2000 year old sword

[Brian]

Dan, move out of the USA and get to the metric system.
0.5% is HALF of ONE percent. It is not 50%
That would be written as 50%
Note the decimal point. Zero point 5%. Less than zero percent.
In decimal terms, 0.5% is 5/10 = half
2% is... 2. So 4 times more carbon.

0.5% is very different to 50%

[Bugyotsuji]

Also note that Continental Europeans tend to write 0,5 using a comma for a point, but it means the same thing as 0.5 (half of one) = 1/2, which is 50% of one, not 50% of 100.

 

Dan, glad to meet you. At last I’ve met someone with math(s) even worse than mine, I think! 

[John C]

4 hours ago, Dan tsuba said:

Just want to make sure I am interpreting everything correctly, so I can learn.

Dan:

I don't think it's a problem with your math, but simply a problem with interpreting the way the data was written. They are talking about percentages and you are trying to convert to decimal. Don't convert. .5% is less than 2%; indeed, 4 times less. If converted to decimal, 2% is .02 and 1/2 percent is .005. So 2 is still larger than .5. Hope that helps.

John C.

[rematron]

.50 is 50% of 1  (50 hundredths of 1 ) so 50/100 or 50%

.02 is 2% of 1  (2 hundredths of 1) so 2/100 or 2%
 

.05 is 5% of 1

 

.20 is 20% of 1

 

.01 is 1% of 1   (1 hundredths of 1) so 1/100 or 1%

 

.5% is half of 1% so instead of 1/00 it is 1/200 or .5/100 

 

to further clarify or confuse

 

[1kinko]

Dan- your problem isn’t math, it’s Latin. Percent is per centum or by the hundred = per 100.

[Dan tsuba]

Hello all!

 

So, thanks to everyone for the help with the percentage math!  I now know more than I ever wanted to know about percentages!  Ha, ha, ha, ha, etc!

 

Anyway, about cast iron and swords.  So, the article referenced in my previous posts is long and involved.  But thanks to all the members’ help, I think I figured it out (or maybe not!).

 

So, the article states that cast iron has a carbon content of 2.11% or higher.  The article states the decarburization procedures used in China lowered the carbon content (down to about 0.4%).  Carbon steel is a steel with carbon content from about 0.05 up to 2.1 percent by weight.

 

https://en.wikipedia.org/wiki/Carbon_steel

 

So, that is how they made soft malleable iron (steel) from cast iron (I hope I got that right – I mean right now my “head hurts” from figuring this stuff out!  Hey, just kidding!).

 

The below graph shows the two different processes for making soft iron (from the article).

 

 

O.K. I figured that out!  So, in China they used the “indirect process” to make soft iron (steel) from cast iron using a blast type furnace.  I have found no research that states they used the same technique to make swords (or other weapons) in Japan. 

 

In Japan they used bloomery iron, the “direct process”, to make steel (made in a tatara type furnace) to forge their swords. 

 

I wonder why?  Was the cast iron blast furnace (and then undergoing decarburization and annealing) to soft steel method a too “time intensive” undertaking?  Were the swords in China cast in molds, then annealed, decarburized,  and then hammered? Was the method “lost to history” from China to Japan?  Were the resulting swords too liable to breakage (even after being annealed?).  Was the tatara furnace a “simpler” means to an end for producing swords in Japan?

 

I know that these questions may hold no interest for some members.  But maybe there are others out there (like me) that finds this stuff fascinating!

 

Anyway, just some more interesting stuff that probably will never be fully figured out!

 

Onward!

 

With respect,

Dan

[John C]

Dan:

The answer to those questions may be D: All of the above! From an historical perspective, remember the Japanese did get much of their information and insight from the Chinese. And indeed, there was a lot of experimentation with different methods of production for probably several centuries. Remember too that most smiths at the time were guided by shintoism and everything, including the water, fire, river sand, and oxygen used to make the sword had a kami, or spirit. It is conceivable therefore, scientific production methods were blended with spiritual methods.

