Bowed steel straightening ???

A

Angus McGunnigl

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May 22, 2002
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I am doing the low-tech annealing using a wood fire.

I have successfully done this a couple times now, however, when I fished out the most recent batch of Nicholson files from the firepit, a couple of them are a bit curved.

After I laid them on the raked out flat bed of coals and put more wood on top, the fire was played with by my younder cousins a bit, un-leveling the files.

Can I get them straight again by warming up in the forge, then clamping them into the vise?

Any advice would be great.

Thanks.
 
ideally you would have wanted to straighten'em before they cooled the first time but, in my limited knowledge and experience with forging files, depending on your ability level you could easily hammer them straight when it comes time to forge the blade...
if you are stock removing you can do like you said, go thru the annealing again and pull them out on the tail end of the cool down and clamp them between 2 pieces of mild steel and let it cool while clamped.
 
If they are indeed annealed and soft just straighten them how ever you want to do it.
A vice and piece of pipe over the blade works. I pound them straight on the anvil.
Just make sure it's soft first check it with a good file if it bites in it will straighten.

Bob
Edited to add do a couple of normalizing cycles before the hardening to take the stress out and reduce grain size.
 
The only thing I might add is that sometimes the metal, even though it's annealed, can have a bit of springiness to it if you hit it with a hammer when it's cold. I can't really see it being all that good for the steel either. I would think hammering while cold could cause internal stresses in the steel, but I might be wrong. Just make sure you wear a face shield and hold it very securely. Actually, probably best to heat it to a normalizing heat and hammer it out straight while it's hot I think. I tried hammering a cold piece of steel and it bounced right up and hit me right in the face....bad idea.
 
Thanks for the replies.

They are nice and soft, so the annealing did work. I put them in a vice and they will bend.

If I do straighten them without any heat(cold), will they want to go back to being bent when they see heat the first time ?
 
Angus McGunnigl said:
Thanks for the replies.

They are nice and soft, so the annealing did work. I put them in a vice and they will bend.

If I do straighten them without any heat(cold), will they want to go back to being bent when they see heat the first time ?
Click to expand...

From my experience, they will not necessarily go back to bent just from heating them, but when you quench them they'll try to warp back to that previous state. So before quenching them, do at least one normalization first. This will take some of the stresses out. Of course I'm not an expert at this, it's just going by my personal (limited):D experiences. I've had to deal with the same problems trying to work with some leaf springs that were bent. I heated them up in the fire to just above non-magnetic temp and hammered them out straight, then I just let them cool down from there. Sometimes it's not necessary to anneal even to be able to do the stock removal, just normalize well. If those Nicholson files are by any chance 1095, then according to what I been told, they should not be annealed really slow anyways, but I'm not sure what they make files out of these days. I like Tai Goo's approach actually when working with unknowns....do whatever "feels" right. Someone with more experience might be able to offer you better advice. Just trying to help.
 
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Thanks again for the reply. I'm going to warm one up slightly in my 2-brick forge and then straighten in a vise.

We'll see how it goes.
 
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