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WIP: Pattern-welded sword from bloomery steel


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Here goes nothing--let's see if I can make a sword from dirt.

 

[Jan 2021]

 

The Plan

 

I'm aiming to reproduce a sword that you might encounter in late 6th- or early 7th-century lowland Britain (ie, an "Anglo-Saxon" community).

 

I want to make something typical of archaeological finds from the period, an "average" sword rather than a reproduction of one specific find.

 

I'm going to make it from ore, with maybe a bit of nineteenth-century wrought iron mixed in for fun and contrast.

 

Sources

 

The best survey of swords from this period is Paul Mortimer and Matt Bunker's new book, The Sword in Anglo-Saxon England: from the 5th to 7th century (2019). Paul and Matt do living history, and they wrote this book for an audience of makers and re-enactors as well as academics. It's a great survey. In the book, Paul shows that herringbone patterns in either 2 or 3 bars were the most common on blades from this period. Matt wrote a great chapter on hilts, most of which were made from unadorned cattle horn.

 

I also re-read all of Brian Gilmour's metallographic analyses of sword blades (Tylecote and Gilmoure 1986, and his briefer studies on blades from Castledyke South, Park Lane, and Saltwood).

 

Sketching out a pattern

 

So, what I want to do: 2 twisted bars on each face of the blade forming a herringbone pattern. These twisted bars will sandwich a core of plain iron. For the edges, I'm thinking a simple stacked bar of bloomery steel, but with the welds turned 90* so as to give the edges a subtle striped pattern (something Gilmour noted on several of the blades from Saltwood which I think would look cool).

 

Like so:

 

sword sketch.jpg

 

So I'll need to make 4 twisted bars, a core, and 2 edges.

 

The metal

 

I've been smelting for 2 years, and I've got a few bloom pieces lying around that should work well.

 

This bloom came out high carbon (hypoeutectic) steel, and it forges very well. I made it on the winter solstice 2019 (photos of the smelt here). I forged half into a dozen knives last summer, but I held onto the other half:

 

IMG_1930.jpg

 

This one, smelted two months ago on the 2020 solstice, is also hypoeutectic steel:

 

IMG_5663[15743].png

 

And this one I made last month is lower carbon mild steel (basically just iron):

 

IMG_5322.jpg

 

I've also got this bucket of bloom scrap that I can melt down into high-carbon hearth steel for the blade edges:

 

IMG_5822.jpg

 

All these blooms were made from a low-phosphorus hematite ore, however, and they don't give great contrast for pattern welding.

 

So I grabbed some mid-P wrought iron to mix in with the twisted bars.


 

Edited by Andrew W
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Making Hearth Steel

 

[Feb 6, 2021]

 

For the blades of the sword, I wanted high-carbon steel. I decided I'd make that by melting my scrap into a charcoal hearth.

 

I recorded a video of the process:

 

 

2lb (.9kg) of scrap, plus a copious serving of high-iron bloomery slag, gave me nearly 2lb of high carbon steel.

 

Hopefully that'll be enough for my blade edges!

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The core bars

 

[Feb 2021]

 

For the twisted core bars, I used more hearth steel (carburized bloom) + some nineteenth-century wrought iron that has a moderate phosphorus content. The last time I used this combination I got a great color contrast, so: fingers crossed?

 

1.5lb (700g) of hearth refined bloom steel + about as much phosphoric iron, ready to weld:

 

IMG_5681.jpg

 

Heating it up...

 

IMG_5687.jpg

 

Success!

 

IMG_5690.jpg

 

And drawing it out into a 1/4" (6mm) square bar:

 

IMG_6143[15754].jpg

 

This netted me enough for 2 bars.

 

So I did it again, getting me 4 x 25" (64cm) long bars.

 

Altogether, to make the 4 core bars and the edges, I used at least 10lb (4.5kg) of unrefined bloom + 2lb (900g) of refined wrought iron. I'll use at least 2 (900g) more lb of bloom to make the center core bar--all to make a sword blade that will weigh less than 2lb / 1kg!

 

---

 

And that's as far as I am right now. Next step: lots of careful twisting!

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Twisting, twisting, twisting...

 

IMG_6164.jpg


The bar on top isn't twisted tight enough yet--I took this photo between heats, then kept twisting tighter.

 

The 1/4" bars are so easy to snap while I'm twisting them! I may have had to scarf weld a few back together.

 

I've twisted 3 of the 4 bars. I'm hoping to do the last after work tonight--more updates coming!

Edited by Andrew W
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Looking good! I've had a lot of issues twisting bloomery pattern welded material, and the vehmaa sword I did has lap welds aaaaaaall over the place. 

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  • 3 months later...

1. damn.

2. I am impressed with your smelting/hearth melting ability. very impressed.

3. Even with modern steels, I start with 8 or so pounds to get a 2 pound sword. That is because of the complex pattern welding. It always seems a shame, doesn't it? Like the old Bugs Bunny cartoon where big lathes were taking trees to make toothpicks. One tree = one toothpick.

4. I know that phosphorus adds contrast to wrought iron or bloomery steel. I seem to remember (sort of) that it can also cause some other properties, like hardness and brittleness. Are there any reasons / how do you work the material with phosphorous differently that you work the non-phosphorous material?

5. Thank you for documenting this. 

 

Help me understand (anybody)

.76% and lower - hypoeutectoid steel < .77% carbon - eutectoid steel - .85% carbon < .86% and higher - hypereutectoid steel 

Edited by Kevin Colwell
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4 hours ago, Kevin Colwell said:

Help me understand (anybody)

.76% and lower - hypoeutectoid steel < .77% carbon - eutectoid steel - .85% carbon < .86% and higher - hypereutectoid steel 

The eutectoid point is where the A1/A2, A3, and ACM lines meet (the valley where austenite formation happens the coldest).  Depending on the phase diagram you're looking at, that could be about 0.76% to about 0.84% (hence why 1080 and1084 are made and are basically the same thing).  The thing to keep in mind is that the Fe-C phase diagram attempts to consider only Fe and C.  Other elements will push A1/A2, A3, and ACM around a bit, so the eutectoid point moves.  From there, 'hypo' means below and 'hyper' means above/beyond.  

 

Also, eutectic is is similar except it isn't with the austenite formation point, but the liquidus (i.e. the lowest melting point).  Working in a foundry, that is the one I am typically dealing with the most, and so often say eutectic when I mean eutectoid.  I had to go back and correct this post as I was typing it.  Stupid habits.  

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thanks Jerrod - I sent you a pm.

 

 

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  • 3 months later...

Hey it's been several months now since the last update.  We're all waiting anxiously for the next post.  This is GOOD - I've sent links to several friends to follow along.

 

Jerrod, THANK YOU so much for starting this thread - it's tagged for me to follow.

 

Ken H>

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On 10/9/2021 at 10:17 AM, KenH said:

Jerrod, THANK YOU so much for starting this thread - it's tagged for me to follow.

Not me.  This is @Andrew W's thread.  

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Andrew W:  Sorry I gave Jerrod credit for the thread, not sure at all why I didn't get it right.  Andrew, I'm more than impressed with your work, please continue the thread.

 

Jerrod, sorry about that, and I'm glad to corrected me so I can correct it.

 

Ken H><

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