Blade Composition and Parry Characteristics

[B.Ko]

After a sword study group tonight my fellow students decided to do very controlled very slow parry drills with metal swords. The first observation was how slippery and the 'skidding' bounce steel blades have when flat parried. With some monosteel spring tempered modern blades, the amplitude of vibration was very noticeable. I then decided to do the same with some antiques. #1 was a big village jian weighing 2.6 lbs, with a wide lenticular shaped blade. There was very little vibration detected, just a fine hum. I then tested a late Qing jian with a wide thin Viking sword like blade. This blade vibrates strongly when pommel is struck but once again when parrying, vibrates in a fine hum.

We then tested some modern blades to see if they had the 'dead soft feel' on the antique steel when flat parrying. The Huanuo sanmai vibrated less than the mono through tempered steel. There was also a monosteel differentially hardened blade I had that is 40- HRC on spine, 50-55 on edge which didn't vibrate much and had a fine hum. My friend had a Jin-shi jian blade monosteel with a more robust geometry than seemed to vibrate less than the more thinner Huanuo monoblades. Note none of these modern blades where as shock absorbing as the antiques. A confounding factor is the differentially hardened blade was mounted in a handle made by Philip Tom which is most likely much more form fitting than a factory jian handle.

So there are some initial observations.
1. Something about antiques...lamination, type of steel, heat treatment or hilt construction makes them absorb shock very well, even in a thin blade that 'wobbles' when struck on pommel.

2. Modern blades with sanmai construction or monosteel differentially treated blades seem to absorb shock better with a fine hum. Note sanmai would have different hardness on spine vs. edge, like the differential blade.

3. A modern blade with a more robust geometry even with spring temper absorbed shock and vibrated less than a thinner blade.

4????Good tight hilt helps too?????


***Note no antiques were damaged in this experiment blade contact was flat vs. flat in a thrust parry drill only.

P.S. My friend...Garrett Chan of Jin-shi sword had some beater swords we did edge to edge contact with just to feel it. The edge catches and there's a sick grating feel as the edges roll or chip each other, often catching the other sword momentarily, very unpleasant feeling.

[gchan]

Basically, we were trying to narrow down the root cause of the tight, responsive feeling on the antiques.

Our conclusion is that it is due to one of the following or, more likely, a combination thereof. This is not an exhaustible list by any means...
1) Actual composition of the blade steels
2) Historical clamshell blade geometry
3) Mass distribution
4) san mei lamination
5) differential hardening
6) form fitting hilt

I am more inclined to believe that the hilt construction, mass distribution, and clamshell geometry are the most infuential factors. Mostly, due to the performance of the modern jian of flat diamond cross section mounted in Philip Tom's handle. My Jin Shi jian (through hardened monosteel) performed quite favourably as well. However, while the mass distribution is roughly correct and it has a semi-clamshell, the handle is not as good as Philip Tom's work.

On the subject of edge on edge contact. We concluded it was best avoided (Hopefully. you already knew that!). As mentioned, the blade binds in the gouges/chips introducing a high degree of uncertainty and less control over your own and your dui fang's blade.

[Nik]

I'll try these tests whenever the polishers are finally ready with my test swords to see whether they exhibit the same problems when parrying. If so, it's probably really down to the steel type (mine are 55Si7). I'll be having two shapes to test too, one thinner for 720g target weight and a thicker for 820-850g. Sanmei constructions with a really hard cutting layer aren't ready yet.

Physically, a through-hardened springsteel should exhibit a stronger tendency to produce bouncing, hence the name. It's certainly possible to use a different, stiffer steel and differential hardening, but that would lead to more effort in production, more drop outs, and thus higher prices.

If it's down to the handle type, there are no excuses. You can make a handle today that is fixed to the blade in such extreme manner that you couldn't remove it with a C4 candybar. All it takes is a little bit of professional effort and precision, like not having a tolerance of 0.5mm when cutting the slit into the handle.

[Scott M. Rodell]

An interesting experiment... probably all the factors Garret mentioned contribute to the self dampening qualities of a good sword & this quality is something that serious contemporary swordsmiths have also noted in antique swords. From listening to the comments from these smiths, it seems that how to get this just right is still something of a mystery, but without questions, blade geometry is a contributing factor...

