2000 year old sword

[Dan tsuba]

Hello all!

 

So, I am a tsuba guy!  But I was doing research on the possibility of cast iron tsuba (long story!) and I stumbled across this “abstract of an article” about a 2000-year-old cast iron Japanese sword.

 

I don’t know, I thought maybe some of you may find it of interest (or maybe not!).  Oh well, here is the abstract of the article-

 

From the website-

 

https://link.springer.com/article/10.1557/opl.2012.630

 

“Long-Term Corrosion of 2,000-Year-Old Ancient Iron Sword

Seiichiro Mitsui, Atsuhiro Fujii, Megumi Higuchi & Kohsuke Nishimura

MRS Online Proceedings Library volume 1475, pages545–550 (2012)Cite this article

 

Abstract

An ancient iron sword (ca 2,000 year old) excavated from Ohtake-nishi archaeological site in Osaka Prefecture, is one of the oldest cast iron swords in Japan. Because of a good state of preservation, such as the sharply-defined “Shinogi” (the longitudinal ridge) on the surface, we studied relationship between the burial environment and corrosion behavior. As environmental conditions, we investigated groundwater chemistry and corrosion rate with iron probe monitor, etc. Regarding corrosion state, we analyzed corrosion depths with an X-ray computed tomography and corrosion products with a portable X-ray diffractometer equipped with X-ray fluorescence spectrometer. As results, we found that the redox potential and dissolved oxygen level as environmental conditions were very low, and that the corrosion rate (7.5×10−4 mm/y) evaluated from measured corrosion depths was smaller than the probe corrosion rate (3.2–5.2×10−2 mm/y) by two orders of magnitude. The results suggested that the corrosion layer of siderite formed on the iron sword surface inhibited corrosion reaction.”

 

Well, I thought it was interesting (maybe I should just stick with tsuba!).

 

Onward!

 

With respect,

Dan

 

[ROKUJURO]

Probably a translation mistake. There are no cast iron swords, except in the "Lord of Rings".

[Dan tsuba]

Hello my friend, Jean!

 

So you found me here on the "Nihonto" forum!

 

As you are well aware, I always appreciate your "challenges".  You keep me researching!

 

Unfortunately (or not), I will have to take the "abstract" of the article at "face value" (cast iron sword).  Unless you or I can find the original article and have it "retranslated"! 

 

I will await your "retranslation" of the article, since I have no idea how to do it or have it done!

 

 

The adventure continues,

 

With respect,

Dan

[Rivkin]

The article's title I am afraid suggests its unprofessional in everything except the corrosion. 

You can't date an excavated sword with a given precision and its unlikely to be that old. 

Cast swords are (mostly) nonsense. There are old swords made from pure iron though.

Next thing we'll see photographs comparing the sword's size to a pack of cigarettes.

 

[Spartancrest]

https://www.google.com/search?q=conan+the+barbarian+casting+the+sword+scene&sxsrf=ALiCzsbiMfjZUD_cGbTAKRXaigwgZ_hZkA%3A1670362442170&ei=SrWPY9GFCuvC4-EP09WpuAU&ved=0ahUKEwjR0ouA-eX7AhVr4TgGHdNqClcQ4dUDCA8&uact=5&oq=conan+the+barbarian+casting+the+sword+scene&gs_lcp=Cgxnd3Mtd2l6LXNlcnAQAzIFCCEQoAEyBQghEKABMgUIIRCgATIFCCEQoAE6CggAEEcQ1gQQsAM6BwgAELADEEM6DQgAEOQCENYEELADGAE6DAguEMgDELADEEMYAjoPCC4Q1AIQyAMQsAMQQxgCOgQILhBDOgQIABBDOgUIABCABDoFCC4QgAQ6BQgAEIYDOgYIABAWEB46CAghEBYQHhAdOgQIIRAVOgcIIRCgARAKSgQIQRgASgQIRhgBUMYKWPprYLRxaAFwAXgAgAHAA4gBijWSAQgyLTE1LjYuM5gBAKABAcgBEsABAdoBBggBEAEYCdoBBggCEAEYCA&sclient=gws-wiz-serp#fpstate=ive&vld=cid:4d83ecf4,vid:81HUn352hZ4

[SteveM]

This is the 2000 year old sword mentioned in the article

 

 

[Dan tsuba]

Hello Kirill R.,

 

I quote your previous post below-

 

“The article's title I am afraid suggests its unprofessional in everything except the corrosion.