John C.

[rematron]

I think one of the possible reasons is it was just easier to make the blooms from the iron sand that was available. Sure it was time consuming but what would have been the rush?  When things take time there is attention to detail and specialization. To the average smith a bloom could have seemed like a more obtainable goal then the energy and technology required to melt iron. And maybe they liked the meditation of the long effort.  
 

I’m pretty sure I’m repeating sentiments and opinions that are elsewhere in this thread so I apologize for that. 

[Jacques D.]

Dan ,

 

Quote

 

In Japan they used bloomery iron, the “direct process”, to make steel (made in a tatara type furnace) to forge their swords. 

 

I wonder why?  Was the cast iron blast furnace (and then undergoing decarburization and annealing) to soft steel method a too “time intensive” undertaking? 

 

 

It is a problem of raw material, satetsu cannot be reduced in a blast furnace.

[Ynot]

Hi Dan, here some more  info for you.

 

 

The primary advantage of the early blast furnace was in large scale production and making iron implements more readily available to peasants.^[30] Cast iron is more brittle than wrought iron or steel, which required additional fining and then cementation or co-fusion to produce, but for menial activities such as farming it sufficed. By using the blast furnace, it was possible to produce larger quantities of tools such as ploughshares more efficiently than the bloomery. In areas where quality was important, such as warfare, wrought iron and steel were preferred. Nearly all Han period weapons are made of wrought iron or steel, with the exception of axe-heads, of which many are made of cast iron.^[31]

Blast furnaces were also later used to produce gunpowder weapons such as cast iron bomb shells and cast iron cannons during the Song dynasty.

 

 

 Blast furnace- Wikipedia

[Dan tsuba]

Hello all,

 

So, thanks Tony for that reference to the Wikipedia article about blast furnaces.  A lot of good information there!  I quoted the entire section on “China” below. 

 

Wow!  It states they used workforces of over 200 men to work their blast furnaces.

 

I can see how in Japan a “family” of maybe 1 to 5 people would prefer to use a tatara furnace to make steel.  John, Jeremy, and Jacques have provided some valuable and great information in their current posts about steel making in Japan.  To me they have “brought it all together” about the difference of making steel swords in China and making steel swords in Japan!

 

Onward!

 

With respect,

Dan

 

“China

See also: History of metallurgy in China

Archaeological evidence shows that bloomeries appeared in China around 800 BC. Originally it was thought that the Chinese started casting iron right from the beginning, but this theory has since been debunked[clarification needed] by the discovery of 'more than ten' iron digging implements found in the tomb of Duke Jing of Qin (d. 537 BC), whose tomb is located in Fengxiang County, Shaanxi (a museum exists on the site today).[19] There is however no evidence of the bloomery in China after the appearance of the blast furnace and cast iron. In China, blast furnaces produced cast iron, which was then either converted into finished implements in a cupola furnace, or turned into wrought iron in a fining hearth.[20]

 

Although cast iron farm tools and weapons were widespread in China by the 5th century BC, employing workforces of over 200 men in iron smelters from the 3rd century onward, the earliest blast furnaces constructed were attributed to the Han Dynasty in the 1st century AD.[21] These early furnaces had clay walls and used phosphorus-containing minerals as a flux.[22] Chinese blast furnaces ranged from around two to ten meters in height, depending on the region. The largest ones were found in modern Sichuan and Guangdong, while the 'dwarf" blast furnaces were found in Dabieshan. In construction, they are both around the same level of technological sophistication [23]

 

