What do you guys think about this sharpness tester.

I own one. I also wrote briefly about it in my sharpness vs cutting ability article. I bought one for testing for my site. I don’t think I would buy one just for selling knives to customers. I’m feeling too lazy to write a full review. I know there is a YouTube video out there where a guy criticizes it for having too much potential human intervention. I don’t necessarily agree with his conclusion that it isn’t a good test just because it can be rigged. Mine did have a couple small issues like with screws not being flush (in the area that the test block sits on). But I like that it is increasing in popularity so that you can compare values with others and that there is a consistent test media. It is a simple device but I don’t know where to buy small scales that keep the highest recorded value on screen so that means I didn’t have to find one myself.
 
I like the idea, but I'm not sure it means much to anybody but the guy sharpening knives. I also wonder how consistent it really is?

Personally, I'm worried more about edge retention than being able to push cut through a piece of fishing line. I can polish up a piece of A36 that's sharp enough to shave with, but it's not going to hold an edge for more than 4 seconds. If you haven't already, check out Cedric and Ada Gear and Outdoors' YouTube channel, and the edge retention tests that he performs. I think these are much more practical for real world applications.
 
BS ! If I ever buy this thing it will proof that I learn nothing after four years on bladeforum !
 
john april said:
i think you could make your own with a digital scale that has the "hold" feature. just measure how many grams it takes to cut string across a fixture.
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Yes you can buy the test block and test media separately so you can even get the same values as other people but provide your own scale.
 
Is there a way that this idea could be used to also include how edge geometry affects cutting performance? You could use them both to calibrate blades for something like CARTA? testing.
If you read Ankersons testing you can see trends but what really sticks out is that edge geometry has a massive affect on edge retention.
 
skillgannon said:
Is there a way that this idea could be used to also include how edge geometry affects cutting performance? You could use them both to calibrate blades for something like CARTA? testing.
If you read Ankersons testing you can see trends but what really sticks out is that edge geometry has a massive affect on edge retention.
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It's hard to tell if the tester is affected at all by edge geometry or just sharpness (edge tip radius). Ideally the sharpness tester only measures sharpness. I know that Jason Stone reported cutting ability tests with rubber on a scale: http://www.cliffstamp.com/knives/forum/read.php?5,72328,72937#msg-72937
 
skillgannon said:
Is there a way that this idea could be used to also include how edge geometry affects cutting performance? You could use them both to calibrate blades for something like CARTA? testing.
If you read Ankersons testing you can see trends but what really sticks out is that edge geometry has a massive affect on edge retention.
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What if you take edge to atom thickness edge tip radius ? What will proof that on this fancy scale ?? That edge will last how long , till you cut twice air ??
 
From watching the video above it does seem like it would be fairly easy to build your own. OR - even easier purchase the $35 thread holder and use your own scale.
 
Ken H> said:
From watching the video above it does seem like it would be fairly easy to build your own. OR - even easier purchase the $35 thread holder and use your own scale.
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@ Ken my friend , let see this situation when someone make test on this scale .One kinfe is 1mm behind edge and have say 5um/whatever that mean/ edge tip radius ....other knife is 0.10 mm behind edge and have 10um edge tip radius .....which knife will cut better in real world and which one will win on this test ?
 
Just because the test is for one specific thing doesn't mean it is useless. If your goal is to measure edge retention the tester could be used to measure sharpness loss during cutting. If your goal is to measure cutting ability you can use the sharpness tester to ensure that the sharpness is the same between different edge geometries. Use a little imagination.
 
My thought was that you measure the sharpness then overall cutting ability with a test that takes into account blade geometry. Once you have a score on those you can do a edge retention test that is hopefully the same or perhaps over time could be weighted for different blade geometry. I'm a bit of a nerd for this sort of thing. I have a feeling that there are a couple of things left to be discovered about cutting and sharpness and sharpening.
 
I own one, and I'm happy with it. I got it because I like things to be measurable. When I send out a knife I want it to have a sharpness of about 150 BESS, just like I measure hardness. That makes for good consistency.
 
