Jump to content

Letting the blade cool too much after the quench


Recommended Posts

 hi all, 

I recently saw a video from a knife maker that said that after the quench, the knife shouldn't get colder than 170F.  So after you quench you should wash the oil out with hot water and straight to the temper. I've always washed and rinsed in cold water. Does it make any difference? I've always thought that since you were starting a temper you should start from below 90. What are your thoughts? 

Link to post
Share on other sites

I believe some steels will retain more austenite if you don't let it reach room temp, which is bad. I even put my 26c3 blades in the freezer after it reaches room temp. No blade cracked so far. 

 

So, depending on the steel, it may or may not be a good thing. Of course, most of the RA can be converted to pearlite/ferrite/whatever during the tempering cycles but if you aim for the highest possible martensite %, you want RA to transform to martensite...

 

 

 

 

  • Like 1
Link to post
Share on other sites

Let me start by saying no negativity is intended.  I'm sure Mr. Rougeau is a fine gentleman, but I do not agree with his theories on heat-treating either 5160 or 1095.  We all have opinions, of course.  Mine is that neither of these steels require a soak at 1500 (and that 1095 only needs to get to 1450, and 5160 needs 1525 to fully harden), and that it's desirable to get the blade to room temperature (or lower) before tempering.  Keeping the blades at 125 degrees isn't going to hurt these steels, but it really makes no difference.   The fact that his as-quenched hardness for 1095 was Rc58 and 5160 was Rc57 shows he is not getting full hardness.  Certainly useable, but not as good as it could be, even tempered back to 52 for testing as he did.  Again, just my opinion.

 

However, as he said at the beginning, this is just an experiment, he is not saying this is THE way to do it.  I like his setup.  But I'd like to see the grain on the 1095 blade.  I suspect it's a bit on the larger side.  

  • Like 1
Link to post
Share on other sites
  • 2 weeks later...

I'm not even going to watch that video. The whole premise of 

On 2/24/2020 at 5:47 AM, Paul Checa said:

the knife shouldn't get colder than 170F.

when talking about 1095 and 5160 is bunk. The fact that he is only getting RC 58 and 57 definitely shows he doesn't know jack diddly about quenching these steels.

I routinely get RC 63 or better out of the quench on my 1095 and I finish my quench in room temp water. (also do this on W2 and O1 and hit 65 RC or better)

Sometimes (when I remember) I also quench in water between tempering cycles.

My blades also sit on a rack until my oven cools down to below 300*F before I temper. That's a few hours of sitting around.

Link to post
Share on other sites

As I recall, someone once held that if his 1095 blades sat at room temp for a half hour before tempering he had a higher HRc when it went into the tempering oven.  Now I've always gone by letting the blade cool enough to comfortably hold in my hands but then I haven't used 1095 for years and have very limited experience with it.

 

Doug

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...