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Paul Hansen
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 Posted: Thu 04 Nov, 2010 1:48 pm Post subject: |
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Good point, but I did already more or less make an exception for the military. Dress swords are similar, I guess: not much time for maintenance. Except maybe when privately owned, but still...
Back when I was beginning to get interested in knives (way before I "graduated" to swords  ), I was very interested in finding "the best steel". But after a while I learned that you have to sharpen and clean anyway. To be honest, I carried my cheap 420 or carbon steel folders more often than my expensive ATS34 folder, just because "I didn't want to mess it up". And I found out that carbon steel develops a character over time that stainless steel just lacks.
All of this doesn't translate well to swords, especially historically inspired swords, because they generally don't nearly see as much use.
Except for training swords of course. In this sense, I find maraging steel much more interesting than stainless.
http://en.wikipedia.org/wiki/Maraging_steel
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Timo Nieminen
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| Posted: Thu 04 Nov, 2010 2:06 pm Post subject: |
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| Paul Hansen wrote: | My question is why someone would use stainless for a sword...
The alloying components make the material more brittle. This can be overcome up to a point, but even among knife enthusiasts it is accepted that top quality stainless (ATS 34, S30V etc.) comes close in performance to the "ordinary" carbon steels, but that these stainless steels do not surpass them. Then the only advantage of stainless is that it is more rust resistant.
...
Nowadays, I challenge anyone to find a reason for using stainless steel in a sword. |
Corrosion resistance is about the only good reason.
420 is supposed to be easily polishable, so maybe OK for display pieces. And what's wrong with it for working pieces? It's relatively soft - it's not high carbon (420 steels are 0.15%-0.35% - don't know if this upper figure is reliable, but the lower one is). Still, it can be hardened to RC57 or so, at least the higher carbon ones. Lower carbon 420 not so much (maybe RC45?). Is RC45 so terrible for a sword blade? Certainly in the historical range. 420 makes up for it by being tough - not likely to fracture. Similar things could be said about 1045 carbon steel as a sword steel, or various other medium-carbon steels. 420 steels look like better sword steels than knife steels!
OK, so it isn't a very good sword steel. Terrible if you're after high hardness. But it's better than many steels that were used historically.
440C can be brittle. But what else would you expect from something with above 1% carbon? Hard, but can be brittle, especially if the heat treatment is off. Same thing can be said about very high carbon carbon steels. Same thing was said about wootz. From the European perspective, wootz blades with 1.2%, 1.3% carbon were just too brittle. Maybe 440C is a very poor choice for a backyard beater sword!
440A and equivalents seem OK. With good heat treatment, they should be sufficiently tough, and sufficiently hard. The 1060 or 1070 of stainless steels.
So, the reason to use stainless: corrosion resistance.
The reasons to not use stainless:
(a) Much harder to forge (I hear)
(b) Much harder to machine - if it's hardened 440, forget it. Oh, and it work hardens easily, so even if you start with it annealed and machinable ...
(c) Harder to get the heat treatment right (I hear)
Appearance could be either pro or con, depending on intent.
The stainless steel blades to watch out for are 440C blades from knife makers who heat treat it like a knife blade. (What about 1095 or tool steel blades from the same?) And, of course, blades of very poor quality.
What I would like to see are numbers for fracture toughness of typical properly heat treated specimens. And tensile strength.
"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.
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Maurizio D'Angelo
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| Posted: Thu 04 Nov, 2010 2:51 pm Post subject: |
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| Timo Nieminen wrote: |
What I would like to see are numbers for fracture toughness of typical properly heat treated specimens. And tensile strength. |
420C...... N/mmq. R = 500
6150 ....... N/mmq. R = 1400-1700
Maraging........... = average 2200
Applications 420-440 :
Surgical instruments, ball bearings, nozzles, valve and pump part
for oil wells, application where good corrosion resistance and
high wear resistance are required. Parts in diesel engines.
Best corrosion resistance is obtained on quenched and low
temperature tempered material with mirror finished surfaces.
Ciao
Maurizio
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Glen A Cleeton
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| Posted: Thu 04 Nov, 2010 3:49 pm Post subject: |
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Well, I've had a nap and some food but I think I could use a beer abd some popcorn at this point
| Quote: | I have reviewed the Full Tang Katana from United Cutlery. I have to say it was a great bargain. I already own the Traditional Katana from Generation 2 but I am reluctant to test the G2 katana because it has a traditional half-tang. The G2 Katana is made from carbon steel and has a 60/40 hardness.The Full Tang Katana is a single piece of 420 J2 stainless steel from tip to tip. It is 3/16 of an inch thick. I mention the G2 katana here because I use it for weight/balance comparison with the Full Tang Katana from United Cutlery.