The effectiveness of the Chinese human and horse powered blast furnaces was enhanced during this period by the engineer Du Shi (c. AD 31), who applied the power of waterwheels to piston-bellows in forging cast iron.[24] Early water-driven reciprocators for operating blast furnaces were built according to the structure of horse powered reciprocators that already existed. That is, the circular motion of the wheel, be it horse driven or water driven, was transferred by the combination of a belt drive, a crank-and-connecting-rod, other connecting rods, and various shafts, into the reciprocal motion necessary to operate a push bellow.[25][26] Donald Wagner suggests that early blast furnace and cast iron production evolved from furnaces used to melt bronze. Certainly, though, iron was essential to military success by the time the State of Qin had unified China (221 BC). Usage of the blast and cupola furnace remained widespread during the Song and Tang Dynasties.[27] By the 11th century, the Song Dynasty Chinese iron industry made a switch of resources from charcoal to coke in casting iron and steel, sparing thousands of acres of woodland from felling. This may have happened as early as the 4th century AD.[28][29]

 

The primary advantage of the early blast furnace was in large scale production and making iron implements more readily available to peasants.[30] Cast iron is more brittle than wrought iron or steel, which required additional fining and then cementation or co-fusion to produce, but for menial activities such as farming it sufficed. By using the blast furnace, it was possible to produce larger quantities of tools such as ploughshares more efficiently than the bloomery. In areas where quality was important, such as warfare, wrought iron and steel were preferred. Nearly all Han period weapons are made of wrought iron or steel, with the exception of axe-heads, of which many are made of cast iron.[31]

 

Blast furnaces were also later used to produce gunpowder weapons such as cast iron bomb shells and cast iron cannons during the Song dynasty.[32]”

[Dan tsuba]

Hello all!

 

So, I was haphazardly searching around the internet (again!) and found an article written in Japan in 2018 about a cast bronze blade.

 

The reproduced blade (at about 6 inches in length) referred to in the article could be a precursor to the “2000-year-old cast-iron sword” pictured in this thread.

 

So, maybe not a “big leap” from casting bronze to casting iron?  That could only occur (casting iron) if the Japanese had early blast type furnaces, as the Chinese did.

 

The article is very interesting (at least for me!) in that it shows how the clay mold for casting was found, and a reconstruction of the bronze blade and how it was cast.

The website is listed below if anyone is interested-

 

https://archaeology.jp/remains/sugu-takauta/

 

I just thought this was an interesting addition to the thread.

 

With respect,

Dan

[Larason2]

As far as I know, the working of "cast iron" was the earliest form of iron working. If you throw a piece of iron containing rock in one of the bellows-fired clay ovens they used to smelt copper, it would also smelt at some point and burn white hot. When you work this though, it crumbles as you would expect cast iron to crumble. If you just keep hammering it though, it gets more and more workable until it becomes wrought iron. All of the technological refinements mentioned here are just that, refinements of the basic process so they don't have to sit there hammering it forever!

[ROKUJURO]

Carlos,

if ypu read carefully about the process of iron-making, you will learn that it is not that simple. The "first" iron was produced in a furnace built for that purpose. It was run at much higher temperatures than copper-making furnaces, needed different (more refractory) clay to build, needed more air supply and a different fuel. The maximum temperatures were about 1.250 - 1.300°C and they produced a kind of "spongy" iron (KERA in Japanese) which had to be refined by hammering, folding and fire-welding. The result is a nicely malleable, ductile iron (not at all crumbling).

As iron has a melting point of 1.538°C, it was impossible in the early iron age to make cast iron. This could only be done after the invention of new technologies. Some cultures like China were forerunners and developed iron casting technologies earlier than others.

[Larason2]

Thanks Jean. In some ways you are right, but in some ways there is more to it than that. Take a look at these three videos:

 

 

 

 

It's true that in each one, the clay is different, and the design of the furnace is different, but in every other aspect, it's pretty similar. The bellows used are the same, the charcoal used is the same, and the basic principle is the same. Now, refractory clay and non-refractory clay are both just clay. Refractory clays just happen to have components that resist higher temperatures, like aluminum silicates. Starting in the Bronze age, the people just used whatever clays were at hand. In the iron age though, it probably became clear that some clays didn't work with iron. It also was probably clear that some furnace designs didn't work with iron. So after learning a certain clay wouldn't work, they found one that did. A furnace that will smelt iron will also smelt copper (1085 degrees C) and tin (231.9 degrees C) and the mixture of the two, Bronze (913 degrees C). So once you've got a good furnace that will smelt iron, you're good to go. Curiously, in Neil Burridge's video, they needed to heat the tin ore to 1200 degrees. Since it's the UK, I assume that's Celsius, but I could be wrong! Not sure why it needed to get that hot, but perhaps you could enlighten me! 

