HT Question

Jarrett Fleming

Jarrett Fleming

Moderator
Knifemaker / Craftsman / Service Provider
Joined
Jun 5, 2011
Messages
1,459
This question has probably been asked before, but I was wondering what you guys that only have one ht oven do about tempering. Obviously a knife blade cools much faster than an oven at 1900 degrees. So my question is do you wait for your ht oven to cool off enough to temper your blades or do you just use a kitchen oven? I know that you want to temper blades when they are still warm, but what negative effects are there if you wait to temper them after they have been out of the ht oven for about an hour.
 
I usually use the kitchen oven, unles I am doing a big batch. Check you oven for temperature swing and spikes before trusting that 400F is really 400F ( not 380-420 agreage).
 
Much depends on the type of steel. I use 01. After quench, I simply wait for the oven to cool down below 250°, then reset for temper heat with 10 minutes extra time to give the oven time to level out, and temper. I have never had an 01 blade crack, nor an A2 blade, but 1095 and some other 10xx steels need an immediate temper, even if just a snap temper.
 
I use a toaster oven that I got at Goodwill and do a lowball temper (about 50 F. below target usually) with an extra oven thermometer to verify the temp. When the digital oven has cooled off I do the regular temper routine, ignoring the first cycle in the toaster oven.
 
Using mostly Stainless,mine spend the night in cryo and temper the next day,for carbon steels I use a toaster oven.
Stan
 
Since I trust my Evenheat more than "Mama's" kitchen oven, I usually do what is called a "snap" temper at around 350-375 in her oven (I have tested her oven with a pyrometer and hit holds pretty true). That will relieve stresses and hold me until my Evenheat cools down. From there, I use the Evenheat to dial in my desired temps according to the steel and its intended purpose.

Even if I am doing a cryo, the snap temper will be used prior to cryo.

Robert
 
Thanks for the responses guys. It sounds like I have been doing the same thing as some of you. I put the blades in the kitchen oven until my ht oven cools down.
 
Last edited:
I start the kitchen oven when I start the kiln so it has time to equipibrate with pizza stones for thermal mass and cookie sheets for infrared shielding

Page
 
Robert Dark said:
Since I trust my Evenheat more than "Mama's" kitchen oven, I usually do what is called a "snap" temper at around 350-375 in her oven (I have tested her oven with a pyrometer and hit holds pretty true). That will relieve stresses and hold me until my Evenheat cools down. From there, I use the Evenheat to dial in my desired temps according to the steel and its intended purpose.

Even if I am doing a cryo, the snap temper will be used prior to cryo.

Robert
Click to expand...

My Evenheat takes FOREVER to drop down to tempering temps, after I soak and quench a blade or two. Rather than piss off the wife and stink up her kitchen oven, I have a single burner heater element and a metal bread pan filled with canola oil, set at about 300. I put the freshly quenched blades in the canola oil until the Evenheat drops down to the proper tempering temps.
 
Since using my kiln I have simply been leaving blades in the oil until the kiln cools down enough to temper. Perhaps I am taking too much of a risk? I use 5160, 1084 and 1095. I don't differentially heat treat at all. I figure 10xx and deep hardening steels would be stable enough to sit for a while... at least out of the air or off a cold bench.
 
After my knives are heat treated I have a 2 hour drive back home, then I temper in the kitchen. Obviously by then the blades have cooled down completely. Am I losing any important qualities by not immediately tempering the knives?
 
You must log in or register to reply here.
Back
Top