Tempering

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hammertime99

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Jan 6, 2015
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I'm New to this knife making stuff. I know that, to temper, you need a specific temperature usually, right? I don't have the money to get a heat treat oven but I have seen people temper them in their kitchen ovens. I don't think my mom would like it too much if I used her oven, does anybody have any suggestions? I know it's not absolutely necessary but I know it'll probably make a better knife.
 
Tempering is done at a range of temperatures. The range depends on the steel you are tempering. The resulting hardness depends of the specific temperature used within that range. Too low a tempering temp and you will end up with a blade that is too hard or brittle or chippy at the cutting edge. Too high a temperature and the blade will be too soft. This can give you a blade that rolls or deforms at the cutting edge or won't hold a sharp cutting edge.

You can safely temper in your Mom's home oven. Just make sure the blade is well cleaned before putting in the oven. I use a citrus/pumice hand cleaner with a small scrub brush then again with regular bar of hand soap to get all the citrus stuff off. A clean blade won't smell or smoke up the kitchen.
 
It is absolutely necessary,get your mom to take you to the second hand store and by a toaster oven.
 
I think you may be missing parts of the process. Tempering is the drawing back of hardness by comparatively low heat, which is done AFTER heat treating or hardening, which is done at precise, very high temps, anywhere between 1400 and 2000 or so based on the type of steel. These temps are not possible in a household oven as you know. Tempering without first doing the heat treat and quench to fully harden the blade does nothing. Blades must undergo both processes to be a usable knife at all. So yes heat treating is absolutely required. Without it's just a pointy piece of scrap steel. Most makers will tell you the heat treating process is really the MOST important part of the whole knife making process. The finest piece of steel available still won't cut worth a damn without optimum heat treat.
 
Grayzer86 said:
I think you may be missing parts of the process. Tempering is the drawing back of hardness by comparatively low heat, which is done AFTER heat treating or hardening, which is done at precise, very high temps, anywhere between 1400 and 2000 or so based on the type of steel. These temps are not possible in a household oven as you know. Tempering without first doing the heat treat and quench to fully harden the blade does nothing. Blades must undergo both processes to be a usable knife at all. So yes heat treating is absolutely required. Without it's just a pointy piece of scrap steel. Most makers will tell you the heat treating process is really the MOST important part of the whole knife making process. The finest piece of steel available still won't cut worth a damn without optimum heat treat.
Click to expand...

I knew I would have to heat treat it, but I was just confused on the tempering part. Thanks for the info though.
 
i4Marc said:
Tempering is done at a range of temperatures. The range depends on the steel you are tempering. The resulting hardness depends of the specific temperature used within that range. Too low a tempering temp and you will end up with a blade that is too hard or brittle or chippy at the cutting edge. Too high a temperature and the blade will be too soft. This can give you a blade that rolls or deforms at the cutting edge or won't hold a sharp cutting edge.

You can safely temper in your Mom's home oven. Just make sure the blade is well cleaned before putting in the oven. I use a citrus/pumice hand cleaner with a small scrub brush then again with regular bar of hand soap to get all the citrus stuff off. A clean blade won't smell or smoke up the kitchen.
Click to expand...

I did not know that. That's pretty insightful, thanks.
 
If you are going to use a home oven or even a toaster oven to temper blades you will want a rack type thermometer to put on the shelf in the oven to verify temperatures. Actual temperatures in home ovens and toaster ovens can be quite a bit off from the dial indicated temp. Also, even when using a rack thermo, the needle can stick. After the oven has come up to temperature give the thermometer a tap or two with a spoon to make sure the temp indicated is right. Often with a tap the needle will jump to the true temp. You can give the thermo a tap periodically during the tempering to be sure. Be quick though as you don't want to lose too much heat from the oven while you're checking. Having a large steel plate with some mass on the bottom shelf will help to stabilize temperatures in the oven.
 
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