Demystifying the Tip

[Angus Trim]

What is there about the tip? It just what you stick in the other guy, right?

Well, the tip is as important as the spine, or any other major part of a sword.

Before going any further, lets differentiate the tip and the point. The point is as far as you can get from the hilt, and still be a part of the blade, and the tip is the area surrounding and supporting the point, including the edges, main bevels, and spine including the area some 2 inches from the point itself. And, on a double edged sword, the point is where the edges meet.

If we look at two extremes, we have some tips designed for cutting, and some tips designed for thrusting. Its probably fair to point out here that on some modern swords designed for aethetics, the tip isn't optimum for either cutting or thrusting.

The function of the tip, depends on other parts of the blade, the edge of course, the main bevels, and the spine. If distal tapered properly {and properly balanced of course} the sword "will follow the point" naturally in a thrust, and if all of the "mechanical" goodies are done right, the sword will track well, and the tip will cut well, if a cutting tip.

Really acute tips are obviously thrusting tips. Tips that are spatulate, are also designed for cutting...... a good cutting tip still works for thrusting in a soft target however, even the wide ones, as they can "cut" their way into the target.

Generally speaking, really acute tips, or dedicated thrusting tips if you will, don't cut well. They are also more vulnerable to bending than the more spatulate tips.....However, a properly supported acute tip works well for thrusting into a target with some real resistance {maille, or cloth armors}. If using one of these swords for cutting though, it is adviseable to avoid cutting with the point, best to stay at least 4 to 6 inches away from the point.

A lot of historical swords were meant to cut with the tip. For this to work, the sword must be harmonically balanced, the main bevels {in the tip area} ground to support the edge of the tip area and point for cutting, and the spine works best in this, if it keeps the blade fairly rigid while the tip is engaged in cutting {ok, the bevels are important for rigidity sake too, but we'll get to this some other time}.

For the tip to excel in cutting, the point itself has to work as a part of the edge, and the edge must have a fairly acute angle, being "sharp", if you will. In general, the wider the tip, the better at cutting, and the thinner the tip's crossection, the better at cutting....... However, one cannot go to thin, or strength suffers.

[Terry Orton]

I see what you're getting at Angus

I dislike "needle" tips as well.

And in the case of some thrusting weapons such as estocs,wasn't the actual tip a bit thicker than the actual spine just behind the thrusting tip to reenforce it?

I recently came into possesion of some old tempered blanks made by a fellow who used to make swords here in Washington a while back.

(Fortunately they had been tempered by Pacific Metallugical,so I just had to be careful not to overheat them as I worked.)

I was grumbling to myself as I reground the aforementioned needle tips he had done to blunter, more servicable ones,and thinned the widths where the ricassos had been so badly undergound,all I could keep in mind was "What the hell was he THINKING?"

Seriously, the blade IS the most important part of the sword.Everything else is simply there to facilitate it's proper use and balance.

And if you sacrifice the basic geometry ,strength and utility for flash and ornament,all you really end up with is a "SOL."

The devil's in the details,but the important ones are certainly more about how it functions than it looks hanging on the wall.

Unless of course,having a wall full of shiny objects is your primary reason for collecting.

Regards,Terry

[Kerry Stagmer]

well yes and no Terry

SOME thrusting tips are thicker where the smith has 'upset' the end before shaping the blade. These are almost always see on daggers and are usually listed as armour piercing, often in Islamic blades

I think that the larger tips you are refering to on estocs are actually on hunting swords of the same dimensions. These swords are often shown along side of Estocs in museum catalogs. Note that these swords often have a hole in the blade for a crossbar. I have handled several Estoc and own a very nice example, each has had a dam near perfect distal taper.

Angus,
great idea to post here! usually i see this kind of post in the bladesmith section. the form and function of the 'tip' is so often over looked by makers today.....

[D. Opheim]

Great post Gus. I have been pondering about this since that "katana vs euro" thread a few weeks back.

The sword that comes to mind is that "head's will roll" blade you showed off at the SAG last week . That nice wide dimond cross section blade that tapers down to a (flathead) spear shaped tip. Considering the distil tapering, it would seem to offer both cutting an thrusting options where the tip is involved. Is that a fair assessment, or do I need more schoolin?