First thing I have to say is when United Cutlery says full tang , they mean just that. The blade in its full thickness runs the entire length of the handle. The handle is two pieces of wood attached to the side of the blade. Three brass pins hold it in place. Click here to see The thickness of the blade, I think, makes up for the softer 420 J2 stainless steel.
This sword is rock solid. I have beat the tire over 2,000 times with it. I have also practiced making proper cuts. I place a piece of cloth over the tire and strike pulling the sword in a drawing motion. If the cloth has a long slice in it, the strike was correctly executed. This sword is also a solid thruster, that easily punctures the sidewall of the tire with no folding. The blade is very thick for it length. The following video demonstrates its blade strength. Blade Test
The Full Tang U.C. Katana is a little short for my taste. It is 36 inches. I find the 41 inches of my G2 Katana more comfortable. In handling, I find that Full Tang U.C. is not as pinpoint accurate as the G2 Katana were I can stop on a dime. I suspect this may be due to the shorter handle on the U.C. providing less leverage. Bottom line is that for $70 I bought a full tang sword that is tough and I can keep my $330 G2 Katana new while I learn to use this type of sword.The Full Tang Katan was bought through Bladematrix.com Click for full Picture Weight: 2 lb 5 oz |
http://mysite.verizon.net/tsafa1/swordreview.htm#katana
Hank Reinhardt used to market these slab handled soft stainless katana and tout them as great for event presentations. Go figure.
Also in regard to the military swords from WKC would be my wonder if any have bothered to read that they do temper a 420 series steel, although adding the disclaimer that the swords are meant for not more than drilling. 420 what though? Few really pursuing this discussion are really covering all the bases, with Buck using 420hc for years and successfully peroducing a durable edge.
Jerry Hossom was at one time using ATS-34 and here is a short sword from some time ago when he was playing with CPM3V but of I recall correctly was doing blades a good bit longer up to 28" or so.
http://forums.swordforum.com/showthread.php?s=&threadid=9760 I have honestly not been keeping tabs on him but a site and forum are available for further information.
Maurizio has now posted some numbers that may make sense for some but not for others. What becomes hard for any to filter for their own benefit is going to be a matter of picking out signal in the noise, which is where these quite general overviews go to being more a matter of who wants to type the most.
Hanwei has progressed to using another steel formula quite approaching corrosion resistant steels. What the formula actually is for those katana may be a secret for some time. Yet, go back again to the soft 420 swords that can take a beating.
I may be way off base but the reasoning behind so many of the cheap stainless swords was exactly a cost factor for production. While some may be harder to machine, boat loads are punched or cut out of sheet with hardmness really not an issue at all. These being the gumby soft blades that are near impossible to sharpen while not developing a frangible wire edge. The other boatloads of wowy zowy inexpensive not stainless katana have replaced some of that market and the truly basement level western medieval type not far behind (and have truly been with us right along as well (ala Cid et al).
The latter part of my first post in this thread goes to what does become a discussion of such diverse value and understanding that the initial question is long lost and some like myself find themselves cutting and pasting the same words year to year as initiatives start to learn but often just parrot without further thought or research. Then translate all the steel designations from country to country so everyone is on the same page 
I'd like to know more about the blade prompting Isaac to wonder how to tell if it is stainless or not. Was it indeed a sword? Can it be better described if not pictured?
Cheers
GC
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Isaac H.
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| Posted: Fri 05 Nov, 2010 12:06 am Post subject: |
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Well maybe I never did confirm that it was a sword ? Yes,it is, and it is straight,doudle edged with fuller and distal taper and it's definately a little on the short side.As I vaguely mentioned before,I am planning on posting a new topic regarding the actual hilting process.It will contain detailed specs on the blade to fulfill everyone's curiosity.I'm having difficulties uploading pictures(to many kb's),but hopefully I'll get a few on there . 
Wounds of flesh a surgeons skill may heal...
But wounded honor is only cured with steel.
We who are strong ought to bear with the failings of the weak and not to please ourselves.
Each of us should please his neighbor for his good ,to build him up.
