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Post by rammstein on Dec 8, 2006 21:28:45 GMT
could someone explain to me what these mean? I see these thrown around quite frequently but have never actually understood its meaning. I'm assuming it has something to do with the blade structure. They are probably unrelated, but I have no idea.
Thanks for any and all help!
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Post by rammstein on Dec 8, 2006 21:29:37 GMT
(edit: pressed wrong button, ack. Sorry about this post)
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Post by Deleted on Dec 9, 2006 0:30:58 GMT
A secondary bevel is what you see when you look at a modern knife edge. You can clearly see a distinct edge on the blade that looks different in texture from the rest of the blade. This is because most modern knife blades are made with a somewhat blunt edge that is not sharpened until the blade has been completed. In other words, if you look at a modern pocket knife blade, you will see a distinct V-shaped edge that has been honed onto it. Most historic swords were ground and polished to a sharp edge from the get go, so that rather than having that V-shaped edge on them, they had edges that are sometimes refered to as "appleseed" edges. In this type of blade, there is no visible grind at the edges of the blade, since the flats of the blade are gradually tapered to a point. Hollow grinding was/is a method used to reduce weight in a blade, while maintaining a good degree of strength. It's tough (for me at least) to really describe what hollow grinding looks like, so I'll post some pics, when I find some. This pic shows a blade with a secondary bevel edge (left) versus the invisible edge on a modern high end sword (right). This second pic (forgive the crudeness, I just drew this up ) shows a cross section of a flattened diamond section blade (left), an example of flat grinding. On the right is a hollow ground diamond section blade. The red arrows indicate where material is ground away to reduce weight, while maintaining the strength and rigidity of the central ridge and a good strong reinforced edge. I'll look for a better illustration when time allows, but for now, I hope this answers your questions.
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Post by rammstein on Dec 9, 2006 1:25:20 GMT
Wow, thanks for the pictures and descriptions. I use hollow grinding many times in my designs of swords, but I've never actually known that that was what it is ;D
About secondary bevel...does it effect in any way the cutting ability and/or perfromance?
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Post by Deleted on Dec 9, 2006 1:56:27 GMT
Theoretically, the more traditional appleseed edge should "slip" through targets more easily, and perhaps be a little stronger, but I've been happily cutting all kinds of stuff (mats, 2 liter bottles, soaked newspaper, etc) for over a year now with secondary beveled swords without complaint. For most people I'd imagine it's more an aesthetic thing than a matter of performance: the originals were made without secondary bevels, so that's what they want. Antique European swords have been found that have secondary bevels, but these are generally believed to have been the results of troops "field" sharpening their swords rather than being made that way by the original smith. In any case, I've had no troubles with them. BTW: Cold Steel's Tai Pan has BOTH a hollow ground blade and secondary edge bevels. ;D www.coldsteel.com/13d1.html
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Post by Deleted on Dec 9, 2006 3:56:27 GMT
I felt like the discussion on secondary bevels might be helped with a more comprehensive photo. This is one I made in about 3 minutes. Please excuse my sloppy mess! I learned the difference off of a similar image. I find that looking for a secondary bevel makes finding out forgeries much easier as most modern SLO's and wallhangers are, more often than not, endowed with a secondary bevel. This is because it is cheaper and faster to grind down an edge on the stainless steel than it is to cast a correct edge. However, as kriegschwert stated, some authentic blades have secondary bevels. This is because troops in the field didn't have the supplies, time, or skill to reforge or correct their blades properly, and thus used some form of whetstone to quickly grind away at the edge. As stated, this really has no noticable effect when cutting with a secondary bevel. It is generally understood that, when cutting normal targets, the secondary bevel will wear down more quickly than an appleseed edge. This is probably because the material flows smoothley(sp?) over the appleseed edge, whereas the mateial probably gets caught on the place where the secondary and primary bevel meet, or for another reason. It's probably also the reason appleseeds cut more fluidly, whereas a secondary bevel can get wedged or stuck in the material. My thoughts on the subject anyway... L.
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Post by Deleted on Dec 9, 2006 5:28:55 GMT
Great additional illustration. Thanks. I will also add that even a flattened diamond (XV, XVIII) or hollow ground sword blade should have an appleseed edge. I just wanted to clarify this, since my above illustration erroneously shows the flattened diamond as a perfect diamond shape (I was trying to do it quickly rather than with complete accuracy). Basically, the edges would look more like the pic below:
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Post by Deleted on Dec 9, 2006 5:37:20 GMT
Right you are! Realistically all blades have meat on them, which gives that "appleseed" look.
L.
