OT: Samurai sword making

Wed, Oct 17, 2007, 6:25am (EDT+4) [email protected] doth say:
Watched this show this week, probably will repeat. Catch it. Explains
how the swords are made, who makes them and the craft of the people
invovled. <snip>

Dunno why, but that reminded me of the Indiana Jones movie, where
the big guy comes out swinging a huge sword. Then Indie draws and
shoots him. LMAO



JOAT
"I'm an Igor, thur. We don't athk quethtionth."
"Really? Why not?"
"I don't know, thur. I didn't athk."

Toller,

> Am I mistaken about the explanation on the show?

Probably not. I was a bit confused myself about the differences in
properties
between the "inner and outter" blade material. I enjoyed seeing how
these swords are made - guess there's no OSHA in Japan! Some of the
work they were doing with the making of steel looked downright
medieval.

The cutting actions of the swords show that they came in different
slashing abilities. (The "5" body sword must be one mean piece of
steel).

I made a DVD of the show and I'll review it again.

I found this site to be quite interesting:

http://www.geocities.com/alchemyst/nihonto.htm

Probably more around.

MJ Wallace

> ... I have never heard of a Western woodworker gloat about a plane iron made in the Damascus Steel tradition; has anyone else?

I bought a small drawknife made of Damascus steel at the wildlife show
in Easton, MD some years ago. I claim it as the World's Prettiest
Drawknife (WPD). It also has curly maple handles.

I probably paid too much for it, but my criterion was "How would I
feel if someone else took this home?" Also, WPD is a Hell of a good
tool.

Joel

On Oct 17, 5:01 pm, Luke Kilpatrick <[email protected]>
wrote:
> Toller wrote:
> > It is way off topic, but since you brought it up, please tell me if I am
> > mistaken.
>
> > The show showed how they forged the high carbon steel shell to a low
> > carbon core, explaining that the low carbon gives the blade flexibility so
> > it
> > doesn't break and the high carbon gives it hardness for cutting. The
> > clear implication was that you have the best attributes of each, getting a
> > flexible hard sword.
>
> > That didn't make any sense; the shell would see more stress when it tried
> > to bend than the core, and being brittle would break long before the
> > material
> > in the core mattered. You wouldn't lose anything by making it all high
> > carbon.
>
> > I went to the website and read that the shell was expected to break in
> > combat and the sword relied on the core to keep it together so it could
> > still be used. Now THAT makes sense, but that is NOT what they said in
> > the show.
>
> > Am I mistaken about the explanation on the show?
>
> As others have said, the show was very interesting and visually
> oriented, but the technical details were, as is usually the case, sadly
> lacking.
>
> The high carbon outer shell of these swords was not used at full
> hardness, which would have rendered it too hard to sharpen and too brittle,
> especially on the cutting edge. It was tempered by a second heating to a
> lower temperature, leaving it still very hard, but not at it's maximum
> hardness. Additionally, it was "backed up" by the softer, but tougher,
> core, and this precluded breakage in any but the most extreme cases.
>
> One thing I'd like to note, for the record. The Japanese
> swordsmiths were absolute masters, because they were able to develop
> processes that could transform their raw, "as supplied" steel into a
> superior product. That raw material WAS NOT a superior steel! The smelting
> process was crude, and produced a nearly hopeless mess that was then beaten
> apart with sledge hammers so as to get little pieces of usable metals in
> various states of carbonization for further processing.
>
> The Nova piece focused far to much on the smelting, and gave the
> incorrect impression that the raw steel was somehow responsible for the
> quality of the finished piece, when this is just plain incorrect. But the
> fires from the smelters sure were pretty!
>
> Luke- Hide quoted text -
>
> - Show quoted text -



My understanding of Japanese sword-making was that they folded the
steel back on itself time after time after time.

So what you would have had was a series of laminations of hardened
steel and softer steel, which must have reinforced each other somehow.

These guys were true masters at the art.

On 18 Oct, 03:35, eric h <[email protected]> wrote:

> My understanding of Japanese sword-making was that they folded the
> steel back on itself time after time after time.

A popular misconception.

Traditional tamahagane steel begins by smelting the ore to iron by the
bladesmith themself, or by a small local group working together. A
significant difference from Western or Middle Eastern practice where
raw smelted iron bars have long been trade goods between refiners and
smiths, often in different countries.

The steel billet was split and forge-welded a large number of times,
just as for wrought iron. They used a blister steel process (soft iron
with carbon soaked into the surface to make a steel) and this re-
welding redistributed the carbon throughout the billet. Traditionally
the same billet is split in two partway through this and one goes on
for a few more cycles to make the high-carbon edge steel. These days
(and for woodoworking tools) the softer steel is usually a recycled
wrought iron, whilst the hard edge steel is freshly smelted. Nor was
the billet strictly "folded" - it's split in two and re-stacked.
Folding it over instead would be a great route to making yourself a
"cold shut" (a weak void) in the apex of the fold.

Once the workpiece has gone from being "a billet" to being "a crude
sword", then the steel is _not_ folded. It might be wrapped once to
weld the two steels, but that's your lot. Some patterns set a hard
edge into a soft wrapper, some wrap a hard sheath around a soft core.
What doesn't happen in the Japanese tradition though, is any notion of
pattern welding such as European practice and particularly the Norse
or Saxon swords. For those patterns, the actual sword structure
reflects large scale twisting or welding. This is clearly visible
afterwards.

If you can see laminations in a "Japanese" blade without looking very
closely, it's a modern Chinese fake (likewise painted dragons!)

As to the crack-resistant behaviour, then this is a complex subject
that changed over history. The primary goal is to avoid a sword
snapping in combat, with a secondary goal being to allow small cracks
but stopping them propagating. "Samurai swords" aren't unbreakable and
never were, and their makers recognised this. Much of the effort to
stop crack propagation was done by differential tempering, rather than
controlling the laminations. Although the edge is one solid piece of
high-carbon steel, it was zoned into hard and soft areas within this
by the heat treatment. The lower-carbon and thus always soft core was
some distance behind the crack-trappinng zone.


There's overlap between swordsmiths and cutlers (kitchen knives), but
negligible overlap between swordsmiths and woodworking tool smiths.
Their techniques and raw materials are quite distinct. As chisels are
stuck with hammers, they use a larger-scale macro-laminated structure
where the "soft" steel is much closer to being an elastic soft iron.
Different tempering wasn't used either - where a chisel is hard or
soft, this is controlled by the alloy, not the tempering.

Read Leon Kapp. Still the best introductory book around on the sword
processes. There's even some woodworking in it - he describes 4
craftsmen, one of whom is a saya (scabbard) maker. Yumoto's old book
is worth looking out for too - probably the first post-WW2 book to
popularise Japanese swords in the USA. If you want to see beautiful
modern pattern-welded work, read Jim Hrisoulas' third book.


And don't ever believe anything you see on a telescreen.
Those things only exist to sell you beer and burgers, not to educate.

>> Watched this show this week, probably will repeat. Catch it. Explains
>>how the swords are made, who makes them and the craft of the people
>> invovled. <snip>
>
> Dunno why, but that reminded me of the Indiana Jones movie, where
> the big guy comes out swinging a huge sword. Then Indie draws and
> shoots him. LMAO
>

Yes, that was a funny bit of movie fiction.
However, IMHO, the sword used in that movie looked like an impractical
version of the Ottoman Empire's Kilij type sword. which I doubt that style
was ever used in real combat. A 'Damascus Steel' scimitar (from the
Crusades era) would have been more practical, (long, thin, curved, and sharp
point) but not as cinematic for the joke.

Sure wish PBS would do a comparison between the steel of a samurai sword and
a Damascus Steel sword. I have never heard of a Western woodworker gloat
about a plane iron made in the Damascus Steel tradition; has anyone else?

I mean, the Ottoman Empire and Damascus steel tradition reached well into
the Caspian Sea region and over to Austria. Thus I am sure the woodworkers
in the Ukraine and as far away as Vienna would know about the value of
Damascus steel for their tools.

Phil

Toller wrote:


> It is way off topic, but since you brought it up, please tell me if I am
> mistaken.
>
> The show showed how they forged the high carbon steel shell to a low
> carbon core, explaining that the low carbon gives the blade flexibility so
> it
> doesn't break and the high carbon gives it hardness for cutting. The
> clear implication was that you have the best attributes of each, getting a
> flexible hard sword.
>
> That didn't make any sense; the shell would see more stress when it tried
> to bend than the core, and being brittle would break long before the
> material
> in the core mattered. You wouldn't lose anything by making it all high
> carbon.
>
> I went to the website and read that the shell was expected to break in
> combat and the sword relied on the core to keep it together so it could
> still be used. Now THAT makes sense, but that is NOT what they said in
> the show.
>
> Am I mistaken about the explanation on the show?


As others have said, the show was very interesting and visually
oriented, but the technical details were, as is usually the case, sadly
lacking.

The high carbon outer shell of these swords was not used at full
hardness, which would have rendered it too hard to sharpen and too brittle,
especially on the cutting edge. It was tempered by a second heating to a
lower temperature, leaving it still very hard, but not at it's maximum
hardness. Additionally, it was "backed up" by the softer, but tougher,
core, and this precluded breakage in any but the most extreme cases.

One thing I'd like to note, for the record. The Japanese
swordsmiths were absolute masters, because they were able to develop
processes that could transform their raw, "as supplied" steel into a
superior product. That raw material WAS NOT a superior steel! The smelting
process was crude, and produced a nearly hopeless mess that was then beaten
apart with sledge hammers so as to get little pieces of usable metals in
various states of carbonization for further processing.

The Nova piece focused far to much on the smelting, and gave the
incorrect impression that the raw steel was somehow responsible for the
quality of the finished piece, when this is just plain incorrect. But the
fires from the smelters sure were pretty!

Luke

eric h wrote:


>
> My understanding of Japanese sword-making was that they folded the
> steel back on itself time after time after time.
>
> So what you would have had was a series of laminations of hardened
> steel and softer steel, which must have reinforced each other somehow.
>
> These guys were true masters at the art.


That's correct. They would take lots of small pieces of steel
from the smelters, sort them into groups having high and low-medium
carbon, using a lifetime of experience, and then begin the process of
forge welding them into larger bars.
Because they could never get homogeneous pieces of sufficient
size, they had to fold and weld repeatedly to get bars large enough
to produce the components of the swords. This process, which is long,
tedious, and never far from disaster, through overheating and ruining
the steel, produced bars having just the desired characteristics.

The Nova piece detailed one method of construction, but in
fact there were several "blueprints" used, all of which combined two
or more bars into the final composite piece that they forged out into
a blade. The common characteristic was that the edge was formed from
a very high carbon bar that was the hardest part of the blade.

Luke

In article <[email protected]>, Luke Kilpatrick
<[email protected]> wrote:

> As others have said, the show was very interesting and visually
> oriented, but the technical details were, as is usually the case, sadly
> lacking.

Start here:

<http://sethgodin.typepad.com/seths_blog/2007/10/what-youre-up-1.html>

He links to a site of a gent who built a forge, starts with charcoal
and iron ore, and makes swords...

--
Help improve usenet. Kill-file Google Groups.
http://improve-usenet.org/

<[email protected]> wrote in message
news:[email protected]...
> Watched this show this week, probably will repeat. Catch it. Explains
> how the swords are made, who makes them and the craft of the people
> invovled. Amazing. It's important to woodworkers, because if you own
> or used Japanese chisels, it's possible it was made by someone who's
> family for generations made swords. The same practices continues with
> how the metals are forged together. One of low carbon, the other of
> high.
>
It is way off topic, but since you brought it up, please tell me if I am
mistaken.

The show showed how they forged the high carbon steel shell to a low carbon
core, explaining that the low carbon gives the blade flexibility so it
doesn't break and the high carbon gives it hardness for cutting. The clear
implication was that you have the best attributes of each, getting a
flexible hard sword.

That didn't make any sense; the shell would see more stress when it tried to
bend than the core, and being brittle would break long before the material
in the core mattered. You wouldn't lose anything by making it all high
carbon.

I went to the website and read that the shell was expected to break in
combat and the sword relied on the core to keep it together so it could
still be used. Now THAT makes sense, but that is NOT what they said in the
show.

Am I mistaken about the explanation on the show?

Dave Balderstone <dave@N_O_T_T_H_I_Sbalderstone.ca> writes:

> <http://sethgodin.typepad.com/seths_blog/2007/10/what-youre-up-1.html>

Good read! Steel making can indeed be an art.

