Extreme Sharpness Comparison - S110V vs Super Blue - Measured Test - BESS

are the values you give in your test above in straight grams, or are they scaled to the BESS scale, which appears to set 0 based on the sharpness of double edged razor blades? This appears to be 50 grams based on DE razor blade measurements.
 
The test looks well controlled, but I'm having trouble believing the results.

Jim has done extensive testing in the past using a different measure of sharpness and found huge differences in wear resistance. Those results mirrored the general results that others have gotten.

And now it's all about sharpening? Nothing else. The steel alloy doesn't matter?

What I have noticed is that different testers have come up with much different BESS scores. Even in Jim's tests, where he cuts off the test when the edge reaches a specific level of dullness. The end-point should show the same BESS score. But the early results have been widely disparate.

Something is wrong, but I don't know what it is. I do not believe that high-wear steels don't offer a wear-resistance advantage over relatively simple steels.
 
Twindog said:
The test looks well controlled, but I'm having trouble believing the results.

Jim has done extensive testing in the past using a different measure of sharpness and found huge differences in wear resistance. Those results mirrored the general results that others have gotten.

And now it's all about sharpening? Nothing else. The steel alloy doesn't matter?

What I have noticed is that different testers have come up with much different BESS scores. Even in Jim's tests, where he cuts off the test when the edge reaches a specific level of dullness. The end-point should show the same BESS score. But the early results have been widely disparate.

Something is wrong, but I don't know what it is. I do not believe that high-wear steels don't offer a wear-resistance advantage over relatively simple steels.
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I only tested for the 1st 5% to 6% of the dullness curve. ;)

Like the title of the thread says Extreme Sharpness comparison.
 
me2 said:
are the values you give in your test above in straight grams, or are they scaled to the BESS scale, which appears to set 0 based on the sharpness of double edged razor blades? This appears to be 50 grams based on DE razor blade measurements.
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BESS scale. ;)
 
Ankerson said:
I only tested for the 1st 5% to 6% of the dullness curve. ;)

Like the title of the thread says Extreme Sharpness comparison.
Click to expand...



Fair enough. Oddly, though, we always hear that the high-wear powder steels lose their sharpness quickly, then retain a working edge for a long time. Not so in this test.

Maybe -- I'm guessing -- that at 400 grit you're tearing out the carbides in the S110V, leaving only a jagged edge of the steel matrix. Or maybe those jagged edges left by the coarse stone don't hold up very well to abrasive cardboard, regardless of the carbides.

I'm still left with the impression that the BESS score is not ready for prime time. We've seen a lot of quite different scores for edges of equal sharpness.

On your test of S125V with an edge shoulder width of 0.006 inches, the edge was still cutting rope at less than 20 pounds up to a BESS score of 621. With Niolox steel, at the same edge-shoulder width, the edge was cutting rope at less than 20 pounds up to 344.5 BESS.

I don't see anything wrong with your testing procedure -- isolating key variables to test for extreme sharpness on a coarse edge -- but it would be an amazing finding if high-wear, high-alloy powder steels don't offer a huge advantage in wear resistance.
 
Twindog said:
Fair enough. Oddly, though, we always hear that the high-wear powder steels lose their sharpness quickly, then retain a working edge for a long time. Not so in this test.
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Didn't cut long enough and wasn't testing for extended edge retention. ;)

Maybe -- I'm guessing -- that at 400 grit you're tearing out the carbides in the S110V, leaving only a jagged edge of the steel matrix. Or maybe those jagged edges left by the coarse stone don't hold up very well to abrasive cardboard, regardless of the carbides.
Click to expand...

Not in this test, not what I was testing for, was only testing for extreme sharpness level.

I'm still left with the impression that the BESS score is not ready for prime time. We've seen a lot of quite different scores for edges of equal sharpness.
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No...

