[Vemnagelignc]

I've been wondering where I can find a good sword smith, or at least a company that does custom jobs for swords....if I can't find that, where can I go to learn how to make my OWN swords?!....*drools*

I would like to make a new type of Double edge japanese straight sword known as the 'Tsurugi Sword' it seems to have gone 'extinct' with the changing of the way of battle throughout japan's history, until it became the katana that is most commonly recognized today.....The tsurugi sword is a RARE gem indeed, one that I want with all my heart and soul to be reintroduced to the world in a modern day, simple design...can anyone help me to realize my dream?

[gkihueonhjh]

I find it strange that such a sword could just go 'extinct' the way it did....by modern standards, the SWORD by every shape and size is considered obsolete, and yields in power to firearms, and ranged weaponry....yet some swords are still considered practical, and still practiced today in various martial arts systems....at any rate, I feel this sword should resurface in a new way...I'm very interested in 'extinct' or 'dying' forms of swordplay and blades for some reason, and I'm sure with applying modern day blade smithing techniques, the power and look of these extinct blades could be fully realized....an era where the sword reemerges....interesting concept...

[Rounteetepehryn]

I've been wondering where I can find a good sword smith, or at least a company that does custom jobs for swords....if I can't find that, where can I go to learn how to make my OWN swords?!....*drools*

I would like to make a new type of Double edge japanese straight sword known as the 'Tsurugi Sword' it seems to have gone 'extinct' with the changing of the way of battle throughout japan's history, until it became the katana that is most commonly recognized today.....The tsurugi sword is a RARE gem indeed, one that I want with all my heart and soul to be reintroduced to the world in a modern day, simple design...can anyone help me to realize my dream?

dude, this is a kendo forum
I'll hazard a guess and say that most of us don't own any swords and the ones that do probably just have an iaitoh for the iai practice.

You may be better off going here
http://www.swordforum.com/

[Mark_NyB]

As far as I know, and I'm no expert (just a Roman history buff at one point), the straightness is a result of the process of creating the sword rather than any real... objective. A straight sword (or gladius in the Roman fashion) was generally made from bars welded together and forged as straight stock before being hammered and ground on both sides for an edge. However, the method of folding metal that the Japanese used to make a sword with one sharp edge generally changes the structure of the metal such that it naturally tends to curve.

I could be entirely wrong, but if you were wondering why straight swords died out in Japan, that's why. Swords with sharper edges were curved because of the process used in making the sharper edges.

[Rugda]

If you are truly interested you can find a concise history here:
http://www.thejapanesesword.com/
There are also pleanty of links and have you heard of this search engine called google? It's pretty swell.
Short easy answer= The straight sword disappeared as the sword evolved. Going back to the straight sword would be like going back to match lock guns after the flint lock was made available.
There’s my good deed for the day.

[Roferurse]

You're getting your terminology a little mixed up here as well as blowing things out of proportion. Refer to Neil's response to one of your other entries for an explanation on terminology. Also, if you read up on the history of swords in Japan, you'll find that as forging techniques progressed, double edged swords were cast aside in favor of single edged swords. From there the straight sword fell out of favor with the rise of mounted cavalry as curved swords were easier to draw from horseback and cut much better. As time progressed and cavalry gave way to single armed conflicts, the style in which the sword was worn changed, the curvature became less pronounced, was worn blade up through an obi, and became shorter. You'll get a much more detailed and informed explanation at the two previously mentioned sites.

Bottom line, rather than speculate and let your imagination run wild and be driven by your own sword fantasies, pick up a book or two, visit the sites we've mentioned, and learn the facts before coming to your own conclusions. Furthermore, Japanese Sword Arts (JSA's) or any other sword based martial arts aren't practiced because they're, "still considered practical," as you want to believe. They are practiced because people are drawn to the rich history that they represent and that they have been preserved in today's modern society. Again, please go and read up on the subject and make informed opinions rather than assumptions with no hard evidence.

