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Post by Deleted on Dec 17, 2009 22:44:09 GMT
Alfight, now I know that you shouldnt sharpen a sword TOO sharp, but I was wondering... I have a Hanwei Bastard Sword and I wanted to know how to tell if a sword is optimumly sharp. I want to know how sharp I SHOULD get the blade. On most of my swords I sharpen them like a razor. I can make a blade split a hair that is laid on the edge, but thats not really how it needs to be. However, I dont know how it DOES need to be. Thanks, I appreciate it
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Post by Deleted on Dec 18, 2009 4:30:39 GMT
As sharp as it will stay when cutting reasonable targets.
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Post by Tom K. (ianflaer) on Dec 18, 2009 15:40:19 GMT
it's really a function of what you will be cutting. if you plan on banging it on people wearing mail armor and bashing through the rings to kill them then you probably don't want it very sharp while if you want to stick it through a slot in some knight's full plate and use it to slice him up you'd want it a little sharper but still not razor sharp.
as I doubt either of the above cases are true (or so I hope)I would assume you intend to cut plastic bottles, tatami, and maybe some bamboo (green stuff) or maybe some dowling. in that case knock yourself out and make your sword a 3 foot razor. if you already are familiar with that level of sharpness and the maintainence it requires then go fpr it.
generally what I do is follow the geometry of the blade and make it as sharp as I can without changing the geometry or thickness of the blade. that can be surprisingly sharp even for blades with serious thickness. I think the thickest edge I've worked was a Fable Blade. and while it didn't ever FEEL all that sharp it could still pop hairs a little and cut paper and paper towel easily. thicker edges can get very shar but they are pretty deceptive to feel. they'll still cut like mad though.
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Post by Deleted on Dec 18, 2009 17:22:55 GMT
Well, I just wondered if there was really an optimum "sharpness" for the sword. Like I said, I usually sharpen them like a razor so I prolly will this one. I say like a razor, but really I just sharpen them untill the edge is so thin it bends over when I run my ceramic rod over it but...
Thanks
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Post by Deleted on Dec 18, 2009 17:35:13 GMT
I wouldn't go with a razor-sharp sword, at least not me personally- my technique leaves much to be desired and an edge that keen will get rolled pretty quick by the likes of me. It also depends on the target in question, as Tom said- the harder the target, the broader you want that edge so that it doesn't roll and you're not left with a crowbar to hack away with, but can still cut.
For my part, I never understood the whole paper thing...why must a sword be THAT sharp? I'm of the mind that proper technique will make the better cut- so long as a sword is reasonably sharp, cutting's not an issue. My thought on that.
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Post by Deleted on Dec 18, 2009 19:12:53 GMT
Different question, how sharp should a modern tactical sword be? I mean, people are not wearing armor today (most don't at least) so IF a sword is made to be used for its real inteded use, what would you call an adequate sharpness? Keep also in mind that tactical sword have a pretty hard life, they're also used to clear vegetation, etc. Just so you know, I AM NOT planning to attack someone with a tactical sword, I just want to figure that out so I can see how well such a "battle ready" edge cuts.
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Post by Deleted on Dec 18, 2009 20:29:06 GMT
I wouldn't go for hair-splitting or paper cutting sharp; when I think tactical I think urban so I'd want a substantial edge...one that could take the abuse its going to inevitably be subjected to.
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Post by Tom K. (ianflaer) on Dec 18, 2009 22:22:39 GMT
A sword or blade that will see hard use against a variaty of targets and circumstances should still be sharp but it should have a nice thick edge geomtry.
as for cutting paper, any edge that is nice and clean will cut paper. all that really shows is that the ede is nice and smooth and clean. those Fable blades I sharpened for Shadowhowler cut paper quite easily but they are nice and wide so I very much doubt they would roll to much of anything. if you did a really good careful job of sharpening and refining it you can cut paper with a 90 degree corner. try rolling THAT edge!
so in answer, I think an edge should always be as sharp as you can get it, what you vary is the angle it comes together at. of course if you sharpen it too much you will change the angle of the edge making it thinner and thus more fragile.
probably the real question to be asked here is: what sort of angle should the edge have? orhow much niku, to use the Japanese term. as to that I think it all is up to feel but obviously the tougher the use the fatter the edge.
competition swords used to cut tatami and bundles of straw are often so thin they would never have served as a functional sword on a battlefield but they sure do make some beautiful cuts.
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Post by Deleted on Dec 19, 2009 11:30:45 GMT
Thanks guys. Yes, I guess then I would like to know the angle of the edge. I normally leave a 1mm edge on my blades before hardening and tempering and then I use files to get the two sides together. There's no secondary bevel, it's more like a strong appleseed shape. The resulting angle is quite similar to an accusharp one but smooth and one single bevel of course. This is the angle seen on my custom H/T longsword and it cuts cored newspaper mats cleanly, though not as cleanly as my ko kat. But I think that's caused by the much wider cutting blade, the longsword is a XVIII and not so much of a cutter. I know this is a stupid question, but is there any way I can test the sharpness of edges on my blades? I don't have tatami so do you think wet newspaper is good enough for determing cutting power?
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Post by Tom K. (ianflaer) on Dec 19, 2009 14:17:05 GMT
if it cuts the things you want it too with little effort then it is sharp enough for your use. I know that's a cop-out answer but it's still true. this is just something you have to experiment with and judge for yourself. like Sam said first as sharp as you can get it and still have it stay sharp when you cut resonable targets. so if you are rolling edges every time you cut, you have it too thin or you are cutting unreasonable targets. that's the real test right there: the cutting. simple right?