You can't date an excavated sword with a given precision and its unlikely to be that old.

Cast swords are (mostly) nonsense. There are old swords made from pure iron though.

Next thing we'll see photographs comparing the sword's size to a pack of cigarettes.”

 

So, you can always contact the authors of the abstract to ascertain how “unprofessional” the article is.

 

And what are your references to verify your statements.  Without references you are just “bullying” and stating rhetoric.

 

I have seen too much of this style of posts on the forum.

 

With respect,

Dan

[Rivkin]

They are corrosion engineers who cite a non-peer review provincial report as their single source on everything related to sword's attribution.

To understand why casting from tamahagane is a bit difficult and quite a bit unproductive, or why dating of archaeological finds is always imprecise one does need a basic knowledge of the subject.

There have been long discussions regarding whether the earliest swords from meteorite iron might have been cast - a difficult subject, which might have inspired some archaeologists to rather aggressive conclusions.

"Theoretically", 2000 years old attribution is possible. Its very hard to argue for or against any exact dates in Japanese archaeology specifically. Practically speaking, its an aggressive side of possible interpretations and using it for article's title makes it a clickbait.

 

Today there are overall almost no people with semblance of broad education. Archaeologists know how to dig, but copy wikipedia about the weapons they dug out, corrosion metallurgists know how to record numbers from their measurement device,  but have zero perception of traditional iron techniques, nihonto luminaries have no cognition of everything and anything besides how to distinguish Awataguchi Kunitsuna from Hisakuni.

 

[Nobody]

I found that the sword was excavated at Otake-nishi Renains in Yao city. The sword was found at the 3^rd excavation (1996-1997) and documented in a report in 2008. It is the first sword which was recognized as a cast iron sword in the area.

Ref. 大竹西遺跡 - Comprehensive Database of Archaeological Site Reports Japan (nabunken.go.jp)

 

Also an archaeologist studying on iron cast in ancient Japan mentioned the sword in his paper (in Japanese).

Ref. KAKEN23520946_Nojima.pdf (hiroshima-u.ac.jp)

 

[Bugyotsuji]

Professor Nojima is quite specific that it is/was cast, and that it is unusual, thus worthy of the iron-casting background research which he undertakes in his paper, kindly linked by Moriyama San above.

[Rivkin]

Japanese is a hard language for me to read, but what I am seeing is that it assumes that its made from cast iron rather than cast as a blade.

I might be greatly mistaken, but at least this would make sense.

 

It has been traditional Chinese position that their early steel was produced by going all the way to pig iron(??) and then decarburizing it. It stems from one of their early publications on the subject. Thus the source of the steel would be called in their literature "cast iron", which is then decarburized.

It is being questioned by modern writers: though there are some indications of ancient pig iron in China, even then it is still a big question whether it was actually (ever) decarburized to be used as steel.

On the internet, there is a relevant discussion here:

https://www.tf.uni-kiel.de/matwis/amat/iss/kap_a/advanced/aa_2_2.html

Yes, modern Chinese sources do often use "cast iron", "cast sword", "wrought iron" and even "cast sword from wrought iron" as synonyms. The question - how is it discerned that its sourced from a cast iron?

Even to state that a particular blade is made from cast iron is intriguing and asks for a question - what is it based upon? What is the proof that something was made from decarburized "cast iron" source?

 

If its cast from iron, its even more intriguing, and begs even more the question how its proven. Does it have very high, >4% carbon content? 

Admittedly the last time I've read such discussion was from 10 years ago, but there was a lot of scepticism regarding any "cast historical sword" claims, and there was nothing I ever seen characterized as definitive proof that this item was cast. Yes, in Chinese sources the definitions like "cast iron" and even at times "cast sword" were sort of common.

[Bugyotsuji]

He seems well aware of the conflicting arguments in this area, but says that he wishes to shed some light where possible. (I fell asleep reading it, but towards the conclusion he does mention a high carbon content.)

[Spartancrest]

I think we are missing the point that early iron swords were patterned after their bronze predecessors and would have been made in the exact same way - cast - we know now that you don't get good steel that way but they had to start at the beginning and work it out - it did not jump from bronze to spring steel in an instant.

You might note on the sword in question the two small holes at the base of the blade and the relatively short tang. Compare it to this example of a bronze weapon with the handle riveted onto the blade. [example on the right] Same technique just "new" material.

 

 

[ROKUJURO]

Dale,

you are correct that we are missing something, and that is the basic knowledge about tool and weapon making from metal in ancient times.

