how to soften a file...

[stebblingur]

Is it enough to heat a file to demagnetizing level and then slowly cool it down, or is there any specific temperature for softening a file or metal, this will be my first knife, and I want to get it right, any pointers would be helpful...

[Drq]

Try searching annealing, or normalizing, or how to make steel soft for that matter. The search function is a wonderful thing.

[Rhrocker]

Stebblinger, that'll work to some degree. I wouldn't worry to much about specific temps unless you have a way to measure them, but using the magnet is a sure fire method. Another important part is a good slow cool, like putting the file in vermiculite, wood ash, or even leaving it in your forge (if gas) and closing off the chamber. An overnight cooldown is best for this method. Then test the file with another file. If you can take "bites" out of your hopefully annealed file, then you're good to go. However, if the file skates off of the annealed file, then you need to repeat and try and cool slower.
All of this being said, good quality knife steel is readily availiable from many places, and could be your best bet for a good knife. If the file you want to use is a currently made product, it may be case hardened, and only a fraction of the
surface is hardened.
Keep us posted and we'll try to help you along. Welcome to th e forum BTW!
Robert

[pkrankow]

I have a 5 gallon bucket with a lid full of fluffy dry wood ash from my fireplace for annealing. It works pretty good. You sometimes need to heat extra metal to bury with the part to anneal so you have more thermal mass.

Make sure there is 2 inches of ash on all sides, especially the ends.

Phil

[ThomasPowers]

Making a knife from a file: there are two ways to do it:

One is to draw temper enough to work on it with abrasives but left hard enough that you don't need to re-heat treat after you are done---have to work it *COOL* though.
For this you need only to draw the temper to what you want the finished blade to be in the kitchen oven. (and then not overheat it when grinding!)

The second is to anneal it: bring to non-magnetic and bury in dry wood ash overnight---using a thicker helper bar also heated to the same temp helps for small files that just don't have enough heat in them to make a good anneal---bury them both together in the ashes. Then you can work without worrying about overheating with the grinder or even use a file to file the file to shape. (and of course re-heat treat afterwards)

[monty]

im nearing the end of a file knife, and i just annealed it by heating it evenly then turning off the air supply to the coke in the forge and allowed it to cool overnight
hope this helps
monty