Sharpening AEB-L at different HRC hardness yield different results

P

PMQ

Joined
Feb 17, 2020
Messages
176
I was just finishing an AEB-L santoku, heat treated to 63-64 HRC, went to sharpen it with a 1000 grit Naniwa diamond stone, tested on paper, and it sound a bit coarse for what a 1000 grit should sounds like. So I grabbed a different AEB-L I previously made, which was 59-60HRC, sharpens it with the same 1000 grit stone, and it sounds not-dramatically-but-noticeably smoother. I of course use the same piece of paper.

I don't think it's a grain growth problem, because I later take the 63-64 one to a 3000 grit and 9000 grit stone, strop with 0.25 micron compound and it could easily split hair.

Is this normal? Thanks.
 
I have used AEB-L at 59-60, and 61-62 rockwell. I think it is the harder steel needing more time on the stone to get the same level of refinement.

I can get 59-60 AEB-L sharp, but 62 AEB-L seems to take and hold a better edge, but takes a little more work. When I use water stones, they sharpen, but working the mud will give a little more polish/refinement to the edge, even at the same grit, especially if I deburr and then continue sharpening with little pressure. It goes from a coarser feeling edge to a sticky smooth sharp edge on the same 1200 stone I use just by changing the technique. Harder steel will be more wear resistant and probably needs a bit more time on each stone to reach it's potential and smooth out.
 
A jeweler's loupe or good magnifying glass will also tell you a lot. The harder edge may be microchipping due to larger carbides or edge tear-out when the wire is removed.
 
Thanks everyone. Here's an update:

The way I sharpen is: I'd form a burr, strop a few times on the stone and strop on compound. So with the input from Stacy E. Apelt - Bladesmith Stacy E. Apelt - Bladesmith , I think stropping only a few times on the stone weakens the burr, but the apex is still toothy, combined with high hardness, this creates microchipping.

I decided to went back to the 1000 grit stone, strop back and forth for longer, this should refine the edge. And what do you know, it's wayyy smoother, feels identical to my other 1000 grit edge. So the problem indeed is microchipping, creating a toothy edge.
 
AEB-L at high hardness is quite harder to work than 61 and lower. I think the burr is very difficult to fully remove too. I like to sharpen it, use it for a few cuts, then check it again and sometimes the burr is still there. Just do more stropping strokes t make sure it is fully gone.
 
If you have a burr big enough to feel with your fingernail on a steel that hard, stropping likely won’t remove it. Try deburring on the stone before stropping.
 
Last edited by a moderator:
You must log in or register to reply here.
Back
Top