- Joined
- May 15, 2011
- Messages
- 29
I saw a legitimate closed question on a Yahoo answer board -- is 440C a good steel for 12" Chinese Butterfly Swords? Most of the answers appeared honest, but the folks answering didn't appear to know much about butterfly swords as one was just a former western knife maker and the other I don't know what kind of martial artist despite his years of experience.
A number of factors go into picking the most appropriate steel for a Chinese butterfly sword pair: (1) how will it be used, (2) is the user willing to follow the maintenance routine required for a carbon based steel, (3) what can the user afford, (4) design.
Most of the folks answering the question had no understanding of (1) or (2) and apparantly no practical experience using properly heat-treated good quality 440C Butterfly Swords. Most Butterfly Swords are used in pairs by one person practicing martial arts forms in the air. These forms are like a dance routine. While the user may cross the blades from time to time, touching the edges, and hold both blades in one hand, the greatest impact these knives receive is the force from fast centrifugal movements or when a gym bag holding the knives is tossed in the trunk or dropped on the floor. Perhaps someone manages to drop one and misses his soft shoe.
Unlike knife afficandos, martial artists, outside of Katana-welding Japanese style folks, are almost universally unwilling to clean a blade, oil it, take the oil off prior to use, clean and re-oil and then store properly. Most will without hesitatation leave steel weapons in the trunk of a car on a humid day or freezing winter day to go to Kung Fu practice after work.
So, the first lesson is as a general matter, these users will not tolerate rust-prone carbon steels. That leaves stainless steels. Given the amount of impact these weapons take, and their short length (10" to narrowing 15" blades), you need to either pick a soft, high chromium stainless steel that can be brought up to the point where it will not bend all to heck during constant light practice, or pick a weapons grade stainless steel that will stand up to the expected use given the dimensions of the blade. In both cases the heat treatment is critical but so is the construction quality; you don't want the blade to rattle or come loose from the handle, especially if it is sharp or pointy.
Most cheap Butterfly Swords are made from low grade 420 or low grade 440 steels with piss poor heat treatment. It is good that they are soft, because they are more likely to bend than break if failure, but sad that they are soft due to poor quality rather than thoughtfulness. You can get a good quality 420J2 or a 420HC with enough carbon so that with proper heat treatment it can be weapons grade. In the latter case, due to the greater capability of the 420HC, you need to worry about leaving the knives at too high an HRC in which case they might be a bit more brittle and fragile than is optimal for a longer blade (and at risk of cracking). Randall uses 440B somewhat interchangeably with 440C, so it should be obvious to all that a good quality 440B can be brought up to weapons grade snuff with a good heat treatment. And no one should question whether a good quality 440C can be made weapons grade on an ordinary knife.
The complaint on the Yahoo board was that ALL of the stainless steels were too brittle to be used in longer 12" butterfly swords. The lesser stainless steels have been used successfully on these training weapons pretty much since the inception of mass manufacturing imports and the noticeable failures are the cheap tangs or poor fitting of the D Guards, which is not to say someone hasn't managed to break a blade instead of bending or denting it, just that it is not so prevalent that I have heard about it and the manufacturers, for liability reasons, were forced to switch to carbon steels. You can easily break a fine tip on a hardened stainless steel weapon if you drop it on a hard surface, but that is not the same thing as going after a target and having the blade break. Anyway, while folks who do not train with Butterfly Swords may consider the el-cheapos wall hangers, folks actually do use them with few complaints over the value proposition except they would like to be able to afford nicer swords. The Wing Lam "combat steel" sharps are unspecified stainless. I have a pair, I have used and abused them including on rare occasion versus staff, my pair is fine except for ordinary wear and tear on the sharp edge when the edges touch in a cross block. Of course I could abuse them to failure but I wouldn't.
Let's take it up a notch and talk 440C. Other custom butterfly sword clients and/or makers thought to use 440C and it worked. Take a 3.5 mm to 6 mm thick blade, harden it in the higher 50's being careful not to go too high, and from a functional standpoint it is good to go for the light use these weapons actually get. Never one to leave well enough alone, I have designed, specified, and/or received local overseas plant made, Hitachi and Bohler 440C steel blades, used, abused, and had them tested. I have used an expensive full custom Hitachi pair, wide hollow grind, narrowing stabber style, for my regular personal training pair for quite a while (as in I can't remember how long), including occasional light contact versus wood weapons, and it is in outstanding shape. Plus, to maintain it I just hit it with rubbing alcohol after every use, keep it was with Renaissance wax, and periodically do a more serious cleaning.
