Make a knife from a file

[trapper9260]

Hi I like to know if someone can explain to me how you would go about ,to make a knife from a old file. I hear about it all but I do not know how to start.
Thank you in advance

[Idz]

The old farmers would just grind away with their bench grinder until it got to the shape they wanted. No fancy heat treatment just grind it til it got too warm, dunk it in a can of water, and grind away some more.

[M-Tecs]

Good basics here:

http://www.instructables.com/id/From...-simple-tools/ you have to click the 9 sets or download.

You can do it without annealing if you are careful not to over heat when grinding. If you are grinding until it turns blue you are getting it too hot and removing temper. Also full hard files are very brittle. They hold an edge very well but easy to break with misuse. Also files are prone to heat checking (micro cracks) when water quenching. Going slow and using a fan to cool is the best to prevent heat checking.

[trapper9260]

Thank you for all your help it will make it easy to understand better.

[JWFilips]

If you are doing it in a coke forge: bring it up to bright red ( no more) and shape it out on the anvil with your hammer ( you can leave the top edge untouched ( shows it "Was" a file)...Let it cool slowly ....Shape it more on a grinder.... Then bring it up back to red heat in the forge again. Quench it ...polish it up bright & shiny. Then lay a piece of steel on top of your forge coal. Lay your polished blank on that piece of steel.... Slowly heat until until you see the annealing colors form...I like to stop at deep straw color then quench and stir in 30 weight motor oil
You have a great knife from a file

[jcwit]

I made a number of knives from files. I would throw them into a well stocked charcoal grill so as to get them to red hot and leave them there till the charcoal was completely burned down and slowly cooled.

Then I would shape to whatever shape I desired, then grind the bevel to the blade as to what I wished.

Then back to the grill again and heat to a salmon red, quench in warm oil till cool, be sure to agitate the blade in the oil to keep it from warping.

Then polish the blade, to me this was always the hardest as the steel is hard and you sure don't want it to catch the wheel and have it go flying!!!!! Not a good thing.

After polishing into a oven, even a kitchen oven is OK, and draw the temper to straw color. I think I used 600 degrees, but not sure.

[BK7saum]

I made a nice thin bladed hollow ground knife from a file when I was a kid. It lasted just fine until dad used it as a pry bar to get at hay strings on some frozen round bales of hay. Snapped right into. I just ground the knife to the shape I wanted and didn't re-temper. I guess it was a bit brittle and hard, but held a good edge cutting hay strings on round bales.

[trapper9260]

Thank you for explain all to me.I was told some things in the past but for what I was told I was not sure for what I was told was correct for the one who was telling and they had no idea of some things they where doing in the first place.Since I see this part on this site that someone on here would know more of how to do it .I have some old file that are shot and did not want to junk them.

[DerekP Houston]

Thanks for the info, I as well have some old rusty files in the garage. It might be fun to give this a try.

[tomme boy]

Heat it till a magnet no longer sticks to it. Then forge it. That is the right temp to forge at

[nockhunter]

Heat it until non-magnetic bury it in some sand and let cool very slowly over night(annealing process), then work it as you will, stock removal or forging. Once you get what you want, heat until non-magnetic then quench in 100 deg oil. Remove the scale build up and then temper in a 450 deg toaster oven (straw color). Final finish to what ever you like, high polish or 500grit to 600grit sand paper.


Here are some knives I've made from files.

Mike

[Steve77]

Those are some pretty knives. What material are you using for the scales red/brown woods?

[Hardcast416taylor]

Used to be a custom knifemaker a few miles from me. I asked him once about making a knife from a file. His response was simple. As long as it is a Nickleson made or another big name file company from in the USA it`ll be good. If it is made in India or some other foreign country, then forget it as a lot of time lost.Robert

[trapper9260]

Heat it until non-magnetic bury it in some sand and let cool very slowly over night(annealing process), then work it as you will, stock removal or forging. Once you get what you want, heat until non-magnetic then quench in 100 deg oil. Remove the scale build up and then temper in a 450 deg toaster oven (straw color). Final finish to what ever you like, high polish or 500grit to 600grit sand paper.


Here are some knives I've made from files.

Mike

Those are some nice ones.Thank you also for your all help.

[Echale3]

I used to run a small custom knifemaking/blacksmithing shop doing 18th century reproduction work catering to reenactors. Several years ago I did a quick tutorial on how to forge a small knife from a piece of steel.

The tutorial can be found here: http://paleoplanet69529.yuku.com/top...e#.VpUydI-cEdU

Whether it's a flat piece of 1095, 1084, 1075 from a specialty shop or a worn out file, the basic forging process is all the same. Although there are many ways to get from a flat rectangle to a knife-shaped object, the way I showed it is how I normally do it for a plain knife.

Anyway, be careful of what file you choose to use--I've never had good luck with Chinese files, their steel can be pretty questionable in terms of quality, and tends to go all to hell if you overheat it in the least, and generally doesn't heat treat well for being used as a knife.

US-made files are generally 1095, which is an excellent blade steel if it's heat treated properly. Heat treating is the critical part--you want a knife that'll hold an edge well, be reasonably easy to sharpen, but won't shatter if dropped or is subjected to lateral loads. What you are going for is a balancing act between hard (holds an edge well but is brittle and will shatter easily) and soft (can take lots of lateral loads and won't shatter but doesn't hold an edge).

The heat treat is pretty much dependent on the type of steel you are using. Personally, I tend to do a differential heat treat, where the spine is softer than the edge. With 1095 and other low alloy types, I generally let the edge get to a straw color while getting the spine to a purple color, which is achieved by heating from the spine rather than heating the entire blade.

