstood it more??

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Re: Edge Sharpness Vs. Application

Post by Scott M. Rodell » Thu Jul 16, 2009 7:40 am

B.Ko wrote:... a thinner blade ... for ... nonarmored foes... why the tougher profile didn't continue for reasons of parrying. Granted one used the flat... the edge may hit another edge even at an angle, wouldn't the beefing edge have withstood it more??
There are always trade offs when comes to blade design, that's why there isn't one perfect sword type. There are different problems to solve, & different ways to solve the same problem, so different tools develop. I assume that as armor disappeared from use, most simply felt greater cutting efficiency was more valuable than a stronger edge. Also the thinner profile allowed a jian to be an inch or two longer, than its fatter cousin. Come to think of it, perhaps the adoption of the riccasso in the very Late Qing so in response to the concerns you are bringing up. A riccasso on a thinner blade does tend to provide the best of both worlds, a thick, tough edge at the base of the blade where one deflects & a sharper edge where the cutting occurs.

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Re: Edge Sharpness Vs. Application

Post by Nik » Thu Jul 16, 2009 8:43 am

One question regarding that ricasso: was that a completely flat section of the blade like in some medieval european swords, or was that simply a flattened edge of ~1mm protruding like 1/3 into the blade, without flattening the rectangular shape of the blade ?

One reason for asking is that I had some fallout with a guy claiming that a jian was "sharp" down to the handle, on the full length.

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Re: Edge Sharpness Vs. Application

Post by Scott M. Rodell » Fri Jul 17, 2009 7:24 am

Nik wrote:... regarding that ricasso: was that a completely flat section of the blade ...?

... a guy claiming that a jian was "sharp" down to the handle, on the full length.
All the ricasso I've encountered on late Qing jian are square sectioned & about 6" in length, see photo below from a jian we just sold at Seven Stars.

Unfortunately, there tends to be a fairly dogmatic, one universal answer fits all approach to swords & particularly jian, amongst Chinese martial artists. As the discussion taking place in this thread shows, there wasn't one & only one way jian blades were shaped. Tradition has it that jian were extreme sharp at the tip, very sharp in the area behind that & less sharp as you travel down the blade to where while the blade is beveled at the forte it might be too dull to cut. Having said this, no research or collector I know has ever handled a jian in its original polish. So it is impossible "prove" this was the standard case. Furthermore, we have plenty of example of jian that have thick cross sections & such steep bevels that they could not be polished "razor" sharp, so that disproves the standard notion of jian sharpness. So the short answer is that for later, &/or civilian self-defense jian likely had very sharp edges near the tip but that not all jian were forged & polished out in that manner.
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Re: Historically Accurate Edge Sharpness

Post by KyleyHarris » Wed Jun 16, 2010 10:46 pm

Hello.
My name is Kyley Harris and I guess this is my first post on this forum. I hope you will all welcome me.

I just received my Cutting Jian from Scott Yesterday.
The Sword is wonderful and I feel that its excellent value for money. Immediately after opening the box I felt that the sword was effectively blunt by my standards and commented on this to Scott via email. He told me a much similar comment to this one, and so now I can understand his perspective and point of view after reading a little more. But I would like to add my comments and opinions to this and hopefully give you all a different perspective on edge sharpness vs Application.

Firstly. I make knives and large blades and shortswords. All the blades I make are designed for hard real world use and take an absolute beating in the outdoors. I make all of my blades with convex edges. on my large blades I use heavy convex edges. Heavier than the Hanwei Jian.

My issue here is the distinction between the blade geometry, and the actual sharpness of the edge. Many modern swords are being ground flat rather than convex because it can bit in deeper which is good on cutting mats. the convex edge is more durable because of the simple fact that there is more steel packed behind the edge to support it and prevent rolling and chipping of the edge. This should not be confused with the actual sharpness of the edge. the sharpness comes from the actual refinement of the steel and polishing where the 2 bevels of the edge connect. the finer the polish and refinement of this edge then the sharper it becomes and the easier to slice paper and bit into material such as skin, flesh & armor. There is no reason that a convex edge should be any duller than a flat ground edge. infact, there is clear proof and evidence that the higher the polish on the terminating edge of the blade the better the blade will resist chipping because there is less steel sticking out at the micro level. Its also been prooven many a time that convex blades, while thicker, can actually cut easier because there is less of the bevel in contact and causing friction.

