Another dumb question - No HT?

B

beta_medic88

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Nov 11, 2008
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Sorry if I'm asking dumb or obvious questions, but I'm in the middle of my first knife and I want to know as much as I can :P. So I was wondering.... is it really bad to not austentize a knife and just temper it? Like, don't kiln or forge heat it up to 1500, just throw it in the oven at ~400 for an hour a few times? I know austentizing it makes it stronger by changing the structure of the alloy, but would it not also be strong just by tempering it? I ask this because I don't have a forge or kiln, so I would have to ghetto-rig a coffee can forge with a propane torch, and I don't think I would have very good temperature control with that and I don't want to ruin my knife with a bad heating. Any advice? Anyone use a real cheap gas forge before?
 
If you want to use the knife,it has to be heat treated. The original heating is the most important part; it's where the steel is made hard. The tempering just draws it down to an acceptable toughness. You can certainly do this yourself in a coffe can forge; it's not complicated, just needs to reach critical temperature (non-magnetic).

There's loads of info on this process. Look around here a bit...
 
You could use Stellite 6K, if you can find it. No heat treat. Very high in cobalt. Holds an edge near forever, and is about as tough as it comes.
 
the heat treatment is very important. The tempering takes some of the hardness out of the steel, for example, you could turn a file into a leaf spring, but it would not be as hard as a file, if that makes sense. Right after hardening, it will be weaker (as in brittle) making tempering necessary.

Hardening a steel like 1080 isn't too challenging, avoid complex steels and ones that need to soak at temperature for a while.
good luck!
 
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LRB said:
You could use Stellite 6K, if you can find it. No heat treat. Very high in cobalt. Holds an edge near forever, and is about as tough as it comes.
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I wouldn't want to shape that with files!
 
Boye Dendritic Cobalt does not need HT- contact David Boye for info. Soft "steel" that rolls edge on bone/hard contact, but works great on softer medium.
 
HT to me is the most important part of the process. The austenizing and quenching at proper temperature is just the first part of the process. It has been said you can take ok steel and make a good knife or you can take great steel and make a crappy knife it's all in the HT.
 
H1 is a steel that comes hardened from the manufacturer. It's best characteristic is it's extremely corrosion resistant. I have no idea where you can buy it.
 
mete said:
H1 is a steel that comes hardened from the manufacturer. It's best characteristic is it's extremely corrosion resistant. I have no idea where you can buy it.
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I thought H1 came unhardened then work hardened as it was ground? Is this incorrect. I wish I could buy some. :grumpy:
 
You can always buy M42 prehardened and just grind it to shape just be careful of the cobalt (use a respirator and have good ventilation). There are other steels that can be had in the hard state and some makers grind after HT to avoid warping. After HT it is much more difficult to grind and you MUST keep it cool or you will undo the process.
 
Could I just temper a file and then grind it or would I need to make it softer, grind, then hard then temper?
 
You could do that, but you would have to be very careful to not over heat while grinding. I have done it, and it is slow going, but will work.
 
heat treating is what makes a knife. it's the process that makes steel hard. it's the difference between a letter opener and a knife. congratulations on making your first knife - when you get finished, you'll be an addict like the rest of us. since it's your first and you don't know about heat treating, just concentrate on the shape and on getting the handle right. send the blade out to someone who does heat treating and spend some time studying heat treating before you try it yourself. if you've picked a simple steel, like 5160, the process is not difficult. but, if you've picked one of the more complex steels, like D2, you need a temperature controllable furnace. a good book on the process is Heat Treatment, Selection, And Application of TOOL STEELS by Bill Bryson

good luck -
 
Air-cooled steels can be sent out for professional heat treat. This may be your best option.
 
Sawce said:
Could I just temper a file and then grind it or would I need to make it softer, grind, then hard then temper?
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If you were to anneal (soften) a file, shape it then harden it again, why not just use a piece of already annealed steel ?

Chances are if you've never ground on hardened steel, you will most likely over heat it and then you'll have to reharden it again. Also in order to shape a hardened file to shape, you'll most likely need a belt grinder as you can't shape a hardened file with another file...and if you could, it would take you probably a year to do so.

The file is already "tempered" to a certain hardness...like the other said, tempering is to soften it a bit as to take the brittleness away and make it useable, otherwise it would just crack if you used it straight from heat treating.
 
Thanks for the help guys. I'm working really hard on adding the bevel now, and i think i'll end up send it out for the HT. I'm working with 1095 so I don't know if that's too complicated to heat, but I'll give it a try maybe on my next knife.
 
1095 is a simple steel, but the heat treat is quite demanding in order to get it right.
 
You can always send the blade out for heat treating. I haven't got my forge built yet, so I am sending my high carbon blades to Bear Claw Oates. The stainless steel I will send to TexasKnife.com

Cal
 
Use 1080, 1084 or similar for easy heat treat, or else buy an air hardening steel like A2 and send it out (or you can just get a maraging steel and age harden it :D) but you will get your best results with a proper blade steel, austentized and tempered.

-Page
 
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