where do you put your heat treat oven?

Concrete board is something like $10 at Home Depot/Lowes. Cheap and fireproof. Probably not necessary for the kiln itself, but you WILL eventually drop something... probably prefer not to drop a 2000 degree chunk of steel on wood.

Also, you might want to check the instructions - Evenheat said to keep my kiln at least (12?) inches from anything else.
 
I have a Paragon on a wooden chest of drawers up high so that the door opens at eye level without me having to bend or stoop when removing knives for the quench.

It is important to be in a comfortable position to reduce the chances of getting burned or damaging the knives when handling them at quench time.
 
To all of you who have an HT oven, I do not have one yet, so I have a really stupid question. O1 is supposed to be tempered somewhere in the range of 400 degrees. The oven in my kitchen says it goes to 500. Normally I use a torch, but would the oven work? I know it probably sounds odd, but I'm sure someone's tried it.
 
I think most folks temper in the kitchen oven.

Many who have a dedicated large shop have an old kitchen oven out there for tempering....... and pizzas.

Now, I am assuming when you say "Temper" you mean after the hardening, which is done at 1500F. Most of us with HT ovens use them to do the hardening and after the quench, clean the blade off and put it into the kitchen oven as soon as possible.
 
Yes, I definitely mean after the hardening. I'm still a novice, but I learned basic heat treating from a veteran Toolmaker I worked with. Thanks for the reply, that would make my life a lot easier. Since I now have someone's attention on the subject though, in your opinion, is it even remotely efficient to harden using charcoal in say one of those backyard firepits you can buy at hardware stores? I'm trying to do as much as possible with equipment I already have until I can sell a few knives and fund new equipment.
 
CAN you harden in a charcoal fire pit....yes.
Is it optimal....no.

The simpler the steel, the better the chances of getting good results. I would say that 1070-1084 would work OK in a firepit, but more complex steels will be problematic.
 
thanks. just for the heck of it I'm in the middle of trying a small 2 inch square of 3/32 O1 Where I work, one of the machine operators uses a manual hardness tester, so when I'm done with this little test, he's going to check it for me. I figured it was worth a try. It's currently tempering in my toaster oven (I'm not going to fire up the regular oven for a 2 x 2 inch square). thanks again for all the advice. I love this site.
 
Maybe this ought to be a separate thread, but just out of curiosity-- what about differential tempering? Or do y'all find that tempering the entire hardened blade at 400F. works-- i.e., leaves it with a satisfactorily hard edge and a spine that holds up under workaday stress without cracking?
 
At the risk of starting a war:
The metallurgists will tell you that a fully hardened and fully tempered blade is most likely better than any partial method. If one needs a difference in spine hardness, it can be drawn down further after the initial tempering is done.
This is in reference to standard blades. If one is going for aesthetics, as in a hamon, then there is a reason to do things partially.
 
After this, I think I should start a new thread, but just an update. I tried a sample piece of O1 as mentioned above. I double tempered it at 400 for 1 hour each running it under cold water in between. It checked for hardness between 58 and 60 RC over 5 different points. I was told that the reason for the variance was the rough ground surface. Thanks for all the tips. I know there is no way I was getting that hardness and toughness with my old heat treating methods ( I tried everything I could to break it).
 
58 to 60 is a pretty good range. The biggest enemy of Rockwell testers is burrs or (sorry for being so technical) Heat treat CRUD. :)

Rob!
 
bladsmth & any others !

Hello! I only joined a coupled of weeks ago and have only ask 2 Questions & 1 was basicly to say hello!
My Question is: Does anyone see a real problem of Heat Treating using a Vertical Blown Forge that has a thermocoupler & Pyrometer installed to control and keep an eye on temp??
Just asking as I haven't even made a Knife or the forge yet as I'm still trying to learn.
I have shifted my thinking from building a Venturi Forge to a blown one after reading here about most of the top Makers useing Forced Air (Blown) Forges and their sucess with them.
And the great thread that was posted about building the almost perfect(nothing is) Automatic Forge with the pyrometers and thermocouplers,fan controls & the solenoid valves for control of the gas.
Well I won't be able to afford the Automatic Type Forge but I plan on building a Blown forge with a thermocoupler & pyrometer.
I can't see any really problems in heat treating with a forge like this as long as I keep a Close eye on Temp & can manually control the Air & gas Flow??
Any advice or thoughts greatly appreciated!!

Mike E.
 
Build a good forge and you can do most carbon steel HT in it.
Stainless steel and some high alloy carbon steels ( air hardening) need an oven and special processes.
The PID control function and two-stage burner can be added to the forge later. The basic forge is the same.
 
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