[defenderfors]

However, the method of folding metal that the Japanese used to make a sword with one sharp edge generally changes the structure of the metal such that it naturally tends to curve.

Swords with sharper edges were curved because of the process used in making the sharper edges.

Folding the steel served to homogenize it and may have aided in carburization or decarburization (the adding in or taking out of carbon from metal). The folds wouldn't have contributed to any curving action.

If I understand correctly, the steel quality available to Japanese smiths was fairly low. They'd take river sand with a high iron content, smelt it, collect the chunks, and test for the one's that were most similar to what they'd seen work well (most likely using a spark test, you can see the difference between high carbon and low carbon steels by looking at the spark pattern).

Because the steel was generally far from perfect, they'd put it through a folding process, that would basically mix the steel to make it uniform. IIRC, the pounding removes impurities as well. And, ad nauseum, depending on the carbon content, there's a temperature at which the steel begins to carburize in the presence of high carbon material, like charcoal, in which carbon begins leaching into the steel. There's also a higher temp, where where the steel will start to "burn," as carbon leaches out of the steel.

The curve of the blade comes from two things, one being the symmetry of the blade. If I understand correctly, more mass on the back of the blade "pulls" more than the sharp side (the "ha"), which introduces the curve. The differentiated tempering (the mune is cooled at a slower rate than the ha, because smiths coat it with clary) also introduces a factor wrt how much the blade curves.

The varying types of steel used could also be a contributor. Because high quality high carbon steel was hard to get, it was often used just for the edge, with lower quality, lower carbon steel used for the rest of the blade. So the mune and sides would be low carbon, the edge high carbon, and both having different amounts of "pull" when the blade is quenched.

I've seen some discussion that the Japanese smiths constructed the blades with the different types of steel in order to improve the overall qualities of the blade (strong on the mune, hard on the edge), but generally with the working smiths who've discussed it, they acknowledge that a blade heat treated by differentially quenching then tempering, and made up entirely of high quality, high carbon steel produces a better blade.

Or I could be completely wrong.

-Charles Lockhart

[gardeniyas]

I could be completely wrong too, but what I'd learned is that the folding action changed the lattice of the metal such that it would curve when cooled rather than cool straight.

Your answer sounds much better, though!

[truttyMab]

I could be completely wrong too, but what I'd learned is that the folding action changed the lattice of the metal such that it would curve when cooled rather than cool straight.

Your answer sounds much better, though!

The folding process has nothing to do with it, the differential hardening process is what causes the blade to curve.

"A process of differential tempering causes martensite to form predominantly in the edge of the blade rather than the back; as the spine has lower retained lattice strain, it cools and contracts, and the blade takes on a gently curved shape." http://en.wikipedia.org/wiki/Katana

A smith can also produce a straight sword with a harder edge by bending the sword toward the edge before the hardening process so that the blade will bend back to straight when the martensite forms.

[Loopyjr]

Its not entirely true that you can make a straight sword just by bending it the opposite direction before tempering. The final curvature of the finished sword isn't something that can be pre-determined with perfect accuracy and you can't be sure that the sword will come out perfectly straight. The curvature can however be altered by the sword smith to some degree after the tempering is completed.

[Zwnkkvle]

Lots of good advice mentioned, take it all to heart. Lots to learn.

Where in the States are you? If you're honestly interested in using a forge and making a blade, try http://www.uoguelph.ca/~iaido/gsjsa_smithing.htm

[DiatryDal]

Its not entirely true that you can make a straight sword just by bending it the opposite direction before tempering. The final curvature of the finished sword isn't something that can be pre-determined with perfect accuracy and you can't be sure that the sword will come out perfectly straight. The curvature can however be altered by the sword smith to some degree after the tempering is completed.

Yeah, I think that's spot on. For an asymmetrical piece of steel I don't see how you could predetermine the amount of curvature that would occur, and set exactly the right amount of curvature in the opposite direction to make the final product straight.

