5160 heat treat

D

Dkbrowndesign

Joined
Jan 5, 2013
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Hello I am a beginner knifmaker and I am starting trying to heat treat. I am using 1/4 inch 5160 bar stock and doing stock removal. I have a really nice gas forge tthat I am heating with.
Today I heated my blade up to non mag then quenched into 10w30 motor oil that I heated to 120' then I put it in my toaster oven at 400 for two 1 hr cycles.i tried a file on it and it still feels soft?? What am I doin wrong here? Any info or corrections would be great!
Thanks Dan
 
You'll need to get 5160 hotter than that. If you're doing it in a forge, watch the colors change. When
the steel changes from red to bright red you're at transformation temp. Ideally, 5160 should have a soak
at temp for 4-5 min....hard to do in a forge.
Motor oil is an iffy quenchant..... canola oil would be better.

If using a toaster oven, shieldthe blade from the heat elements..they go higher than the set temp.
Use an oven thermometer in the toaster oven.
 
It's very difficult to go by colors alone. A better way, in the absence of measurements, is to watch
as the colors change. When you see a clear difference between red and bright red...the bright red
will likely be at transformation temp....I say "likely" because what one sees as bright red, another may
call orange. The important thing is to watch for the change.

Thanks...
 
The file bites in to the 5160 pretty good even after my heat treatment,what other indicators are there for hardness ??
 
If the file cuts, the blade is underhardened by either under or over heating.....or you have
a layer of decarburization. Try cutting a little deeper and see if the steel is harder beneath the surface.

Check hardness before and after tempering.

For a small shop,file testing for hardness is the most common way. Next step up would be a proper
hardness tester.
 
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