[John Lundemo]

Originally posted by Angus Trim
What is there about the tip? It just what you stick in the other guy, right?

Well, the tip is as important as the spine, or any other major part of a sword.

Before going any further, lets differentiate the tip and the point. The point is as far as you can get from the hilt, and still be a part of the blade, and the tip is the area surrounding and supporting the point, including the edges, main bevels, and spine including the area some 2 inches from the point itself. And, on a double edged sword, the point is where the edges meet.

If we look at two extremes, we have some tips designed for cutting, and some tips designed for thrusting. Its probably fair to point out here that on some modern swords designed for aethetics, the tip isn't optimum for either cutting or thrusting.

The function of the tip, depends on other parts of the blade, the edge of course, the main bevels, and the spine. If distal tapered properly {and properly balanced of course} the sword "will follow the point" naturally in a thrust, and if all of the "mechanical" goodies are done right, the sword will track well, and the tip will cut well, if a cutting tip.

Really acute tips are obviously thrusting tips. Tips that are spatulate, are also designed for cutting...... a good cutting tip still works for thrusting in a soft target however, even the wide ones, as they can "cut" their way into the target.

Generally speaking, really acute tips, or dedicated thrusting tips if you will, don't cut well. They are also more vulnerable to bending than the more spatulate tips.....However, a properly supported acute tip works well for thrusting into a target with some real resistance {maille, or cloth armors}. If using one of these swords for cutting though, it is adviseable to avoid cutting with the point, best to stay at least 4 to 6 inches away from the point.

A lot of historical swords were meant to cut with the tip. For this to work, the sword must be harmonically balanced, the main bevels {in the tip area} ground to support the edge of the tip area and point for cutting, and the spine works best in this, if it keeps the blade fairly rigid while the tip is engaged in cutting {ok, the bevels are important for rigidity sake too, but we'll get to this some other time}.

For the tip to excel in cutting, the point itself has to work as a part of the edge, and the edge must have a fairly acute angle, being "sharp", if you will. In general, the wider the tip, the better at cutting, and the thinner the tip's crossection, the better at cutting....... However, one cannot go to thin, or strength suffers.

Thanks Dawg, I have a customer who has been trying to design his custom sword blade, he has sent several drawings the latest had an acute tip, but for the duties he was describing wanting to use the sword for, the tip he designed would have been a poor cutter and a little weak for cutting with tip. I suggested like you that for his cutting porposses the tip should be wider to support the tip cuts. I will reffer him to this informative thread.

[Angus Trim]

Originally posted by Kerry Stagmer


Angus,
great idea to post here! usually i see this kind of post in the bladesmith section. the form and function of the 'tip' is so often over looked by makers today.....

Hi Kerry

Long time....*g*

I posted this on the General Forum, to go along with the thread "Demystifying Distal Taper". With questions bringing more points out, and with contributions from Al Massey and Michael Tinker Pearce, Dennis Boas saved the thread, for later inclusion in an article.

Its my hope this thread turns into something like that, questions, and contributions from knowledgeable smiths like yourself..

[Angus Trim]

Originally posted by D. Opheim
Great post Gus. I have been pondering about this since that "katana vs euro" thread a few weeks back.

The sword that comes to mind is that "head's will roll" blade you showed off at the SAG last week . That nice wide dimond cross section blade that tapers down to a (flathead) spear shaped tip. Considering the distil tapering, it would seem to offer both cutting an thrusting options where the tip is involved. Is that a fair assessment, or do I need more schoolin?

Yep, its a compromise tip, one that will cut, and is still thin enough for thrusting...

[Angus Trim]

Originally posted by John Lundemo
Thanks Dawg, I have a customer who has been trying to design his custom sword blade, he has sent several drawings the latest had an acute tip, but for the duties he was describing wanting to use the sword for, the tip he designed would have been a poor cutter and a little weak for cutting with tip. I suggested like you that for his cutting porposses the tip should be wider to support the tip cuts. I will reffer him to this informative thread.

