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Grinding techniques of the medieval period


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Hello,

This is my first post on the forums and after lurking for a while I've come across a subject that has been spoken around the forums quite a bit but never in a very specific way.(Or perhaps it has and I just completely missed it. If this is the case feel free to post a link to such a post.)

 


I'd like to start a topic regarding the techniques and grinding setups of the medieval period(Early or Late) to see if anyone has any information or perhaps would be inclined to share personal theories of how metal weapons/tools we're grinded in this timeframe. 
To be more specific, I'm very interested in understanding how long blades we're grinded on those huge water-powered sandstone grinding wheels found in europe.

 

 

I myself have recently started making quite a long sword myself, and because of my fear of ruining it on my belt grinder, I decided to rough grind it by filing and draw-filing (after forging it as close to finish as possible) and although I love using files, after heat-treating the blade the files are no longer a suitable option to make the final grind on the sword.
This made me stop and think, perhaps historically because of how large-scale sword production was, rough grinding a sword with a file was a luxury not available to the grinder user of the period, and on top of that once the sword is hardened and tempered there's no point ruining files trying to finish it like that.

Why not just cut out the files entirely and develop the skill to use a grinder effectively from rough grind to finish.
 


And that brings me here to this topic today.
I'd like to learn (if possible as this knowledge may not be available) how exactly a skilled grinder in the medieval period would rough grind and finish grind a sword, what techniques would he use differently for a hollow grind versus a diamond cross-section and how he would hold it steady.
 

Based on sparse images of grinding in the medieval period in addition to a few images of renaissance era grinding and so forth, as well as testing myself on how to grind a long blade only on my belt grinders wheel section I will illustrate my own theory on how a sword would be grinded, whether diamond cross-section or hollow-grinded. Following my theory will be  questions on what I simply have no idea about regarding this subject.

So here goes just gonna list them off one by one,
So for a diamond cross section, the sword would have to be grinded vertically up and down the grinding wheel very carefully in a straight line and not follow the curvature of the wheel so as not to develop any shallow spots where the sword is held to the wheel for too long.
I believe this would be the same method whether for rough grinding or finish grinding, as long as the blade doesn't get too hot on the finishing (but since grinding wheels of the time have water troughs I doubt it ever gets too hot)
technique 1.png

Hollow grind cross-section or concave would require the blade to be pushed side to side horizontally on the wheel until enough of a concave shape is acquired.
Whether this was done for finish grinding AND rough grinding I'm not sure. I've seen people say that for heat treating it's best to keep it diamond in cross-section, then grind it into a hollow grind shape afterwards.
Also I'm unsure when grinding this way if it is preferable to grind the top bevel (in the bottom illustration as 1.) or the bottom bevel (number 2.) on the grinding wheel.

Perhaps one of them is more stable than the other? I've no clue.
technique 2.png

Finally after the finish grinding is complete the edge must be grinded as well.
Although there are many different edges found on surviving medieval swords I will try to illustrate the three types I know and how I think they we're made.
For hollow grind and appleseed edges, I believe they we're made horizontally on the wheel.
Whereas for a straight flat grind edge I believe would have been done vertically on the wheel.
technique 3.png

Then I believe the blade would be clamped and polished on a bench of some kind thereafter with some form of gritty substance on a rag, brought to a desired shine or buffed on a water powered polishing grinder and assembled with it's corresponding parts for final sale/use.

That is as far as I know, how grinding would be done for this specific period, please do correct any faults or misconceptions in my theory.
Now for what I really have no clue on;

1. Did they free-hand grind these long blades or did they use a jig?
I'm not sure how much force a gigantic grinding wheel spun by waterpower has, but I'm assuming it must have some bite to it. If it indeed does, how would the user keep the blade stable enough in their hands to grind clean bevels? Does anyone believe with practice one can have enough stability to get the job done, or are there any photos/evidence of jigs being used?
 

2. Is there any images or evidence of blades being handles vertically on these grinding wheels?
Although my drawn examples have worked for me to work a diamond cross-sectioned blade vertically on the wheel, I have yet to see any evidence of it being done this way.
Images of grinding swords are rare but so far I've only seen blades held horizontally or at a diagonal.
This makes me wonder if it simply wasn't held vertically.
How were Swords really made_.jpg

(This might be vertical, but it looks diagonally placed on the wheel to me. I can't ask the artist to explain in detail what he meant unfortunately.)


3. Lastly, I believe I've read somewhere on the forums how the blade could be held on the thighs of the user to stabilize it for grinding on the wheel.
Can anyone confirm this or am I just making stuff up at this point.


If you've made it this far I thank you for giving my post a read.
If you have any ideas or theories please do reply, I'm keen on knowing more about how grinding was done historically.
Likewise any corrections are appreciated.
 

Best regards,
Spencer Farrell

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I think you're pretty much correct, actually.  I've been looking for a video from years ago of an Italian shop with a big water-powered stone wheel.  There was a guy grinding a riding sword on it, and he used every orientation and surface of the stone and blade to get the results he was after.  

 

You may also want to look at the later posts in this thread:

 

I put a bunch of links to older threads about stone wheels.  The common theme is that they were always used with body weight, and usually used with a backing board to apply even pressure.

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  • 4 weeks later...

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