Thread: Crucible steel file

I quench it in oil and then agitate (move around) for a bit (say 10 to 20 seconds or so), then take it out and quench it in water the rest of the way. the water bit is not necessary from a heat treatment perspective, it's just so I can hold it with my hands without burning myself. A forge doesn't need to be expensive btw. You can easily make one from scrap.

See here for how I built my forge:
http://onikudaki.be/content/54-building-forge

Wow! That forge looks great! I think my BBQ might be getting another purpose this winter. Il have to keep that one quiet from the wife. I have one if her old hair dryers lying around somewhere too, I could try and see if that would work. I would get more satisfaction out of forging on a home made version rather than just using one out of the box. Il have a route around and see what parts I can find. Thanks Bruno.

Depends a lot on the age of the file as to whether it is crucible steel or not, but as it is stamped on it I see no reason to disbelieve it.

File makers belonged to the same guild as cutlers, and way back it was a very skilled trade that had more respect than that of cutlery - it was cosidered harder to make file than a knife, for example.

Obergs 1943 Machinery Handbook lists files as being commonly made from crucible steel up to and past the time of electric melts.

After that other steels were commonly used, high carbon steel, W1 and W2 water quench steel, even case-hardened steel, for example.

The old crucible steel files were valuable items - far more expensive than an equivalent bar of steel, and highly prized, so much so that they were often re-cut when worn, which could have carbon-loss issues.

Regards,
Neil

Originally Posted by Bruno

To be honest: don't overthink it.

That is the best advice I have read in a while, some of the best learning comes from going through the process and observing. Once you have read the theory, the best way to learn it is by doing.

Charlie

Charlie

Thanks to Neil for posting about crucible steel. It is what Sheffield was known for in its heyday and I would not be surprised to find it in an old file. Crucible steels then were very clean, meaning minimum crud or alloying content, nothing but carbon and iron. As such, the HT regimen for 1095 would be a sufficient starting point, although the crucible steels could have carbon content slightly higher than that. Without specific testing you are taking your best guess.

Bruno's point should be considered every time a mystery steel is used. Smiths for thousands of years have gotten things hot and quenched them in all manner of substances and then learned from their experience as to what worked. Science, as we know it today, has only been involved for a short percentage of that time. Keen observational skills have stood humankind in good stead for a lot longer. A great many more blades have been made using non-scientific methods than otherwise and were perfectly serviceable for their lifetime. Keep it simple for simple steels like this crucible steel file.

DO NOT use a brine solution to quench this material unless you are sure you want cracks or a broken razor.

Thanks so much for all your help, I'm part way through fabbing a forge up, pretty close to brunos specs but with a van wheel rim instead of a BBQ, I had one handy and it seems a but more substantial. Il post pics when it's done. Oh, and 5kg of kitty litter!! I'm all for the trial and error method, I have a stack of files to upcycle and I'd rather do something wrong and change my methods than follow a bunch of step by step instructions and not really know why it's right.

From my experience with making things from files, it is very important to anneal the file before you start working with it. Heat to just above non-magnetic, and cool very slowly - I use a bucket of vermiculite - it takes many hours to cool to the touch.

Is that to make the file easier to work with skipnord? I ran into problems when trying to drill the pivot hole, hss bits didn't touch it, come to think of it neither did my centre punch! I'm going to get a cobalt bit to drill the hole before I ht.

Absolutely! Once it's annealed, it is dead soft, and drilling is no problem. That's exactly the problem I had before I figured out it had to be annealed. Good luck with your project.

Originally Posted by Manchestertattoo

Is that to make the file easier to work with skipnord? I ran into problems when trying to drill the pivot hole, hss bits didn't touch it, come to think of it neither did my centre punch! I'm going to get a cobalt bit to drill the hole before I ht.

Keep in mind that this is only important if you are only going to use stock removal.
If you are going to forge, annealing up front will not do anything.