Hi John

We talked about a lot of this stuff three years ago. But, in the mean time, a lot of us have learned more, and conversely, a lot of people have joined the forums since. I felt its time that we start discussing some of this again, and help folks understand where we're comin' from when designing a sword for use..... Now the tip...

[Keith Larman]

Well, here is my contribution for what its worth.

Often in my world (the Japanese sword) I see home done polishes that sacrifice the very thing you're talking about. Same on production swords. Or go too far the other direction trying to save it. It ain't easy...

I've written in the past about Niku and the role it plays in blades. That article (which was originally posted here, fwiw) is now up on Rich Stein's Japanese Sword Index as well as referenced on Bugei's site for those who want to go back to it. The niku is the essentially curvature of the surface of the side of the blade from back to edge -- sort of a clamshell look. There are no secondary bevels. The entire side of the blade up to the ridge line *is* the edge. This provides support to the edge and allows for the very hard edge to handle more shock and stress from misaligned cuts than it might otherwise be able to handle.

Many production blades sacrifice this very feature. They flatten the entire edge of the blade in order to get at acute an angle as possible on the edge. They also push the back ridge line up towards the back further increasing this angle. They cut soft stuff *really* well. They also bend really well. And the edges chip on anything tougher than soft, soaked mats. So I guess if you only goal is cutting grass with your sword, there ya go. But there was a reason for the "meaty" design of the sides of the Japanese blade. It was for a lot of reasons. Nothing exists in isolation.

Yeah, yeah what does this have to do with the tip?

Shinogi zukuri designs should have a defined kissaki, at least when the blade is new. The yokote (the line separating the tip from the body of the blade) ideally is a physical thing. It is the line where the side of the blade (the ji) begins to slope towards the tip forming the tip. Now think about this for a moment. If the ji surface itself is curved, that line (in one dimension) is really curved itself along that ji surface (going in another). Toss in complications like the flaring out of the tip you often see in some blades (like Howard Clark's). And... The blade still needs to form that same meat, "niku", in the kissaki. It should gently curve from the back of the blade towards the edge, and from the yokote towards the tip, and constantly shifting and changing depending on the direction you see.

So why is this all important? Well, in the olden days swords were tested day in and day out by guys whose very lives depended on their swords. And the design they used *overwhelmingly* was the shinogi zukuri design. Of course this had to do with how they were used, the opponents they faced, etc. But they were not primarily facing rolled up wet grass... And most old styles include things called "tsuki" or "thrusts" with the sword (no, not all Japanese swordsmanship is slicing -- sometimes you're shish-kebobbed). If you've ever seen Tony Alvarez doing demos you'll sometimes catch him doing a tsuki into a large target -- it makes my hair stand up each time I see it. Wow. Gotta hurt.

So... This is all why that shaping there is so very critical. Not only does that tip have to be usable for tip cuts (across the eyes, throat, chest, etc. in various styles) but also able to deal with thrusts into opponents who may very well be armored or where you might hit dead on into bone (the sternum, a rib, whatever). So the tip has to be supported from the tip back, from the edge back at a diagonal, and from the edge to the back of the sword. I.e., the formation of that tip *should* be very smooth, subtle, and complex.

Many production katana have no kissaki at all in the sense I'm talking about here. Some keys to that is noticing that the yokote doesn't seem to correspond to anything else in the blade geometry. The shinogi doesn't change direction right there where the yokote meets it. The edge doesn't start its turn to the tip where the yokote meets that. Some production swords do something really interesting and actually change how they shape the blades such that there is a ko-shinogi (the small shinogi line of the tip) and the edge does start to flow back at the point where they scuff on a cosmetic yokote. They put in all the supporting surrounding things but the bloody things don't do any of the subtle other changed to the actual surface I"m talking about. So in fact it is no better than it being totally cosmetic. Many *can't* do much with this because the blades are already too thin and without any shaping to make it possible. So you're really looking at an attempt to duplicate the look but without duplicating the functionality... Marketing I suppose it what its all about. Or showing what people think they should see but realizing that many buyers don't realize that there is a difference.