Also, in terms of quenching 1095, 1084, etc., use oil, not water--water cools very quickly, and the differential thickness of the blade means differential cooling rates. The edge cools quickest, so it hardens first, while the thicker spine cools slower, and as it cools, it contracts, stressing the already hardened (read:brittle) edge, which causes edge cracks.

[M-Tecs]

Nice tutorial - thanks

[Ballistics in Scotland]

The steel is excellent for the purpose, but you should grind it a bit deeper than it takes to remove the teeth. Their creation seems able to strike invisible hair-cracks into the steel, and that is where a more disastrous crack will begin.

A knife also needs to be tempered to quite a bit more than straw colour, which is pretty much what the original file would be. Or even a straight razor, for which the same steel would be excellent. Brown with a touch of purple in it is better for general purposes. You would find it difficult to control the temperature evenly on a metal plate, and a shallow dish of sand would be better. Mechanical engineers sometimes use baths of melted salts, of a mixture chosen for the right melting point, but that is a bit much trouble for one-time use.

Mind you, if you are going to put a lot of work into this, it might make sense to buy a precision ground bar of O1 tool steel. This comes annealed, ready to be hacksawed or filed, and while I think file steel will harden satisfactorily in oil, O1 certainly will. There is plenty of it on eBay, although you might have to search with 0 meaning zero, rather than O for oil which it really is.

Here is one of mine in O1 from a long time back. I did the etching with enamel paint and Letraset transfer lettering, then cream gun blue. A first attempt ought to be single edged, though, since a very slight difference on the near-180 degree angle of the spine on one side and the other, will result in its taking a sideways curvature. Even with single edged you need to make sure the centre-line is marked truly, and that the edge goes there.

Attachment 157931

[Windwalker 45acp]

Files used to be W1 and W2, which are designated water quenching steels, even so, still harden with oil, preferably light oil.

I've forged hundreds of knives, mostly big bowies, with maybe 40-50 gentlemen pocket knives with exotic handle material (mastodon ivory) and steels, damascus, etc. It's very addictive and enjoyable.... if my old back would still allow it, I would still be hammering.

Stock removal, which sounds like you're leaning towards, will make a good knife, not the best, but as good as most of the big manufacturers if you do your part.

Good luck and take your time.

[Echale3]

The steel is excellent for the purpose, but you should grind it a bit deeper than it takes to remove the teeth. Their creation seems able to strike invisible hair-cracks into the steel, and that is where a more disastrous crack will begin.

Any sharp angle will create a stress point, the teeth of a file are no different in that regard.

A knife also needs to be tempered to quite a bit more than straw colour, which is pretty much what the original file would be. <snip> Brown with a touch of purple in it is better for general purposes.

I run the edge to a dark straw tending a bit towards brown, but then I differentially temper, so my spine is run to purple tending a bit towards a pale peacock blue/green. I fully agree that straw is still too hard for a knife if that's the full-width color.

You would find it difficult to control the temperature evenly on a metal plate, and a shallow dish of sand would be better. Mechanical engineers sometimes use baths of melted salts, of a mixture chosen for the right melting point, but that is a bit much trouble for one-time use.

Actually, using a heated bar to control tempering is quite easy and the differential temperatures, as evidenced by the colors running across the blade from spine to edge, can be quite well controlled. You do have to be observant, though.

Mind you, if you are going to put a lot of work into this, it might make sense to buy a precision ground bar of O1 tool steel. This comes annealed, ready to be hacksawed or filed, and while I think file steel will harden satisfactorily in oil, O1 certainly will. There is plenty of it on eBay, although you might have to search with 0 meaning zero, rather than O for oil which it really is.

Most American-made files of good quality (we're not talking Northern Tool or Harbor Freight merchandise) are made of 1095 which is a rather nice knife steel.

Here is one of mine in O1 from a long time back. I did the etching with enamel paint and Letraset transfer lettering, then cream gun blue. A first attempt ought to be single edged, though, since a very slight difference on the near-180 degree angle of the spine on one side and the other, will result in its taking a sideways curvature. Even with single edged you need to make sure the centre-line is marked truly, and that the edge goes there.

Nice knife. If you normalize the blade properly prior to heat treat, you will remove the stresses from the steel and unless you quench improperly, warping will be minimized if not eliminated entirely. Keeping things fairly even, especially when forging a blade, is more or less a matter of experience and accuracy with the hammer, as well as keeping the number of hammer blows and intensity pretty well evened out side-to-side. Other than that, it's not as critical as one might think.

[Ballistics in Scotland]

Attachment 158006


Normalization of steel, a process very similar to annealing, is useful, especially when the metal has been forged. When you hit the end of a fairly malleable steel rod (an improvised punch, say), it doesn't just shorten all along its length. The extreme end is deformed into a sort of nail-head where it meets the hammer. In the same way forging affects the outside layers more thoan the interior of the metal, and one of the main skills of a good smith is to make sure he affect s it to about the same depth everywhere, and especially on both sides.

But if the blade is asymmetrical, as shown abovoe in exaggerated form, it will take a sideways curve in hardening, no matter how well it was normalized. (I can't, for some reason, get out of attaching as a thumbnail an earlier version in which the asymmetry of the single-edged blade wasn't clear enough.)

Fore and aft distortion isn't necessarily very harmful. The traditional Japanese swordsmiths reckon on forging the blade a shade straighter than it is intended to end up, and imparting 3/8 to 1/2in. of extra curvature along its length by hardening. The best of them have a wastage rate at this point, but if successful, it may actually strengthen the cutting edge. That curvature is probably affected (though whether increased or reduced I can't work out for sure) by coating the body of the blade with clay, to slow the quench and let it remain resilient while the edge is very hard. Myth notwithstanding, that edge often doesn't come to as acute an angle as western knifemakers often use.