Larrin said:
Just because the test is for one specific thing doesn't mean it is useless. If your goal is to measure edge retention the tester could be used to measure sharpness loss during cutting. If your goal is to measure cutting ability you can use the sharpness tester to ensure that the sharpness is the same between different edge geometries. Use a little imagination.
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I can bet that you can 100% predict what given steel can do on base on composition on that steel.....

Edge retention , toughness , rust resistance ...etc ........................ of any steel is given in the moment when someone like You define composition of that steel . You can not expect from AEB-L to have edge retention of 10V or S125V and vice versa , you can not expect from 125V to be tough as AEB-L . About my imagination ...I will keep dreaming that some day you will succeed to design new steel with combined properties of both mentioned above ....... ABL with edge retention of 10V :thumbsup:
 
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skillgannon said:
My thought was that you measure the sharpness then overall cutting ability with a test that takes into account blade geometry. Once you have a score on those you can do a edge retention test that is hopefully the same or perhaps over time could be weighted for different blade geometry. I'm a bit of a nerd for this sort of thing. I have a feeling that there are a couple of things left to be discovered about cutting and sharpness and sharpening.
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I know I mentioned preferring Cedric and Ada's retention test, but now that you mention it, this tool could certainly be used for edge retention tests. The guy on the Cedric and Ada channel uses push cuts in paper as his test for when then knife has lost its edge, but something like this would be potentially much more informative, IF the repeat-ability is there within a reasonable range (whatever that may be, I suppose). You'd have to set some standards of measurement, such as measure cut #1, cut X pieces of 1/2 sisal rope, then measure cut #2, cut X more pieces, measure cut 3, etc...
 
Stromberg Knives said:
I own one, and I'm happy with it. I got it because I like things to be measurable. When I send out a knife I want it to have a sharpness of about 150 BESS, just like I measure hardness. That makes for good consistency.
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Since you own one and have used it a good bit, perhaps you can tell us if there is any difference in edge geometry. Using the same style of blade, one with a 10⁰ per side bevel, other with perhaps 20⁰ (or 30?) per side bevel, is there any difference is the sharpness reading? This would be assuming both blades were sharpened to the very sharpest edge possible.
 
Stromberg Knives said:
I own one, and I'm happy with it. I got it because I like things to be measurable. When I send out a knife I want it to have a sharpness of about 150 BESS, just like I measure hardness. That makes for good consistency.
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Somewhere on this forum exist topic about that BESS numbers and machine for measurement , opened from one guy from Australia , I think . He managed to sharpen knife to be able to push cut cigarette papir in some distance from holding point... Seeing that, I take it as a challenge to do same .It was not easy task at all , but in the end I succeed ...I did not have exactly the same paper so I use what I found here but that don t matter .Do you know how long last that kind of sharpness on edge on my knife ? Zero time ! Than my light go on and I take new Gillette and make several short cut in cardboard .................and I check sharpness .... and that was eye opener not to lose more my time with zillion BSSS numbers of sharpness. My point is / I have no idea how sharp is 150BSSS edge/ that can be maybe disadvantage to you .Customer will be very happy how sharp is his new knife after first try .. . . and very soon will be disappointed , why my new knife don t cut like yesterday ?? But that knife is still very sharp /I call it working sharpness/which edge will hold for long time , depend on steel how long of course . . .
I found that topic . . .. . https://www.bladeforums.com/threads/sharpness-chart.1535016/
 
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Larrin said:
Just because the test is for one specific thing doesn't mean it is useless. If your goal is to measure edge retention the tester could be used to measure sharpness loss during cutting. If your goal is to measure cutting ability you can use the sharpness tester to ensure that the sharpness is the same between different edge geometries. Use a little imagination.
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Larrin Larrin , carbides are a factor for edge holding and they are very hard ...that know even I . Now , carbide have size and volume , right ? They take space in steel ...let say we have 10 carbide in 1 square or 1 cubic mm. Now , if one side of edge /edge is triangle shape just to complicated to me things to explain :D / is 1mm wide we have let say in total 20 carbides on edge .Another knife have half mm. wide edge side and have total 10 carbides ? Theoretically first edge should last longer because have more carbide , even it is thicker.......?
What I really want to know is this .......... whether the carbides wear with use of knife or they simply fall out when matrix that holds them wear around them ?
 
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