 

Now the difference between "cast iron" and "steel" is the amount of carbon in it. All of these kinds of forges generally produce iron with lots of carbon in it. It's true that depending on how you do it, you can get steel, that's the outer layer of the Japanese Kera. However, even in Japanese Keras, the inner layer usually has a very high carbon content in the iron, and the material is used as cast iron. When the Japanese smith comes to look at the kera, they get pieces from the middle if they want cast iron, and pieces from the edge if they want tamahagane (steel). As shown in other videos, they test the pieces to make sure they get what they want. It's not that easy to produce low carbon steel in one of these bloomery furnaces as above though, so most of the time, they really only produce high carbon iron, or "cast iron." If you look at the last video, it's clear the bloom of iron they produce is crumbling! I'd be surprised if there's any steel in there, but it's not impossible. It turns out that some of the iron age iron is a combination of "wrought iron" and steel, because clearly some steel can be produced in these primitive foundries. However, at least in a bloomery furnace like the one above, it's a lot easier to produce high carbon iron, hence, the predominance of cast iron. I suppose it depends on your definition of what is "nicely malleable, ductile iron." If it crumbles a couple of times, then becomes workable, is it steel, cast iron, or a mix of the two? I don't think the first iron age smiths knew, but they were happy with it as long as it worked! The technology to smelt iron sand is different than the technology to smelt other ores like hematite as well. It's actually easier to get steel with the Japanese techniques used to smelt iron sand than the ones used in bloomery furnaces for hematite.

[ROKUJURO]

Carlos,

I am a full-time bladesmith and an experimental archaeologist with an emphasis on the European iron age. I have run several bloomery kilns of the celtic type here in Europe, so I understand the matter. By the way, we (I worked with a team) always used magnetite.

You seem to mix up high carbon steel and cast iron. In a TATARA, there is always a mix of iron, steel, and a certain amount of cast iron being produced - this is all called TAMAHAGANE. The latter material - cast iron - needs higher temperatures to be able to take up more carbon, and this is only possible when it is near the melting point. In a bloomery kiln/TATARA, you have different temperature zones, and near the vents it can be so hot that the iron starts to melt in droplets which gather further down in the kiln, adding to the KERA. (iron melting point is 1.538°C)

I have a sample from my own iron-making that I use for demonstration. It is a small bar of about 2 kg, and on one end of it, it is pure iron with almost no carbon, the other side is almost cast iron. I like to show that by the spark comparison generated with the grinding wheel.

Today, the cast iron ingots of the TATARA are sold to swordsmiths to be used in an OROSHIGANE kiln to be combined with (low-carbon) iron to increase the carbon content. Some smiths use broken TETSUBIN (water-kettles and other cast-iron scrap) as a high-carbon source. 

You wrote:  'I don't think the first iron age smiths knew, but they were happy with it as long as it worked! ' Yes, that is probably true. But they did not know what to do with the cast-iron that came out of the kiln as by-product, so they threw it away. Later medieval smiths searched these waste piles for the cast-iron and thus were able to recycle Celtic cast-iron in their early charcoal-consuming blast-furnaces.

I have explained that multiple times here on the forum - this one was for you now! 
 

[Dan tsuba]

Hello my friend Jean, (and hello to all!)

 

So Jean, you stated-

 

“I am a full-time bladesmith and an experimental archaeologist with an emphasis on the iron age. I have run several bloomery kilns of the celtic type here in Europe, so I understand the matter.”

