Differentiation between keenness and sharpness has been best done by Todd Simpson:
Keenness is measured at the very apex of the edge, while Sharpness is determined by thinness of the edge behind the apex, and depends on the edge angle.
https://scienceofsharp.wordpress.com/201...-and-keen/
https://scienceofsharp.wordpress.com/201...en-part-2/

The BESS test line is severed in the test by combination of a cut and tear.
The test line is about 200 micron in diameter; to cut it the edge has to go through at least a quarter of that, i.e. at least 50 micron, where the tear starts developing, and the test line eventually gets severed.
Owing to this, the BESS score that we see on the instrument reflects both the keenness and sharpness of the edge.

We know by experience that a higher angle edge, e.g. 40 degrees included, scores worse on the BESS Edge Sharpness Tester than a lower edge angle, e.g. 20 degrees included, even when the edge apex in both splits hair, i.e. the keenness is the same. This difference in the BESS score is due to the "sharpness" component of the testing.

There are 3 testers in the world that quantify sharpness: the US BESS Edge Sharpness Tester for $179-259, the New Zealand Anago for approx. $20,000, and the UK CATRA for approx. $50,000 - 80,000. For a small-scale sharpener the BESS Edge Sharpness Tester is the only feasible. Only a few of the larger knife making factories use the CATRA testing, while the Anago is used by some makers of the industrial knife sharpening equipment.

Of all 3, only the BESS Edge Sharpness Tester tests both the keenness and sharpness, and can tell about sharpness in the razor range.

CATRA can not be used to evaluate the edge sharpness, because the edge is abraded beyond shaving sharp in its 1st cycle, the edge gets practically dull by the 4th cycle (can't cut print paper), and the full test includes 60 cycles. CATRA best evaluates role of the blade geometry and the steel wear resistance in the cutting ability.
The NZ Anago evaluates the edge sharpness, but not the keenness.

Please forgive me, but when I saw this rare nugget of knife sharpening wisdom I couldn't help but share.

https:/ /www.youtube.com/watch?v=SJMphMQ3pYc

Now, I applaud the following dude for his skepticism and willingness to perform testing to verify Internet wisdom.  If he had only been an Exchange member we could have saved him from wasting his precious life minutes in the testing.

https://www.youtube.com/watch?v=2vvMFOUkwC0

Life lesson:

Always believe everything you read from knife sharpening gurus on the 'Net.  And... join the Exchange.

I used worn Blaze 120 grit(about 15 degree), and Super fine scotch brite belt.(higher degree) 

   

   

Center sharpness: 197, 301, 209 BESS.(Average is 236 BESS)

Fail

Ok, this is probably a dumb question. I have an extra WS3000 unit laying around, but am on vacation and don’t have access is to it. Thinking of buying a Viel and using the WS3000 motor to power it to sharpen knives. 

The Work Sharp 3000 runs at 580rpm, so if one uses the 3” Viel drive wheel with it, the belt speed should be 455.5 ft/min (used this calc: https://www.blocklayer.com/pulley-belteng.aspx, I’m no engineer, so maybe that’s wrong). That seems plenty slow (good). 

Even with the stock 6” drive wheel, the sfpm is 911. Still good. 

But I think the WS motor is only 1/5 hp, but higher torque. I don’t slow it down sharpening chisels. 

I’ve never taken apart the WS3000, so I’m not sure what’s in there. 

What say you?

Many people said finishing 1000 ~ 2000 grit(whetstone) is the best for use. I think it's good balance of sharpness and micro serration. 

But sharpness testing with Edge Tester is done by push cutting action. So, is it impossible to measure the merits(edge retention, better at slicing) of a toothy edge with an Edge Tester?

This forum seems to be primarily the province of subwoofer so we thought that it would be a good place to display one of the fruits of his ideas. The picture shows an assemblage of the various test fixtures used by subwoofer at the recent Sharpest Knife UK competition. Please take note of the new cut-away fixtures sitting on the table.  These fixtures are designed to allow closer measurement access to the heel of the knife. It also makes measurement  of shorter blades easier as well as oddly shaped blades. Thank you to subwoofer for his contributions here! These new fixtures will be introduced for sale this fall and will be priced at $49.00.

Thanks once again to subwoofer for organizing and managing another very successful sharpest knife competition in Europe! Here are the results and a few pictures:






The Competition Table:

In case you were not able to come along, the competition table was setup in the ‘social/display’ area of the show.



The Competition In Progress:

A few photos of the competition measuring in progress.

ng the heel of the blade.


Reloading the test media (I did this a LOT).

The Results:

And the Results – an impressive quality to the entries with the overall second place score thanks to a superb BESS score of 51!! A typical double-edged razor blade fresh out of the packet scores 60, so this is very impressive.
Testing the tip of this blade.


Logging all results.


Time was flying.

Do any of you Viel owners sharpen scissors with it's new scissors sharpening arm/clamp or the Twice as Sharp arm/clamp?

Is there some sort of adapter allowing use of the Twice as Sharp arm/clamp tool?

With either the Viel or TaS scissors clamp, how well does it work? 

With it, do you do scissors on or off platen?  

Thanks.

https://www.youtube.com/watch?v=0CL4okt-QxA