We know that copper accompanied the late Neolithic period. Copper could be made in a direct reduction process, and our ancestors found technical means to melt the copper in ceramic containers and cast it in stone molds into desired shapes. It was then processed by hammering and grinding, and this exact technique was continued into the bronze age.

The bronze alloys were composed in a way that the tin content was low enough to prevent the bronze becoming brittle, so heavy hammering was possible and necessary for final shaping and surface hardening - very important for a durable cutting edge of tools and weapons! 

It is well known that Tut Anch Amun had an iron dagger with him in his grave - long before the iron age started! There was no way to produce this dagger blade other than by shaping it with a hammer, and had it not been meteor iron with a high nickel content, it would not have had the ductility to be shaped this way. Sometimes, the right material has to meet the fitting technique, and technical progress often was just a matter of coincidence!

We should not forget that the ancient Egyptians had bronze razor blades. These would not have been useful without hammering them to achieve the necessary surface hardness. 

Intentionally producing cast iron items would have posed some obstacles in early times.

1) You had to have a fuel with high energy density (= charcoal; mineral coal came up in medieval times only).

2) You would have needed very powerful blowers (= bellows), and

3) you would have to have refractory recipients to melt and handle the melted iron. These refractory containers had to be pre-fired prior to the casting process.

Also, you would have to have refractory mould material. (in the related threads of this forum some members were using the term "sand casting". This could be misleading as mould material has to contain an amount of clay to make the forming of the mould possible. The finer the sand and the higher the clay content, the finer the surface of the cast item will be. In the same time it has to be observed that a higher clay content would make a mould less fire-resitant, and also prone to shrinking in the drying and firing process).

As I mentioned before in some threads, cast iron (= pig iron) was often a by-product of early iron-making. It was waste material as our ancestors could not use it. We cannot exclude the possibility that single attemps were made to use cast iron very early, but on a parallel line, Chinese stoneware ceramics (fired up to 1.260 - 1.300°C) started to be made in the HAN dynasty (206 BC – 220 AD). This may give us some insight into the technical development of those times.

Having said this, I would like to emphasize that - even if this 2.000 year old blade was indeed made from cast iron - we cannot conclude from it that sword blades (or other items like TSUBA) were made on a large scale by this method as it did not produce a useful and usable tool (or weapon).

A short comment on the widely used term "patterned steel". By this, we understand the Viking technique of a controlled use of different kinds of iron (not alloys in the modern sense of the term; small amounts of impurities like phosphorous led to the desired contrasts in the iron) to produce a repeatable pattern in a finished iron work-piece. This technique required a well developed forging technique with a lot of fire-welding (always connected with the risk of flaws!) and a long production time. This method became obsolete by about 800 CE, when Frankish smiths found ways to produce homegeneous steel with controlled carbon content. Swords made this way were easier and faster to make with the same (or even better) technical properties and performance.  (https://www.tf.uni-kiel.de/matwis/amat/iss/kap_b/backbone/rb_4_2.html)

Bladed weapons made before this Anglo-Saxon Viking era of patterned steel (prior to ca. 5th century; https://artsandculture.google.com/asset/sword-from-the-ship-burial-at-sutton-hoo/uQGATpxRArOXnw ) were made by homogenizing the steel as best as possible (by stretching out, folding and fire-welding) producing a random pattern on the blade. This was the technique from the beginning of the iron technology which was started at about 800 BC by the Celts in Europe.

[Apercus]

There are many good articles on archeotechnology of early iron production all over the world. I’ve read several detailed analysis of ancient eastern (Chinese, Japanese, Indonesian, etc.) I’ll see if I can find some of them and post links when I get time. There is an annual publication which is a collection of papers on ancient metallurgy. I will try to find copies of the ones I have.
A simple internet search on the subject would reveal many articles. Ancient forge work was often far more sophisticated than we tend to give credit for. Like any other time in history there was exceptionally good techniques made by isolated smiths concurrently with poor work in other areas. It’s a fascinating subject.

[Rivkin]

Late Bronze Age swords were generally forged; forged bronze with proper chemical combination outperforms iron but not steel.

There is a question whether these were first cast and then forged, and many argue they were. Generally, casting of a large utilitarian object is difficult, cavities and other defects plentiful, even in bronze if its just left as is after casting, the hardness and overall practicality is quite limited.

