Testing cutting capabilities of different bevel grinds

[Natlek]

The BESS value is the maximum weight you need to push your knife through a certified test medium. BESS test give sharpness of edge , and says nothing how the knife would cut different materials ?
Why in same manner we don t test different bevels , like hollow grind , full flat grind , convex , chisel flat grind , chisel hollow grind , scandi grind ......?
I can make small blades for that test in same steel , same dimension , same hardness ,same sharpening angle .......
What I am not sure is what to use to cut on that test ? Cardboard, placed vertically, yellow hard cheese / I don t know name for it on English / , potatoes ........ what to cut for test like this one ? Of course, what we are cutting should be larger than the width of the knife blade .
I'm not sure which grind would be the winner , individual or on total average result ?
Is this done so far ?

 

[AriesTheCam]

I would imagine a thin stock of like .018 or thinner hollow would probably be the sliciest grind.. maybe full flat, scandi, or chisel would compete with thin stock as well. On the cutting medium your guess is as good as mine. I wonder if there is an established thing out there people use other than hair and cardboard (the cardboard would be my guess honestly).

 

[3fifty7]

For a cutting medium something manufactured like non reinforced clear pvc hose in 1” diameter cut into 1.5” lengths. Then split on edge 1” into the 1.5” piece for the test.
If they are all sharpened to the same sharpness say within 25 points of each other on a BESS tester. I’d have to place my bet on a hallow grind.

 

[Natlek]

For a cutting medium something manufactured like non reinforced clear pvc hose in 1” diameter cut into 1.5” lengths. Then split on edge 1” into the 1.5” piece for the test.
If they are all sharpened to the same sharpness say within 25 points of each other on a BESS tester. I’d have to place my bet on a hallow grind.

All same BTE thickness , all same sharpening angle and all same sharpness .
That is good idea with pvc hose , I think on more and different cutting medium for test .Medium should be twice as wide as the width of the blade .
Hollow blade would have more contact surface , I am not sure how it would perform on sticky cheese for example ? More cutting medium more surprises would be , I think ? Say cutting medium is cardboard . I am not sure that full flat will outperform scandi grind .....

 

[Blade Lab]

I've been tinkering around with a setup to test blade geometry. The current design uses cardboard suspended from a strain gauge set to maximum force. I've been using some cardboard inserts I bought on Amazon, thinking that it would be a good way to get consistent results. The idea is to push the blade through the cardboard and determine how much force is required.

It's not working predictably at the moment because it's hard to keep the cardboard from tilting/twisting. I tried inserting the cardboard loosely between two sets of dowels to add stability, but it's not good enough. Ultimately I think I'm going to have to rig something where the strain gauge is underneath the cardboard instead of having the cardboard suspended from the gauge.

 

[old4570]

Hmmm , Im using 10mm twisted sisal rope .. ( 50 meter lengths )
You can Go Bigger DIA , but at an exponential cost increase .
Cardboard might vary , depending on size / source / manufacturer ..
You want something that will offer :
A) repeatable results
B) Comparable results

You want to minimize the variables as much as possible :
So a test that causes a knife to fail after one or two slices would be ????????????????
And a test that causes a knife to fail after 1000 slices might be ?
The twisted sisal returns anything from 50 ( Poor something ) to maybe 500 ( good something )
And exceptional might go high , like my SPY27 Spyderco hit 1150 on a ground edge ( kind of outstanding ) .
So ?

 

[Stacy E. Apelt - Bladesmith]

In use the PT-50B Edge-On-Up system from Sharpening Supplies. It gives a good test to show if the edge is truly sharp yet. It gives a BESS rating.
It is especially good for checking edges on culinary blades. Every test is repeatable and the consumable test media is accurate. I find it a very good test for those who need extremely sharp edges.

It does not rate edge life or hardness but lets me know that the knife is as sharp as it should be. I already know that the blade is properly hardened from hardness tests and I know what the edge life should be by the steel I picked and the HT regimen.

I still slice up a 6X4" piece of cardstock to check the entire edge for even sharpness. You can feel any spot that is not as sharp as the rest.

 

[Another Shepherd]

"The CATRA Automatic Edge Tester can…
… objectively compare various knife blades and determine which one is superior to another.
… monitor the consistency of quality of cutting performance against the norm of manufacturing, to be sure that the knives are within the standard values agreed upon.
… be used as a development tool to enable research into the optimum steel, heat treatment, surface coating, edge geometry and finishing operations to suit the application."

https://www.catra.org/wp-content/uploads/2022/08/AET_Brochure_Aug22.pdf

 

[old4570]

Semi Auto edge tester :

The test media is 366 Pounds + VAT ( British Stirling ) How much the machines are ?

 

[Natlek]

Hmmm , Im using 10mm twisted sisal rope .. ( 50 meter lengths )
You can Go Bigger DIA , but at an exponential cost increase .
Cardboard might vary , depending on size / source / manufacturer ..
You want something that will offer :
A) repeatable results
B) Comparable results

You want to minimize the variables as much as possible :
So a test that causes a knife to fail after one or two slices would be ????????????????
And a test that causes a knife to fail after 1000 slices might be ?
The twisted sisal returns anything from 50 ( Poor something ) to maybe 500 ( good something )
And exceptional might go high , like my SPY27 Spyderco hit 1150 on a ground edge ( kind of outstanding ) .
So ?

English is not my mother tongue, so maybe that's why you didn't understand me .I don t want to test edge retention .I want to test how different main bevels like full flat , convex , hollow grind , scandi grind ....how much force is necessary to cut same medium . In fact, I want to test the friction of the entire blade as it passes through the different medium we are cutting .Plan is to make 3 inch long , one inch wide blade in same thickness , all cut from one piece of already hardened steel .All bevels should have same TBE and same sharpening angle and all sharpened on 800 grit DMT diamond plate . Cutting medium should be 2 inch height in order for the entire blade to pass through the medium. I don't know about the thickness, maybe an inch or half an inch, it depends on which medium I cut .
I will use digital kitchen scale for this test .I have pretty good idea how to set up everything for test .I'm not sure what to try as a cutting medium , more medium more surprises. What I want to test is which
which shape of the blade will go through the cardboard with less force ........

 

[old4570]

Ok . your after slicy !
Thin blades , with tight bevels will slice the best ..

Cardboard is ?
you want a tough medium to cut ..
Check out "home slice" on youtube ..

 

[Natlek]

Ok . your after slicy !
Thin blades , with tight bevels will slice the best ..

Cardboard is ?
you want a tough medium to cut ..
Check out "home slice" on youtube ..

I know that thin blade will cut best . All blade same thickness but different bevels and same thickness behind edge and same sharpening angle ..............I am not sure which one will win
One blade is hollow /2.5mm on spine / other one is /san mai / full flat grind and 3mm on spine .Not same but ....hmmmmmmmmmmmmmmmmm
Ok , I will make them this spring , except convex blade .I am not sure that I can grind * perfect* convex ..