 

So, your emphasis is on the iron age.  My research indicates the iron age was from about 1250 B.C. to 550 B.C. (in Europe) and maybe from about 900 B.C. to 100 B.C. in China.

 

You state you have run several “bloomery kilns”.  Yet in referenced articles on this thread, it is stated that the Chinese used “blast furnaces” to make cast iron (and possibly used clay molds to cast pieces) and then further work the cast iron through annealing and decarburization.

 

This weblink (under the “History” section) tells all about Chinese blast furnaces and when they were developed and used-

https://www.chemeurope.com/en/encyclopedia/Blast_furnace.html

 

And it can be assumed (and it is not too much of a “stretch”) that the Japanese could have learned blast furnace technology from the Chinese.

 

So, have you made cast iron in a blast furnace?  If you did, have you cast it into clay molds and then annealed it and decarburized it (as stated in a previous post on this thread - that may be how cast iron was produced and worked)?

 

Now, let’s think about this.  During the warring states period in China (and there are many internet sites that can verify this) an army consisted of about 100,000 men (and I don’t know how many armies there were).  So, if a general wanted to make as many weapons as quickly as possible, casting them out of cast iron is a good way to do this.  Although (if the items that were cast were swords) they may not last a long time, but they were still a “weapon”.

 

“Zhao adopts cavalry (306 BC)

Li Mu then prepared a large army that consisted of 1,300 war chariots, 13,000 cavalry, 50,000 picked infantry and 100,000 expert archers. With the full army he carried out military exercises. Then he scattered this large force around the pastures and the countryside.”  (from the internet looking up “what did the warring states armies consist of).

 

Those “cast iron” swords would be a cheap and ready weapon for those 100,000 expert archers when they ran out of arrows (in medieval European times those swords were known as “archer’s swords” although they were not cast, but forged).

 

Also, the Japanese fought many wars in the period from about 250 A.D to 700A.D.  So, maybe cast-iron weapons were easier for them to produce “in quantity” also for their archers?

 

Now the internet states that the samurai were a class of warrior that came about in the 10^th century A.D. (900 A.D.).  I have also found that the oldest Japanese forged sword found in Japan dates to about 600 A.D. (although that is difficult to “pin” down). 

 

Anyway, maybe the Japanese transitioned from blast furnaces (cast iron swords) to tatara type furnaces (forged iron swords) when “large scale” wars were not happening as frequently, and the smiths had more time to make better blades. 

 

Also, a tatara furnace would be more of a “family” type operation for making forged swords and not a huge operation as evidently a blast furnace operation was for making cast iron (also referred to in a previous post on this thread).

 

Anyway, just some “food for thought”.  I find this interesting, as probably no one will ever “know for sure” what transpired in the development of sword making in China or Japan.

 

With respect,

Dan

 

 

[rematron]

I’m starting to get confused by the term ‘cast iron’ and please excuse me if I’m just having a moment. So there is the term ‘cast iron sword’ that keeps coming up and when I hear that I think of the opening scene of Conan the Barbarian (1980) and forging a blade from liquid iron/steel (which my ten-year old self loved the idea of but I’ve long since learned that is not the way it was done. Hahaha) And then I also see ‘cast iron’ as an iron bi-product that is generated from smelting iron ore or iron sand but was never actually molten. Am I missing something? I probably am. 

[Ynot]

 

The Iron and Steel Museum (鉄の歴史館, Tetsu no Rekishikan) commemorates the history of the iron industry in Kamaishi City. Magnetite was discovered in the mountains around Kamaishi in the 18th century, and Japan's first blast furnace was subsequently constructed there in the 19th century, marking the start of modern iron production in the country.

 

Cast iron is for farmers, plows etc..

