The folding technique you describe sounds/looks a lot like a part of a program I saw called “The Living Treasures of Japan.” Their pre-eminent swordmaker was shown, along with his assistants, endlessly[or so it seemed] folding over the metal bar used in one of these much sought-after swords. What is it in this technique that makes the swords so good? Realignment of molecules? Gradual dispersal and removal of impurities? Is it a Zen thing? A fascinating piece, not truly a lost art, just one the Japanese are trying not to add to THAT list.
Hmmmm… I swear I just heard wind chimes…
At first thought it seems that it would be lacking to some extent. That laminated structure is very nice for making a sword that is both resistant to crack propagation and strong. From what I understand, the cracks don’t travel well through the layers, so you can make a sword that is more highly tempered, and can still have the battlefield usability that one should need.
This is where there is a danger in considering one scientifically measured characteristic and extending it to a more general characteristic. Such as - harness versus keeping an edge. One could simply compare hardness numbers and say “Well, if 440C is harder than the steel used in Damascus swords, then it should keep a better edge.” However, the edge of the weapon is not depending on just the hardness. At a microscopic scale, the edge has to maintained by:
- Hardness and resistance to impact penetration.
- Resistance to cracking, chipping, flaking off, and other spalling of the metal at a microscopic level.
However, even with those two main factors, there are others at play. Falling back to the good online reference earlier, http://www.tms.org/pubs/journals/JOM/9809/Verhoeven-9809.html, it’s worthy to note the construction of the swords (and there are some nice micorgraphs on that page). It seems to me that the folding process is concentrating Fe3C (carbide) particles between the folded layers of the steel - thus, if I am reading it right, making a sword that would have an edge made up of steel, steel with lots of carbide, steel, steel with lots of carbide…you might I guess have an edge that close up looks sort of like this (exaggerated scale):
F = iron-rich bands
C = carbide-rich bands
F
CFC
FCFCF
CFCFCFC
FCFCFCFCF
CFCFCFCFCFC
FCFCFCFCFCFCF
It seems to me, speaking off the cuff, that a sword with an edge like that would be able to keep an edge much better than its Rockwell hardness would imply. And given its laminated structure, it seems it would be more resistant to some of the failure mechanisms that occur along the edge (depending, of course, on the thickness of the banding). This would imply that my (hypothetical) 440C sword, although harder and stronger via testing, might actually underperform the Damascus one in terms of keeping its edge.
Now, vapour coating the 440C steel with titanium nitride (which would also make it have a pretty cool gold colour, like my zirconium nitride drill bits I love soooooo much 
) would give it an very hard surface that might make up for some of it - but what happens when the surface wears due to actual combat use? You can’t re-vapour coat it in the field, after all. You would have to sharpen it, and re-coat it. So from a practical standpoint of a sword which could stand up to numerous battles, it wouldn’t work.
In short, I think that speculating further on this to compare one versus the other in terms of hardness leaves some question now in my mind what might be better - the Damascus sword or the 440C one. Or even if they might be roughly equivalent.
Una
Always happy to oblige! 
I like Randi, but he doesn’t provide any cites either. Randi says can’t be any better than random says.
All right, it seems that the moving of megaliths is less interesting than making swords, but not to me.
This site covers some of the ideas of how the Moai were moved and challenges to them by Joanne Van Tillburg. Basically, there is no evidence of wear on the stone to indicate that they were dragged using ropes. While Heyerdahl may have moved them easily over flat ground, most of Easter Island isn’t flat, being volcanic and such. Also, by the time europeans got to the island, it was treeless. Van Tilllburg believes that the species of palm that was common on the island was used in the moving of the statues. There are also some holes arond the island that were roughly the size of the trunk of the trees, and may have served to help move them. Nova did a show about Easter Island and they tried a few stratagies to move the Moai that worked and didn’t cause damage that would be present in Heyerdahls method.