Many of the newer Paul Chen's do have all the geometry installed in the kissaki. Some don't. The practical lines do not at all. The higher end ones do. And while they are a dramatic improvement, well, given the price you're paying you're not going to see the subtle shaping. Here the kissaki is formed but without nearly as much subtle shaping and rolling in of the surface. This is *very* time consumning to do. And you cannot do it on a grinder, belt or otherwise. It has to be done on stones, carefully, methodically, and with a great deal of control and experience.

I just finished a blade recently for a customer of Bugei. San Mai construction katana by Howard Clark. I spent 2.5 full days on the tip *alone* on the first stone. Partly because it had some issues when I started. But also because I simply had a lot of shaping to do. And there is *no* rushing that shaping.

But done correctly it is a beautiful thing. As you polish and begin to get the geometry "clicking" into place, the yokote begins to literally form itself. You don't polish in the yokote, you don't polish in all that supporting geometry, but it forms itself when all that supporting shaping of the tip is carefully done on the surface of the tip. Everything else appears magically. The production swords look more like someone tried to install the supporting geometry but didn't bother with the imporant surface shaping. So it looks odd to the experienced eye. But done right by forming the surface correct, the rest forms itself. And how you have a tip that is optimized for thrusts, optimized for slashing with the tip, and optimized for slicing cuts of the whole blade.

And it looks pretty darned cool when they're done well.

Again, just reasons why really good polishes are very expensive and time consumning. Does it matter if the shaping isn't as good? Not if you're not cutting more realistic targets. And not if you're not concerned with the traditional shape. But there is a whole lot more to this one small "detail" than just "Froo-Froo" artsy stuff as many like to imply. And there are a thousand details just like this that run across the entire blade shape. And mounting. And fittings. Etc.

As one fella told me once, the tip is a blade unto itself. It has its own rules, its own needs, and its own complexities. And over the years I've found that I"ll spend more time working on that little one inch long surface than on any other part of the blade. It is *that* important to a "correct" shape and function.

It ain't all about art. The artistry comes from the understanding of the subtlety of performance.

[D. Opheim]

Originally posted by Keith Larman
It ain't all about art. The artistry comes from the understanding of the subtlety of performance.

Bull's eye!

[Don Nelson]

Originally posted by Keith Larman
Well, here is my contribution for what its worth.

Often in my world (the Japanese sword) I see home done polishes that sacrifice the very thing you're talking about. Same on production swords. Or go too far the other direction trying to save it. It ain't easy...

I've written in the past about Niku and the role it plays in blades. That article (which was originally posted here, fwiw) is now up on Rich Stein's Japanese Sword Index as well as referenced on Bugei's site for those who want to go back to it. The niku is the essentially curvature of the surface of the side of the blade from back to edge -- sort of a clamshell look. There are no secondary bevels. The entire side of the blade up to the ridge line *is* the edge. This provides support to the edge and allows for the very hard edge to handle more shock and stress from misaligned cuts than it might otherwise be able to handle.

Many production blades sacrifice this very feature. They flatten the entire edge of the blade in order to get at acute an angle as possible on the edge. They also push the back ridge line up towards the back further increasing this angle. They cut soft stuff *really* well. They also bend really well. And the edges chip on anything tougher than soft, soaked mats. So I guess if you only goal is cutting grass with your sword, there ya go. But there was a reason for the "meaty" design of the sides of the Japanese blade. It was for a lot of reasons. Nothing exists in isolation.

Yeah, yeah what does this have to do with the tip?

Shinogi zukuri designs should have a defined kissaki, at least when the blade is new. The yokote (the line separating the tip from the body of the blade) ideally is a physical thing. It is the line where the side of the blade (the ji) begins to slope towards the tip forming the tip. Now think about this for a moment. If the ji surface itself is curved, that line (in one dimension) is really curved itself along that ji surface (going in another). Toss in complications like the flaring out of the tip you often see in some blades (like Howard Clark's). And... The blade still needs to form that same meat, "niku", in the kissaki. It should gently curve from the back of the blade towards the edge, and from the yokote towards the tip, and constantly shifting and changing depending on the direction you see.