 

 

 

Tony

[Larason2]

Thanks Jean, Dan and Jeremy. Jean, that was a helpful response, I think I'm starting to get what was going on. I think the problem is that many people (myself included!) refer to any high carbon iron as "cast iron." While it's true that cast iron needs a bit of a higher carbon content, not all high carbon iron can be cast, so it's probably better to only call iron that has enough carbon for casting and is/was cast as "cast iron." If high carbon iron is worked enough though, the iron particles in it increase in length, and it becomes "wrought iron"

 

Now, the swords dug up from the early iron age are known to not be as good as the carbon steel swords we have now, and I suspect this is for a few reasons. One is that they weren't heat treated, an important reason why modern swords are so much tougher. Another though, is that they probably contained impurities including some grains of iron with a carbon content above 2.1%, which were a by product of the bloomery process by which many of them were made. Here's an interesting article that supports that:

 

https://www.tf.uni-kiel.de/matwis/amat/iss/kap_a/advanced/ta_2_3.html

 

So my thinking is that the "cast" iron sword in the original article is most likely one of these swords made from a bloomery type process. I would think that since by that time there was a fair bit of contact between europe/the middle east and asia, this basic process would have probably made it over there, or they independently discovered the bloomery process in asia, since it is in some ways similar to the bronze smelting that they obviously had experience with. So I think that is the default, and most likely technology used to make the blade referred to.

 

I read on another page that Chinese iron casting started around 300 BC, so it could potentially be a technology used to make the blade. However, I don't think that's likely, because it wouldn't make a very good sword! There are some posters that suggested it could be ceremonial, like those Korean stone swords, but you usually don't have any ceremonial item that is known to otherwise be a dud. In fact, they would have to be careful not to drop it on something hard. Those Korean stone swords would break if used, but you could still use them to impale!

 

Now, could they cast them, then work them to make them better? This is possible, but at that point, they're basically making wrought iron swords, which are a lot of work to make, and the result would probably still be inferior to the bloomery swords mentioned above. That's why wrought iron is so expensive even today! So this is possible, but I think also unlikely.

 

I don't have access to the original article, but the way that the abstract is worded suggests to me that they are ignorant of the finer details of a bloomery iron vs. cast iron vs. wrought iron sword. It probably just has a bit higher carbon content, so they called it cast iron. So I think it is most likely bloomery iron. As stated on previous posts, the structure of the iron can vary a lot, since these swords were made so many different ways across the world.

[Jacques D.]

Pure iron melts at 1538°C, industrial cast iron (2% carbon) melts at 1738°C. The melting temperature of steel varies according to the carbon content, the lower the carbon content the lower the melting temperature.  It has become customary to call blast furnace steel cast iron because the material is recovered in liquid form.  

[ROKUJURO]

16 hours ago, Larason2 said:

...... While it's true that cast iron needs a bit of a higher carbon content, not all high carbon iron can be cast, so it's probably better to only call iron that has enough carbon for casting and is/was cast as "cast iron." If high carbon iron is worked enough though, the iron particles in it increase in length, and it becomes "wrought iron"......

 

Now, the swords dug up from the early iron age are known to not be as good as the carbon steel swords we have now, and I suspect this is for a few reasons. One is that they weren't heat treated, an important reason why modern swords are so much tougher. Another though, is that they probably contained impurities including some grains of iron with a carbon content above 2.1%, which were a by product of the bloomery process by which many of them were made.....

 

I read on another page that Chinese iron casting started around 300 BC, so it could potentially be a technology used to make the blade. .....

 

Now, could they cast them, then work them to make them better? This is possible, but at that point, they're basically making wrought iron swords, which are a lot of work to make, and the result would probably still be inferior to the bloomery swords mentioned above. .....

Carlos,

today, we have a rather clear vision about iron alloys.

Generally, all malleable material today is called 'steel' independent of the carbon content. Traditionally, non-hardenable 'iron' is/was called iron when it had a carbon content below 0,22 %. 'Wrought' iron got its name from the way it was refined after coming out of the bloomery kiln; historically, it is the first man-made iron. Not hardenable.   
(Low-alloy carbon) steel is hardenable because of a carbon content that (in practice) exceeds 0.3% and goes up to 1,6%. 