"Andy Dingley" <[email protected]> wrote in message
news:[email protected]...
> On 18 Oct, 03:35, eric h <[email protected]> wrote:
>
>> My understanding of Japanese sword-making was that they folded the
>> steel back on itself time after time after time.
>
> A popular misconception.
>
> Traditional tamahagane steel begins by smelting the ore to iron by the
> bladesmith themself, or by a small local group working together. A
> significant difference from Western or Middle Eastern practice where
> raw smelted iron bars have long been trade goods between refiners and
> smiths, often in different countries.
>
> The steel billet was split and forge-welded a large number of times,
> just as for wrought iron. They used a blister steel process (soft iron
> with carbon soaked into the surface to make a steel) and this re-
> welding redistributed the carbon throughout the billet. Traditionally
> the same billet is split in two partway through this and one goes on
> for a few more cycles to make the high-carbon edge steel. These days
> (and for woodoworking tools) the softer steel is usually a recycled
> wrought iron, whilst the hard edge steel is freshly smelted. Nor was
> the billet strictly "folded" - it's split in two and re-stacked.
> Folding it over instead would be a great route to making yourself a
> "cold shut" (a weak void) in the apex of the fold.
>
> Once the workpiece has gone from being "a billet" to being "a crude
> sword", then the steel is _not_ folded. It might be wrapped once to
> weld the two steels, but that's your lot. Some patterns set a hard
> edge into a soft wrapper, some wrap a hard sheath around a soft core.
> What doesn't happen in the Japanese tradition though, is any notion of
> pattern welding such as European practice and particularly the Norse
> or Saxon swords. For those patterns, the actual sword structure
> reflects large scale twisting or welding. This is clearly visible
> afterwards.
>
> If you can see laminations in a "Japanese" blade without looking very
> closely, it's a modern Chinese fake (likewise painted dragons!)
>
> As to the crack-resistant behaviour, then this is a complex subject
> that changed over history. The primary goal is to avoid a sword
> snapping in combat, with a secondary goal being to allow small cracks
> but stopping them propagating. "Samurai swords" aren't unbreakable and
> never were, and their makers recognised this. Much of the effort to
> stop crack propagation was done by differential tempering, rather than
> controlling the laminations. Although the edge is one solid piece of
> high-carbon steel, it was zoned into hard and soft areas within this
> by the heat treatment. The lower-carbon and thus always soft core was
> some distance behind the crack-trappinng zone.
>
>
> There's overlap between swordsmiths and cutlers (kitchen knives), but
> negligible overlap between swordsmiths and woodworking tool smiths.
> Their techniques and raw materials are quite distinct. As chisels are
> stuck with hammers, they use a larger-scale macro-laminated structure
> where the "soft" steel is much closer to being an elastic soft iron.
> Different tempering wasn't used either - where a chisel is hard or
> soft, this is controlled by the alloy, not the tempering.
>
> Read Leon Kapp. Still the best introductory book around on the sword
> processes. There's even some woodworking in it - he describes 4
> craftsmen, one of whom is a saya (scabbard) maker. Yumoto's old book
> is worth looking out for too - probably the first post-WW2 book to
> popularise Japanese swords in the USA. If you want to see beautiful
> modern pattern-welded work, read Jim Hrisoulas' third book.
>
>
Thanks for your explanation, not that I understood it all. My single
metalurgy class was 35 years ago.
Watching the show I thought it would be better to wrap a hard cutting edge
in soft steel. I guess someone agrees with me!

As with most TV shows they focused on exciting visuals and spent
way too much time on the smelting process and far to little time on
accuracy.

I found this book at my library. It is far more informative.
Title : The craft of the Japanese sword
Author : Kapp, Leon, 1943-
Publisher, Date : Tokyo ; New York : Kodansha International ; New York, N.Y. :
Distributed through Harper & Row, 1987. - Edition : 1st ed.
ISBN : 087011798X (U.S.)

Art

"Toller" <[email protected]> wrote in message
news:3%[email protected]...
>
>
> The show showed how they forged the high carbon steel shell to a low carbon
> core, explaining that the low carbon gives the blade flexibility so it
> doesn't break and the high carbon gives it hardness for cutting. The clear
> implication was that you have the best attributes of each, getting a
> flexible hard sword.
>
> That didn't make any sense; the shell would see more stress when it tried to
> bend than the core, and being brittle would break long before the material
> in the core mattered. You wouldn't lose anything by making it all high
> carbon.
>
> I went to the website and read that the shell was expected to break in
> combat and the sword relied on the core to keep it together so it could
> still be used. Now THAT makes sense, but that is NOT what they said in the
> show.
>
> Am I mistaken about the explanation on the show?
>
>