This being said, for some reason Chinese publications on bronze weapons always emphasized casting and downplayed the consequent forging. I am not at all familiar with Chinese bronze weapons to make any comment on why is it the case and whether Chinese bronze age technology was that much different from everybody else's. It is also worthy of note that European non-specialized (i.e. not archaeometallurgy or specialized metallurgy, but rather those of generic archaeologists) publications can simply say "cast sword", and in general it is not sufficiently correct.

 

Moving to iron, for a very long time there was a popular theory of "transitional metal". The notion is that processing iron ore requires much higher temperature compared to bronze, and obtaining cast iron - exceptionally high temperatures (whether it was actually used to produce weapons is another story; for example, in tatara about 5% of output is cast iron), so it is not clear how one would transition from bronze to iron overcoming the need to invest in a high temperature (and larger in size) setup, especially as aside from steel, iron products are generally not superior to well forged bronze.

The notion was that there must have been iron which did not require the ore, and/or could be melted at very low temperatures. Meteriote ore is quite pure and does not need much refinement; somebody in the 1960s looked up high Nickel alloys, guessed they have a lower melting point, and postulated that meteorites can contain those (being a Professor of history he did not check with meteorite people), and thus not only meteorite iron could be used as is, it can also be "cast" into weapons.

 

So until very recently any pre-1000 BC iron item was automatically given a description "meteorite iron", and sometimes it was also "cast".

Today both are in doubt, as you do need to actually test an item whether its meteorite, and most things tested are not, and certainly "casting" a typical meteorite iron does require very high temperatures.

 

Moving forward to the possibility of having "regular iron" cast weapon.

First it would require great sophistication to acheive the temperatures needed. High carbon content can help, and for a while high carbon steels like wootz were believed to have been "cast", which was since then generally disproven. Even with >3% carbon we are way in the upper portion of what is achievable unless there is a massive blast furnace and a significant effort expanded specifically to cast something out of iron.

Second, casting would require forgetting that bronze weapons need to be forged to be of quality. If an iron sword is cast and not forged, it leaves you most likely with an object having significant defects, and certainly sub-par performance compared to any decent bronze.

Third, there has not been an iron blade which was studied destructively to definitively confirm that it is indeed was cast, not forged. Everytime the use of high carbon steel was identified, somebody always said "it must have been cast", but the consequent tests always showed it was not. So if there is a definitive proof that there is a cast sword, its quite a big thing. If its another guess, then its definitely not. Chinese literature generally uses the word "cast" quite often, and by itself its a very long discussion why, what it means and how its justified.

[Jacques D.]

On 12/6/2022 at 10:02 PM, Rivkin said:

 

You can't date an excavated sword with a given precision and its unlikely to be that old. 

 

 

Why ?

[Jacques D.]

On 12/7/2022 at 2:22 AM, Dan tsuba said:

Hello Kirill R.,

 

I quote your previous post below-

 

“The article's title I am afraid suggests its unprofessional in everything except the corrosion.

You can't date an excavated sword with a given precision and its unlikely to be that old.

Cast swords are (mostly) nonsense. There are old swords made from pure iron though.

Next thing we'll see photographs comparing the sword's size to a pack of cigarettes.”

 

So, you can always contact the authors of the abstract to ascertain how “unprofessional” the article is.

 

And what are your references to verify your statements.  Without references you are just “bullying” and stating rhetoric.

 

I have seen too much of this style of posts on the forum.

 

With respect,

Dan

 

Don't worry, it's Rivkin and his usual nonsenses 

[Dave R]

People inventing the wheel again. There is a lot known about early iron production, and much information available.... Finding it on the internet though is another matter due to search engines pollution with most popular as opposed to most useful.

 Early iron refinement starts with bowl furnaces/hearths, bloomeries and blooms of mixed slag and metallic iron.... Which is where the repeated folding and hammering comes in.

 

https://exarc.net/issue-2022-1/at/little-bowl-could-experimental-iron-smelting-bowl-furnace

 

[Apercus]

Kirill’s analysis seems very reasonable and astute. I think any smith would readily see the problems and unnecessary efforts associated with producing a cast blade. For all the effort you end up with a fragile thing. The earliest “steel” was actually forged iron that had carbon introduced through carburization. it’s a simple process and requires much less effort and resources. The iron blade is simply coated with organic based materials, placed in an iron container and heated to a red heat. The longer it is held at heat the deeper the carbon penetrates the iron. If you hold it long enough the carbon will penetrate as much as an eighth of an inch. You then have a “steel” edge that can be heat treated. This technology was around in Europe at least 1500 years ago but it’s hard to believe that almost any smith working with forging iron would not have “discovered” the effects in any era or location. It’s almost unavoidable if you work in a forge very much.