The Jian I received, as Scott has stated, could not even cut paper. infact on very close inspection, my one had a hair line of steel up most of the blade that the 2 bevels did not infact meet. It could bludgeon its way through a plastic bottle, or cardboard but with a much larger amount of force.

I have polished the edge of my jian using 400 grit belts. I would like to make it especially clear that this has not thinned the convex, or removed any more than a microscopic amount of steel from the sword. All I have done is polish the edge so that it is more refined, but at the exact same angle as originally. The difference is that it can now cleanly slice paper. it can cleanly cut empty bottles. it can nearly shave. The blade will not be weaker because the actual geometry is the same. if anything, the edge will be stronger because the refinement of the edge helps resist the micro-chipping of steel from impacts against targets.

I have personally made and sharpened hundreds of convex knives. on my larger blades with heavier thicker bevels than this jian I have tested them cutting bamboo, wood, sheet steel, aluminum poles.. continuously hitting the edges at full impact as hard as I can to try and damage them. in all my tests its the thickness of the convex bevels that protect the edge from rolling. all of my blades will still cleanly slice paper after repeated impacts on wood, steel etc because the bevel support the sharpness of the edge better.

After sharpening the jians edge it now goes through material with almost minimal effort as I would expect.. but it is the same blade with the same thickness and edge strength as before.. its just sharper and it wont chip any easier than before because there is the same amount of support in the bevels.

Well.. Thanks for listening and I hope my opinions are of value.

I have uploaded some videos of my new sword and I hope to share them with you soon when I find the right location.

All in all. I think its just an amazing blade for the price. I should also add that the harmonic balance and the nodes on the blade are absolutely perfect.
Scott M. Rodell wrote:Over the years, as I've done more & more cutting with different blades, & discussed the results with people like Paul Champagne, I've questioned many of the things that were taken as gospel concerning the sharpness of Chinese swords, especially jian. In short, I don't think they need to be as sharp as we always assumed they were, to be effective. And as B. Ko's post above suggestions, there is some danger of potential to damage a blade if the edge is too thin & sharp. Also there has been a tendency in the Chinese martial arts world to over simply, that is, to go for the one answer fits all approach. IN other words, jian were sharp as "X." As I examine antique jian with edge geometry in mind, I find that there is quite a scale of different edge sharpness, from the very tough, that barely slices at all, to the quite thin, very sharp. Clearly these are different tools to do different jobs, so there wasn't a one solution fits all.

Recently I've been testing the prototype of the Cutting Jian I designed for Hanwei. It has historically accurate edges that are not razor sharp like the swords Huanuo produces. However, this edge is just sharp enough to cut paper, though not with a nice clean slice, but with a slight "tearing." When I tested this less sharp edge on white & clear plastic bottles (i.e. very soft targets), it cut then quite easily. Likewise, as you can see in the photo below, this edge slices thru mats as effortlessly as the sharper edges. So clearly, an edge does not have to be razor sharp to cut thru soft targets, however, the question remains, is there a difference when it comes to cutting thru a soft target covered with cloth? I plan to answer this question with test cutting in the near future.

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Re: Historically Accurate Edge Sharpness

Post by Scott M. Rodell » Sat Jun 19, 2010 1:50 pm

KyleyHarris wrote:... a different perspective on edge sharpness vs Application...

My issue... is the distinction between the blade geometry, and the actual sharpness of the edge. Many modern swords are being ground flat rather than convex because it can bit in deeper which is good on cutting mats. the convex edge is more durable because of the simple fact that there is more steel packed behind the edge to support it and prevent rolling and chipping of the edge. This should not be confused with the actual sharpness of the edge. the sharpness comes from the actual refinement of the steel and polishing where the 2 bevels of the edge connect. the finer the polish and refinement of this edge then the sharper it becomes and the easier to slice paper and bit into material such as skin, flesh & armor. There is no reason that a convex edge should be any duller than a flat ground edge. infact, there is clear proof and evidence that the higher the polish on the terminating edge of the blade the better the blade will resist chipping because there is less steel sticking out at the micro level. Its also been prooven many a time that convex blades, while thicker, can actually cut easier because there is less of the bevel in contact and causing friction...
So Kyle, would you define edge sharpness as having 2 components, the angle of the blade surfaces & the smoothness of the metal (i.e. the grind finish)?

BTW, thanks for your straight forward critique of my Hanwei Cutting Jian...

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