Toolmaker challenge: Bronze-age tools

[Jamie Buxton]

In another thread, we've been talking about the woodworking practices of the ancient Egyptians, three thousand years ago. (http://www.sawmillcreek.org/showthread.php?t=115265) The Egyptians were Bronze-Age people. That is, their woodworking tools were made of copper or bronze. Several people in the other thread have said that bronze should be able to make a cutting edge as sharp as steel, although not as durable. That makes me curious. I'm not a tool maker, but many of you on this board are. I'd like to see one of you make a bronze tool, harden the edge, sharpen it, and report on its performance. Perhaps the simplest tool to attempt would be a chisel.

There are lots of kinds of bronze, so maybe part of the challenge is to learn what bronze the Bronze Age people had, and use that to make the tool.

How 'bout it, tool makers?

[David DeCristoforo]

Ancient cultures were able to accomplish things that we, with all of our science and technology, cannot even figure out how they did it much less replicate their results using only what they would have had to work with. The one thing they did have that we seem to lack was plenty of time. I'm sure you could put a good cutting edge on bronze. It would just need a lot of resharpening.

[Joe Cunningham]

Archaeologists do a lot of experimental reproductions, so there might be some done already. We used to make chipped stone tools, find a road kill, butcher it and study both the bones and the tools for wear indications. We'd also keep track of how long we could butcher before we needed to resharpen the tool.

We'd also create the stone tools and look at the waste stone, as often that was all we'd find--the flakes that resulted from tool creation, and not the actual tools. We could tell quite a bit about the skill of the tool maker from this waste.

Studies in Egypt maybe not so much, as the researchers there tend to be epigraphers rather than archaeologists. They have such a wealth of information, that they don't need to do these kinds of experimental studies.

[george wilson]

I am a toolmaker Jamie. The problem is not so simple in reproducing bronze. Question is,what exact alloy of bronze did they use? And not only the Egyptians,but other ancient cultures as well?

Contrary to all the movies,such as Troy,the sword wasn't used much in the bronze age. The spear was the primary weapon,due to the fragility of bronze. They did have swords,but used spears more.

When they made a replica of the Antikithera (sp?) device,the maker said he was using the same tools the ancient Greeks used. Then,he takes out his modern Grobet needle files,and proceeds to file gear teeth! Still didn't tell us much about exactly how the device was made.

I have used bronze castings of several alloys over the years.Like steel,there are many different alloys that range from the very easy to work,to much tougher alloys. However,the tougher alloys usually involve aluminum,manganese,phosporus,and other metals unknown to the ancients. As I said,I made a very hard brass by adding 20% lead,which they did have. However,the item I cast was a chariot plane,not a strip,or some shape suitable for sharpening.

I don't have my furnace anymore. Foolishly,I left it 3 houses ago,as space was a premium,and I didn't really have anywhere to keep it.

[Joe Cunningham]

George I'll ask a professor friend of mine. He studies Syria and Jordan during the Neolithic, but he might be able to point me to some studies on the alloys used for bronze tools. Sadly such things are often buried in academic journals or unpublished Ph.D. dissertations.

[David Myers]

Sadly such things are often buried in academic journals or unpublished Ph.D. dissertations.

Information published in scientific journals isn't buried. Its been carefully preserved, usually after peer scrutiny, and methodically indexed.

All this so that when a question arises, such as the composition of bronze tools from a particular ancient civilization, we can find an answer. ;)

[Sam Takeuchi]

Something to get your started? (http://www.reshafim.org.il/ad/egypt/trades/metals.htm)

As usual, missing a few pages, but there are good stuff here (http://books.google.com/books?id=eMWeJToZlh0C&pg=PA149)

[David Myers]

This report is on an Egyptian pre-Bronze Age copper axe head, circa 4000 B.C.

This axe head had the following composition:
Copper 97.35%
Nickel 1.28%
Arsenic 0.44%
Lead 0.17%
Iron 0.15%
Manganese 0.06%

http://www.nature.com/nature/journal/v130/n3286/pdf/130625a0.pdf

(let me know if you can't see the PDF file)

[george wilson]

Nothing of much note there,except the nickel content. That should add some toughness or hardness. To what degree,I can't say.

[David Myers]

This article details the proportion of tin in various egyptian bronze artifacts:

http://www.nature.com/nature/journal/v57/n1486/pdf/057594a0.pdf


This article doesn't focus on bronze, but there is a nice example of an Egyptian chisel (Fig. 1). Looks like an Egyptian pig-sticker:

http://www.nature.com/nature/journal/v125/n3162/pdf/125859a0.pdf

[Bill Houghton]

Ancient cultures were able to accomplish things that we, with all of our science and technology, cannot even figure out how they did it much less replicate their results using only what they would have had to work with.

I suspect there's a lot of mythology about that notion: the problem isn't that they had mysterious knowledge we've lost and could not reproduce; it's that no one has devoted the time to learning what they knew.


The one thing they did have that we seem to lack was plenty of time.

When the work day was 12 hours (or, more accurately, dawn to dusk), and the work week had six and a half or seven days in it, there were indeed a lot more hours available.

Let's also remember how important practice is: when you use just a few tools to perform a limited number of operations repetitively, you get pretty good at it. We modern amateurs are often doing a huge variety of things at which we can get only so good.

Also, if the best tool you've got is only so good, you become very good at understanding its limits and using it to those limits.

[Joe Cunningham]

This is more Aegean than Egyptian, but it might be a starting point. You can probably find it at a local Uni library.

2007 Metallurgy in the Aegean Early Bronze Age, edited by Peter M Day and Roger C P Doonan

http://www.oxbowbooks.com/?

[Wes Grass]

"what exact alloy of bronze did they use?"

That's just it, they didn't. Use exact alloys that is. Alloy content would have been all over the place, with no way of knowing *why* one batch might make better cutting tools (maybe an accidental addition of nickel or iron), and others would be better for sculpture (better corrosion resistance).

I ran across some information on the Incas, that showed some art work with varying alloys in it. Appeared as though they selected them by color, as the stronger alloys (as we know now) they had weren't deliberately used in the areas where structure might have been important.

So color could have been an indicator they used to decide if a batch should be set aside for tools. And they probably knew from experience that ore from one area was better suited than another, due to various 'impurities' in it that they had no control over. Or that throwing a couple of 'these rocks' in the pot did the trick.

Doing this for real would require some time to experiment with alloys, and how much hammering is needed to get sufficient hardness. And how much is going too far. And I don't think I want to load up my stones sharpening one of these, so I guess we'd be stuck using the traditional Egyptian scary sharp method ... which probably involves sand and goatskin, or something like that.

Added:

More reading: Google Books, Experiments in Egyptian Archaeology.

Looks like they attained a hardness of roughly 20 Rockwell C by hammering. But that may not mean much, as they're using the Vickers scale and these things don't always directly compare. But they noted it was harder than they could get mild steel to work harden.

[David Myers]

This article details the proportion of tin in various egyptian bronze artifacts:

http://www.nature.com/nature/journal/v57/n1486/pdf/057594a0.pdf


This article doesn't focus on bronze, but there is a nice example of an Egyptian chisel (Fig. 1). Looks like an Egyptian pig-sticker:

http://www.nature.com/nature/journal/v125/n3162/pdf/125859a0.pdf

The links above require a login/password, so I took a few screenshots. Here is the axe head (its composition is detailed in a post above) and the chisel. I'm happy to email the pdfs to anyone who would like a copy of the full articles.