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Post by Deleted on Dec 9, 2006 14:40:29 GMT
This is more a question in regards to knives than swords but it fits the topic. Is it possible for a bevel to be so severe that it is near impossible to get a sharp edge on the blade? I bought some inexpensive knives to pratice sharpening (using hand stones, I have yet to invest in a belt sander). One of them in particular seems impossible to get sharp, it came dull to begin with and I have had no luck getting a good edge on it.
I get a decent start with the rough stones but whenever I switch to a finer one I end up rolling the edge. Granted it is not a high quality knife to begin with, it has a very severe bevel sort of like one you'd find on a throwing knife which if I understand correctely is made for strength rather than sharpness, I could be wrong and would love to learn more.
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Post by Deleted on Dec 9, 2006 18:59:42 GMT
This is more a question in regards to knives than swords but it fits the topic. Is it possible for a bevel to be so severe that it is near impossible to get a sharp edge on the blade? I bought some inexpensive knives to pratice sharpening (using hand stones, I have yet to invest in a belt sander). One of them in particular seems impossible to get sharp, it came dull to begin with and I have had no luck getting a good edge on it. I get a decent start with the rough stones but whenever I switch to a finer one I end up rolling the edge. Granted it is not a high quality knife to begin with, it has a very severe bevel sort of like one you'd find on a throwing knife which if I understand correctely is made for strength rather than sharpness, I could be wrong and would love to learn more. I am not real certian on this, but I'll post my thoughts anyway. Theoretically a blade can be sharpened from almost any bevel. Therefore, no, a bevel cannot be so sever as to prevent the blade from holding a sharp edge. The primary questions are: "What kind of steel is the blade made from?" and "What is the purpose of the blade?" Here is a good overview on sharpening and re-edging blades. Click meL.
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Post by Deleted on Dec 10, 2006 4:17:23 GMT
I would be concerned that if you try to shappen away the secondary belevel you will be removing too much of the metal from the blade for a very impractical reason, asthetics. While small knives with secondary bevels don't cut well and swords with bevles won't impress people by cutting paper cards with their sharpness, I have found that belevels are effective enough on swords because the sword is moving at speed with mass and momentum behind it. I prefer swords with natural edges but I do not remove belevels off swords that come that way like my Valiant swords.
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Post by Deleted on Dec 10, 2006 6:57:36 GMT
This is more a question in regards to knives than swords but it fits the topic. Is it possible for a bevel to be so severe that it is near impossible to get a sharp edge on the blade? I bought some inexpensive knives to pratice sharpening (using hand stones, I have yet to invest in a belt sander). One of them in particular seems impossible to get sharp, it came dull to begin with and I have had no luck getting a good edge on it. I get a decent start with the rough stones but whenever I switch to a finer one I end up rolling the edge. Granted it is not a high quality knife to begin with, it has a very severe bevel sort of like one you'd find on a throwing knife which if I understand correctely is made for strength rather than sharpness, I could be wrong and would love to learn more. In a way, the whole subject of secondary bevels is a knife topic, since a bevel like that is usually not very suited to heavy-duty hacking, but is perfectly good for carving a turkey. When one buys a (modern reproduction) sword, it will usually have a secondary bevel, but a decent set of files and a high threshold for tedium can give one something like a proper bevel. While this may take a couple of hours or more with a sword, and twice that if it came unedged, knives have an awful lot less edge to worry about... if your knife isn't taking a good edge fairly quickly, since your technique seems sufficient to sharpen most knives, I'd have doubts about the metal and/or heat treatment. The edge on a good, all-purpose knife should have a (Rockwell C) hardness of 55-62, which isn't really consistent with rolling the edge. If it's an inexpensive knife made of some sort of anonymous stainless, you may not be able to accomplish anything more than endless practice.
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Post by Deleted on Dec 11, 2006 14:54:06 GMT
I would be concerned that if you try to shappen away the secondary belevel you will be removing too much of the metal from the blade for a very impractical reason, asthetics. While small knives with secondary bevels don't cut well and swords with bevles won't impress people by cutting paper cards with their sharpness, I have found that belevels are effective enough on swords because the sword is moving at speed with mass and momentum behind it. I prefer swords with natural edges but I do not remove belevels off swords that come that way like my Valiant swords. I agree - you shouldn't remove a secondary bevel unless you have an excellent reason to do so, you'd just be removing too much metal from the blade. Katana rarely need to be polished because they are designed with wear down evenly when used in proper form. (i.e. slashing instead of hacking) However, a secondary bevel will need to be touched up, even if used for slashing. Therefore, a primary bevel suits a katana well. However, with modern knives and european swords, secondary bevels work fine. They are designed to slash and hack and chop. Because of this the blade will constantly need to be resharpened. It takes someone with considerable skill to polish a primary bevel, but a secondary bevel can be repaired by almost anyone. Therefore, secondary bevels work better in this sense. L.
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