I have abused several of the Modell Design LLC 440C type steel hot drop forged integrals in the following ways. On several occasions using factory seconds I chopped the heck out of wood boards or rods (a Tiger Fork shaft). Swords were fine, wood was shavings. Did I mention those blades were hollow grind with an unsharpened edge? I have also bashed edge against rounded spine (rounded spine took some shallow nicks, edge dented, blade did not shatter in my hand) and edge on edge (nice dents). Since these are 440C hollow grind weapons designed and advertised for use only in one person forms practice, I was going overboard. Certainly a blade could have shattered in my hand but it didn't because of the design of the blade (including but not limited to profile, thickness, distal taper), steel choice and careful professional heat treatment, and LUCK (abusive testing, don't do this at home). Modell Desing LLC only made a limited number of these integrals (sold out rapidly).
I have film of our associate forge's master going nuts on some dead trees, playing machete, with 4 mm thick Bohler 440C blades on the new Modell Design LLC Long Stabbers (14 3/8" long blades, 4mm thick, wide hollow grind, 1 mm unsharp edge), again professionally heat treated. He had a blast, the swords were fine, the trees weren't. I took a new pair of these and smashed blade against blade using flats, edges, spine. I dropped a knife flat on concrete a few times and then dropped it tip first. The spines were nicked, and the edges were dented or nicked, but the blades did not shatter. Oh, contrary to my expectation the tip did not bend or shatter, you can barely see some push back on some edges, but then we have spent a lot of design time on the tip issue. There is no doubt in my mind that I would not want to be the person holding a staff I had paid for in weapon vs. weapon versus the Long Stabbers, which are in any event specifically designated only for forms practice and not for weapon vs. weapon or cutting exercises.
Incidentally, one of the best Western Knife makers does a beautiful full custom pair of CPM S90V butterly sword sharps, I believe made originally for a Hong Kong school. A top Chinese forge used lamellar stainless (not high carbon/nickel) on a full custom pair of long, sharp traditional blade BJD for me, and it was their choice to use stainless.
I am confident that if I spent enough time intentionally abusing stainless steel, medium or high carbon steel knives, I could destroy them. ALL BLADES can fail and will with enough persistance. Just think about the cracks that appear in airplane wings.
So, is stainless steel ever appropriate for Butterfly Swords used for one person training (no cutting, no weapon vs. weapon)? To reject stainless steel as a potentially appropriate material for Chinese Butterfly swords automatically is an error. I assume that as a result of the comments in the Yahoo board to the effect that 440C is never appropriate for butterfly swords, and that one fellow would never pay that much for a pair, the question asker declined to purchase a pair of integral firsts at the original discounted price of $275 or the later full price of $399. A friend of mine declined an offer of $500 for his pair of seconds. I just spoke to a fellow today who was picking up a pair of Long Stabbers, more appropriate for his lineage, and he said he would not part with his integrals. That said there are so many ways to go wrong with any Butterfly Sword that you should think about who is supplying them and exactly what you are getting.
Now let's talk D-2 semi-stainless, in my opinion the best high carbon steel for ordinary knives. For a long sword, like a Jian, I would recommend a top grade high carbon steel with a water quench on the expert heat treatment. You will have blades crack during the water quench that would be just fine with an oil quench, but you will never reach the optimum performance on a 1075 or 1095 with an oil quench. But for a Butterfly Sword, given all that was said above including the maintenance issue, D-2 is just excellent and it all goes back to the factors noted above. Once again some might argue the steel is innately too brittle for a 12" or 14" blade. There is (or was) film posted on the everythingwingchun.com web-site of the crazy forge master tapping on some shop vice kind of thing with an unsharpened D-2 Butterfly Sword and cutting into it AND of him putting the blade in a vice and bending it back like it was one of those Chinese flexible spring steel swords. The D-2 Butterfly Sword was fine. "Kids, don't do this at home." That kind of testing is just plain abusive and dangerous.