[B.Ko]

The Huanuo sanmai was a flattened diamond profile and thinner than the monosteel flattened diamond from JIn-shi Sword. Yet it had less vibration. I suspect the laminate structure also plays a role to the amplitude of vibration as well. Also the laminate structure would alos result in differing HRC on spine and edge.

[J HepworthYoung]

I was going to keep this a secret idea and work on it privately, it might not pan out anyway, but it also might be a good one. I have been planning on using laminate materials to make practice swords that handle more like the real ones, I have been researching composite laminate bow technologies of various cultures and believe that it is possible to make mostly wooden jian out of laminate materials that has a live feel compared to normal wood.

I bring this up here because it literally pertains to blade composition and parry characteristics in a training sword made of non-metallic laminate materials, and here I have received valuable information about the diversity of behaviors of metallic swords.

One of the ideals in a bow, which may prove advantageous to sword as well, is to prevent shock or excessive vibration from going into the person wielding it. Laminate bows tend to be more ideal for this reduction, however their shape is just as important. This is the same type of situation that is now apparent in regard to these swords.

So to offer a potential facet of consideration, once proper dimensions are achieved and proper lamination is as well, then not only is the hardness of the steel laminate parts important, the compression strength and the tensile strength of the laminate materials may vary in ways not totally related to the hardness of the blade. In fact the relative hardness of the edge and softness of the side parts may be secondary and the tensile and compression strengths may be primary. Ergo test cutting is ideal for the sword that has passed the test of resilience and limited shock transfer, in order to pursue an ideal in terms of total function. And suddenly: the tests I have read about great swordsmiths putting their swords through now seem far less extreme and nearly mandatory.

Now I cannot help but wonder, what of the potential for parrying exists in the exquisite bronze swords made in China long ago? Their are laminate, or appear to be if I am not wrong, and they are sharp. Their geometry may prove insightful.

Anyway if anyone wants to work with me on making laminate wooden type jians that have more of a life feel and dimensions/weight ratio, PM me. I have several concept designs for the laminate core of the blade using some interesting materials, such as ground nut shell flour composite, nut shell can have a higher compression strengths than animal horn!

[Nik]

I had my first near-to-production sample blade in my hands today, and I have to say, I am also astonished at how much difference slight shape changes and probably especially the steel type makes. The slightly broader blade made from 55Si7 was *much* stiffer than the last sample from C45, which was a mere attempt at getting the correct measures and shape for the target weight and balance.

However, when you are planning to do a small series of wooden blades made by some workers you know, do not underestimate how much work it is to get everything right. Especially until they understand that minor variations from the intended design are not ok, but change the outcome probably drastically. I spend a lot of time driving there, discussing things, finding solutions, and dismissing "fixes" to problems that have undesirable effects.

[Graham Cave]

I was going to keep this a secret idea and work on it privately, it might not pan out anyway, but it also might be a good one. I have been planning on using laminate materials to make practice swords that handle more like the real ones.

This is something that I considered when designing my sparring jian but in the end decided that lamination was not the best option. The reason is, that for sparring, the edge needs to be sufficiently rounded in order to spread the force of any blow that makes contact with the duifang, and so minimise potential damage. Also the tip needs to be thick enough not to penetrate the bars of a face mask. [Both aspects are covered in the TCSL rules and regulations]. These criteria determine a minimum blade thickness of 3/4" or 19mm. Solid wood is therefore a suitable choice because this at this thickness, the weight of blade also approximates to the weight of the real thing.

I have been researching composite laminate bow technologies of various cultures and believe that it is possible to make mostly wooden jian out of laminate materials that has a live feel compared to normal wood.

If you are not wishing to produce a sword that conforms to the TCSL regulations, then you may be able to build a blade with a thinner profile by using laminated wood. What you may have to do however, is to include some heavier material into the blade to compensate for the weight reduction.

I bring this up here because it literally pertains to blade composition and parry characteristics in a training sword made of non-metallic laminate materials, and here I have received valuable information about the diversity of behaviours of metallic swords.

If you are concerned about getting the dimensions closer to a metal blade in order to mimic the parrying characteristics, then it might also be a good idea to consider the finish you apply to the blades. Ideally you will want the blades to be coated with a material that has similar frictional properties to that of steel, this way, you will get more of a true contact with the duifang's blade.

