Rockwell Hardness Test on a Hamon?

C

cjwb2012

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Dec 7, 2013
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Hey guys! Although this is my first post on this site I have been coming here for information for a few years now. The amount of knowledge the members on this forum share is amazing so thanks! My question is has anyone performed a Rockwell hardness test on a hamon of a blade? I just completed a small kitchen knife with a hamon. Now I'm completely obsessed with them! The blade is made out of 1095 and I have a decent visible hamon. I used refractory clay I had left over from my forge to coat the blade and left about a half inch(typical wavy line) of the edge exposed and quenched the entire blade in oil(I understand you would probably get better results using a brine quench but I don't have the courage to try it yet!). If one were to test the hardness of the blade on the hamon and then the portion that was covered with the clay (refractory material) would there be a considerable difference in hardness? Thanks for any comments! Rob
 
Unfortunately, most Rockwell testers can only give an accurate test on something that's FLAT.... so testing the bevel of a blade is going to give skewed results.


However! ;) In one of my big heat treating experiments, I cut slices right off the end of some 1-3/4" W2 round bar, then did several different time/temp/quench tests using my digitally controlled salt bath and Park50 quench oil.

I had 5 discs with crazy differential hardening... they looked like leopard spots with very cloudy transitions. I surface ground the tiles so they were nice and flat, and nearly mirror polished, then Rc tested them.

The as quenched hard spots were 65-66 C, the soft areas in-between were 45-47C.

I think those numbers would transfer pretty well to a differentially hardened blade that had good thermal cycles, quench medium, etc. :)
 
With W2 I'm getting 67-68.5 Rc (as quenched) in the hardened section and mid 40s' where the clay was.

61-63 Rc after tempering.
 
I have the same results here. I test after first temper at 350f, and hardened areas are mid 60s and softer areas are mid 40s. I'm not brave enough to test right out of quench.
 
Awesome guys thanks for the info! Looks like mid 60's for the edge and mid 40's on the softer areas across the board. Thanks again!

Nick - In the middle of your damascus camp knife write up. Beautiful work! Now I cant put my laptop down...Thanks! :thumbup:
 
cjwb2012 said:
Awesome guys thanks for the info! Looks like mid 60's for the edge and mid 40's on the softer areas across the board. Thanks again!

Nick - In the middle of your damascus camp knife write up. Beautiful work! Now I cant put my laptop down...Thanks! :thumbup:
Click to expand...

This is what got me into knife making. I went through that thread when I was off work recovering from knee surgery. I've been hooked since.
 
I try to run my clay back onto the ricasso area so it gets hard about half way where the guard is going to be. I can test the hardness on the flat that way.
 
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