On your test of S125V with an edge shoulder width of 0.006 inches, the edge was still cutting rope at less than 20 pounds up to a BESS score of 621. With Niolox steel, at the same edge-shoulder width, the edge was cutting rope at less than 20 pounds up to 344.5 BESS.
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Yeah and the same blades.... Niolox was done at 420 cuts at 20 LBS...... The S125V was still at 12 LBS at 420 cuts. ;)

The short answer is the Niolox edge smoothed out and stopped biting because it didn't have the carbide content while the S125V blade kept cutting due to the high carbide content (Stayed aggressive).

So it took more force for the Niolox blade to cut through the rope than it did for the S125V blade.

BESS measures the actual apex width.

You are thinking about two different measurements here and thinking they are the same, they aren't at all.


I don't see anything wrong with your testing procedure -- isolating key variables to test for extreme sharpness on a coarse edge -- but it would be an amazing finding if high-wear, high-alloy powder steels don't offer a huge advantage in wear resistance.
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That is what happened and what I got at the very narrow scope that I was measuring... Again a very narrow scope.

Expand that narrow scope and things change quickly.
 
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Were you slicing with the whole edge or just using a limited section?
 
I like this device. Would be curious to see what would happen to the initial sharpness if one would drop the edge angle lower and lower until you end up with a zero blended edge.
 
Double post for some reason....
 
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What kind of stones did you use? Since vanadium carbides are harder than alumina oxide, I wonder if that plays any role when going for a polished edge.
 
Very good thread Jim. Another surprise. It seems like you could write a few articles putting together some of the things you have done the last few years. Heck, a book.People publish books with less raw data than you have accumulated over the last few years.

Posting those results here will have people asking for more testing from you. :) I can donate some money for supplies if needed. Just let me know.

Joe
 
The Mastiff said:
Very good thread Jim. Another surprise. It seems like you could write a few articles putting together some of the things you have done the last few years. Heck, a book.People publish books with less raw data than you have accumulated over the last few years.

Posting those results here will have people asking for more testing from you. :) I can donate some money for supplies if needed. Just let me know.

Joe
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Hi Joe,

I have some experiments planned for the future, just have to get things worked out before I can proceed.

Jim
 
Let me get this straight: 15° per side, that is an aggregate of 30° inclusive, that's extreme sharpness?!

I'm not even sure that this kind of way open edge is anywhere near optimal for chopping wood all that well (I think 10° per side will do noticeably better)... I've put edges smaller than 15° on a low-sabre grind TOPS... And I've pried 2" thick planking with a 10° per side 0.020" thick edge bevel in an emergency... A bit of bending but not bad, with huge lateral effort on it... Is that standard of sharpness due to the Manilla rope test? Then you need another medium, because it is completely skewing real life use... I've seen that Manilla rope actually heats up the edge after prolonged cutting: That is not a good sign for its validity as a reference...

Gaston
 
Manila rope heating up the edge during cutting? Give me a break. You would have to get the steel above its tempering temp. (300 F min.) in order to have any negative effect.

Maybe you should repeat all of Jim's testing at 10 degrees per side and post the results.
 
Have you examined the edge after more cutting with these two steels? How does the edge tester work: is it optical or mechanical? Just curious and wonder what the numbers translate to.
 
I'm not even sure I understood all of what was in the original post but it sounds good Jim. :thumbup:;):D

Keep on keepin' on... :D:cool:
 
Czechmate said:
I'm not even sure I understood all of what was in the original post but it sounds good Jim. :thumbup:;):D

Keep on keepin' on... :D:cool:
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Basically it was just testing the very 1st part of the dullness curve to focus on extreme sharpness level to see if there was any real measurable difference between the 2 extremes steel wise (S110V and Super Blue).

Focusing on extreme sharpness as people seem to believe that one extreme is better than the other at holding that level of sharpness.

Based on my testing there isn't any difference, that's actual measurable difference at this level of sharpness in the narrow scope that was measured.

That's sharpened the same way, at the same level of sharpness, again measured sharpness level then tested every 10 ft of cardboard for sharpness for a total of 50 ft of cardboard.

This is something that I have actually noticed over the years in my rope cutting, but that's looking for large differences and I didn't have a device to actually measure sharpness levels accurate enough to put any real numbers to it before now.
 
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