You could do it in a lab setting, I think, because you could take out most of the random factors to some level: purity and qualities of the metal, machine out small defects, get very accurate temperatures, use a known solution for quenching. I'm not sure how modern machine shops handle differential quenching, but I'm sure they have something.

In a smithy, where you're eyeballing it, I don't see it happening by anything but dumb luck.

-Charles

[taesrom]

I could be completely wrong too, but what I'd learned is that the folding action changed the lattice of the metal such that it would curve when cooled rather than cool straight.

Your answer sounds much better, though!

Two things cause the swords to curve. First, as you pack the edge down with a hammer, the spreading and flatteing of the steel will put a pretty hefty curve in, and you actually have to periodicaly straighten the blade, or it will curve too much. The second is the hardening. As the steel gets hot, it expands. When quenched, the edge will be "locked" in this expanded state (quickly cooled), wheil the back cools more slowly, and shrinks back down. This shrinking pulls the edge back, and curves the blade. It also put huge amounts of stress in the steel, wich is why more blades get ruined during the quench than anywhere else.
Folding is only done to homoganize the steel. The steel used by the Japanese was VERY good steel. Almost no impurities, but carbon was not evenly distributed, folding fixes that problem.

[PristisoliTer]

Because the steel was generally far from perfect, they'd put it through a folding process, that would basically mix the steel to make it uniform. IIRC, the pounding removes impurities as well. And, ad nauseum, depending on the carbon content, there's a temperature at which the steel begins to carburize in the presence of high carbon material, like charcoal, in which carbon begins leaching into the steel. There's also a higher temp, where where the steel will start to "burn," as carbon leaches out of the steel.

It has more to do with where in the fire you are. If you put a piece of steel on top of your charcoal(carburizing layer of the fire), and let work its way down into the fire, carbon will be added in small quantities to the piece . If you put it on the bottom of the fire, close to the tuyers(oxidizing layer of the fire), the air flowing over the steel will combine with the carbon, and leach out as CO2 .

[sleepergun]

I could be completely wrong too

Yups, you are

[Rqqneujr]

It has more to do with where in the fire you are.

Because where in the fire you are can and will determine the temperature that the steel can get to.

If you put a piece of steel on top of your charcoal(carburizing layer of the fire), and let work its way down into the fire, carbon will be added in small quantities to the piece. Yeah, at the simple level that's just case hardening. But by putting it near the top of your charcoal, you're putting it in a cooler part of the fire, so you're heating it up in the presence of carbon, and keeping it at the temperature needed to work the carbon in. It's not like the charcoal fire is magic, you can get the same thing using a propane forge if you put material in to source carbon from.

If you put it on the bottom of the fire, close to the tuyers(oxidizing layer of the fire), the air flowing over the steel will combine with the carbon, and leach out as CO2 . Depending on your setup, you don't need to be near the tuyers to find a part of the fire that'll decarb your steel, there can be other places in your fire that are plenty hot enough, and you don't need direct air flow. Charcoal seems more forgiving than coal or gas, but you can still screw your metal up through decarb without having it close to the tuyers.

-Charles

[ZonaPutaX]

Yes, yes the curvature of a sword can be altered some what after the hardening process. In my previous post I wasn't trying to explain the entire smithing process just point out that the Japanese weren't stuck with curved swords because of the process, as was stated in this post:

I could be entirely wrong, but if you were wondering why straight swords died out in Japan, that's why. Swords with sharper edges were curved because of the process used in making the sharper edges.

Is it possible to make folded, differentially hardened, straight blades? Well, I made one when I took this course: http://www.youtube.com/watch?v=4l2PbvBeGkE

Here it is: http://i646.photobucket.com/albums/u...8/IMG_2126.jpg

[xrumerang]

Did the Europeans develop differential hardening pre 1700?