questions for knife makers pertaining to cooling annealed steel.

[NorthBorder]

I have been making knives from old files. This is getting to be a pretty fun hobby. I just bought a small forge and want to start heat treating. First thing I want to do is anneal the handles so that I can drill some holes in the to attach scales. My questions are 1) do you heat the blade until it becomes non magnetic for annealing? And 2) what type of medium do you put the blade in to cool it slowly, or can I just turn off the forge and let it cool naturally. I was thinking of using sand or kitty litter but that is just an idea. Any advice would be muchly appreciated.

 

[DMW1116]

What other equipment do you have? I used a Mapp gas torch to spot anneal the handle area for my first (and only) file knife. Heat to red in the dark and let it air cool. It will be soft enough to drill. If you only have the forge, heat the tang with that and air cool. It's not as soft as possible, but it's soft enough to drill holes.

 

[Big7]

Best way without a bunch of equipment is to heat DARK red- like blood or crayon and stick it in some used glass bead blasting media and just forget about it and let it cool slowly.
Next best is 400*F then 200*F oil.

Old files are made of O-1 Tool Steel. Look all that tech data up on line or find a book from a tool steel company. The now defunct Crucible Steel Company Had the best steel and the best data. If you can find that book, that's the one you want.

O-1 is probably one of themost forgiving of all to work with. If you screw it up, do as I described above and start over for as many times as it takes on the tang and 2, possibly 3 times on the blade.

I don't get on here much but if you need any help, message me with your questions. I got you.

Not a knife maker per se' but Tool and Die 40+ years.

 

[hso]

I have been making knives from old files.

First thing I want to do is anneal the handles

Don't you anneal the file before grinding it? Guess not. Wow, grinding on a file will eat belts, but you don't have to heat treat the steel to harden it.

drill some holes in the to attach scales

Use a propane or MAP gas torch to heat the handle to non-magnetic and then let it sit covered in white oak ash, vermiculite, or pearlite until you can handle it with bare hands. It is annealed and you can drill it.

How have you been putting handles on before this?

 

[NorthBorder]

Don't you anneal the file before grinding it? Guess not. Wow, grinding on a file will eat belts, but you don't have to heat treat the steel to harden it.-Tube



Use a propane or MAP gas torch to heat the handle to non-magnetic and then let it sit covered in white oak ash, vermiculite, or pearlite until you can handle it with bare hands. It is annealed and you can drill it.

How have you been putting handles on before this?

I just learn by watching U Tube University. Not a lot of annealing before grinding and sanding when the make knives from old files. Having said that I did anneal a couple of knives the other day. One came out brown and one came out blue. I annealed them together so I don't know why the color differences. I will put a finish grind on them to see how they come out.

I made some scales from resin and was able to attach them to one knife that I was able to drill thru. Since then, I bought some Rodman drill bits that are able to drill thru hardened steel and had a little luck before the bits became dull.

 

[hso]

Not a lot of annealing before grinding and sanding when the make knives from old files.

Apparently you can't trust U Tube U. A file is hard and needs to be annealed before grinding...unless you're forging the file and it anneals in the forge before you start beating it into shape.

 

[DMW1116]

I won’t say it’s the right way, but I just ground mine without heating except the tang for drilling. It took a WHILE, but I was also using a 1x30 belt sander.

 

[Flat Rock]

you can heat it to non-magnetic and just a little more and put it in vermiculite till cool
it should drill ok after that.
then do your grinding, then heat treat.
get the right oil for your quench, forget about canola
also, get yourself some knife steel (1084 is a good start)
and go from there.

 

[hso]

old files.

Where are you getting your files?

get yourself some knife steel

YES! Scrap seems cheap, but you will learn more buying blade steel like 80 CrV that will consistently grind and heat treat than working with mystery metals. Nichols files used to be great, but now there's too much variability in file steel.

 

[NorthBorder]

I get those old Simmonds and Nicholson files from a used tool dealer for about $1 each versus paying $18 for one 12" piece of CrV.
Making these knives is mostly just a fun hobby to learn something new. Its not a serious endeavor to make a fortune. I may not know the metal content but each brand is probable pretty consistent.
@Flat Rock you do some fantastic work. Those knives are beautiflul.

 

[BobCat]

Wrt Post #3 - you are right, but actually the Crucible Steel book is at http://www.crucibleservice.com/eSelector.htm and there are a couple other relevant links from there - the 2010 Knifemaker PDF is at http://www.crucibleservice.com/PDFs/Knifemaker REV June 2010.pdf and a knife steel selector is at http://www.crucibleservice.com/pdfs/SelectorKnifePocketRotatedCrucibleLLC.pdf

 

[slicksleeve]

I’ve used a few files, and a whole bunch of farriers rasps. I heat them to a glowing orange. I used to touch them to a magnet, but now I can tell by looking. Bury them in the sand around my firebrick and forget it for a few days. Heat treating, the same color, not magnetic, then plunge into the burnt motor oil until it cools. Clean up on wire brush, then wash with soap and water. Bake in oven at 400 until the metal takes a purple hue. That makes an excellent edge holding blade.

 

[hk940]

You can drill hardened steel with a masonry bit at the top speed of your drill press, it will really burn thru not drill.

 

[DMW1116]

I’ve used a few files, and a whole bunch of farriers rasps. I heat them to a glowing orange. I used to touch them to a magnet, but now I can tell by looking. Bury them in the sand around my firebrick and forget it for a few days. Heat treating, the same color, not magnetic, then plunge into the burnt motor oil until it cools. Clean up on wire brush, then wash with soap and water. Bake in oven at 400 until the metal takes a purple hue. That makes an excellent edge holding blade.

This isn’t exactly a k I’ve makers forum but I’d generally recommend against motor oil for quenching. It produces pretty nasty smoke and doesn’t cool many steel quickly enough to fully harden them.