Using old files for blades

M

malcolm47

Joined
Oct 11, 2005
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I have read a lot of threads on different forums about using old files for blades. I have a few questions that hopefully someone can answer. If you use a large file to make a bowie/chopper, will the blade be too brittle and chip when used? If so, how do you prevent this? Do you anneal the handle part before or after you grind the blade? How far do you anneal the handle (does it matter if you go a little ways onto the blade)? What does everybody use to hold the handles onto the knife? Has anyone tried making a blade out of some of the damascus billets that are being sold on ebay? Thanks for any info...................Malcolm
 
I'm working on 2 now, one is a 5" tanto blade, the other is a 4" utility knife shaped one. The tanto came about when I cut the angle to make a drop point, and it looked good so I left it. The utility is the same, just made from a smaller file and sharpened on the opposite side. The morale of the story is that after cutting half way through the larger file and hitting it with a hammer, I still couldnt break the piece off. I had to cut 90% through before hitting it with the hammer would break the piece off. Check the file as you grind down, try to notice the hardness or at least changes. Some are case hardened and after grinding away some they soften dramatically. Nicholson Black Diamond have a good reputation for being fully hardened, although some opinions say they have gone down hill over the years. I softened the tang about midway through the grinding, and it ran a little far up the blade, maybe and inch or so, but its too late now. I would be a little hesitant to use a file as a chopper, but the above test indicates it might work. The one I tested was at 64 HRc hardness. This might have been a soft reading, as it was covered with 40 grit scratches, and hardness tests are more accurate with better finishes, to a point. I'm planning on using some flared brass tubing to hold some cherry wood scales on the larger one. The smaller one will be a hidden tang w/ epoxy. I'm not saying this is the right way, its just the way I'm trying first. Be prepared to do some grinding. Files are very hard, and I would recommend grinding the teeth off to eliminate any stress concentrations. A bench grinder helps for the rough shaping.
 
first project- old nicholson into a knife...

started the process saturday, annealed in a chimney starter for a charcoal grill (using charcoal)...had favorable results

got the shape roughed out with a grinder(hand, angle, 4-1/2"), gonna start my semi-finish grinding(with a crappy 1" beltsander) tomorrow night...

wish me luck =]

-nadz
 
annealed in a chimney starter for a charcoal grill (using charcoal)...had favorable results
----------------------------
nadz
please describe the way you did this...

tnx/ al
 
If you merely heat the file to a bright red and let it cool, you can file on it, drill it, or whatever. They anneal pretty easy. You will need to normalize it three or more times, or until it no longer warps from the normalizing heat. If you don't, it's a good bet it will warp in the hardening quench. In my experience, I have made a few hundred of file blades, I suggest a point in first quench, and file steel is not real picky about the quench oil. Use oil, or brine. I like oil myself. After the quench, temper at 450o, to 460o, three one hour heats, and you will have a nice, tough blade. I use only Nicholson's, or black diamonds when I can, or simmons. That temper range will give you about 55 to 56 RC.
 
yeah, i scored and broke the file so i could work with a usable length, put it in the center of the starter and filled tightly with charcoal...lit...let it just sit in there til it cooled...

i dont know if this is orthodox...but i do know my crappy beltsander isnt going to cut the mustard for knife blade grinding...

crappy sander:http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=2485

i think im going to have to mod my bench grinder to accept maybe a 2" belt...maybe attach a pulley to the back or something...

hey does anyone use this 'style' of belt sander?

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=38123



thanks and glad to be a new member


-nadz
 
Hello, new member here. The new issue of Home Machinest has an article about making a knife form a file. It explains how to anneal, harden and draw the steel and about what hardness it will be.
 
Nadz,
I Have One Of The Hf 4x36 Sander. Works Well With Handle
Material Shaping. I Haven't Done Any Blade Profiling With It,
Except For Thinning Down A Kit Knife In The Handle Area. Worked Well For That.scales Did Not Have Any Gaps Angainst The Handle.
And It Runs Withvery Little Vibration And Mine Not Fastened
In Place.
 
thanks, but what about blade shaping? i mean i really dont know the difference between a belt "sander" and a belt "grinder"...

is it in the belt?

the length of the belt?

it seems that 2000sf is a recommended speed, if so this should be ideal? right?

i know i know, i should go and get myself an expensive belt grinder from (insert company name here) but at this time, its just not in the cards...

so in the spirit of playing with the hand i have been dealt, i think im going to try to use a 'budget belt sander'...


experienced members speak up =]

i dont want to shoot myself in the foot



-nadz
 
If you are working with wood, its a sander, if you are working metal, its a grinder. That's pretty much the difference.