These guys claim to have engineered the best sword ever. (And I do mean engineered. Here’s the Wired article on how they did it.)
Oh, and Una, you might want to lurk here. It’s a BBS for machinists and they post notifications of sales and places with good prices on equipment frequently. (You’ll no doubt find some of their comments about engineers “entertaining”. ) Brigeport’s recently changed hands and from some of the comments on the board, I gather that the quality of the newer machines is lacking, so you might want to snag a slightly used model. (Not hard to do, since many machine shops are going belly up these days. A pity that, I may have to look at a career change because of it.)
Tuckerman
The hardness tests sound intriguing, but ultimatley they tell me nothing about how good a sword has turly been created.
The quality of blade is NOT summed up in it’s hardness. There are many, many other qualities that need to be addressed.
Having two blades pressed against each other edge to edge says absolutely 0 about wether or not this would be a functional sword.
Swords are not MEANT to be used in this way. You do not go smashing your sword’s edge against another sword’s edge or a very hard material. It doesn’t matter what kind of steel is involved, you WILL eventually ruin the sword (even on this test the ‘super’ sword chipped.
Another point made by the article is the ultimate goal of the team: to create a sword that could ‘hypothetically’ cut through a medieval (japanese) sword (a katana is very different form a european sword, but let’s ignore that for now).
But what if they did accomplish this? Who cares if the sword, having several thousand pounds of pressured applied to it consistently could chop through a medieval blade? How does that help the swordsman on the battlefield?
Ultimately I see these guys looking at the problem very one-dimensionally. This is not their fault. They simply lack knowledge of HOW a sword was used, and in what way it is expected to function by a man on the battlefield.
An anology would be (just fo the top of my head), a group of scientists who know nothign about formula 1 racing decide their going to buil the ultimate formula 1 car.
They use the fastest engine most powerful engine. They use the most aerodynamic shell, etc.
But come race day they loose the race. Why? They didn’t take into account gas consumption. The darn thing kept running out of gas. Also, control, stability, and handling were nto taking into consideration, consequently the car went super fast in the straight aways, but it did not perform well at all on the curves.
I hope you get my point
Really? I thought that was the whole idea of a swordfight…
Ever heard of armor? A sword that could cut through another sword and still maintain 90% of it’s edge would probably go through armor (and the poor bastard inside of it) rather easily, don’t you think?
**
Bad analogy. Really. An aerodynamic shell is going to improve fuel consumption, and high speed on the straightaways is going to be an asset. If the driver’s good enough (and really, if you’re going to shell out the money for one of those cars [BMW’s budget is in the tens of, if not hundreds of, millions of dollars] are you going to let your cousin Charley drive the car? I think not.) He can use it all to his advantage. He blasts through the straightaways as fast as he can, thus putting enough distance between himself and the other drivers that he can afford the extra time spent in the pits refueling the car. (See, he’s going to know about the increased fuel consumption because they’re going to have to take the car out and test it before they get to race it. The rules require that sort of thing, ya know?)
More on metallurgy:
The one thing most are foprgetting here is the era from which “Damascus” came. Iron has been around for a while, but steel considerably less so.
As Una pointed out earlier, most of the swords and other edged weapons up to relatively recently (middle ages or later) were predominantly simple wrought iron. You have to remember that most metals of the day were fabulously expensive- there have been more than a few times through history, very long periods, where iron and steel cost more than gold or silver.
This was usually because of the huge investments in manpower it took to make it- the ore had to be mined, then refined, then smelted, then poured and forged into bars. And also keep in mind this involved many steps we take for granted- their coal was often very expensive, or the formation of coke for their forges took a lot of time, wood and care.
Now, converting iron to steel was as simple as adding carbon. But that in itself was a tricky maneuver. No one figured out how to add it directly to the molten iron (and keep it there) until only a few hundred years ago. Back in the mideval European and Japanese times, they literally “folded” the carbon into the iron.