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Post by YlliwCir on Dec 20, 2009 19:27:47 GMT
I find the patented Tom K. beltsander method works well without haveing to think about it too much. It gets my blades hair popping sharp but they don't "feel" that sharp to the touch. This confused me at first because I thought the leather belt was dulling my blades, but Tom pointed out that wasn't the case and when I tried shaving hair off my arm I was soon arm hairless. It seems the leather belt was removing the burr edge that "felt" sharp to the touch. But I digress from the topic. Tom's metod gives me the hair popping edge and is durable. I cut regularly and the edges hold up well because the appleseed edge this method applies gives the blade plenty of meat to it also.
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Post by Tom K. (ianflaer) on Dec 20, 2009 20:37:35 GMT
ooooh it's patented now? groovey, I'll bank those royalty check!
I agree with Ric (obviously) the belt sander is pretty much perfectly designed to do appleseed or lenticular edges. flat diamond edges can be a bit tricky but aren't too hard if you are careful. you really gotta remove that burr edge. it may feel sharper but it really isn't, it's just more ragged, a nice smooth, polished edge cuts better and lasts longer
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Post by Deleted on Dec 21, 2009 3:09:54 GMT
I found this in my book. Hey, that's pretty neat! karma +1 Do you have the following page?
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Post by brotherbanzai on Dec 21, 2009 18:43:13 GMT
Hey lgarretto, I don't think there is any set rule about sword sharpness. Just depends on what you want, what you'll be cutting, how long you want your blade to last and how much maintenance you're willing to do. I personally would consider paper cutting sharp too sharp for my western swords. However, they will all cut pool noodles to bamboo without any problem. If you are going to get your edge so thin that you can bend it over with a ceramic rod, I would stay away from hard targets. Though if you want to slice up tomatoes for your salad, that would be perfect.
I personally would sharpen the middle third or so of the blade sharp enough that I can feel it catching on the grooves of my thumb print as I pull my thumb across (NOT along) the edge, but not so sharp that it will cut paper. This is where I'll be doing the majority of cutting. I consider that a rough guide without having to actually go out and cut something to test. I would sharpen the last 1/4 -1/3 of the blade toward the tip a bit sharper than that so it can be used for little quick cuts. The third or so of the blade toward the cross-guard I would leave comparatively dull as I won't likely be cutting anything down there and (if there were ever actually a sword fight) that's the portion of the blade where you would be catching your opponents blade. A little extra meat at the edge will help protect your blade is you're off a bit and catch his edge on your edge.
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Post by Tom K. (ianflaer) on Dec 21, 2009 21:45:45 GMT
I find myself wondering just how sharp paper cutting sharp is. this may sound funny but from BB's description of the edge catching the grooves of his finger print I think I could slice paper with that sword. the more I do it the more I begin to feel that slicing paper is more of a parlor trick than a real test of sharpness. yes, you need a certain amount of sharpness to be able to do it but not that much really. I'd love to be able to handle everybody's swords and try to slice paper with them and feel their edges to see what people consider sharp and not. the more I examine the issue of sharpness the more it seems like we have not yet been able to nail down a real objective method to measure how sharp a blade is.
in the end if it cuts your targets cleanly and easily and doesn't take damage from them it is sharp enough.
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Post by brotherbanzai on Dec 22, 2009 16:39:23 GMT
Interesting thought Tom. In my iaido class we used to "cut" sheets of newspaper with our blunt iaito. And I mean very blunt. Was more of a nice clean tearing though. When I think of "cutting paper" I mean holding the paper between two fingers and slowly drawing the blade across it and having the paper cleanly part. If when you say "cutting paper" you mean hanging the paper up (or tossing it in the air) and cutting it by swinging the sword through it then we are thinking of potentially different levels of sharpness. Funny, not only have we not nailed down an objective method of assessing sharpness, we might not have even nailed down what we mean by cutting paper
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Post by Tom K. (ianflaer) on Dec 22, 2009 18:49:45 GMT
no, I mean holding a piece of regular printer paper in my left hand and using my right hand with the sword to slice ribbons of paper off. I do know what you are talking about on cutting suspended paper as a training excercise and I've seen video and heard stories of schools (especially Gumdo) that do it with bokken even.
I find that with the right angle of the blade, cutting close to my fingers and fast enough draw that I can cut paper with pretty much any sword that isn't out-right dull. I was able to cut paper with a H/T bastardsword out of the box. of course after a day or so the scabbard had blunted it to the point I could no longer do it but it was be no means what I would call sharp to begin with when I did cut the paper.
so yeah, I'm increasingly of the opinion that slicing ribbons of paper off the sheet is not a very good test. at least not to anybody not holding the paper. if you are holding the paper you know how much you had to fiddle to get it to cut and you can feel how easily it slices but to anyone else it just doesn't help much.
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Post by Deleted on Dec 22, 2009 20:41:05 GMT
True, but I think at least you can say how easily the blade sliced the paper. That's good enough to get a feeling for the sharpness. Even for someone not holding it. In the end it seems that as long as a blade cuts what it should, it's sharp enough.
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Post by Deleted on Dec 22, 2009 22:32:23 GMT
sharpness also has to do with the polish of the blade in my opinion. I find mirror polished blades are much "sharper" and make cleaner cuts than satin finished or other finishes. I think a blade should be as sharp as necessary to complete the task you need it for, I don't think every blade should be paper cutting sharp or razor sharp.
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Post by Tom K. (ianflaer) on Dec 22, 2009 22:47:44 GMT
higher polish = smoother surface = less friction and drag = easier cutting = sharper at least in feel.
BW: agreed
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