One of the ideals in a bow, which may prove advantageous to sword as well, is to prevent shock or excessive vibration from going into the person wielding it. Laminate bows tend to be more ideal for this reduction, however their shape is just as important. This is the same type of situation that is now apparent in regard to these swords.

That's interesting, and really beyond my sphere of practical experience. One of the major factors here is the glue/resin used. The more laminations of wood there are, the more layers of glue there are and consequently the greater the proportion of glue/wood. If the wood laminations are thin enough, then they will become saturated with the glue/resin and you will have made a material that is more akin to fibreglass than plywood. Essentially, this means that the properties of the glue/resin may be greater in determining the characteristics of the sword than the characteristics of the wood. Actually, fibreglass is an interesting option because it could allow for the inclusion of fillers that would adjust the weight of the blade......barytes (barium sulphate) for example, is an industrial filler which is really quite a heavy mineral. Well, I'm starting to ramble now, and interesting as I find this, my personal preference is for a more eco-friendly product. I make an effort to source non-toxic and renewable materials and recently have even started to use organic oils for finishing my wooden swords.

Anyway if anyone wants to work with me on making laminate wooden type jians that have more of a life feel and dimensions/weight ratio, PM me. I have several concept designs for the laminate core of the blade using some interesting materials, such as ground nut shell flour composite, nut shell can have a higher compression strengths than animal horn!

Nut flour might have a high compression strength but such particle boards are notoriously weak when it comes to tension. The tensile strength of this material will be entirely dependent on the strength of the resin bonding.

I'm very happy to talk things through with you if you want to email me at the Tiger's Den.

- Graham

[B.Ko]

Garrett and I examined a Hanwei Rodell Jian today and it brought us back to the vibration/parry issue.

For my best antiques the grip seems to be located by a vibrational 'node' of 'minimal amplitude'. Therefore when striking the pommel, little vibration hits the hand, same during a parry. This works so well it can't be coincidental. Garrett also told me that on his latest jian, a wider tang and better fitting handle also reduced vibrations in handle.

Now the Hanwei cutting jian does seem to have more 'vibration' in the handle when parrying or pommel is struck. We'll have to test in cutting to see if this is so during cutting. the synthetic grip may not absorb force as well as wood????

Garrett and I also came to the conclusion that my attention to such details likely borders on pathological as most modern practitioners focus on how the blade cuts. Myself I worry more about proper edge robustness to survive parries, as well as how the sword absorbs the tremendous stress of combat. All of which I am not likely to ever face, but I do enjoy swords that exhibit such qualities!!!!

[Robert Bemoras]

This is very interesting to me. I have one question that to me seems important. At what point does the softness of a blade,(i.e. the ability to absorb shock)detract from its ability to withstand the abuse of heavy cutting?

[B.Ko]

I've discovered some new insights into all the chips one finds on the antiques. Last night Garrett and I experimented with our beater swords. His was through hardened to 50-55hrc. Mine was differentially hardened 50-55 on edge, 40 on spine. Both of these swords were of modern construction with flattened diamond blade geometry, especially mine which was a very flat diamond.

We carefully measured off distance so point would not reach each other and gave some light to moderate thrusts for strong and weak side upper torso parries. Even with body rotation to present flat of blade we discovered there was some edge contact, especially against a thrust with blade aligned horizontally as Laoshi teaches. You basically deflected duifang's blade edge with your blade flat and as you body is turning there is some minor edge/edge contact. Result was glass like chips on edge of sword like I see on antiques. And this occurred in a controlled experiment with focus on turning waist and AVOIDING edge/edge contact as much as possible.

When we have some beater swords with proper blade geometry we will repeat these experiments.

To those of you cringing at this post, I think such experiments have to be done to give us a better understanding of how the swords behaved, stood up to combat. I noticed there's a lot of modern test cutting but few tests with sharp blades on parrying. Since Garrett and I do have some beaters we don't care about we are happy to do this.

I do think that the antiques proper clamshell profile does help as in actual combat, the power and unpredictability of how the two blades will meet would be even greater than experienced in our controlled test.

