Reddit reviews RMP Knife Blade Steel - 1074/1075 High Carbon Annealed Steel Billets, 1.5 Inch x 12 Inch x 0.187 Inch

If you want a piece of steel for cheap and have the tools to make one, this here will get the job done

Personally, if the file isnt completely dulled, i'd save the file as old files tend to be really fucking good and just buy new steel. Because of rising fuel prices, rising minimum wages, and easier availability to annealed steel stock that's exactly what you want, there's just about no reason for someone who's not already an expert on metallurgy to work on a file as a knife.

The reasons you would would be:

1. Leaving it hardened, and just being very gentle with a grinder and keeping it cooled (so you dont have to work with heat treating it at all).
   
   
2. Artistic value (however if you're making a camping knife, i'd hazard a guess at the goal of this not being to flex your bladesmith skills at an art show)
   
   
3. For someone who's already great at annealing and doesnt care about the ridiculous time sink it is, a relatively cheap sunday project.
   
   The reason im against it is because annealing properly is a process that (for someone who i'd assume doesnt have a high-powered, accurate forge and the skills to maintain the temperature) can easily fry and decarb the metal (bad) and if done right, takes a while and gas. The time it takes and the gas cost would be equivalent to, if you live in any western country (which im assuming from your username and english that you do) at least 20$. With that money, you could just hop onto amazon and buy something like this https://www.amazon.com/RMP-Knife-Making-Blank-Annealed/dp/B074927X9K/, which is longer than the file most likely is (giving you more options) and is already annealed.