The initial primitive refinement of ore into iron is almost always in the form of a “lump” or a crude cast form. There will always be a need for forge work to establish the final shape and remove impurities.  That approach has been well documented as being used in cultures across the globe. I would be surprised to see any real evidence of a “cast iron” ancient sword. ( carbon content >3%). 

[Dan tsuba]

Hello all!

 

So, I was “looking around” the internet (again!) and found another interesting abstract of an article (in the Journal of Anthropological Research, vol. 70, 2014,Copyright © by The University of New Mexico).

 

 I think it is neat in that it deals with bronze and cast iron production at the same sites in ancient China (and somewhere in the article it states about molds for cast iron weapons – but I don’t want to read it again to find the exact quote!).  It is a lengthy article and I have included the weblink below the abstract.

 

EVERYTHING OLD IS NEW AGAIN? (Abstract of article)

 

Rethinking the Transition to Cast Iron Production in the Central Plains of China  

 

Wengcheong Lam Department of Anthropology, Harvard University, 11 Divinity Avenue, Peabody Museum, Cambridge, MA 02138, USA. Email: wlam@fas.harvard.edu

 

"The transition to a cast iron industry was essential to the development of ancient China. Previous studies, however, did not address precisely how this process occurred and how the preexisting bronze industry could have served as the foundation for the transition. This paper develops a framework focusing on three parameters—techniques, assemblages of final products, and production organization—to investigate the mechanism of the transition to cast iron. Results of two case studies indicate that the three parameters do not demonstrate dramatic changes between the two industries. Also, cast iron and bronze foundry workers were not segregated; they often worked side by side at the same foundry. Very likely, the cast iron foundry workers adopted and adjusted the original bronze production techniques and, consequently, maintained the preexisting organization. This study illustrates how cast iron manufacturing developed based on the indigenous bronze production in the Central Plains of China, and aims more broadly to contribute to the discussion of technological transitions in archaeological contexts."

 

The entire paper can be found at this website-

(well Brian stated I linked to the file with my own p.c. (thanks Brian , so I took that link out of the post), I don't know how else to do it  - Maybe you can access the  "Journal of Anthropological Research, vol. 70, 2014,Copyright © by The University of New Mexico" and it can be downloaded-the specific pages are p. 511 to p. 542 --  or this may be another way to access the article-

 

https://www.journals.uchicago.edu/doi/epdf/10.3998/jar.0521004.0070.402

 

Anyway, I am trying!  Computers are still "new" to me.  I would rather use an old "land line" phone than a "smart phone" that keeps dropping my calls!).

 

 

Another adventure continues!

 

With respect,

Dan

 

 

 

[Brian]

You've linked to the file on your own pc

[Jacques D.]

What is the study cited by Dan about? About the effectiveness of siderite on steel corrosion. What does this have to do with the forging of ancient swords?  Nothing. 

ps one can perfectly date an old sword with C14 dating

[Dan tsuba]

My apologies Jacques,

 

I guess I was not clear on the first abstract I quoted.  I cited too much of the abstract!  I was just showing interest in a 2000-year-old cast iron sword that was found in Japan.  That was the first time I encountered or read something like that  And I was very interested!

 

With respect,

Dan

[Apercus]

Looks like an interesting article. Thanks for the reference 

[Rivkin]

The idea that Chinese used cast iron is not new, its been around for a long time, as is the idea that they decarburized cast iron. There are about 30-40 high profile articles on it.

It does not mean the iron swords were "cast". That's a claim one seldom finds, and when one does and pushes the author typically there is backtracking to "cast iron". Cast iron will be present in any tatara, for example, though in a small quantity.

 

The issue with decarburization is that the proof which you see in the most recent Chinese articles is based on observing a very wide distribution of Chinese sword properties and attributing this fact to some being made from wrought iron and others from decarburized cast iron. However the distributions shown are continuous (i.e. its not two distinctive groups but a huge cloud of properties where you draw a line separating "wrought" from "decarburized") and there is a myriad of other factors which are evident. For example, some tested blades among pre-10th century finds would be forged extensively, others barely at all (i.e. no real lamination), some are pure iron others are decent steel etc. etc.