So why is this all important? Well, in the olden days swords were tested day in and day out by guys whose very lives depended on their swords. And the design they used *overwhelmingly* was the shinogi zukuri design. Of course this had to do with how they were used, the opponents they faced, etc. But they were not primarily facing rolled up wet grass... And most old styles include things called "tsuki" or "thrusts" with the sword (no, not all Japanese swordsmanship is slicing -- sometimes you're shish-kebobbed). If you've ever seen Tony Alvarez doing demos you'll sometimes catch him doing a tsuki into a large target -- it makes my hair stand up each time I see it. Wow. Gotta hurt.

So... This is all why that shaping there is so very critical. Not only does that tip have to be usable for tip cuts (across the eyes, throat, chest, etc. in various styles) but also able to deal with thrusts into opponents who may very well be armored or where you might hit dead on into bone (the sternum, a rib, whatever). So the tip has to be supported from the tip back, from the edge back at a diagonal, and from the edge to the back of the sword. I.e., the formation of that tip *should* be very smooth, subtle, and complex.

Many production katana have no kissaki at all in the sense I'm talking about here. Some keys to that is noticing that the yokote doesn't seem to correspond to anything else in the blade geometry. The shinogi doesn't change direction right there where the yokote meets it. The edge doesn't start its turn to the tip where the yokote meets that. Some production swords do something really interesting and actually change how they shape the blades such that there is a ko-shinogi (the small shinogi line of the tip) and the edge does start to flow back at the point where they scuff on a cosmetic yokote. They put in all the supporting surrounding things but the bloody things don't do any of the subtle other changed to the actual surface I"m talking about. So in fact it is no better than it being totally cosmetic. Many *can't* do much with this because the blades are already too thin and without any shaping to make it possible. So you're really looking at an attempt to duplicate the look but without duplicating the functionality... Marketing I suppose it what its all about. Or showing what people think they should see but realizing that many buyers don't realize that there is a difference.

Many of the newer Paul Chen's do have all the geometry installed in the kissaki. Some don't. The practical lines do not at all. The higher end ones do. And while they are a dramatic improvement, well, given the price you're paying you're not going to see the subtle shaping. Here the kissaki is formed but without nearly as much subtle shaping and rolling in of the surface. This is *very* time consumning to do. And you cannot do it on a grinder, belt or otherwise. It has to be done on stones, carefully, methodically, and with a great deal of control and experience.

I just finished a blade recently for a customer of Bugei. San Mai construction katana by Howard Clark. I spent 2.5 full days on the tip *alone* on the first stone. Partly because it had some issues when I started. But also because I simply had a lot of shaping to do. And there is *no* rushing that shaping.

But done correctly it is a beautiful thing. As you polish and begin to get the geometry "clicking" into place, the yokote begins to literally form itself. You don't polish in the yokote, you don't polish in all that supporting geometry, but it forms itself when all that supporting shaping of the tip is carefully done on the surface of the tip. Everything else appears magically. The production swords look more like someone tried to install the supporting geometry but didn't bother with the imporant surface shaping. So it looks odd to the experienced eye. But done right by forming the surface correct, the rest forms itself. And how you have a tip that is optimized for thrusts, optimized for slashing with the tip, and optimized for slicing cuts of the whole blade.

And it looks pretty darned cool when they're done well.

Again, just reasons why really good polishes are very expensive and time consumning. Does it matter if the shaping isn't as good? Not if you're not cutting more realistic targets. And not if you're not concerned with the traditional shape. But there is a whole lot more to this one small "detail" than just "Froo-Froo" artsy stuff as many like to imply. And there are a thousand details just like this that run across the entire blade shape. And mounting. And fittings. Etc.

As one fella told me once, the tip is a blade unto itself. It has its own rules, its own needs, and its own complexities. And over the years I've found that I"ll spend more time working on that little one inch long surface than on any other part of the blade. It is *that* important to a "correct" shape and function.

It ain't all about art. The artistry comes from the understanding of the subtlety of performance.

