Friday, January 13, 2023

Blade find from Belgium??


On 2023-01-13 6:36 AM, "C..." * wrote:

 I am a metal detectorist based in Belgium. I stumbled across your website and hoped maybe you can help me?
I recently found an iron blade, which from my own experience looks very old. It looks like forged iron, feels like it weighs a lot for a small object.
I was wondering if you can advise me of an approximate period it might be from and its use? I have been trying to research it online, it reminds me of a small Viking period knife from the examples I have found. Maybe from the 9th -10th century, so I was thinking maybe mid to late Medieval. I could be completely incorrect though. When I found it a part of the end crumbled off, I believe it was a bit more pointed.

The blade has an interesting slight curve. The area I found it in has human history dating back thousands of years.

I thank you in advance for any help you can provide. Please find some photographs attached.

The original request e-mail, highlighted in bold are the elements that I flagged when I first read it.
Below is my reply, with images provided by "C..." inserted as considered.

Well - a lot to unpack here. Sorry to say I may not prove that helpful. I warn you that you may know much of the following already!

That is likely your first problem. Two World wars that chewed up most the ground, and left so much stuff buried. Very small country, intensively populated and farmed - for like forever...

Find location may provide you with some clues - my advice is first to check the history on the piece of ground where you uncovered the object. If the result is 'too much history to narrow occupation' that pretty much ensures that unless there are significant marks or design to the object, you are just not going to narrow it down.

Ok - not copper alloy, but...
One possible narrowing would be distinguishing between post Industrial (c 1855) mild steel, and earlier forms of wrought iron as the material.
Wrought iron - especially very old wrought iron, corrodes in a different and distinctive way. The slag inclusions from its creation in bloomery furnaces often causes it to erode to display a linear grain. Steel on the other hand, more typically erodes with flake like patterns.
Looking at the object, it *appears* more like a 'modern' steel.
You could check this using a destructive spark test - or better still via a (costly) lab test, both for carbon content. Wrought iron has basically no carbon. 


One warning is that the level of corrosion to the object appears limited, not what I would expect from centuries buried. As you surely know, the condition of the ground at location of discovery is a big clue there.


First thing that jumps out is the cross section. This is a 'sabre' grind - with a rectangular back, then the angled bevel to the cutting edge. Viking Age blades are basically all V profile grind. This to get the most function out of the least amount of metal. A sabre grind requires more material, but does result in a stiffer blade.This remains the case through the Medieval period - again shifting into the 'early Industrial = 1600's'.

One of the things I do to help me understand photographs is reduce one down to 'size as' and print it off. To help visualize what the original object shape was, I then will extend the lines into what seems a logical profile. 
Reduced to life size @ 13.5 cm / 8 cm blade

 The object has an extremely wide and thick back compared to a sharp taper to the cutting edge. There does not seem excessive amount of material missing on the blade side (ie - corrosion or wear effects). Attempting to pull measurements off the images, the back is about 5 mm thick and about 10 mm wide, with the bevel about 15 mm wide. As you mentioned, there is a clear blade side concave curve. (Which has to be intentional, the forging process naturally flexes the blade to a convex curve!) This curve has to relate to the function of the tool. The point, extending the existing lines forward, is very thick and blunt - again obviously for strength. 
(showing cutting edge)

All this would intentionally create a tool that was extremely strong, but a relatively blunt cutting edge. The curve would suggest use in a sliding cut action - not a straight chopping direction. Given the total blade length at about 8 - 9 cm, the overall result is an extremely rugged tool - far more than is required for the length. But also one that would not have a very effective cutting edge. (Yes - even with some of the edge material obviously corroded away).

The tang is very short, remains at about 4.5 cm. Good chance it just has been corroded or broken away however, so need to be a bit careful about applying too much to this. That said, it does not taper very much down it's length, which may suggest most of the original remains. Not much (remaining?) for secure mounting into a handle. It does appear thicker at the extreme end than at the joint to the blade however, and is clearly rectangular (close to) rather than circular in cross section. This all may indicate something about the original mounting method. A lot of Norse knives have rounded tangs - which passed through a hole drilled or burned into the hilt material, then secured with a metal disk as the end of the tang was peened over like a rivet.

Overall, I see a short, very strong but blunt blade, more likely to be made from a steel alloy.
My first guess would be part of an agricultural tool - like a tooth from a drag harrow.
Although I admit I am not familiar with the design requirements, another possibility could be some kind of pruning or hand harvesting tool (apples?).

If you can find someone (university?) who has a hand held XRF analyzer, this is basically micro destructive and would give you the relative elemental composition of the material. That might be the easiest way to determine relative technology of the metal itself.

Sorry - this from my computer desk and working from such limited information. May not be the commentary you were hoping for?

Good luck with this - and keep looking! Here in Ontario, our history is so relatively shallow (any iron object around my area will be no older than about 1615) - and in comparison so thin. My own home at Wareham was settled (by Europeans) about 1840 - 50. The First Nations just avoided this area, as other than deer and small game, there were no resources available that made the area worth exploiting.

* The images included here are "C..."s. I have intentionally omitted his last name. 

(Note the provision included on the bottom of any longer e-mail replies from me : " To those receiving long detailed replies to specific questions : My own written response may be edited and re-used as a blog posting."

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February 15 - May 15, 2012 : Supported by a Crafts Projects - Creation and Development Grant

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