[B.Ko]

Garrett and I repeated some of the parrying tests with his Jin-shi 'beater sword' and an example of the Hanwei Rodell Cutting Jian. Some observations.

1. Aligning blade flat prior to turning waist and parrying is vital to avoid edge nicks. However in the speed of even moderate drills, often timing is off on one or more party's end and edge/edge contact occurs, causing nicks. When I was able to align flat, depending on relative hardness of the blades, the softer blade will have a shallow cut into flat of blade.

2. The Hanwei Rodell jian sustained a 3mm long, .5mm or so deep nick. When I measured hardness both the Jin-shi blade and hanwei measured about HRC50-55, however, it's not an exact hardness measurement. The Jin-shi blade had a 'semi-clamshell' profile. The Hanwei jian's profile is not a beefy as the true clamshell on my antique jian blades. The Jin-shi blade suffered tiny nicks all under 1mm in size.

3. The nicks were easily polished out using a sharpening stone in less than 20 minutes work. The resulting disruption to natural curve of the blade was very slight, barely noticeable. This leads me to think the antique blades with large scalloped edge profiles either suffered a large nick or more likely had numerous repairs after damage from multiple encounters.

We'll be testing the Jin-shi vs. Huanuo blades next.

Overall these experiments give a glimpse of the reality of fighting with swords, even with techniques emphasizing avoidance of edge/edge contact, it will still occur. Also it also shows swords are NOT indestructible and polishing out nicks and chips were a part of weapon maintenance. For my own needs I'm going to focus on blades with a beefy clamshell even though it will decrease soft target cutting performance. Weapon toughness is more important.

[B.Ko]

Next up for tomorrow evening is the Jin-shi Beater Jian vs. Huanuo Royal Peony Sanmai!!!!! I'll post tomorrow after the results!!!!

[B.Ko]

This evening Garrett and I tested the Huanuo Royal Peony with Sanmai blade against his Jin-shi standard production sword that's he's using as a beater. We paid extra attention to getting the blade flat before turning the waist to deflect but as long as the upper thrust is with a horizontal blade, the dreaded edge to edge contact still occurred during parries.

Swords were nicked again. The Huanuo Royal Peony suffered some nicks about a mm deep and 2mm long or so. The edge seemed rolled so it may have been cut into. The Jinshi blade had some smaller nicks about .5- 1mm deep, and only about 1mm long. it seems the blade on that sword is tougher than the Hanwei Jian, an old Guertin blade, and a Huanuo Sanmai blade. I convinced Garrett to send the sword to Philip Tom to examine to see what's contributing to the toughness. Some things we discussed:

1: his sword is made of 1095 steel. I have no idea what the other swords are made of. Some of the nicks looked like 'cuts/gouges' so the 1095 steel may be a couple of HRC higher in hardness.
2: The Jin-shi blade has a semiclamshell contour, about 1/3 the distance between edge and spine, you can see a contour change as a different reflection of light. The guertin and Huanuo were flat diamond, the Hanwei has a contoured blade, but no where as beefy as some antique jian I own.
3: our guess is that his sword is slightly harder, and has a more robust geometry leading to a tougher sword. the edge still cut paper.

We tested a number of swords from opposite ends of the spectrum of cost. The more expensive ones didn't necessarily fare better in the parrying tests. If one wanted a good sword for practice I would try to find one with a more curved geometry and stick to basic models as it WILL get banged up.

[gchan]

(New) insight?

A proper clamshell not only strengthens the edge, but waaay more importantly it actually drastically reduces the possible range of angles where edge to edge contact could happen at all. One can parry at a fairly steep angle with no edge contact. With a flat grind you must go out of your way, curl wrist (which breaks structure) to parry cleanly and perfectly on the flat. Also of note is that I believe all parries are actually done at oblique angles. Perfect spine to edge would involve turning wrist unnaturally.

Thus, one could conclude that edge trauma on clamshell blades is the result of poor technique, fighting someone inexperienced, or having someone with a flat ground edge parrying you. Direct edge on edge between two blades with clamshell geometry is not possible with proper execution. I would go so far as to say that flat ground blades are not even remotely suitable for repeated combat. Merely the act of crossing swords virtually guarantees that edge trauma will occur.