Now, let's say you are planning on serious weapon vs. weapon training sessions, what would you want on your butterfly sword? Well, if it is weapon vs. weapon unless you are nuts you want a dull edge. If you can make the edge a few millimeters wide and round it like a half circle you have maximum survivability. However, most martial artists do not want their training weapons to be a flat slab of steel or ultra-heavy so the wider that edge, the more client resistance you face. Still, a rounded edge (if you can manage not to sharpen it) is safest to you, will survive better, and less likely to destroy your opponent's weapon. No question any BJD (Wing Chun shorthand for Butterfly Swords) that is properly designed and constructed as a weapon can maim or kill another human being regardless of it is sharp, thats a given. Next, what kind of a grind is best? Easy, no grind (flat slab) and that really wide rounded edge but (1) client resistance and (2) so heavy it is slow and you can no longer block in time. Next best choice, a traditional lenticular grind with as wide an edge as your client will tolerate. There is the most steel supporting the edge. Worst choice, and not recommended for hard impacts, is the hollow grind because that creates the finest possible edge, with the least support. It is best for soft targets like flesh, but there is still some risk of nicking when you go through the body and hit bone. A lot of folks with hollow grind combat knives find that risk acceptable. What steels are good? Assuming proper prudent heat treatment, the traditional beater steel grade for training weapons would be, say, around 5160 or 5165 medium carbon steel (requires the full maintenance route) taking care not to under or over harden (heat treatment is king). Ive got to put D2 in there also but it just isnt fair to your opponents weapon, this is a steel used to cut other steels (so is 440C ...). Plus, once you have an actual person behind that weapon well, maybe D2 isnt a good idea. I would reserve the high carbon steel for forms practice and actual combat, not for abusive weapon vs. weapon training. I sincerely doubt that folks with ultra-expensive Japanese Katanas are busy smashing them into other weapons.
What about cutting exercises? The carbon based steels are indeed more resilient; stainless is inappropriate (despite the testing noted above). I would use a lenticular grind and a sharp edge. The traditional sharpness was more like a hatchet than a razor; more capable of surviving nicking. Which is more appropriate for cutting exercises?
Regardless of the use, each weapon must be inspected prior to every training session. This is especially true if the weapon has been subjected to the stress of weapon vs. weapon work, in which case it will degrade over time at a more accelerated rate until failure.
If you have not already read them, Kung Fu Tai Chi magazine published two of my articles on butterfly swords. Regards, Jeff Modell, Modell Design LLC
A number of factors go into picking the most appropriate steel for a Chinese butterfly sword pair: (1) how will it be used, (2) is the user willing to follow the maintenance routine required for a carbon based steel, (3) what can the user afford, (4) design.
Most of the folks answering the question had no understanding of (1) or (2) and apparantly no practical experience using properly heat-treated good quality 440C Butterfly Swords. Most Butterfly Swords are used in pairs by one person practicing martial arts forms in the air. These forms are like a dance routine. While the user may cross the blades from time to time, touching the edges, and hold both blades in one hand, the greatest impact these knives receive is the force from fast centrifugal movements or when a gym bag holding the knives is tossed in the trunk or dropped on the floor. Perhaps someone manages to drop one and misses his soft shoe.
Unlike knife afficandos, martial artists, outside of Katana-welding Japanese style folks, are almost universally unwilling to clean a blade, oil it, take the oil off prior to use, clean and re-oil and then store properly. Most will without hesitatation leave steel weapons in the trunk of a car on a humid day or freezing winter day to go to Kung Fu practice after work.
So, the first lesson is as a general matter, these users will not tolerate rust-prone carbon steels. That leaves stainless steels. Given the amount of impact these weapons take, and their short length (10" to narrowing 15" blades), you need to either pick a soft, high chromium stainless steel that can be brought up to the point where it will not bend all to heck during constant light practice, or pick a weapons grade stainless steel that will stand up to the expected use given the dimensions of the blade. In both cases the heat treatment is critical but so is the construction quality; you don't want the blade to rattle or come loose from the handle, especially if it is sharp or pointy.
Most cheap Butterfly Swords are made from low grade 420 or low grade 440 steels with piss poor heat treatment. It is good that they are soft, because they are more likely to bend than break if failure, but sad that they are soft due to poor quality rather than thoughtfulness. You can get a good quality 420J2 or a 420HC with enough carbon so that with proper heat treatment it can be weapons grade. In the latter case, due to the greater capability of the 420HC, you need to worry about leaving the knives at too high an HRC in which case they might be a bit more brittle and fragile than is optimal for a longer blade (and at risk of cracking). Randall uses 440B somewhat interchangeably with 440C, so it should be obvious to all that a good quality 440B can be brought up to weapons grade snuff with a good heat treatment. And no one should question whether a good quality 440C can be made weapons grade on an ordinary knife.
