New Approach to Knife Making ... Files

Mike Jones

Google Master
I have not made any knives for a while. The main reason was that school was getting in the way, and taking all my time. Another reason was me getting a job, so I work some days. I am really not satisfied with how my knives are turning out though. The fit and finish will improve, but the quality of the blades suck. I have been using 1084 steel and hardening them in my garage with torches and canola oil. I know that that's why they suck.

I'm also pretty opposed to sending blades out to be hardened by someone else. So, because of this, I'm going to try to make some knives out of files. By that, I mean taking a quality file, tempering it down, then grinding. I'd have to keep it cool enough not to ruin the temper I produced.


I emailed Michael Morris, because he makes wonderful knives using this technique, so I know he has experience and could help me, but I thought I'd ask some questions here, so I can get an idea of others experiences. Of course I won't be able to start these for at least a week or so due to my surgery (see the Dog Run section to read about it) so I have a few questions that I asked Mr. Morris.



1. What temperature should I temper the files at? I think I heard that 450 should get them around 58 RC.

2. Would my 2x72 belt grinder (with 60 grit belts at the coarsest) and my disk grinder be able to shape the blade and handle?

3. How should I keep the file grooves free from debris?

4. How can I drill holes in the tangs? Should I take a torch to the tangs to get them tempered much higher, while keeping the edge cool? I was hoping to not have to use carbide bits.

5. What's the best way to cut the hardened file? Mainly to shape, but if I wanted to remove a few inches from it, I don't see grinding with a belt grinder as a very productive way.



Thanks for any help!
 

EdCaffreyMS

"The Montana Bladesmith"
Everything is going to depend on the files you use. Currently the ONLY files that I am sure are high carbon steel are Nicholson files....the standard grade is 1095, and the ones branded "Black Diamond" are similar, but with a 1.27% carbon content.

Almost any other brand of file you come across is going to be case hardened, and will be pretty much worthless for a blade.

To answer your questions, I'll number, then answer based on my experience.

1. You about right IF the steel is 1095.

2. Certainly! Because they are hardened material, your going to go through a lot more belts and discs than if the steel were annealed, and as you mentioned, you must be careful about heat build up.

3. If you do get debris in the file teeth, it should be easy to either rinse out, or brush out.

4. Your right on here. I personally think that tang should be as tough as possible, and therefore don't harden them on my knives. Tempering back the tang(s) for drilling, using a propane torch will usually work.

5. If the material is hardened, you really don't have a lot of choices for shaping besides grinding. If you use angle grinders or cut-off wheels your going to overheat things and destroy the "temper" (hardness). Just about everything we do in knifemaking is a give and take situation....by choosing to use hardened material, your going to give up the ease of shaping and grinding that you would have with annealed material.
 

Mike Jones

Google Master
Thanks for the help, Ed. I will try to use Nicholson, unless I find some at a garage sale for like ~$1 for a good sized piece. Wouldn't hurt much to try at least, unless of course I see that it's from China, then I'd probably back away.
 

James Terrio

Well-Known Member
Just a couple things to add...

I've had good results from American-made Simmonds files as well as Nicholson. I can't recommend any other brands. Even if you have to buy them new, they're not much more than new barstock. ($8 gets you a good size ba$tard file.)

A plumber's propane torch will work for drawing back the tang so you can drill/shape it more easily. But you have to be careful! Since this type torch doesn't get as hot as other sources, it heats up the metal slowly over a larger area than say an acetylene set-up. This makes it easy to accidently run the hot area up into the blade where you don't want. Don't ask me how I know! Anyway err on the side of caution and check often. Putting the blade in the biggest vise you have will help some, as the vise will act like a heat-sink.

Get a clean shiny surface on the file, so you can observe the temper colors. (This goes for the first temper on the whole blade, too... btw err on the side of caution then too, and do the first temper at a lower temp than you think you'll need; kitchen ovens are often inaccurate. You can always sand off the temer color [it's just a thin layer of oxidation] bump the temp up and do it again. Two tempers doesn't hurt anything anyway.)

A yellowish to pale-straw color is good for the blade, it will be tougher than the file started out but still hold an edge. You can go all the way up to blue on the tang itself. Here is a helpful temper color chart.

You can save a little time cutting to length and knocking off the corners near the tip with fiber cut-off wheels in a rotary tool, but leave plenty extra room so you can grind of the heat-affected-area, work slow and cool often. As Ed said, they build up a lot of heat in a small area. I wouldn't even attempt using an angle-grinder.

Don't be intimidated, remember that an awful lot of factory blades and smaller custom blades are ground after heat-treat for various reasons. Just keep it cool.

File knives are cool and can make very good blades. Are they as good as full-custom blades? Doubtful. But done properly, they're better than a lot of the stuff on the shelf at Wally World.

Have fun!
 
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Mike Jones

Google Master
Thanks James for morenifo on the tempering. I think I may have a source for new/very lightly used files for around $4 a piece.

File knives are cool and can make very good blades. Are they as good as full-custom blades? Doubtful. But done properly, they're better than a lot of the stuff on the shelf at Wally World.
I'm just trying a pre-hardened piece of steel, because I don't want to send out for heat treating, and my backyard heat treating sucks. Even if the knife isn't as good as a knife from Ed, Bruce, Tracy, or anyone pretty much on this forum, it will be a better knife than what I've been able to make. I believe I will also be able to sell one after I have enough practice with them. Selling a knife will be huge for me.
 

