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Keith S.
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Posted: Wed 05 Aug, 2020 10:12 am Post subject: Work Hardened Bronze |
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I have a question about work hardening bronze. I know that Neil Burridge works the material along the edges of his blades to make them harder. How ubiquitous was this practice, and when examining an antique, how does one tell that this has been done? Does it leave hammer marks? or are these polished out on most surviving examples?
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Mikko Kuusirati
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Posted: Wed 05 Aug, 2020 11:52 am Post subject: |
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Neil himself talks about this a bit in this video: https://www.youtube.com/watch?v=qGqPnzkRZp4
"And sin, young man, is when you treat people like things. Including yourself. That's what sin is."
— Terry Pratchett, Carpe Jugulum
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Dan Howard
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Posted: Wed 05 Aug, 2020 4:45 pm Post subject: |
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It seems to have been done fairly regularly with blades. The result produces a hardness that is similar to that of medium-carbon steel (non quench-hardened).
Author: Bronze Age Military Equipment, Pen and Sword Books
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Paul Hansen
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Posted: Thu 06 Aug, 2020 12:49 pm Post subject: Re: Work Hardened Bronze |
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Keith S. wrote: | How ubiquitous was this practice |
I think the vast majority (if not all) of bronze age swords had work hardened edges.
It also makes sense, it significantly increases the hardness (and thereby edge keeping ability) without adverse effects.
Keith S. wrote: | and when examining an antique, how does one tell that this has been done? Does it leave hammer marks? or are these polished out on most surviving examples? |
That depends a bit on the edge thickness. On thin edged blades (e.g. with a mid rib) the hardened edge is clearly visible as a kind of "secondary bevel".
On thicker edged blades, it can be more difficult to see.
Original with high detail photo's:
https://m.lauritz.com/en/auction/sword-ireland-bronze-1100-to-1050-bc-wilburton/i4191198
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Keith S.
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Posted: Fri 07 Aug, 2020 6:09 pm Post subject: |
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Thank you all for the responses! If there is a particularly thick bronze blade which has been polished and shows no hammer marks, is the presence of work hardening determined by testing the hardness of the blade on the core and edges? I created this thread because I will be examining some chinese dagger-axes sometime soon and I have not heard of them being work hardened, so I would like to see if I can tell myself.
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Paul Hansen
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Posted: Sat 08 Aug, 2020 2:03 am Post subject: |
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Keith S. wrote: | Thank you all for the responses! If there is a particularly thick bronze blade which has been polished and shows no hammer marks, is the presence of work hardening determined by testing the hardness of the blade on the core and edges? I created this thread because I will be examining some chinese dagger-axes sometime soon and I have not heard of them being work hardened, so I would like to see if I can tell myself. |
I suppose that any form of destructive testing is ouf of the question then... (All hardness tests are somewhat destructive)
Any hammering will leave some kind of deformation.
I don't have the Khopesh pictured above but I do have a Naue II from Neil. It doesn't have the very clear hardened edge like on the Carpstoungue sword pictured above but more a kind of convex / lenticular profile with a slighty concave area towards the edge, if that makes sense. I did handle the Khopesh a couple of years ago, if I remember correctly, the profile is nearly purely convex.
If you have a good camera with a macro lens, you can try making a lot of close-up pictures. Would be really interesting to see!
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Sean Manning
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Posted: Sat 08 Aug, 2020 2:09 am Post subject: |
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Keith S. wrote: | I created this thread because I will be examining some chinese dagger-axes sometime soon and I have not heard of them being work hardened, so I would like to see if I can tell myself. |
The Chinese bronze weapons are a different technology than the European ones, they figured out some tricks like high-tin alloys which European smiths never did, and probably the reverse.
Jeroen Zuiderwijk did some research on both traditions, he hangs out on the Bladesmiths Forum and has a Facebook Page.
weekly writing ~ material culture
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Keith S.
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Posted: Wed 12 Aug, 2020 3:56 pm Post subject: |
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Sean Manning wrote: | Keith S. wrote: | I created this thread because I will be examining some chinese dagger-axes sometime soon and I have not heard of them being work hardened, so I would like to see if I can tell myself. |
The Chinese bronze weapons are a different technology than the European ones, they figured out some tricks like high-tin alloys which European smiths never did, and probably the reverse.
Jeroen Zuiderwijk did some research on both traditions, he hangs out on the Bladesmiths Forum and has a Facebook Page. |
Thank you for the the info! I am aware of the high-tin bronze weapons in China, but many dagger-axes also fell in the standard 11-12% tin range, I am wondering if work-hardening was done on any of these.
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