Cast iron got its name from the process and has a carbon content between (roughly) 2 and 5 % of C. You can also cast iron and steel, but these are different industrial processes and temperatures! To make - and use - cast iron, you have to have a very differently developed technology compared to the bloomery process. As mentioned, better refractory material for the furnaces and molds, better ventilation machines, high-energy fuel, and of course (this is often left aside) you have to handle the white-hot liquid metal! You don't just open a tap and it runs into your molds, as some seem to believe. You need crucibles of suitable material and you have to be able to handle them.

To give you a picture: The bloomery process and the iron casting technology are separated by a technological development leap which can be compared with the technological differences between a car that can go 100 mph and one that can make 200 mph. I hope that helps to understand a bit, and I don't even mention the manpower situation. I can run a small bloomery kiln all by myself if everything is well prepared and set. A larger TATARA will need a team of 8 - 10 helpers (minimum per shift in a 3-day process), while casting iron will require a big organization first, solid constructions and larger teams of workers.

Bronze casting (not copper smelting!) on the other side could be done on a very small scale. I have seen it executed by a famous collegue (Markus Binggeli, Switzerland) with simply a hole in the ground, some charcoal, a clay crucible, a mould, and a small bellows. 

All cultures started iron production with some kind of bloomery furnace and forging the resulting metal with hammer and anvil. Different products and increasing population numbers lead then to the develepment of casting techniques, but if we stay with Japan and the SAMURAI sword (which is the main subject here) we can clearly say that iron casting had no significant importance. So it would really help to leave the fiction of cast iron swords (and TOSOGU) behind.

[ROKUJURO]

3 minutes ago, Jacques D. said:

Pure iron melts at 1538°C, industrial cast iron (2% carbon) melts at 1738°C. The melting temperature of steel varies according to the carbon content, the lower the carbon content the lower the melting temperature......

Jacques,

my information are that cast iron has a melting temperature of 1.150°C (eutectic) or a bit higher depending on the alloy. Usually, alloys have a lowered melting point due to contamination, so a higher C content will lead to a lower melting point.

[Dan tsuba]

Hello again all!

 

So, I include a quote from a recent post to this thread:

 

“but if we stay with Japan and the SAMURAI culture (which is the main subject here) we can clearly say that iron casting had no significant importance. So it would really help to leave the fiction of cast iron swords (and TOSOGU) behind.”

 

First off, the main subject here is Nihonto.  That means Japanese sword.

 

https://nihonto.com/Japanese-sword/  (this link shows a picture of a chokuto straight blade Japanese sword).

 

In the above quote the word “fiction” was used (referring to cast iron swords and Tosogu).

 

Well, there is a whole other thread on cast iron Tosogu (“Tsuba casting molds?) in the Tosogu section.

 

As far as Japan and the Samurai culture is concerned, I personally feel that cast iron also played a part (as seen from this thread) in the development of the Samurai sword.

 

As mentioned below, there was a “straight sword” used in Japan prior to the more well known “curved sword” used by the Samurai.  It was historically significant in the development of the Samurai type sword.

 

“The chokutō (直刀, "straight sword") is a straight, single-edged Japanese sword that was mainly produced prior to the 9th century. Its basic style is likely derived from similar swords of ancient China.[1][2]”

(from --  https://en.wikipedia.org/wiki/Chokut%C5%8D – also more information given about this type of sword on the link).

 

What is of interest is that this type of sword (and pieces thereof) is shown in pictures on previous posts to this thread.  Also, mention of these types of ancient swords possibly being made from cast iron is also stated.

 

Below are a couple of more links to describe the “chokuto” type of ancient Japanese sword-

 

https://www.japanaccents.com/swords/ancient-Japanese-sword

https://digitalcommons.lsu.edu/cgi/viewcontent.cgi?article=4728&context=gradschool_theses

(view pages 21 to 25)

 

So is the straight Chokuto type sword (first developed in China) a part of Nihonto, absolutely!

