Roman mail - iron tubing -- myArmoury.com

Dan Howard · Posted: Mon 09 Jul, 2012 6:13 am Post subject: Roman mail - iron tubing

I've just been given a reference to an article demonstrating that the solid links in Roman mail, from at least the 3rd century onwards, was made by cutting them off tubes with a lathe.

B. A. Greiner, "Zur Herstellungsweise römischer Kettenhemden (Lorica Hamata)", in: G. Seitz (Hg.), im Dienste Roms, Festschrift für H.U. Nuber, Remshalden 2006, S. 199-204.

Apparently this method is even faster than punching out links from plate. I didn't even know the Romans had iron tubing.

Matthew Amt · Posted: Mon 09 Jul, 2012 7:12 am Post subject:

Wow, that's bizarre! I didn't know they made iron tube, either, at least not with a seam strong enough to make mail rings.

But to make tube, you have to start with sheet, right? Then laboriously roll or wrap it and THEN weld the seam. And we're not talking 2" diameter pipe, here, this would have to be in the 6mm range. Geez... You need to get the metal (c. 1mm thick) to a welding heat without burning it up, then onto a rod-like mandrel that is 4 or 5 mm in diameter, and hammer or at least squeeze the seam shut. Without getting it stuck on your mandrel. I guess you don't need a very *long* tube, but still... But if it's going onto a lathe it needs to be darn regular, and do you end up wasting the end because of how it is secured in the chuck? Is there a dowel or rod through it? What do you cut with?

Wouldn't a ring sliced from a tube with a forge-welded seam look a lot like a ring made from square wire (possibly sliced from sheet) with a forge-welded joint?

I know, I know, I need to read the article! My skeptic alarm seems to be going off, though. Really love to see more details about this! Thanks, though, it's fascinating!

Matthew

Henrik J. Fridh · Posted: Mon 09 Jul, 2012 7:19 am Post subject:

Wow, very interesting stuff, thank you. Wasn't it in the 3rd century onwards the romans started using heavier maille? With the armour now having sleeves and reaching down to the knees or below the waist atleast?

Nathan Gilleland · Posted: Mon 09 Jul, 2012 9:35 am Post subject:

It's an intriguing idea for the modern hobbyist at least. I wonder how hard it would be to find steel tubing of an appropriate size and how hard it would be to cut rings from it? From a historical context, without reading the article, I too am a little skeptical, but I can see how it would result in more efficient material usage and less stock waste... Confused

I might have to look into getting some tubing and grabbing my tube cutter! Wink

Paul Hansen · Posted: Mon 09 Jul, 2012 12:08 pm Post subject:

Matthew Amt · Posted: Mon 09 Jul, 2012 1:19 pm Post subject:

Oh, yeah, lathes were known for centuries before then. Helmets and other metal vessels were often spun on lathes, not to mention the usual wooden furniture parts.

I don't want to say that the Romans did *not* have the technology to do stuff "invented" in later centuries (e.g., they may have had mills for rolling sheet iron), but these seamless tube methods look like kind of a stretch to me, no pun intended.

Lead water pipes were made at least sometimes by wrapping a long strip and just soldering the two edges together, inside-to-inside, so the cross-section is more teardrop than round. Clearly that's on the "crude" end of the technology, and not suitable for mail rings! I don't doubt they could do better. BUT...

Matthew

Matthew Bunker · Posted: Mon 09 Jul, 2012 1:53 pm Post subject:

Finds of iron tubes start to turn up in glassworking sites across the Empire from the third century whereas previously the blowpipes would have been ceramic. These were airtight along their length and smoothwalled internally and externally.

Spread of applications for new technology?

Presumably the article Dan cites contains an ESM analysis of sample ring structure to back up the claim?

Dan Howard · Posted: Mon 09 Jul, 2012 2:33 pm Post subject:

I don't read German and don't trust onlne translatiors. I was hoping that a German speaker here with access to the article could translate the relevant passages for us.