Hi, Keith;

Well written as usual. I do wish more of the so-appointed Katana experts who seem to be showing up here in greater numbers lately, who insist that Katana are "light", "agile", and "flimsy" swords compared to European Medieval swords would take the time to seek out knowledgeable and experienced discourses such as the one you've provided here.

Back to the tip/point discussion: Three years ago I didn't know squat about swords, nor sword design. I was strictly one who based his estimations on tip performance on raw asthetics. Once I started acquiring functional swords, I found that I could not resist studying virtually every square centimeter of each piece. As I studied the tips and points, I was suddenly faced with asking myself questions such as:

1. Would this point and tip design be adequate to thrusting into a soft target?

2. A semi-hard target?

3. A pretty danged hard target?

4. Does it seem likely the tip would flex or bend if it didn't connect straight and true? Would it have enough stiffness to "hold its course" and continue on?

5. Did the tip/point appear to have enough material above the edges and back from the tip to minimize the chances of breaking, bending, or rolling the tip or edges?

6-10. Same questions, but for cutting instead of thrusting.

It doesn't take long when working with tempered steel to learn how easily it can be dinged when it is thin enough, and/or lacks sufficient support from the rest of the blade.

After a very short while I came to have a real appreciation for the cleverness of the designs I studied.

I wish I had been clever enough to formalize and articulate the thought that has been rattling around in my own head for the last couple years - the tip is an entire blade unto itself. Indeed. Absolutely true.

Don

[Justin B.]

Originally posted by Angus Trim

Really acute tips are obviously thrusting tips. Tips that are spatulate, are also designed for cutting...... a good cutting tip still works for thrusting in a soft target however, even the wide ones, as they can "cut" their way into the target.

Generally speaking, really acute tips, or dedicated thrusting tips if you will, don't cut well. They are also more vulnerable to bending than the more spatulate tips.....However, a properly supported acute tip works well for thrusting into a target with some real resistance {maille, or cloth armors}.

I just thought I'd add a bit on this.

Yes, broad tips can cut their way into soft targets during a thrust. But be sure to keep in mind the cutting part. If the edges have been even slightly dulled from a previous cut, it can easily take several hundred percent more force to shove the tip in during a thrust. Also, on subtances that don't respond well to cutting, such as bone or some armors, the broader tip will be at a severe disadvantage. Geometry (how "pointy" the tip is) is what will either allow the blade to penetrate easily, or fail miserably.

I would also encourage everyone to refrain from making blanket statements such as "really acute tips... are also more vulnerable to bending than the more spatulate tips.....". I think you can agree that tip thickness is far more important than width when it comes to bending strength. (somewhere on the order of 8 times more important, if I remember correctly) It may so happen that many acute tips are also quite thin, but that certainly doesn't have to be the case. For instance, a slender spear point with a reinforced center ridge will still resist bending far better than a thin butcher knife with a tip twice as wide.

[Angus Trim]

Originally posted by Justin B.
I just thought I'd add a bit on this.

I would also encourage everyone to refrain from making blanket statements such as "really acute tips... are also more vulnerable to bending than the more spatulate tips.....". I think you can agree that tip thickness is far more important than width when it comes to bending strength. (somewhere on the order of 8 times more important, if I remember correctly) It may so happen that many acute tips are also quite thin, but that certainly doesn't have to be the case. For instance, a slender spear point with a reinforced center ridge will still resist bending far better than a thin butcher knife with a tip twice as wide.

Hi Justin

We're not talking about a knife here, and "in the cut", if you will, the action of cutting, more force is applied to the plane of the blade {the plane of the edges if you will} than in the plane of the flats. Consequently, the more acute point is more vulnerable to damage. We're talking about a sword here, not a thin butcher knife.

I have never had to try to straighten a spatulate point *in the plane of the edges*, and seriously doubt whether I could. On the other hand, I've seen five of the more acute points damaged *in the plane of the edges* from a blown cut, or from pulling the tip out of a hard target {like plywood or a stump} which had been wiggled in the plane of the edges, and bent. These can be straightened, where the more spatulate tip could not.

