What is the Lowest BESS score you can get with Tormek?

[cbwx34]

Did you sharpen in the following order?

SG(#220) -> SG(#1000) -> SJ?

SG(#1000) -> SJ

The knife had been previously reprofiled... this sharpening was a few alternating passes on the SG wheel at 1K... then to the SJ wheel... around a dozen or so passes per side, with the last 2-3 light alternating passes.

[wootz]

By what you describe, you've got an edge at <= 80 BESS.
It is not in the Sharpness Chart, but if it can split a chest hair, but cannot a head hair yet, it is 70-80 BESS, you may try this test as well.

I have several M390 knives in my collection, and the SJ won't work on them but one.
I tried edge-leading and edge-trailing, at the exact edge angle, at +0.4-0.5 degree and at a less to no avail, except that one blade that yielded the best of 80 BESS on one occasion.
The blades they get of the M390 steel depend on the heat treatment quality, and I would say the heat treatment hasn't been done to its best if M390 responds to SJ at all.
It is not supposed to.

[cbwx34]

By what you describe, you've got an edge at <= 80 BESS.
It is not in the Sharpness Chart, but if it can split a chest hair, but cannot a head hair yet, it is 70-80 BESS, you may try this test as well.

I have several M390 knives in my collection, and the SJ won't work on them but one.
I tried edge-leading and edge-trailing, at the exact edge angle, at +0.4-0.5 degree and at a less to no avail, except that one blade that yielded the best of 80 BESS on one occasion.
The blades they get of the M390 steel depend on the heat treatment quality, and I would say the heat treatment hasn't been done to its best if M390 responds to SJ at all.
It is not supposed to.

Red hair or green hair? (Inside joke)

I'm not much on the "hair tests"... I think a lot of it is technique.  But it will whittle a chest hair, and to my surprise even a head hair in some spots on the blade.

I'm a bit dubious when I read "this stone won't work on this steel".  Most will have some effect.  If you take one of your M390 knives that it doesn't work on... you see absolutely no difference?  Polish only one side, and see if it looks different than the other.  Raise the angle 3-4°, and make a few passes on one side... any evidence of a microbevel?  Is there 'black' showing up on a cleaned SJ wheel?  If yes to any of these... it's doing something....

As for this knife, all I can say is the bevel was definitely polished by the SJ wheel, although not a perfect mirror... I can still see scratches from the SG wheel... but more mirror than hazy (if that makes sense).  (Why am I typing)...



Anyway, it's holding up well cutting some cardboard.  But I don't have any other M390 to compare to at the moment.  It is a Kershaw and at the lower end $$ wise from what I'm seeing on the net... so being more a "mass production" knife... wouldn't surprise me if the heat treat isn't optimal.

Thanks!