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Herbert Schmidt




Location: Austria / Europe
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PostPosted: Thu 13 Nov, 2008 12:03 am    Post subject:         Reply with quote

Personally I think the sharpness of swords is the same as the cleanliness of our cars:
Some tend to polish, vacuum and wipe down their car almost every week while others won't clean it at all.
The same applies certainly to swords: some would have kept a keen edge on them while others didn't bother. You can kill with a blunt blade and not everyone was an accomplished fencer.

Basically you will find this reflected in the exsting originals. Some are blunt and probably never were very sharp (judging from the existing edges) while others are still sharp enough to cut.

This question is really futile. The question is: how much sharpness do YOU want? The sharper, the more fragile the edge is but the better it will cut (the difference is huge), especially when not much force is applied.

I don't know why this question pops up regularly. You don't have to be a wizard to work it out.

Herbert

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Jean Thibodeau




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PostPosted: Thu 13 Nov, 2008 3:30 am    Post subject:         Reply with quote

Herbert Schmidt wrote:

The sharper, the more fragile the edge is but the better it will cut (the difference is huge), especially when not much force is applied.

Herbert


As to edge damage I agree a fine highly sharpened edge will show damage or a notch much more than a very rounded dull blade but I have a theory that this is self-limiting in depth everything else being equal.

Here is a mental experiment to illustrate:

Take an Albion Liechtenauer which shows very little damage even when used strongly against another Liechtenauer; Mine barely shows anything !

1) Lets take the same profile and add an extra 3 mm on each edge of total width to the sword and bevel this to a very sharp edge. ( To have the same base dimensions + secondary bevels )

2) Now lets use two of these as in the previous example and the edges will be damages and notch or have the edge roll if the metal is soft enough, chip if too hard.

Now my question or supposition is that if one used the original dimensions of the Liechtenauer the depth of the notch would be almost all in the extra 3 mm of width that forms the secondary edge or 3 mm: So when we get back to the thickness of blade at the start of the secondary bevel the amount of damage would be the same but the blade would in time start to look like a saw.

Just to illustrate with theoretical arbitrary numbers:
1) Depth of damage to blunts on blunts = .5 mm ( Shallow and wide rounded dimples rather than notches )
2) Depth of damage to sharp = 3 mm +.5 mm or possibly less, like 2.5 mm of depth, if equal force is used as the secondary bevel would absorb the damage and not reach the original dimensions of our blunts.

Now if one hammers rolled edges back in combination to some grinding one can repair the edges so that they would look almost like new or one could simply round out the notches to eliminated or reduce the stress riser leaving some cosmetic damage and a reduced saw tooth appearance: So one can do a full re-sharpening or just work out the places where there are notches. The difference between functional repairs or full restoration of clean aesthetic edges.

In my mind so as to not accelerate the wear on the sword the first spot repairs would be done until the amount of accumulated damage made a full re-profiling ( new edges ) worth doing: A wide blades sword should be able to take many such repairs before the profile or width of the blade really changed the nature of the blade i.e. a type XVIII starts looking and functioning like a type XV.

So I guess what I'm suggesting is that fine edges display much more damage but the damage is limited to the finer secondary edge while a blunter sword will show less depth of damage but the main core of the blade above the secondary edges will be about the same: So the down side of fine edges is mostly cosmetic and unavoidable when used.

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Matt Easton




Location: Surrey, UK.
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PostPosted: Thu 13 Nov, 2008 6:54 am    Post subject:         Reply with quote

Douglas S wrote:
Matt Easton wrote:
Fiore dei Liberi describes fighting 5 unarmoured duels, wearing "nothing but" an arming jacket and leather clothes.

Having said that, in relation to this discussion, I consider halfswording with no gloves to be perfectly safe.

Matt

Does Fiore not mention gloves?


Sorry, I made a typo - where I wrote 'clothes' above I meant 'gloves'. I must have got distracted.

Matt

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Chris Fields




Location: Tampa, Fl
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PostPosted: Thu 13 Nov, 2008 10:06 am    Post subject:         Reply with quote

Jean

I have to disagree with you a little here. Based on pieces I have actually used, or seen being used, and broke. However, most of this is based on Chinese Jian and Dao, and not western swords (most chinese jian have similar flatten diamond cross sections with convex edge geometry similar to western swords I believe). A sharp blade taking a nick or hit on the edge is not really comparable to a blunt taking an edge on edge hit. What happens to a sharp blade that takes a heavy edge to edge hit, is that the nick, or chip in the blade will most likely lead to a crack which can propagate quickly, where as a blunt just gets a dent and normally does not have any cracks created, much less propagated. Do to the cracks in the sharp blade, time and use to failure is unknown, so the blade should probably be disguarded for use for personal saftey reasons. Where as blunts can take that damage and keep on going with no issue.