Romans 15:1-2
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Glen A Cleeton
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| Posted: Fri 05 Nov, 2010 12:41 am Post subject: |
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Try www.onthegosoft.com/shrink_pic.htm if your photo hosting site doesn't help with sizing and compression. Some have a few extra tools such as www.imagecave.com Even the camera's software and settings can help for internet presentations.
Shrink Pic lives on your desktop, works seamlessly and automatically but also has some manual controls that can be utilized.
Dimensionally large can still be data frugal while still getting the image across.
Cheers
GC
a fer instance
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Maurizio D'Angelo
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| Posted: Fri 05 Nov, 2010 12:58 am Post subject: |
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| Glen A Cleeton wrote: |
Maurizio has now posted some numbers that may make sense for some but not for others. What becomes hard for any to filter for their own benefit is going to be a matter of picking out signal in the noise, which is where these quite general overviews go to being more a matter of who wants to type the most.
Then translate all the steel designations from country to country so everyone is on the same page
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those numbers mean:
a steel 420C has a 3 times less resistance to a steel like 6150 (European 51CrV4) and 4 times lower than a maraging steel.
Those numbers tell us that the failure for the 420C is easier for the same section.
Ciao
Maurizio
Last edited by Maurizio D'Angelo on Fri 05 Nov, 2010 11:31 am; edited 1 time in total
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Nathan Robinson
myArmoury Admin
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Karl Schlesien
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| Posted: Fri 05 Nov, 2010 3:56 pm Post subject: |
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The Japanese in II. Weltkrieg produces very servicable stainless steel blade for Marine ans Army (gunto).
I have owned very many and have handled up to sixty such katana made from stainless steel.
All are still very bright as the time that they weer made. They cut just as fine as a carbon steel katana.
Here are links to some very good sites on this anti-rust or stainless steel katana ( 耐錆鋼刀 ).
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http://www.h4.dion.ne.jp/~t-ohmura/gunto_121.htm
http://www.militaria.co.za/nmb/viewtopic.php?...t=takayama
Ans a quote from the last web site:
"Being a Takayama-to, it likely is one of the "stainless" blades that were produced for the navy.
Therefore the hamon will be artificial, and polished on. The polisher would have been responsible for the final lines and maybe adding the "hamon"
As such, they would not be allowed into Japan, and therefore a Japanese togishi could not repolish one.
A Western polisher would though. (But why would you want to, if there is no hamon or hada to bring out?)"
"Therefore the hamon will be artificial, and polished on."
I have aktually seen two that have beens tempered with a hamon it the traditional style. Rare? Oh yes very rare!
Has any knive makers tryed to temper a stainless blade as the Japanese do?
Some times I must try this.
Saluto Maurizio!
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Maurizio D'Angelo
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| Posted: Sat 06 Nov, 2010 1:38 am Post subject: |
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Ave a te, Karl
you wrote:
"All are still very bright as the time that they weer made. They cut just as fine as a carbon steel katana. "
is perfectly plausible. A katana in AISI 440 has a very hard but the most important thing and that has an excellent resistance to cut. But its tensile strength is low. If that katana is taken of the hands of an angry reenactor,  for a fight, it breaks more easily than a sword made of the same section with a different steel.
Ciao
Maurizio
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Paul Hansen
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| Posted: Sat 06 Nov, 2010 4:45 am Post subject: |
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| Maurizio D'Angelo wrote: | a steel 420C has a 3 times less resistance to a steel like 6150 (European 51CrV4) and 4 times lower than a maraging steel.
Those numbers tell us that the failure for the 420C is easier for the same section. |
Yes, but I think that charpy V values are more interesting than tensile strength.
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Maurizio D'Angelo
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| Posted: Sat 06 Nov, 2010 11:46 am Post subject: |
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| Paul Hansen wrote: |
Yes, but I think that charpy V values are more interesting than tensile strength. |
Paul you are right.
I want explain why I speak the resistance = R
Charpy pendulum impact test, determines the amount of energy absorbed by a material to fracture during a single blow of a hammer (it's a test machine, of course)
In other words, the force required to break the test. Is usually expressed in joules, at least in my country.
Is very useful to balance hardness and toughness. In general, however, swords do not offer too much, the hardness is a parameter that can not be changed, no one would like a sword of 38 HRC, in all media tend to be above 50 HRC.
Perhaps we should consider a sword as a structure that breaks not only with an impact, but with a concept of fatigue, (this is my personal opinion, for what it is worth) the resistance takes me to a good start with the modulus of elasticity.
