Checking the sharpness
- This topic has 23 replies, 11 voices, and was last updated 09/26/2019 at 8:18 pm by
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Truth be told, my wife has really inexpensive test equipment she uses to check my work and it seems to work really well. 🙂
The advantage of the BESS test is that it provides some level of quantification rather than just a qualitative measure of sharpness. Quantifying the sharpness is useful for meaningfully comparing sharpening results obtained from differing grit progressions, differing edge angles, convex vs hollow grind vs V-grind, comparing strop progressions, and so forth. Trying to compare the results of these kinds of changes in a qualitative sense can be difficult and even subjective.
At the end of the day, the only test medium that actually matters is the actual intended cutting application. If your kitchen knife does a great job on a ripe tomato then it will probably be sharp enough for all of your other kitchen tasks. Anything beyond that is for enthusiasts and nerds like myself.
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I was just havin fun.. being a nerd of many things, I have been sucked into the perfection hole with more than a few hobbies 😉 Video calibration was a real deep one!..
How much does one spend on consumables with these sharpness meters?
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The $23 spool of testing media is supposed to be good for 325 tests. That’s about 7 cents per each test! I test a kitchen knife, at least, at the tip, the middle and the heel, before sharpening and again after sharpened so with 6 tests per each knife, that’s around 54 knives tested per spool. The cost is less then $0.50 per knife. 54 knives is a lot of sharpening. I guess it’s pretty economical in the consumables. The disposable one-use clips would be considerably more costly at around $1 per knife for the 6 tests.
Marc
(MarcH's Rack-Its)4 users thanked author for this post.
Oh please . . . That is “the” dumbest way to show people how to test for sharpness YIKES. And why is he wearing his bathrobe for the video hahaha. Spend a few bucks and buy the basic “Edge on Up” edge sharpness testing device.
He is Samurai. Maybe his next blade is a sword.
This is my “paper” test for sharp edges. I would ask that others with the BESS tester replicate the test to see if your numbers match mine.
So, just got home from work and pulled out my PM2 to do the paper slice. I don’t start the slice at the edge, I create bump by folding it over my finger and then slicing.
I’ve been using the knife for more than a week or two since the last touch up.
It failed the test. So, I went out to the garage and tested the edge – it was 155gf. Then I used a leather strop from an old belt for about 20 passes per side. The next test was as close to the previous spot as possible and it was 131gf.
Now both the 20lb printer paper and news print page sliced cleanly.
Just FYI, almost every time I use the knife outside the garage I strop it on my pants before I put it back in my pocket. Working in the garage, I strop it on the belt almost every time I use it.
Ed K.
The basic Bess unit comes with these little square disposable cardboard looking testing media. I preferred the testing medium that is a thin thread like material which comes in a spool which resides inside the upgraded aluminum testing fixture. This fixture is better than the plastic one that comes on the $129 model. It also comes with a fulcrum that you hold the tip in the fulcrum with your left hand and then press the blade down like a guillotine like motion light pressing it down until the thread breaks.
Since their testing medium is expensive my choice of the middle $179 model ($50 more or .96 cents more a week for year one) . . . was based on the longer term cost savings.
Due to the cost of each test I only run one test at the start of a reprofile and take a pic of which knife I’m sharpening and its reading on the screen. I only test the part of the knife that is just ahead of the handle which is the section that gets the most cutting use. Also, my reasoning for this is I use the WE system for its abillity to lock in the blade and give me the same results across the entire length of the blade. I’m not looking for perfection. I take another pic after I’ve sharpened it testing in the same spot.
Since I’ve purchased the tester I’ve been amazed on how many times I’ve gone through my complete progression routine 100 up through DLF’s and stropping and thought now I have a smok’in sharp folding knife only to test it and find its testing at upwards of 250 on their readout scale. I then drop back to the 800’s and progress again from that point. Then it test at 120-135 which is close to single edge razor blade sharp as viewed by scale card they include with it. There is something to be said about raising a burr with each stone set. I just don’t do that because its too time consuming for me and a waste of expensive premium steel with my collection.
One note of caution for current owners of this tester . . . I’ve fallen away from using the fulcrum too much as one can to easily fudge their results. The fulcrum method one can easily impart an ever so slight slicing into the testing thread motion. I see users on other forum sites show these incredibly low pics of numbers like 80 and I know they are slicing instead of using a pushing down motion. Using a guillotine motion as I mentioned above where I hold the tip and near the handle freehand with my hands on the outside edge of the tester (not touching any of the sensitive scale section) without using the fulcrum I can closer replicate within a few reading numbers if I choose to do a 2nd test because I’m not “slicing” into the thread at all.
Expedia,
One note of caution for current owners of this tester . . . I’ve fallen away from using the fulcrum too much as one can to easily fudge their results. The fulcrum method one can easily impart an ever so slight slicing into the testing thread motion. I see users on other forum sites show these incredibly low pics of numbers like 80 and I know they are slicing instead of using a pushing down motion. Using a guillotine motion as I mentioned above where I hold the tip and near the handle freehand with my hands on the outside edge of the tester (not touching any of the sensitive scale section) without using the fulcrum I can closer replicate within a few reading numbers if I choose to do a 2nd test because I’m not “slicing” into the thread at all.
I also generally do not use the fulcrum for the reason you cite. But, I predominantly sharpen short blade folding knives. When you want to test the tip area or a Tanto blade, there isn’t enough blade to rest on the fulcrum. Or, like you point out, the blade edge is at an angle to the test media and slicing occurs.
For those who sharpen mostly kitchen knives / longer blades, the fulcrum can be useful and accurate.
Ed K.
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