Its a difficult topic. Admittedly the standards of pre-10th century iron swordsmithing were quite random everywhere and attributing the source of distributions to a single specific factor can be challenging.

 

With all this, I have to admit I never saw a metallurgist article convincingly arguing for an iron sword which is cast, which is different again from sword being forged from "cast iron"

[Dan tsuba]

Hello again Kirill,

 

Sir, as you can tell I know nothing about the development of cast iron swords.  I was just very interested in the fact that there is a 2000-year-old cast iron sword that was found in Japan.  I really enjoy the “learning process”!

 

I have re-researched (is that a word?) the article titled “Everything Old is New Again”  stated in my previous post and found (on page 528) the below quote about a cast iron weapon mold found at an archaeological site-

 

“Some molds used for casting weapons, coins, and belt hooks also have

been found at the two foundries. It is highly likely that the last two types of

molds were used for casting bronze objects.”

 

So, let’s say a sword was cast in iron.  Would it then be “hammered” to further flatten and shape it?  Would that be considered “cast iron” or “hand worked” or both?

 

The adventure continues,

 

With respect,

Dan

 

[Rivkin]

9 hours ago, Jacques D. said:

What is the study cited by Dan about? About the effectiveness of siderite on steel corrosion. What does this have to do with the forging of ancient swords?  Nothing. 

ps one can perfectly date an old sword with C14 dating

 

Jacques, I admit to seldom being able to respond to your comments due to certain functionality of the forum.

Truth is born in the arguments... among friends. Or at least some semblance of such. Not in claims who says "nonsense" or not.

Similar courtesy was and is extended to Guido, Darcy, Reinhard and a number of their friends, Currant and others. Every collecting subject has a group of friends-dealers-"did it for 30 years" folks. I do admire their loyalty to one other.

 

Part of my attitude, admittedly, stems from a certain level of bigotry: social, educational, otherwise. Part of it however is admitting inability to address rather complicated technical issues in a format which would be compatible with hostile forum-based exchanges.

 

For example, Chinese claim of decarburization from cast iron being the dominant process is very complex and multi-faceted. The underlying economy would greatly benefit from reliance on excavated coal, which is what we see in late medieval/early modern age parts of Europe when its experimented with or adapted a similar method. Chinese historians do claim transition to excavated coal took places. Carbon dating such blades would be then rather difficult, and this method is relatively seldom used with satisfactory efficiency - for this and other reasons. When it works well, it gives you a reliable range of possible dates, when it does not, it does not.

 

Proving the "cast sword" is cast is a duty of article's author. I can't for the life of me be of much use here, besides stating my opinion regarding the past history of similar claims, for a number of technical reasons, and that the current claim seem to emanate from publications which are technical reports rather than proper journal articles. I personally don't see much evidence the opinions given were defended against a qualified and well, hostile (admitting that in Chinese literature "cast" is indeed one of the key terms), peer review process. The language in which the corrosion report is written, the phrasing chosen, they are unfortunately consistent with a report format, rather than a proper article. Which is what it is.

 

If its indeed cast, the proof provided would be an important milestone for understanding of the early (Chinese?) metallurgy.

[Jacques D.]

You are still you and will be for ever... 

 

http://history.alberta.ca/energyheritage/coal/early-coal-history-to-1900/unearthing-ancient-mysteries/ancient-china.aspx#:~:text=Even before civilization began to,modern world in coal use.

https://www.irocks.com/china-crystalline-treasures-e-book-mining-history

 

worth reading :

 

https://muse.jhu.edu/article/725769#:~:text=According to archaeological discoveries%2C cast,%2C 116%3B Han et al.

[ROKUJURO]

12 hours ago, Dan tsuba said:

.....So, let’s say a sword was cast in iron.  Would it then be “hammered” to further flatten and shape it?  Would that be considered “cast iron” or “hand worked” or both?.....

Dan,

in the meantime, there has been written a lot about the properties of cast iron. I will repeat one of them for you: You cannot forge cast iron! Even if heated well, it will break like a cookie under the hammer. There is no shaping and flattening in the forge - I have tried it myself.

And to expand a bit on this: Cast iron (there are several types of it) in general has a very coarse inner structure (= "grain") compared to forged steel, that will not allow to grind a workpiece down to the desired shape.  To give you an idea, image a cake with whole hazelnuts. You cannot cut a fine slice off it without the hazelnuts breaking out. If you transfer this picture to cast iron, it can never achieve a satisfying (fine) cutting edge as the coarse inner structure does not allow it. 

Just basics.