But like I said, after making some 1400 swords and sword blades, I have not seen a spatulate tip bent *in the plane of the edges*. I have seen five of the more acute bent that way..... so, it may seem like a "blanket statement", but if that's true, its a statement from the experience of having made 1400 sword blades......

Still have yet to make my first knife though, so what is true for sword blades, may not be true for a knife....... just don't know.....

[Justin B.]

Oh, oh, oh. (where's the foot-in-mouth emoticon?)

In the knife world, it's nearly impossible to generate enough power to bend the blade in the plane of the edges, so it didn't even occur to me that's what you were talking about. Yes, your comments make perfect sense now. Bending strength depends on the cross section of the metal in which ever plane we're talking about.

[Terry Orton]

The more I mess with these, the more I realize I need to know MORE.

I can understand there are a great many styles of swords and they all act just a bit different.

So far, for Europen ones, the basic "spearpoint" seems the best compromise of piercing power vs resistance to bending or breaking.

And I know for coreography work that a lot of reenactors do,they consider "needle points" to be far too dangerous,even with essentially dull blades.

Now the only way I see to resolve these "blade perfomance" issues is to consult the techies amoung us and set up some system with a universal constant,like a device.

Something 1. to hold and swing the blade in a prescribed arc and force,with a standard mount that acts like a hand, only more rigid and repeatable.

For the vibration node, that's a bit harder.Perhaps another mount in a cloud chamber with the right degree of force being applied along a fixed part of the edge, then looking at how the vibrations affect smoke passing by the blade,aka wind tunnel?

Seriously, until a way is devised to do scientific testing,these will remain unresolved issues.

Perhaps those of you in aerospace testing applications can shed some light on workable proceedures.

A blade in motion acts a lot like an airplane wing, even though it isn't an airfoil.

But I'm sure that vibration problems in wings were documented and dealt with as early as the 30's and 40"s.

Anyone "In the know" care to comment?

Regards Terry

[Angus Trim]

Originally posted by Justin B.
Oh, oh, oh. (where's the foot-in-mouth emoticon?)

In the knife world, it's nearly impossible to generate enough power to bend the blade in the plane of the edges, so it didn't even occur to me that's what you were talking about. Yes, your comments make perfect sense now. Bending strength depends on the cross section of the metal in which ever plane we're talking about.

Hi Justin

Actually, your comments brought up some good points. And there are some cutting tips that are vulnerable to thrusting, as there is no crossectional thickness to support them.

I'm sure glad that Keith joined the conversation, as even using those fancy Japanese terms, he got the point across that the sword is an organic whole. The tip as such, is an extremely important part of the design, but in and of itself it won't work without the rest of the sword. However, sometimes to gain a better understanding of how things work, one needs to break things down a bit and isolate them.......

[John Lundemo]

The type XV's and XVI's have this long tappered tip, very gracefull and deadly in the thrust and the long slender tip could get in between armour plates, but tip cuts are out of the question, compared to a type twelve, whose tip is spatulat in shape . If you accidently struck an amoured apponent on his armour full blast with the tip you could loose the tip, with a XVI . The Mainz Gladius had a long tappered tip and the tips broke off sometimes on armour. The pompei styled ones were alot stronger in the tip area because the tip area was shorter, hense more steel to reenforce the tip for cutting as well as thrusting. The penetration on the thrust was not as deep though. The XVI being stiffer with it's high ridge diamond cross section, is not as flexable to lateral blows and I agree with Gus, might not absorb the shock as well as an oval or hex cross section and maybe take a set, but in a thrust devestating even against plate! Compromise, that's the name of the cookie. I guess one sword can't do it all, so incorporating all needs into one sword you get something like a type XIV.5 or 6 and you have an excellent cutting edge with a pointed tip that is wider than a XV or XVI. This is the type of sword that is good on heavy armoured knights and cutting is excellent on lighter armour such as leather. Just an example

[Kerry Stagmer]

it is interesting to wonder... can you guys come of with reasons why the thickened 'upset' armour peircing points are so seldom seen on swords? it seems that hunting weapons with such points would seldom be used on armoured foe!!

I'll grab some illustrations and post if i can