Tofta church mail coif -- myArmoury.com

Dan Howard · Posted: Tue 13 Nov, 2012 4:31 am Post subject: Tofta church mail coif

Mark Hale posted this in an earlier thread

Peter Johnsson · Industry Professional

Here is a pdf of a report (in Swedish) about the metallography of the Tofta coif:

www.arkeologiuv.se/cms/showdocument/documents...22_gal.pdf

Google-translated snippets from the text:

"The three rings from the ring fabric which have been analyzed are of two different types,
two are complete rings and one is a riveted ring. All three have oval cross sections.
They have all been analyzed in different directions as well as metallographically
chemically. The iron is in all rings mainly ferritic, ie. carbonless
iron. The ferritic iron is much softer than a carbon steel. In the
both the rings, and the rivet, has a phosphorus content was observed.
Phosphorus present in concentrations about 0.15 to 0.20 weight percent. The riveted
ring missing phosphorus, or occur only sporadically in the lower level.
Phosphorus affects iron material properties by increasing its hardness
slightly, but mainly increases its toughness. The latter has often been
coveted feature for wire drawing."

"The results from this study of two different ring types from
ring fabric from Tofta is that the rings are made of a
phosphorus-iron rings which probably has been punched out of a sheet. the riveted
ring shows no clear signs of being manufactured by punching
or from a wire even if the latter is likely. longitudinal
manufacturing traces, which is typical of drawn wire, emerged (according to
from the client) during the conservation process, which confirms
adoption of manufacturing technology. This ring also differs in terms of
composition because it lacks phosphorus, a substance which, however,
present in the spent rivet."

I will edit in more text when I get time to do so.

I also have an essay on this coif by Tommy Hellman who made an analysis of the coif, its pattern and rings but at the moment of writing I am not sure where I have this text. If I find it I shall post further info.

Mart Shearer · Posted: Tue 13 Nov, 2012 9:10 am Post subject:

Using Google translator to speed the process:

Randall Moffett · Posted: Tue 13 Nov, 2012 9:45 am Post subject:

Very cool find. It is in great condition. I wonder where one can find punch rings of specific designs?

RPM

Gregory J. Liebau · Posted: Tue 13 Nov, 2012 12:22 pm Post subject:

Holy mackerel! I'm in the middle of modifying an Indian-made coif for a 13th century affair, and this is wonderful inspiration. I'm confused about what the leather bit is actually doing, though. Is it holding up a ventail? I can't see any major distinction in the mail bits to tell whether it's solid or separate under the bust's chin. Also, it looks like the cord must be made of rawhide, judging by its color and level of preservation, yes? Thanks for sharing!

-Gregory

Mart Shearer · Posted: Tue 13 Nov, 2012 5:39 pm Post subject:

Mart Shearer · Posted: Tue 13 Nov, 2012 6:05 pm Post subject:

S. Sebok · Posted: Wed 14 Nov, 2012 7:59 pm Post subject:

The way that coif fits is similar to how mine fits, all the way up to the chin. The way the rings look reminds me of GDFB indian made wedge riveted maille. It looks like it's 9MM in diameter to me.

Mart Shearer · Posted: Wed 14 Nov, 2012 8:16 pm Post subject:

It is clearly round riveted.

Jared Smith · Posted: Wed 14 Nov, 2012 9:17 pm Post subject:

That is one of the highest phosphor amounts I have ever seen stated for mail. It normally is about half that, which enhances drawing properties, but can be softened. This would "bake" harden. I would expect it to have high strength after working, but not be very ductile. Are there any other similar period weapons or other objects of similar phosphor content?

http://www.keytometals.com/page.aspx?ID=Check...amp;NM=211

Mart Shearer · Posted: Wed 14 Nov, 2012 10:39 pm Post subject:

As Peter quoted:

"The results from this study of two different ring types from
ring fabric from Tofta is that the rings are made of a
phosphorus-iron rings which probably has been punched out of a sheet. the riveted
ring shows no clear signs of being manufactured by punching
or from a wire even if the latter is likely. longitudinal
manufacturing traces, which is typical of drawn wire, emerged (according to
from the client) during the conservation process, which confirms
adoption of manufacturing technology. This ring also differs in terms of
composition because it lacks phosphorus, a substance which, however,
present in the spent rivet."

So the drawn wire rings are phosphorus-free, though the rivet seems to contain phophorus as well as the punched rings. 18th century wire for clavichords and harpsichords (P-wire) is also wrought iron with similar phosphorus levels.

http://en.wikipedia.org/wiki/Wrought_iron

"Coldshort iron, also known as coldshear, colshire or bloodshot, contains excessive phosphorus. It is very brittle when it is cold. It cracks if bent. It may, however, be worked at high temperature. Historically, coldshort iron was considered good enough for nails.

Nevertheless, phosphorus is not necessarily detrimental to iron. Ancient Indian smiths did not add lime to their furnaces; the absence of CaO in the slag, and the deliberate use of wood with high phosphorus content during the smelting, induces a higher P content (> 0.1%, average 0.25%) than in modern iron. Analysis of the Iron Pillar of Delhi gives 0.10% in the slags for .18% in the iron itself, for a total P content of 0.28% in the metal and accounts for much of its corrosion resistance. Furthermore, the presence of phosphorus (without carbon) produces a ductile iron suitable for wire drawing, for piano wire.[15]"

S. Sebok · Posted: Wed 14 Nov, 2012 11:11 pm Post subject:

Tjarand Matre · Posted: Thu 15 Nov, 2012 12:08 am Post subject:

I have been to Tofta church and seen the coif exhibited there. It looks exactly like my Indian maille, especially the wider overlap.

Dan Howard · Posted: Thu 15 Nov, 2012 12:33 am Post subject:

Your indian mail must be different to any indian mail that I've seen.

Dan Howard · Posted: Thu 15 Nov, 2012 12:58 pm Post subject:

Randall Moffett · Posted: Thu 15 Nov, 2012 1:19 pm Post subject:

Which ones have you been buying? I am thinking about making a full hauberk and chausses in the next few years so I have been pricing and such but the loose rivets are tricky as they seem to vary batch to batch from what I have seen.

RPM

Dan Howard · Posted: Fri 16 Nov, 2012 1:02 am Post subject:

I've only ever bought washers. The measurements have been virtually identical from one batch to the next. Maybe one in a hundred washers has a curved "bite" out of an edge which rendered it unusable.

This is the last purchase I made.
http://www.seastrom-mfg.com/washerdetails.asp...702-476-30

Randall Moffett · Posted: Fri 16 Nov, 2012 6:03 am Post subject:

Dan,

Thanks. I'll have to figure out what size I need and look at costs. I figure I'll need 10,000s of links in total so likely some 10-20k of solids if I do every other row.

Are these custom Dan?

RPM

Dan Howard · Posted: Fri 16 Nov, 2012 1:20 pm Post subject:

The links I bought were standard washers they already had in stock. I don't think they would have a part number for custom jobs.

Mart Shearer · Posted: Fri 16 Nov, 2012 3:08 pm Post subject:

http://www.gnom.dk/projekter/ringbrynjehistorie.pdf
Early Iron, Arne Jouttijärvi