They’d take a bar, hammer it out so it was longer and thinner, and while it was bright-red-hot, dip it in a tray of finely-ground coal or pulverized coke- both of which are basically pure carbon. (Una is gping to pop in here and give me a spectrographic breakdown of Anthracite vs. Bituminous or something, but I can take it. 
)
Anyway, this applied a thin layer of carbon to the surface of the iron. They’d then fold that bar over and hammerweld it back into one piece. This gave them a block with a thin- microscopic, really- layer of carbon-iron on the outer surfaces, and a slightly thicker layer of carbon-iron in the center, with two layers of the plain iron seperating them.
Then, they’d hammer it out into a long bar and do it all again. Fold it a second time, and now you have an eight-layer thick sandwich- varying layers of iron and carbon-iron.
Do this two or three times, and you have a bar maybe a half-inch thick (in it’s “raw” state) with perhaps a hundred layers, alternating soft iron and somewhat harder carbon-iron (which is, of course, steel.)
This process was basically the only way they knew how to add carbon to iron to get the steel, but it worked. It was, however, fantastically expensive in both materials, time, and resources (coal/coke, wood, ore, etc.)
The best Japanese 'smiths would go one more step, and laminate layers with varying levels of carbon into one blade: a bar of fairly soft iron for the back, or ‘spine’, a bar of very hard steel for the edge, and two thin layers of medium-hard for the flats/sides. The soft spine would give it the flexibility and shock-resistance to keep from breaking, the sides would be just hard enough to withstand blows and still add a measure of rigidity, and the edge, of course, would be hard enough to hold a keen cutting surface.
[aside] When you hear of “folded” steels, that’s what they’re talking about- folding the carbon in. When they’re talking about “folded 1,000 times” or some such nonsense, they’re talking out their sphincter. One bar folded becomes two layers, folded again it becomes four, then eight, then sixteen.
If the finished blade is then about a quarter-inch thick, each layer would then be about 0.015" thick. That’s with four folds making sixteen layers. Six folds would make 64 layers, each just under four thousandths of an inch thick. Folded “a thousand times” would, last I checked, make “layers” considerably thinner than the diameter of the iron atom itself.
Layers much under about eight to ten thousandths of an inch (0.008" to 0.010", roughly that of a sheet or two of paper) don’t work as well, as there’s not as much differentiation between the high and low carbon zones- it basically just becomes one chunk of medium-carbon steel.
[/aside]
Getting back to the original argument, the fact of the matter is- and Una illustrated quite well- that those supposedly miraculous “Damascus” blades aren’t in fact all that great.
However, they were astoundingly good for their day. Therein lies the key: Just as in the land of the blind, the one-eyed man is king, here, in a world of soft iron, a somewhat harder steel is king.
The folded-steel blades were everything we’ve heard: harder, more flexible (iron just bent- steel, properly tempered, bent and sprung back) held an edge longer, could cut through softer iron armor all too easily, and so on. For all this, they gained the reputation of being miraculous- rumor has it that an early, well-made steel sword was the source of the legend of Excalibur. A steel sword that could cut through existing iron weapons but would not bend or break would have been seen as truly miraculous.
However, we have since learned more about how to put carbon into the raw steel directly, to burn out other impurities, to add other traces for additional benefits (molybdenum for hardness and wear resistance, vanadium for flexibility, chromium to add corrosion resistance, etc) we’ve also learned how the carbon forms austentite and martensite within the iron- the key it it’s hardness- and we’ve learned a great deal on heat-treating. (We can now quench to 300 degrees below zero, anneal in baths of molten salts, and more precisely temper.)
The concept and process of “Damascus” has not been lost- like the above mentioned ideas of Battleship armor and buggywhip making, or how about barrel cooping?- it’s simply been more or less abandoned when better processes have come about. We no longer need to laboriously hand-fold the carbon into the iron, we can buy the steel with a fairly precisely known quantitiy of trace elements and carbon already in it.
However, there are still people making them the “old fashined way”. One example of some top-notch blades is Bugei Trading Company, from whom you may order your choice of hand-forged katana made to your spec- length, curve, tip, temper edge, fittings, etcetera. Their “inexpensive” “mass produced” blades start at a thousand bucks.
Stage fighting, perhaps. This is indeed what you see in the movies. This is NOT how medieval warriors used the sword.
No, I don’t think so. First of all, the article was talking about placing the blades together at very high pressures. They were NOT talking about the force of a man swinging the thing.
Steel CANNOT cut through steel with the forces we’re dealing with here. It may shatter a weakened blade, but it’s not going to cut through it, this is just fantasy.
[QUOTE]
Bad analogy. Really.
[QUOTE]
Maybe it was. I know very little about formula 1 car’s it was just an off-hand example I thought up. But I think you get my point, even if the facts in the example don’t quite add up. Anyway it could still work if, when designing the engine to be extremely fast, they negelected to think about gas consumption. If the engine guzzles down gas like crazy it isn’t going to help things.
My main point was that since these people are not taking into consideration very important factors, the end result will be no better, in fact perhaps worse, than the real thing when it comes to the swordsman on the battlefield.
No, I don’t think so. First of all, the article was talking about placing the blades together at very high pressures. They were NOT talking about the force of a man swinging the thing.
Steel CANNOT cut through steel with the forces we’re dealing with here. It may shatter a weakened blade, but it’s not going to cut through it, this is just fantasy.
[QUOTE]
Bad analogy. Really.
[QUOTE]
Maybe it was. I know very little about formula 1 car’s it was just an off-hand example I thought up. But I think you get my point, even if the facts in the example don’t quite add up. Anyway it could still work if, when designing the engine to be extremely fast, they negelected to think about gas consumption. If the engine guzzles down gas like crazy it isn’t going to help things.
My main point was that since these people are not taking into consideration very important factors, the end result will be no better, in fact perhaps worse, than the real thing when it comes to the swordsman on the battlefield.
Argh! darn hamsters!
As long as the idea of “real swordfighting” is going to be bandied about, how do we know precisely how a medieval knight would have used his sword? Assuming that manuals of protocol existed, the number of men who could read them, even among the arms-bearing classes, would have been small. Even for those who read, the restricted nature of publishing would have made it unlikely that a manual would have found its way to a fighting man. Last, the exigencies of the field would have made textbook training look pretty silly. So what source do we go to in order to figure these things out? I would say that we have no idea how they actually used those swords. Therefore, we cannot say exactly what they would have needed in a sword. In fact, the style of fighting might not even have been dictated by the available weaponry (a la Of Arms and Men). We have no idea what they were doing with those swords in battle, except in extremely limited circumstances when we can find bones with cutmarks.
Last, I just want to throw in my two cents on the issue of steel. The metals we have available today are so far superior to what was available then as to be different metals entirely. Ancient swordsmiths were ruled by their limitations, limited by what they could make the metal do. Modern metalworkers are limited only by what the metal can do.
I asked this same question last year:
http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=144584
What’s that got to do with swordfighting?
Good thread. Very civil. Thanks for the link.
Well… sort of. There were two types of Damascus steels used- the “wootz” type and the folded(pattern-welded) type. The art of making the folded type was never lost- that’s why you could buy Damascus shotgun barrels in the 1880s! However, like you said, it’s not that strong, and those barrels aren’t safe to fire with today’s shotgun shells.
“Wootz” damascus was a type of Damascus steel where the patterns in it were not due to folding of different colored steel- it’s a property of the steel itself, and the smiths brought it out through various grinding and forging techniques.
And I think what I’d said earlier is still more or less true- it wasn’t so much a lost art as a lost source of steel. Without the ingots from that particular part of India, there wasn’t any more wootz Damascus steel being made.
Some quotes from my post, click here for more info because some are taken out of context and contain more info in the thread:
jjimm: My great-grandfather was one of the last people in the UK able to make clay brick kilns. With him died the art. Not of course that it’s needed anymore.
Athena: blacksmithing, computer software/ability to read old files
Mr. Blue Sky: reverse engineering the Kitty Hawk flyer
Duckster: The Mayan calendar
Sampiro: Supposedly the Incan quipos contained vast amounts of information, but there was nobody alive within a generation of the Spanish conquest who could read the knots.
Muad’Dib: Many Chinese inventions
Ringo: Well, I didn’t easily find much in the way of definitive sources, but I seem to recall that the Nazis had a method of artificially synthesizing oil that didn’t survive WWII. UL or not?
Honkeytonkwillie: I think you’re refering to a method used to produce a gasoline-like fuel from natural gas. “White gas” maybe? I don’t remember much, but I heard about it a few years ago as a possible means of transporting natural gas from the North Slope. It had high energy overhead, something like 30% of gas would be consumed in the conversion alone, even before transport.
The Scrivener: Hand-grinding lenses, in the manner of Anton Van Leewenhoek (the Dutch inventor of the microscope), perhaps? Although a certain crafted aspect survives in the creation of one-of-a-kind superlenses for the Hubble Telescope and its like. Also, slide rulers, mimeograph machines, IBM punchcard systems, and Chinese typewriters (with their massive trays holding hundreds of character tiles) are all falling into history’s tech dustbin. Not that they couldn’t be revived in a pinch, I suppose… but I can’t imagine the circumstances. Does anybody know from personal observation if the abacus has fallen out of use in Asian commercial establishments? I wonder if, outside certain rubber-producing developing nations, if any industry still uses natural rubber – vulcanized or unvulcanized. In the medical field, there’s a pressing need for today’s physicians to be able to readily recognize smallpox, bubonic plague, etc. and to immediately alert the proper authorities. Those are diagnoses that no early-Renaissance-era physic would have had difficulty with. the turntable/cartridge/needle combo
BobT: I work in a BIG public library and I used to be responsible for the 680 section of the collection, which I always called “screwball technology”. There were books on how to repair your jacquard loom, how to be a wheelwright, how to fix a Conestoga wagon, stuff like that. Some books covered processes and technologies that I had no idea what they were about.
Agback: The technology for producing a purple patina on bronze was known in Classical times, lost in the Middle Ages, and recently recreated. The technology for producing so-called ‘Damascus Steel’ was known in mediaeval India, but was lost. There have been several claimed re-creations of this technology. The technologies for producing and rowing the classical galleys called ‘triremes’ and ‘quinquiremes’ were lost in Roman times (a possible consequence of the introduction of catapults at sea). There used to be a heated controversy among historians about several basic issues, but now that several reconstructions have been built and rowed we seem to be conveging on agreement about the basics: how many banks of oars, how many rowers per oar, what a rower’s ‘cushion’ was made of and what he wore it for, etc. So it certainly seems possible to lose individual items of technology, but perhaps a case could be made that those above are all cases in which technologies were abandond because they had become obsolete. Perhaps the most fascinating example is the loss of the ability to make fishhooks and to fish by the indigenous people of Tasmania. For unknown reasons, about 3500 years ago, Tasmanians stopped making fishhooks, fishing, eating fish. They were still not doing so in the early 19th Century, though the fish were (by that time at least) perfectly wholesome.
DRomm: The rheostat in motion picture projectors
Telemark: In New England, starting (IIRC) in the 1960’s, people started to preserve and restore old covered bridges. Unfortunately, no one really knew how to build them anymore. Some timber framers found some old timers who had worked on them way back when and recreated the art. Now there are a small number of folks who restore old bridges and build completely new ones.
Krokodil: In the 1930s, John J. Earley developed a type of masonry called Polychrome.