Since most materials are weaker in tension than compression, this is the zone where cracks tend to form and grow. The resistance is a barrier to that normally are called forced dislocation.
Ciao
Maurizio
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Timo Nieminen
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| Posted: Sat 06 Nov, 2010 2:26 pm Post subject: |
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Some Charpy V-notched energies (from ASM metals handbook):
Cast carbon steels:
Carbon content, Charpy V-notch energy
0.2%, 85J
0.3%, 58J
0.4%, 38J
0.5%, 23J
0.6%, 15J
0.7%, 11J
0.8%, 9J
D2 tool steel, 30J
420 (52HRC), 20J (AZoM has 19-42J, depending on tempering temperature)
440C (57HRC), 2J (AZoM has 9J)
All samples quenched and tempered, tested at room temperature. Carbon steel values read from graphs, others from tables.
I didn't find Charpy energies for 440B or 440C. If found some Izod V-notch energies of 3J, 4J, 5J for 440C, 440B, 440A (2, 3, 4 ft.lbs), 14J (10ft.lbs) for 420. This would suggest about 8J for 440A, which is about 2/3 of the value for carbon steel of similar carbon content (0.6-0.75%).
I don't have values for carbon steels comparable to 440C (0.95-1.2%).
These values all depend on the details of the quenching and the tempering, so the numbers need to be treated with some caution. However, I'd conclude from these that
(a) stainless steels have about 2/3 the "strength" of carbon steels of similar carbon content when it comes to fracture,
(b) the medium and lower end of high-carbon stainless steels (420, 440A) are as strong as (higher carbon) carbon steels that are considered good or adequate sword steels, and
(c) 440C can be brittle.
(AZoM = A to Z of Materials, www.azom.com)
"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.
Last edited by Timo Nieminen on Sun 07 Nov, 2010 7:10 pm; edited 1 time in total
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Bennison N
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| Posted: Sun 07 Nov, 2010 5:45 pm Post subject: |
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I don't have anything to add to this discussion, but I just had to say that I'm amazed at some of the stuff I learn on these forums! Awesome, you guys!
"Never give a sword to a man who can't dance" - Confucius
अजयखड्गधारी
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Paul Hansen
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| Posted: Mon 08 Nov, 2010 1:06 pm Post subject: |
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| Maurizio D'Angelo wrote: | | Is very useful to balance hardness and toughness. In general, however, swords do not offer too much, the hardness is a parameter that can not be changed, no one would like a sword of 38 HRC, in all media tend to be above 50 HRC. |
For modern reproductions, I tend to disagree, but also take a look at this article:
A. Feuerbach, IAMS Journal 25, 27-43 (2005)
http://www.ucl.ac.uk/iams/journal.htm
| Timo Nieminen wrote: | | These values all depend on the details of the quenching and the tempering, so the numbers need to be treated with some caution. |
This is often claimed by many, especially by maker/manufacturers. Personally, I think that the steel mills and the international standards have a good idea on how to heat treat steel  . It may be short-sighted of me, but I tend to be skeptical regarding the claims of makers stating that their heat treatment is somehow much better than the competition's. Correct temperature control is of course important, but there are enough industrial hardening shops with really good equipment who really know what they are doing.
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Maurizio D'Angelo
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| Posted: Mon 08 Nov, 2010 4:53 pm Post subject: |
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Ciao Paul,
the article is interesting, I had read something on Kaminsky Early Medieval Weapons in the North Caucasus for my research on Byzantine swords.
As for the rest I do not understand why you do not agree. If I chose a steel with a hardening treatment and a hardness assigned, how do I change the value of Charpy V? Within certain limits, the value will fluctuate slightly, but does not solve my problem. But if I can get down with the hardness then the Joule necessary to break the test will be longer. For me it is simple or not I understand your point of view. I said you're right, the Charpy value is important, but I tend to associate the concept of fatigue ... there is a large amount of steel that stand up well to the first impact but then die of fatigue.
I think only one parameter is not enough, that's all my thoughts. Perhaps we are poorly understood? 