The complaint on the Yahoo board was that ALL of the stainless steels were too brittle to be used in longer 12" butterfly swords. The lesser stainless steels have been used successfully on these training weapons pretty much since the inception of mass manufacturing imports and the noticeable failures are the cheap tangs or poor fitting of the D Guards, which is not to say someone hasn't managed to break a blade instead of bending or denting it, just that it is not so prevalent that I have heard about it and the manufacturers, for liability reasons, were forced to switch to carbon steels. You can easily break a fine tip on a hardened stainless steel weapon if you drop it on a hard surface, but that is not the same thing as going after a target and having the blade break. Anyway, while folks who do not train with Butterfly Swords may consider the el-cheapos wall hangers, folks actually do use them with few complaints over the value proposition except they would like to be able to afford nicer swords. The Wing Lam "combat steel" sharps are unspecified stainless. I have a pair, I have used and abused them including on rare occasion versus staff, my pair is fine except for ordinary wear and tear on the sharp edge when the edges touch in a cross block. Of course I could abuse them to failure but I wouldn't.
Let's take it up a notch and talk 440C. Other custom butterfly sword clients and/or makers thought to use 440C and it worked. Take a 3.5 mm to 6 mm thick blade, harden it in the higher 50's being careful not to go too high, and from a functional standpoint it is good to go for the light use these weapons actually get. Never one to leave well enough alone, I have designed, specified, and/or received local overseas plant made, Hitachi and Bohler 440C steel blades, used, abused, and had them tested. I have used an expensive full custom Hitachi pair, wide hollow grind, narrowing stabber style, for my regular personal training pair for quite a while (as in I can't remember how long), including occasional light contact versus wood weapons, and it is in outstanding shape. Plus, to maintain it I just hit it with rubbing alcohol after every use, keep it was with Renaissance wax, and periodically do a more serious cleaning.
I have abused several of the Modell Design LLC 440C type steel hot drop forged integrals in the following ways. On several occasions using factory seconds I chopped the heck out of wood boards or rods (a Tiger Fork shaft). Swords were fine, wood was shavings. Did I mention those blades were hollow grind with an unsharpened edge? I have also bashed edge against rounded spine (rounded spine took some shallow nicks, edge dented, blade did not shatter in my hand) and edge on edge (nice dents). Since these are 440C hollow grind weapons designed and advertised for use only in one person forms practice, I was going overboard. Certainly a blade could have shattered in my hand but it didn't because of the design of the blade (including but not limited to profile, thickness, distal taper), steel choice and careful professional heat treatment, and LUCK (abusive testing, don't do this at home). Modell Desing LLC only made a limited number of these integrals (sold out rapidly).
I have film of our associate forge's master going nuts on some dead trees, playing machete, with 4 mm thick Bohler 440C blades on the new Modell Design LLC Long Stabbers (14 3/8" long blades, 4mm thick, wide hollow grind, 1 mm unsharp edge), again professionally heat treated. He had a blast, the swords were fine, the trees weren't. I took a new pair of these and smashed blade against blade using flats, edges, spine. I dropped a knife flat on concrete a few times and then dropped it tip first. The spines were nicked, and the edges were dented or nicked, but the blades did not shatter. Oh, contrary to my expectation the tip did not bend or shatter, you can barely see some push back on some edges, but then we have spent a lot of design time on the tip issue. There is no doubt in my mind that I would not want to be the person holding a staff I had paid for in weapon vs. weapon versus the Long Stabbers, which are in any event specifically designated only for forms practice and not for weapon vs. weapon or cutting exercises.
Incidentally, one of the best Western Knife makers does a beautiful full custom pair of CPM S90V butterly sword sharps, I believe made originally for a Hong Kong school. A top Chinese forge used lamellar stainless (not high carbon/nickel) on a full custom pair of long, sharp traditional blade BJD for me, and it was their choice to use stainless.
