a little confused.

A

andrewfinnie13

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Jun 20, 2009
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I wrote a thread about being bored and wanting to make some knives out of files, and had questions about anneling. The response i got was a great response, but when i went into the arcives i found different instructions whick has left me a little confused. Here they are:

1.the response i got yesterday consisted of leaving the files in a fire over night to annel and then shape, grind, and all that jazz and then harden. Which I believe is one step longer than just using regular flat bar steel.

2.The instructions I read in the arcives consisted of just one simple step of heating the knives up to 425-450 deg for two hours twice and vioalla..


I understand that there are probably many ways to to make files out of knives and all but are the two methods listed above both correct? Or is the latter one step method missing the steps that the first method list... Please help me.
Thanks
 
450F will not be enough to anneal files. I don't know that the fire is the best way to do it, but they will definitely not be soft enough at 450F.
 
450F is not to anneal them, but to temper them, assuming you don't kill the heattreat in the grinding process (and certainly don't forge them at all!)
 
That's what it sounds like to me as well. Basically, the instructions are to use the files existing heat treatment instead of redoing the heat treatment after your work. You'd have to cold work the file into the desired shape (grinding and dunking the file in water between passes so you don't over-heat it). After the work is done, you can temper the file by heating to 425F or so. This makes sure the fine cutting edge when sharpened isn't too brittle.

--nathan
 
Are you forging them or stock removal? If you are stock removing them you don't have to neccesarily have to have them annealed (is recommended if its a full tang design though, else you will have to use carbide drill bits which are expensive and easy to break), just be careful to not ruin its temper during grinding and dip it in water every 2-4 passes or so. (depending on what grit wheel/belt you use)

If you do want it annealed though to make everything easier, the fire might would work, but I would suggest consructing a type of firebox around it to trap the heat.

The second step you read in the archives refers to tempering, not annealing, which you will need to do whichever way you choose.
 
ok.. maby im getting my terms messed up...i understand heat treat and annealing. but maby im not correct on the tempering... what exactly the definition of termpering?
 
Annealing is done to get the steel in a more-workable state by getting it to form pearlite which is easier to work than martensite which is found in a properly hardened blade.

Hardening is done to take that same blade and form austenite at a crucial temperature range, and then cool it at a steel-specific rate to form martensite (and not pearlite). This is what hardens the steel.

Tempering is done to relieve stress in the newly created martensite. There is a lot of internal stress after initial quench, and tempering allows some of this stress to be reduced in a controlled manner to prevent brittleness. Tempering also lowers hardness (typically, the hotter the temper, the lower the RC hardness). In the case of your file, it has been manufactured and heat treated so that it is at a high hardness relative to other steels. This allows it to work well at removing metal without wearing out. Unfortunately, you may experience some brittleness at the edge if you simply sharpened the file as is, so you need to "draw back" the temper (reduce the hardness...relieve more stress) even more.

All of these procedures fall under the umbrella term of "heat treatment". Typically, many makers use "heat treating" to refer to hardening and tempering.

--nathan
 
Ahh... Ok i understand now...So instead of anneling the file down to lets say 35 rc and harden then temper. I could shape the blade using the grind and dip technique and them temper it at 425-450 for two hrs x2 and then effextively bring down the rc to knife level that has the strength and the flexability? is that the correct description, or am I missing something still??
 
Sounds like you've got it. Of course, this is assuming that your file is a good one of the proper steel to form a quality knife. Regardless, give it a shot and see what you get.

Oh, and don't forget to post pics once you're done! :)

--nathan
 
if you have the chance, use an old file. a lot of what can be bought new is no longer high carbon steel. most of the china stuff is mild steel that is just case hardened. nicholson is a good brand to look for.
 