I just killed my 4x36. The same model you linked to. It's not the best, but I have done about 5 or 6 blades on it. I basically abused the machine, which is why (I believe) it died. All my knives have been from 1/4 inch x 2 5160, and I have done alot of hogging on that thing putting in tons of distal taper, etc.

If you get it, get the extended warranty on it, its just a few $, and If I had gotten it, I would already be back up and running with a new machine.

I added a peice of ceramic platen material on it just a bit before it died. I wish I had done ot much sooner. Night and Day difference. If you get that grinder, DEFINATELY get a peice of pyroceram for the platen.

I think it was a decent machine, but I'm getting a bit more serious about this hobby err.. addiction, so now I'm a little stumped as to where I should go from here grinder wise. I want a KMG, but I dont want to wait a few more paydays before I can grind some steel..

Hope this helps.
 
hey man, great advice...

i think im going to start with a model similar to that...maybe find something used or burn some of my lowe's and HD giftcards...i just want a good place to start...

im planning on ordering some 3/16 stock from admiral steel...what a great site!



-nadz
 
My Step dad made one when I was a kid a very long time ago into a Bowie knife from an old Body file.. he still has the knife and I know personally it was been through at least 15 car hoods .. the thing is still in one peice and a hell of a knife IMO...... I will find a pic of it and post it up..
 
The 1x30 harbor freight sander is what I have now. Its ground 3 knives so far w/o any trouble (woodknocking sound). I dont use quite so heavy stock though. My thickest has been 5/32". Also, use fresh belts, and I like the 40 grit blue ZrO belts from the local wood working shop. I didnt anneal the entire blade. The file hardness is what I'm after, and the reason for starting with a file in the first place, although, the 1095 I bought will reach HRc 66 w/o too much effort. I did anneal the handle area, and a little too much of the blade. It did warp, but since its annealed I should be able to straighten it. Hopefully, I'll get it done this weekend, but not likely.
 
Made many knives from files,only I forge mine.so mine have been normalized and hammered then normalized again then re-heat treated.I personaly would never leave a file at it original hardness for a knife ,I did once when I was 16 and didnt know any better,didnt hold up without chipping....

As for a grinder you should always get the best you can afford.That said you can always get the 2X48 grinder attachments and then extend the ideler head up to fit a 2X72 belt...The best grinder will have a variable speed motor or pully setup,slower speeds generate less heat with allot more control as you grind.

I would profile and set the bevels in with a sidegrinder before I burnt up another 3X48 grinder as they are not ment for ruff grinding steel,I know as I burnt up a few myself before I got a 2X72 grinder and only used the small grinder to work handle material.
Just my ramblings here,
Bruce
 
You really need a 6 x 48, with a cast iron deck that has a lip on the sides so that you can allow the ricasso area to hang over and still sand the rest of the blade. It needs a fairly strong motor in order for you to bear down on your work when needed. I consider these table sanders as a necessity for finishing and truing. One can grind an entire blade on one of these, but it is easier if you have another way to rough the blade in first
 
nadz, Search this forum for a post I did on how to convert a 4x36 to a 2x72 (today it is on page 13) it is very easy and the pic's show you what to do...:cool:
 
yeah, i think roughing in with a side or bench grinder may be a good option with a file-knife...i am going to explore ebay on a bit better of a grinder...luckily i have a HF tool store in my town, so i might catch a break there...


thanks everyone for the great info



-nadz
 
I have a worn out 12" file I found that I want to make into a large dagger. I was wondering if I heated it in the over for a while if I could soften it enough to file down with my sharp file without making it so soft that it would need to be HT'd again. I only have hand tools, and no forge at all. Could this work?
 
Chimp_With_Knife said:
I have a worn out 12" file I found that I want to make into a large dagger. I was wondering if I heated it in the over for a while if I could soften it enough to file down with my sharp file without making it so soft that it would need to be HT'd again. I only have hand tools, and no forge at all. Could this work?
Click to expand...

Possible yes. But (there's always a but) it will take a looong time using just hand tools. That is assuming the file is not a case hardened piece of mild steel. You'll probably go through a couple of files by the time all is said and done if you just use files and heat just enough to use a new file. Unless you have a lot of persistance you may well get discouraged and give up.

Do a search on "homemade forges" or "one brick forges". Check out the blueprints on iforgeiron.com This will let you anneal the file and heat treat it again. This will make the job much easier and faster. Some have used angle grinders (gotten cheap from a pawn shop) with success.

ron
 
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