Again, this is an "in general" statement. =)
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Jean Thibodeau




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PostPosted: Thu 13 Nov, 2008 1:17 pm    Post subject:         Reply with quote

Chris Fields wrote:
Jean

I have to disagree with you a little here. Based on pieces I have actually used, or seen being used, and broke. However, most of this is based on Chinese Jian and Dao, and not western swords (most chinese jian have similar flatten diamond cross sections with convex edge geometry similar to western swords I believe). A sharp blade taking a nick or hit on the edge is not really comparable to a blunt taking an edge on edge hit. What happens to a sharp blade that takes a heavy edge to edge hit, is that the nick, or chip in the blade will most likely lead to a crack which can propagate quickly, where as a blunt just gets a dent and normally does not have any cracks created, much less propagated. Do to the cracks in the sharp blade, time and use to failure is unknown, so the blade should probably be disguarded for use for personal saftey reasons. Where as blunts can take that damage and keep on going with no issue.

Again, this is an "in general" statement. =)


Yes and this is why I assumed that one would have to at least round out the nick to eliminate or reduce the stress riser effect.

The initial blow might cause the beginning of failure at the bottom of the nick but I was under the impression that it would be continuing use without repair that would cause repeated stress at the stress riser and eventually cause failure.

How long this would take and how vulnerable a sword would be with one or many nicks in it might vary a great deal on hardness, uniformity or lack of uniformity of hardening or carbon content in the blade.

My idea was more a comparison of geometric scale of the damage and I'm sure that taking all factors in consideration eliminating nicks by resharpening is a better idea than leaving nicks in the blade but that one might not reprofile a blade every time one got a small nick i.e. a lot of spot maintenance and the edges might no longer haves deep nicks but become sort of wavy and irregular ?

Note I got a deep looking nick in my Generation 2 Dordogne hitting a nail in a cutting stand/post and it looked really deep but it took surprisingly very little sharpening to make it almost invisible and I didn't resharpen or reprofile the whole blade: The " RAW " nick just looks a lot worse, like really REALLY deep but if one measures it it might be only .5 mm to 2 mm or 3 mm deep at most and even the small nicks just look so much worse on one's sword. Wink Laughing Out Loud

Some related Topics or at least some of the posts are:
http://www.myArmoury.com/talk/viewtopic.php?t...mp;start=0
http://www.myArmoury.com/talk/viewtopic.php?t=11888&start=0

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Jean Thibodeau




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PostPosted: Thu 13 Nov, 2008 1:48 pm    Post subject:         Reply with quote

Got a nasty nick in an axe that looked real deep but the steel was mostly bent over: A little hammer work reduce the nick by 90% and a little file work and then diamond hone work and 10 minutes later the nick was completely gone and the profile of the axes looked about the same.
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Chris Fields




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PostPosted: Fri 14 Nov, 2008 6:28 am    Post subject:         Reply with quote

I understand what your saying, but sometimes the initial edge to edge impact that causes a large nic may form a microscopic crack right away, and once it's there, filing the nic down or smoothing it out won't help. For small nics and such, yeah, they can be worked out, but for heavy edge to edge hit, i would avoid completely, becareful with sharps!
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Matt Easton




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PostPosted: Sat 15 Nov, 2008 10:13 am    Post subject:         Reply with quote

Medieval manuscripts do show a fair number of broken swords. It happened. So what? Happy

Matt

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Herbert Schmidt




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PostPosted: Sat 15 Nov, 2008 11:36 pm    Post subject:         Reply with quote

You also see lots and lots of deeply nicked blades in museums, especially in their back rooms. That was just common.

Or as Matt so eloquently said: So what?

Herbert

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Chris Fields




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PostPosted: Sun 16 Nov, 2008 6:44 am    Post subject:         Reply with quote

So.... nothing really Happy I was just commenting on Jean posts and stating that edge to impacts on sharps has a much different effect than edge to edge impacts on blunts.