Torsten F.H. Wilke · Posted: Mon 09 Jul, 2012 4:37 pm Post subject:

I believe that one could make single piece tubing fairly easily back then by first hot piercing a larger forged cylindrical bar, then drawing it down to a homogeneous diameter through successive die plates between annealings. On the last draw, you would end up with a very consistent, work-hardened product too....

Dan Howard · Posted: Mon 09 Jul, 2012 4:45 pm Post subject:

Sean Manning · Posted: Mon 09 Jul, 2012 6:09 pm Post subject:

I am busy with thesis reading, but I will order the article and have a look. I give this proposition a fairly low level of credence (perhaps its just a speculation by the authors?), but that will probably change once I read their argument.

Dan Howard · Posted: Tue 10 Jul, 2012 12:46 am Post subject:

Chistian over on RAT summarised the article as follows:

Leo Todeschini · Industry Professional

I have no reference for the following so apologise in advance.

I spent the week with Alan Wilkins and Tom Feely (respected Roman artillery people) a month ago and they were saying that there is now evidence that the Romans were importing rolled steel sheet and seamless tube from China.

I know no more than that.

Tod

Matthew Amt · Posted: Tue 10 Jul, 2012 5:38 am Post subject:

Dan Howard · Posted: Tue 10 Jul, 2012 5:58 am Post subject:

I have no problem believing that the Romans had rolled plate and iron tubing but why on earth would they need to get them from the Chinese? The Romans had one of the most advanced metalworking industries on the planet. I think they might have misread Sim and Kaminky's new book.

Kurt Scholz · Posted: Tue 10 Jul, 2012 7:33 am Post subject:

This book is hard to get. It's only available in Frankfurt a. M. and in Leipzig in university libraries.
https://portal.dnb.de/opac.htm;jsessionid=DD8D587638028FED0BA228BA2E6EFE50.prod-worker4?method=showFullRecord&currentResultId=Woe%3D10922616X%26any&currentPosition=0
I can do the translation, but I need a text.
It isn't necessary that tubing means round tubes, you can also have triangular or other cross sections and even a seam that would make welding or soldering easier.
German: "Rohr" = English "tube" does include objects with triangular cross sections (linked example below) in the German meaning of the word, although we take it to normally mean round cross section and would emphasize a deviation from that perceived standard.
http://german.alibaba.com/product-gs/triangul...81450.html
From a German POV the defining characteristics are being hollow, inflexible, have some length in comparison to the cross section diameter and one piece to handle.

Matthew Amt · Posted: Tue 10 Jul, 2012 7:42 am Post subject:

Yeah, but if they're slicing up the tube to make mail rings, it's probably safe to assume the tube is more or less round in section!

Matthew

Matthew Bunker · Posted: Tue 10 Jul, 2012 7:59 am Post subject:

And, if anything, you'd imagine that round(ish) tube was easier to make than any other section.

Kurt Scholz · Posted: Tue 10 Jul, 2012 9:53 am Post subject:

Sorry, stupid me misunderstood something. I thought the rings of the mail were tubes.

The other stuff is fairly simple and well documented in the Middle Ages at least. Create an iron bar, pull it through a matrix to create wire, wrap and hammer it around the object of the shape of the mail rings (in most cases round) and chisel ring segments away as you go. The chiseling is done fastest by just going down one side of the wire wrapped object - the wire tube. There are several medieval illustrations of that process, but I seem unable to find them online.

There are two possibilities now, the ends can be riveted or forge welded together and while you're forge welding, you might want to make the ring more rectangular in cross section. For fast construction 50% riveted, 50% welded for stability. The rings with rectangular cross section might look superficially similar to specimen punched from plate and you need a thin section for a metallurgist to see the difference.

Torsten F.H. Wilke · Posted: Tue 10 Jul, 2012 12:58 pm Post subject: