Making knives from files

Cojab

Well-Known Member
Like the title says, I was wondering who has made knives from files or really, horse shoeing rasps. I saw some custom knives made from them that I thought were very nice. What is your experience with this. Do you need to temper the files before you work on them. I am assuming the files are too brittle to use as a knife without some kind of heat treating.

I am planning on getting some instructional books and I'm sure this has been covered but I was hoping to get some info from you guys here. Any books you guys recommend and wheres the best place to source them if you dont mind me asking.

Thanks
 
http://www.michaelmorrisknives.com/

Michael Morris makes most (if not all) of his knives from files. He even has a couple of youtube vids showing segments of a longer video where he makes one. I believe he tempers them before he grinds and let's it go at that. Some makers anneal to soft, then re-harden and temper. It all depends on what kind of tools you plan on using or have available.

It's definitely cool to see a recycled file or rasp, especially for guys like ferriers and what not who can appreciate what the tool USED to be. If you're JUST getting into making knives though, I might start with some known steel and go from there.
 
Tracy has a good sellection of knife books at his store. You can find it listed below or go to USA Knife Maker Supply. The $50 Knife Shop is good, if you want something that deals with stock removal, How to Make Knifes. There are others but I have read those two. Check under the video section too.

The one problem with old files is that you will occasionally run into cheap modern files that are made from case hardened, low carbon steel. These will not have enough carbon in them to harden. This is one reason that I recommend that beginners start out with a known steel.

Doug
 
My first twenty or so knives were made from files, and I still make one occasionally.

First off, test the file to make sure it is not case hardened. Heat the tang up to critical heat (around 1500f), then quench in water or a thin oil til it's cool to the touch. Wearing safety gear (eye protection and chainmail, paying special attention to the throat area) stick it in a vise and see if it bends... if it does bend, spend your money with Aldo on some known steel and save yourself some grief... if it breaks, you have steel that can be made into a pretty good knife. Heat the file up to a dull to medium red (we call this a sub-critical anneal) and let it air cool. At this point you should be able to drill a hole in it, and cut it with a hacksaw or a file. Shape it into a knife blade, leaving maybe a millimeter thickness to the edge to avoid warping and decarb. Don't worry about giving it a mirror polish at this point, just finish it up to 150 to 220 grit. Because we don't know exactly what type of steel the file is made out of, other than the fact it will harden enough to break, heat-treating will not be as precise as we would like but we can still make it into a functional knife. Heat it up to 1500f again, this time the entire blade not just the tang... if you want, do a web search on 'decalescence', in a perfect world this is the indicator that you have reached the temperature you want to quench from, unfortunatly it is not that easy to spot unless lighting conditions are ideal.... Or you can just use a magnet. When the magnet stops sticking to the steel, we call this the 'curie temperature' and it gives us a ballpark figure as to how hot the steel is, other than glowing hot. Bad thing is, you need to go hotter than that to get hot enough by about 150 degrees, this is why decalescence is such a wonderful thing if you can spot it... Anyway, get it up to the curie point, plus 150 degrees hotter than that, then hold it at that temperature without getting it any hotter for 5 to 10 minutes, or as long as you can without the blade getting any hotter than it already is. One minute is better than a few seconds, the 10 minute ideal can be hard to reach with primative equipment and may not be absolutely necessary with a simple carbon steel but the heat-treat gurus insist... Now you need to quench the blade to reach full hardness. These types of steel they like to make files out of are generally termed water quenching steels, but water delights in cracking blades, and brine isn't much better than tap water if you're new to this, so I suggest an oil quench. What type of oil? the thinnest oil you can get... the lower the viscosity of the oil the faster it sucks away the heat. I've found that, if a professional quenching oil is not available, the cheapest, lowest quality canola oil will do if push comes to shove. By the way, before you quench the blade, make sure you are finished with every bit of shaping on the blade that involves cutting metal with metal, after it is quenched it will not work anymore... So once the blade is hot enough and has been allowed to soak as long as you feel comfortable with, quench the blade as quickly as possible. Just stick it in the oil and use a cutting motion to swish the blade in the oil. Do not move the blade from side to side, as this will cause it to warp in an unpleasant manner. Once the blade has cooled to about 500 degrees you can take it out of the oil and wearing gloves (thick gloves, I might add) straighten any warps and let it air cool, or let it cool in the oil and fix any warps in the tempering process. Tempering... you will now need to temper the blade, and it is best to do it immediately after the blade is cool enough to touch. See, once the blade is hardened it is too hard, and tempering softens it up in a controlled manner to just the right hardness for a knife. If you don't temper it, the edge will chip easily and the blade will break with just the slightest amount of bending. So, wipe the oil off of the blade and stick it in the oven preheated to 450 degrees for two hours. Take the blade out of the oven, let it cool, then do it again for another 2 hours. At this point, the blade may still be a bit hard for a knife, only testing will tell for sure. Sharpen the blade, grab a piece of dried oak and start wittling.... or, take a brass rod about 3/8" thick and clamp it in a vise, and holding the knife like you're sharpening it, press the blade into the rod until the edge flexes. If the edge flexes, you're good... if it chips, stick it in the oven again at about 20 degrees hotter and temper it and test it again until the edge no longer chips when flexed over the brass rod (note, brass is traditional, but any metal will do for a flex test, a screwdriver works if nothing else is handy). Test the blade some more after this, it is after all unknown steel, but it doesn't have to be untested steel... Once you are happy with the temper, thin the edge down to whatever thickness seems reasonable to you (I take it down to a burr, then sharpen on stones for what we like to call a microbevel), sand it down to a nice finish (600 grit makes a nice working finish, 2000 grit makes for a really nice working finish), and put a handle on it... and don't sharpen the blade before you put a handle on it, otherwise you will bleed at some point.
 
Wow, thats a bunch of information. Thanks for taking the time to write that all out. I have some books on the way so help is coming for me!! Unfortunatly its going to have to wait for a while cause bear and elk season is now here. I was hoping to be carrying my own knives in the field this year but it will happen. Thanks again for the replies.
Doug and AR, what known steels would you recommend and why if you dont mind me asking.
 
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