 

Is the possible use of cast iron in Tosugu and Nihonto “fiction”, absolutely not!

 

The adventure continues!

 

With respect,

Dan

 

[Brian]

Chokuto were NOT cast. Pieces have been polished. They exhibit hamon and hada and hataraki. Let's not just invent things to enhance the narrative.

[Larason2]

Thanks Jean, I think your last post clarifies and settles the question for me. Modern Japanese sword making is really an extension of the bloomery process, so they never really got into casting for it. As mentioned, casted swords are no good, so the Japanese would never have bothered with it, even though they had a process for cast iron. So there's no question that the sword in the article was made using some sort of bloomery style process.

[Dan tsuba]

Hello all (again!)

 

So in a previous post it was stated-

 

“Chokuto were NOT cast. Pieces have been polished. They exhibit hamon and hada and hataraki. Let's not just invent things to enhance the narrative.”

 

In rebuttal-

 

First, I never stated that Chokuto were cast.  Please read the post more carefully.

 

And if the entire thread is read, the possibility of cast iron being used in ancient swords appears viable. 

 

Notice, I did not state “all” ancient swords!

 

And to state “Chokuto” were NOT cast” is extremely final.  All throughout this thread I have stated my references and resources.  Where are yours?

 

In conclusion the statement “Let’s not just invent things to enhance the narrative” is misleading.  I didn’t “invent” anything.  Again, read the entire thread. 

 

Also in rebuttal, I could just as easily state “Why is there so much negativity and ‘closed minds’ when it comes to cast iron possibly being used to make swords (or tsuba)?

 

Dan

 

[Jacques D.]

6 hours ago, ROKUJURO said:

Jacques,

my information are that cast iron has a melting temperature of 1.150°C (eutectic) or a bit higher depending on the alloy. Usually, alloys have a lowered melting point due to contamination, so a higher C content will lead to a lower melting point.

 

Sorry i'm mistaken, I misread my source  which says that the melting temperature of cast iron is 200° C lower than that of steel => 1250° . That said, there is nothing to prevent casting molten steel

[Brian]

14 minutes ago, Dan tsuba said:

And to state “Chokuto” were NOT cast” is extremely final.  All throughout this thread I have stated my references and resources.  Where are yours?

In conclusion the statement “Let’s not just invent things to enhance the narrative” is misleading.  I didn’t “invent” anything.  Again, read the entire thread. 

Also in rebuttal, I could just as easily state “Why is there so much negativity and ‘closed minds’ when it comes to cast iron possibly being used to make swords (or tsuba)

 

I don't have to prove a negative. You have to prove the hypothesis. Nothing scientific has shown antique or ancient Japanese swords were ever cast. None of the extant examples is cast. And since the history of Japanese swords is considered to have started about the 1000's....take that as your starting point.

[Dan tsuba]

My friend Brian,

 

Don’t advise me what to do!  So, you can state any opinions you want without backing it up with research or references.  That must be nice! 

 

And the “good old boys” will give you emoji “hearts” and “likes” because you are the administrator of this forum.  It just seems like this forum has become a “popularity” contest!

 

Remember, when I posted a thread on the “Forum technical details and maintenance” section about the “New medal rating system” you immediately locked it!  What was your fear?  I refer members to this-

 

https://www.militaria.co.za/nmb/topic/42120-new-medal-rating-system/

 

It has been my pleasure to start threads that have accumulated much interest from members.  My “Tsuba casting molds?” thread has 10.9k views.  My “2000-year-old sword” thread now has 5k views.  And many of my other threads have also accumulated much interest. I have learned much from the information on this forum and I thank all the members.

 

Unfortunately, I now believe that the forum has digressed from an educational perspective to more of a “let’s back each other up” and give us all “likes” and “put down anyone that doesn’t see things our way” perspective.

 

So, Brian.  I respectfully request that you “lock me out” of the forum.

 

Dan