Ciao
Maurizio
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Timo Nieminen
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| Posted: Mon 08 Nov, 2010 5:05 pm Post subject: |
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| Quote: | | Timo Nieminen wrote: | | These values all depend on the details of the quenching and the tempering, so the numbers need to be treated with some caution. |
This is often claimed by many, especially by maker/manufacturers. Personally, I think that the steel mills and the international standards have a good idea on how to heat treat steel :confused: . It may be short-sighted of me, but I tend to be skeptical regarding the claims of makers stating that their heat treatment is somehow much better than the competition's. Correct temperature control is of course important, but there are enough industrial hardening shops with really good equipment who really know what they are doing. |
A good manufacturer will know what they're doing, but even then, "correct" is in the eye of the beholder. To make a good small knife blade of 440C, you want hardness, but don't need much toughness - it isn't going to be swung around with 10s of joules of spare energy available to break it. This is even more the case when heat treating metal-cutting tools vs heat treating sword blades.
Consider the values for Charpy V-notch energies for 420: 19-42J. The manufacturer can choose to be at the upper end of this, but this likely means ending up with lower hardness.
Since functional sword blades aren't exactly a major product in terms of the amount of steel used, figures for the properties of "typical" heat-treated steels are not necessarily that of steel with close to optimum heat treatment for a sword blade.
And that's without getting into fancy stuff, like bainite, differential hardening, cryogenics, etc. Or incompetence, which can and does have a significant influence on some products.
"In addition to being efficient, all pole arms were quite nice to look at." - Cherney Berg, A hideous history of weapons, Collier 1963.
Last edited by Timo Nieminen on Tue 09 Nov, 2010 4:34 pm; edited 1 time in total
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Paul Hansen
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| Posted: Tue 09 Nov, 2010 3:35 pm Post subject: |
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| Maurizio D'Angelo wrote: |
As for the rest I do not understand why you do not agree. |
That's because I made a mistake... I should have written that I agree that modern made swords should be around 50 HRC.
Sorry about that...
| Maurizio D'Angelo wrote: | If I chose a steel with a hardening treatment and a hardness assigned, how do I change the value of Charpy V? Within certain limits, the value will fluctuate slightly, but does not solve my problem. But if I can get down with the hardness then the Joule necessary to break the test will be longer. For me it is simple or not I understand your point of view. I said you're right, the Charpy value is important, but I tend to associate the concept of fatigue ... there is a large amount of steel that stand up well to the first impact but then die of fatigue.
I think only one parameter is not enough, that's all my thoughts. Perhaps we are poorly understood? |
I'm not sure how to interpret your concept of fatigue.
http://en.wikipedia.org/wiki/Fatigue_(material)
From Wikipedia:
| Quote: | | ASTM defines fatigue life as the number of stress cycles of a specified character that a specimen sustains before failure of a specified nature occurs |
In this sense, it's of course important for a sword, but not of the greatest importance, I think.
In simple terms, what does a sword need to do?
- Be able to hold a cutting edge (hardness / HRC)
- Not break while parrying (impact / Charpy V)
- Not break if you hit something with it (this is perhaps a bit complicated, but to me it seems like a combination of impact and perhaps a bit of bending (= tensile strength))
- Be able to resist the above for a useful period (fatigue)
- Resist getting somehow bent in a battle (tensile strength)
So in terms of material properties, it seems to me that impact energy and hardness are the most important parameters.
But in my opinion, in todays sword and knife market, there is too much focus on hardness alone. Probably because it's easy to measure and because it has a direct effect on how often the user will need to sharpen it. But since hardness and impact toughness are generally inversely related, having a sword with a blade that is too hard is not a good idea.
| Timo Nieminen wrote: | | A good manufacturer will know what they're doing, but even then, "correct" is in the eye of the beholder. |
Yes, of course. And you are right that the common industrial standards are not made with swords or knives in mind. So I'm not implying that there is no room for experimentation or improvement from a technical point of view.
Nevertheless, I have a feeling that there is a bit too much marketing going on with steel types and even more so with heat treatment. Steel type can at least be verified. If maker A claims that his method of heat treatment is better than that of maker B, then nobody has an objective way (besides destructive testing at a laboratory) to verify this claim. And that is what makes it an effective marketing tool.
But at the end, I feel that "spring steel" (whatever that is), for the vast majority of users, is more than adequate for both knives and swords. It's certainly better than anything used in the pre-industrial age.
In today's world, it becomes interesting to have "the best" sword. However, sometimes I feel that these swords are so good, that in this way they have little in common with the original swords. The hardness results in Dr. Feuerbach's article mentioned above, as well as in the myArmoury article:
http://www.myArmoury.com/feature_bladehardness.html
show a much wider range than would be acceptable now. Let alone the uniformity of the hardness over the blade... It seems that many medieval swords should have been rejected by modern standards. But apparently, they were usable enough for the people who relied on them...
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