Ones an old nicholson and the other is an old craftsman i purchased from my local pawn shop both for 1.00... I know the nicholson is good but im kind of weary about the craftsman. It is old but still weary... and yes i will post pics... im anxious to make them... got some designs picked out. two campers... ill scan and post pics of designs laiter.

thanks guys
 
oh yeah... by the way... is there a place onling that i can buy used files.. i seem to remember one of the knife sites posting used files for sale for knife making....

thanks again
 
andrewfinnie13 said:
Ahh... Ok i understand now...So instead of anneling the file down to lets say 35 rc and harden then temper. I could shape the blade using the grind and dip technique and them temper it at 425-450 for two hrs x2 and then effextively bring down the rc to knife level that has the strength and the flexability? is that the correct description, or am I missing something still??
Click to expand...


No, you don't quite got it yet. ;) You need to anneal it first - It's complex but the overnight fire thing should work pretty good if it was a decent file.

Then you have to shape a knife - profile, bevels, drill holes etc.

Then you have to harden it - high temps like 1500F - over non magnetic by maybe 50 or more degrees.

Then you have to quench it in - oh heck, I'm not even going there. You have seconds or less to get it cooled and the choice between water / brine / or some thin oil will be the difference between a shattered blade or a continuing project.

Next step is tempering - cause any of the above will give you a blade as brittle as glass. This is the 400F (more or less) stuff you've heard about.

Last is finishing the blade without overheating it. Doing a blade like this is an admirable undertaking, but it is not really a beginner project. You might want to start with a known steel - already in the annealed state. The stuff really is cheap especially when you compare it to the headaches of an unknown stock.

My 2 cents

Rob!
 
Rob, I don't see why he couldn't grind with the file in the hardened state.

Many makers harden their blanks prior to grinding bevels. You just have to have a decent grinder.

You do bring up a good point as far as drilling holes, but you should be able to get by that by drawing back the temper even further in the tang with a torch and using carbide drill bits.

--nathan
 
Boy, what a lot of different info. I've done it the hard way for a long time, annealing, grinding, heat treat and temper but I believe there are several makers that have good results by just drawing the hardness of the file back by tempering at 450 or so and then grinding. This way you are not grinding a really hard file. Of course you need to keep the blade cool while grinding so as not to ruin the Hardness you got from tempering it back.
 
silver_pilate said:
Rob, I don't see why he couldn't grind with the file in the hardened state.

Many makers harden their blanks prior to grinding bevels. You just have to have a decent grinder.

You do bring up a good point as far as drilling holes, but you should be able to get by that by drawing back the temper even further in the tang with a torch and using carbide drill bits.

--nathan
Click to expand...

i really dont have a decent grinder... i have a 2X42 craftsman... I have assembled a couple of knives already with it and it has worked ok... i know its under powered and all so. do I temper and the shape or just bag the whole file thing and wait till i can afford the $34.00 for steel and shipping?..which I am tired of never having.
The reason I am trying to do it this way is i am an auto tech... my pay is based on piece work.. if i dont have work i dont make money and theres little to no work and to top it all off... my wife and i are expecting our first, she is also going to school going to school and she is unemployed. The money we have is tight and ive been pinching for months now trying to get enough to buy everything I need but have come up short in the funds for steel dept. So I went for a much cheeper alternative..used files.. I am very frustrated and all i want to do is make a damn knife i can call my own. i do not have the extra funds to send out to heat treat after annealing so my options are slim. I am sorry for the small rant but its either the easy file way or no way at all..

I really appreciate all the advise and info, dont get me wrong. Thats not what i wanted to portray in my little pissed off rant and rave. As i said earlier... there are more than one way to skin a cat and obviously by the info i have retained from you fine gentlemen, that statement is most true. but I guess I will have to pick and choose which method i will try and i will most definitely post pics...destroyed file or not... it will be done.

thank you very much everyone
 
Cold grinding a file to shape and then tempering the blade and annealing the tang then finishing it is the easiest way to go. It can all be done by hand or with basic tools.(except for the grinding). I have seen some fantastic knives made this way. They hold a great edge.
 
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