I guess the only "so what" to take from that is a lesson of safety for the modern martial artist. Becareful using a sharp once it has a deep nic on the edge, unless flying pieces of sharp blades are considered safe.
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Michael Pikula
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PostPosted: Mon 17 Nov, 2008 11:10 am    Post subject:         Reply with quote

I hope that this little bit of info might help... I have seen edge on edge tests done on a broken sword blade just to see how deep the nick would go, which was about as much as expected, though I don't recall the exact depth. Then about a week later the broken section was repeatedly hit up against mild steel, about 3mm thick and finally a 3 inch or so section broke off. Upon inspection it broke where one of the previous nicks was and there was a slight creep line after the nick where rust started to creep into the blade in a mico-crack. Just thought that someone might find it interesting or confirm some thought/theories.
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R D Moore




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PostPosted: Wed 19 Nov, 2008 6:39 pm    Post subject:         Reply with quote

This thread discusses just this point:
http://www.myArmoury.com/talk/viewtopic.php?t...red+cracks

nicks can create fisures that may fatally weaken the steel.

"No man is entitled to the blessings of freedom unless he be vigilant in its preservation" ...Gen. Douglas Macarthur
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Michael Pearce
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PostPosted: Fri 21 Nov, 2008 12:37 pm    Post subject:         Reply with quote

Oakeshott describes many medieval swords found in good, original condition as being 'as sharp as a good kitchen knife' which is very sharp indeed. Sharp things cut better than dull things and always have and medieval folk were certainly smart enough to know this!. Even if we are talking about a blow that doesn't penetrate armor a sharp sword will concentrate force more effectively than a blunt one.

I've heard the argument about over-zealous curators regrinding blades but I am unconvinced given the number of unmolested blades that display the same sort of edge geometry, cross section etc. as the supposedly 'over-curated' swords.
Matt is dead on- it is perfectly possible to grip the blade bare-handed for half-swording without getting cut. It is even possible to grab the blade of a sharp sword or rapier without getting cut, even without gloves. I've demonstrated this on several occasions.

Michael 'Tinker' Pearce
-------------
Then one night, as my car was going backwards through a cornfield at 90mph, I had an epiphany...
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Jesse Eaton





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PostPosted: Sat 22 Nov, 2008 4:42 am    Post subject:         Reply with quote

Matt wrote:

The middle ages lasted, according to most historians from AD500-AD1500. For most of that period 'knights' carried one sword, one lance/spear and a shield.

Yes, but there are examples from the crusades of Knights carrying two swords. One loger sword across the saddle and and a second, shorter, arming sword at his side. The longer hand and a half/bastard/long/war (or what ever else you want to call it delivered heavier blows and has exceptional reach and speed for a one handed weapon, but at close quarters, the arming sword is more easily drawn, quicker, etc. I think that's what James Fox was getting at. I think that he's wrong about it being common practice for most of the middle ages though. It come back into vogue with the German Dopplersoldners of the Landskenecht in the way of a secondary katzbalger or messer carried at the hip or across the small of the back for close quarters combat or loss of their primary, but I wouldn't want to call them 'knights', at least not to their face Happy

The danger in grabing a sword is not it's sharpness, though it is a factor, but it is the velocity that really counts. I practice with a 'dull' longish sword. By dull I do not mean a 'blunt', it has an edge but lacks a secondary bevel. It cuts beautifully when given the proper motivation. The cuts are nothing close to the slash of a razor sharp blade of a modern katana or similar sword, but it does the job handily. There is a straw mat cutting demo by Clements on the arma website that shows the cutting effectiveness of the relatively unsharpened longsword. Now I don't expect that every practitioner can cut like Clements, some of actually have to work for a living Happy, but the point is made. The blade does not need to be razor sharp. There is also an article on ARMA's website about the sharpness of swords called 'what makes an effective sword cut' that argues for 'dull' blade theory which some of you may have read, but don't find convincing. I find it convicing enough to believe that 'dull' blades were used and common, but have to add that there are lots of reasons to have a 30-40 inch razor blade.

There is another article that I read a while back, but I can't seem to recall where I read it, but it was an analysis of wounds and blade types. In it, the author concluded that duller blades were used when strikes were made to the chest, the collar bone in particular, and sharper blades were used when soft tissue (ie muscles) were the primary target. The idea was that duller blades were less likely to get caught in bone structures while sharper blades allowed for effective slices across muscle tissue. This is the argument I find most convincing, but I just wish I could remeber where I read it Sad.
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Jesse Eaton





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PostPosted: Sat 22 Nov, 2008 4:43 am    Post subject:         Reply with quote

BTW Tinker blades rock!!!!
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Matt Easton




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PostPosted: Mon 24 Nov, 2008 10:18 am    Post subject:         Reply with quote

Jesse Eaton wrote:
Yes, but there are examples from the crusades of Knights carrying two swords. One loger sword across the saddle and and a second, shorter, arming sword at his side.


I mentioned the examples Oakeshott gives. Do you have others to cite?
Please stick to proper historical sources rather than Wikipedia and The History Channel. ;-)

Matt

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