LRB

Well-Known Member
Two tempers at 450° to 475° will give you about what you're after. Use your kitchen range, but with an oven thermometer. Let it cool to room temp in between tempers. Run at least an hour per temper, two hours is better. Oven ranges fluctuate in heat, but if you can bury the blade in dry sand, it will help to keep the blade heat more even. All steels will have retained austenite after the quench. The first temper will convert much of this to martensite when it cools. The second temper will convert most of any that remains. That is why two tempers is usually recommended for most steels.
 

James Terrio

Well-Known Member
Glad to be able to help, Mike. I started making file knives for the very same reasons; I honestly think it's a great way to get started. I wonder if this shouldn't be a sticky, because the subject comes up pretty regularly and probably aways will!

A fun tip... I like to leave some of the original file "pattern" on the ricasso, spine etc. because it looks cool and lets the buyer know what it's made from. Polishing the high-spots, applying cold blue or something similar, then repolishing the high spots gives a real nice contrast and helps prevent corrosion in the low spots. Of course you can blue/force patina the whole thing however you want, too.
 

Mike Jones

Google Master
The contrasting colors by bluing sounds like a great idea!

I just ordered some 40g blaze belts to man handle the hardened steel. I thought I remembered those things being a lot more expensive, but now they're pretty close to my usual belt prices.
 

RodneyJ

Well-Known Member
Mike
Have you seen are tried to use the one brik forge im new to knife making and i made one to heat treat my first knife in. it worked fine and only took about 30 minutes to make this would give you the option to use other high carbon stell and not be limited to just files
 

Mike Jones

Google Master
Rodney, Yeah, I've seen the one brick forge, and I thought about it, and I still may, but to at least be able to sell a few knives, I'm going to try to make them from files. I'd like to eventually get a HT Oven to be able to be semi accurate in the 1500s or so, but the one I want (SC) is $500.
 

schwatk

New Member
New Approach

Mike,

I was wondering why you state "I have been using 1084 steel and hardening them in my garage with torches and canola oil. I know that that's why they suck. "

I'm new to bladesmithing and that is pretty much what I'm about to start doing. I've got 100' of 1084 and will be heat treating it in Vet. Grade Mineral oil. Is there something I don't know and am I already setting myself up for failure or dissatisfaction with the outcome?

Just wondering if I should try something different.

Thanks for any and all help/advice.

Joe
 

Mike Jones

Google Master
Mike,

I was wondering why you state "I have been using 1084 steel and hardening them in my garage with torches and canola oil. I know that that's why they suck. "

I'm new to bladesmithing and that is pretty much what I'm about to start doing. I've got 100' of 1084 and will be heat treating it in Vet. Grade Mineral oil. Is there something I don't know and am I already setting myself up for failure or dissatisfaction with the outcome?

Just wondering if I should try something different.

Thanks for any and all help/advice.

Joe
I had been using blowtorches to get the blade to a yellow color, that I assumed to be around 1500 degrees F. I "hardened" over 10 blades that way. Some of them got hard, some did not. I have no way of knowing what temperature it is at, or having the heat evenly distributed. Maybe I was impatient in heating them and I went too quickly, or maybe I need my eyes checked because the colors I thought I saw were wrong. I also have no way to check the hardness of the steel, other than skating a file, which it always seemed to do, even if the blade was crap.

Many people have had success in making 1084 steel hard using the method I had been using, or the one-brick-forge that Rodney suggests. I just made one too many unsuccessful knives that way and just got too discouraged to make another. I made a guy a knife to test out and let me know how it worked, and that's what set me off mostly. He has a $20 knife from Walmart that outperformed mine.


But to answer your question, you may be successful doing it with a backyard setup. I wasn't, but that's why I'm going this route until I buy a controlled Heat Treating Oven from Sugar Creek.
 

schwatk

New Member
New Approach

Sorry to hear of your problems.
I'm sure I'll have plenty during the learning process too.
Keep at it. I'm sure it will all be worth it in the long run.

Take care!

Joe
 

rasret01

Well-Known Member
Mike - if it helps any, I just got the 24" sugar creak oven without the digital controls (couldn't afford them), and it has taken my knife making to new levels. The manual controls mean you have to stay close and pay attention to the temps, but the oven works great. Before, I was using a gas forge and having the same issues as you. Have faith, hold on, and save your pennies for that oven.

Dick
 

Mike Jones

Google Master
Dick, That's the kiln I am looking to buy. They're located about an hour away from me, so I could probably pick it up instead of have it shipped. I can't afford the digital controls either, but because it does come with a manual control, that's what I'm going to be saving for now.
 

Justin King

Well-Known Member
You can switch out the manual control on the SC for a digital PID at just about any time. Depending on how the oven is set up you may need a few other components but having built my own HT oven from scratch recently, I was surprised at how simple a beast they are. The SC oven is a good value if it works well, mine cost me a little over 300$ and a good deal of labor to build.
 

Mike Jones

Google Master
Well today, my blaze belts arrived in the mail, along with some files. The files are currently in the oven and when I take them out, I'll start grinding.
 

Mike Jones

Google Master
Well I was going to just practice getting a decent grind on a small file, but my dad suggested that I make HIM a knife out of it for chopping off roots and leaves on vegetables in our garden. So, that's what I just ground.

Because I haven't ground anything for a while, I did the rookie mistake of pushing harder at the plunge than the rest of the blade, so now the blade is about 3/16" narrower :eek: But the blaze belts sure took material off just like it was annealed stock!


I decided not to worry about pins for this knife's handle, so now I'm waiting for the epoxy to harden and I can finish it up. I think I'll grind another blade from a small file while I wait.
 
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