I am confident that if I spent enough time intentionally abusing stainless steel, medium or high carbon steel knives, I could destroy them. ALL BLADES can fail and will with enough persistance. Just think about the cracks that appear in airplane wings.
So, is stainless steel ever appropriate for Butterfly Swords used for one person training (no cutting, no weapon vs. weapon)? To reject stainless steel as a potentially appropriate material for Chinese Butterfly swords automatically is an error. I assume that as a result of the comments in the Yahoo board to the effect that 440C is never appropriate for butterfly swords, and that one fellow would never pay that much for a pair, the question asker declined to purchase a pair of integral firsts at the original discounted price of $275 or the later full price of $399. A friend of mine declined an offer of $500 for his pair of seconds. I just spoke to a fellow today who was picking up a pair of Long Stabbers, more appropriate for his lineage, and he said he would not part with his integrals. That said there are so many ways to go wrong with any Butterfly Sword that you should think about who is supplying them and exactly what you are getting.
Now let's talk D-2 semi-stainless, in my opinion the best high carbon steel for ordinary knives. For a long sword, like a Jian, I would recommend a top grade high carbon steel with a water quench on the expert heat treatment. You will have blades crack during the water quench that would be just fine with an oil quench, but you will never reach the optimum performance on a 1075 or 1095 with an oil quench. But for a Butterfly Sword, given all that was said above including the maintenance issue, D-2 is just excellent and it all goes back to the factors noted above. Once again some might argue the steel is innately too brittle for a 12" or 14" blade. There is (or was) film posted on the everythingwingchun.com web-site of the crazy forge master tapping on some shop vice kind of thing with an unsharpened D-2 Butterfly Sword and cutting into it AND of him putting the blade in a vice and bending it back like it was one of those Chinese flexible spring steel swords. The D-2 Butterfly Sword was fine. "Kids, don't do this at home." That kind of testing is just plain abusive and dangerous.
Now, let's say you are planning on serious weapon vs. weapon training sessions, what would you want on your butterfly sword? Well, if it is weapon vs. weapon unless you are nuts you want a dull edge. If you can make the edge a few millimeters wide and round it like a half circle you have maximum survivability. However, most martial artists do not want their training weapons to be a flat slab of steel or ultra-heavy so the wider that edge, the more client resistance you face. Still, a rounded edge (if you can manage not to sharpen it) is safest to you, will survive better, and less likely to destroy your opponent's weapon. No question any BJD (Wing Chun shorthand for Butterfly Swords) that is properly designed and constructed as a weapon can maim or kill another human being regardless of it is sharp, thats a given. Next, what kind of a grind is best? Easy, no grind (flat slab) and that really wide rounded edge but (1) client resistance and (2) so heavy it is slow and you can no longer block in time. Next best choice, a traditional lenticular grind with as wide an edge as your client will tolerate. There is the most steel supporting the edge. Worst choice, and not recommended for hard impacts, is the hollow grind because that creates the finest possible edge, with the least support. It is best for soft targets like flesh, but there is still some risk of nicking when you go through the body and hit bone. A lot of folks with hollow grind combat knives find that risk acceptable. What steels are good? Assuming proper prudent heat treatment, the traditional beater steel grade for training weapons would be, say, around 5160 or 5165 medium carbon steel (requires the full maintenance route) taking care not to under or over harden (heat treatment is king). Ive got to put D2 in there also but it just isnt fair to your opponents weapon, this is a steel used to cut other steels (so is 440C ...). Plus, once you have an actual person behind that weapon well, maybe D2 isnt a good idea. I would reserve the high carbon steel for forms practice and actual combat, not for abusive weapon vs. weapon training. I sincerely doubt that folks with ultra-expensive Japanese Katanas are busy smashing them into other weapons.
What about cutting exercises? The carbon based steels are indeed more resilient; stainless is inappropriate (despite the testing noted above). I would use a lenticular grind and a sharp edge. The traditional sharpness was more like a hatchet than a razor; more capable of surviving nicking. Which is more appropriate for cutting exercises?
Regardless of the use, each weapon must be inspected prior to every training session. This is especially true if the weapon has been subjected to the stress of weapon vs. weapon work, in which case it will degrade over time at a more accelerated rate until failure.
If you have not already read them, Kung Fu Tai Chi magazine published two of my articles on butterfly swords. Regards, Jeff Modell, Modell Design LLC
