# What is your sharpness test?



## memorael (Sep 21, 2011)

So what do you do to tell if your edge is ready or not?

I like stropping on a very hard piece of leather and at around a 60 degree angle, when I think it is ready I usually try to do a very small nick on the leather which needless to say is hard as a rock. If it doesn't satisfy my leather cutting I usually go back to the 1k and start over.


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## EdipisReks (Sep 21, 2011)

the bent paper test and hair whittling are usually reliable enough indicators for me, if i'm sharpening for actual use. i have lots of tests if i'm just sharpening to see how sharp i can get a knife.


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## WillC (Sep 21, 2011)

Depends, I used to push cut thin cigarette papers, but a ripe tomato seems a more suitable test for a kitchen knife. I can pretty much feel when an edge is there now as it is sticky to the touch, like a razor blade.


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## chazmtb (Sep 21, 2011)

I run the edge accross my fingers.


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## Andrew H (Sep 21, 2011)

chazmtb said:


> I run the edge accross my fingers.


It sounds crazy but this really works.


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## G-rat (Sep 21, 2011)

I just make sure I have at least some piece of produce I can cut after I'm done sharpening. Usually an onion or tater. That way I'm testing on what I would need the edge for anyway. But I always also basically shave my left arm half bare and giggle the whole time like a mad man. Then I cut paper into shreds and leave it all over the house like a weirdo and as it piles up make my wife angry....She's pretty awesome though and loves a sharp ass knife.


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## Citizen Snips (Sep 21, 2011)

G-rat said:


> I just make sure I have at least some piece of produce I can cut after I'm done sharpening. Usually an onion or tater. That way I'm testing on what I would need the edge for anyway. But I always also basically shave my left arm half bare and giggle the whole time like a mad man. Then I cut paper into shreds and leave it all over the house like a weirdo and as it piles up make my wife angry....She's pretty awesome though and loves a sharp ass knife.


 
you are a madman

first i check with my fingers running along the edge. if i feel scared i move on. i check if the edge catches my thumbnail. if it does i move on. then i check to see if it can shave. if it shaves i move on. 

from there i usually try it out on extra produce. this along with feeling the edge are really the best way to see how good an edge is. just put it to use


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## jason (Sep 21, 2011)

Three finger test, or the new test that will be an industry standard, for sure.


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## Vertigo (Sep 21, 2011)

G-rat said:


> But I always also basically shave my left arm half bare and giggle the whole time like a mad man. Then I cut paper into shreds and leave it all over the house like a weirdo and as it piles up make my wife angry....She's pretty awesome though and loves a sharp ass knife.


 This. I'm pretty happy as long as it cleanly shaves a patch of hair off my left arm, and whips through whatever paper I have nearby. After a few knives, it looks like I had a ticker tape parade celebrating my recent battle with mange, but whatever.


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## stevenStefano (Sep 21, 2011)

I just use paper because I sharpen at home. I know it would be better to actually cut food, but I can usually feel differences in how easily a blade cuts paper so I think it is still fairly useful


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## G-rat (Sep 21, 2011)

jason said:


> Three finger test, or the new test that will be an industry standard, for sure.


 
That looks like the best way to spend your time that other people would think was a waste of time. So fricking awesome!


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## Ichi (Sep 21, 2011)

:aikido:I run my fingers along the edge.
Then I sing... "I am stuck on Band-Aid, 'cause Band-Aid's stuck on me!" :thumbsup2:


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## mr drinky (Sep 21, 2011)

jason said:


> Three finger test, or the new test that will be an industry standard, for sure.



That's funny Jason, I was just going to post that. 

k.


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## jason (Sep 21, 2011)

It's surprisingly fun!
I was just happy to split the plane before Murray!


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## Cadillac J (Sep 21, 2011)

chazmtb said:


> I run the edge accross my fingers.



This is all I do anymore...and I know when my edge is going to be one bad mutha phucker. Knife then gets put away until its next use...I've yet to be disappointed at all.


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## mr drinky (Sep 21, 2011)

Hey Jason, you PM isn't working, but I was going to ask you if one of the paper airplane throwers was you. The description says a 'Jason' was a thrower.

k.


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## HHH Knives (Sep 21, 2011)

I normally check the edge by feel by running my fingers down the blade. And then slice paper and cut whatever little bit of hairs I have left on my left arm.  

Not trying to steal this thread. But can someone direct me to a post or more info on the 3 finger test..


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## Michael Rader (Sep 21, 2011)

That paper airplane test was fun. Going to have to play with that myself, but MY plane will be made out of steel AND it will be on fire... AND thrown by a dragon...

And regarding the three-finger-test, I believe that was also started or popularized by Carter. Basically, you put your thumb on the spine of the blade, lightly press down with three fingers and slide - very carefully - up the edge feeling for that light "bite" of the edge into your fingerprints. This is not a drag across the edge, but a very controlled and careful slice up the edge. You are feeling the edge this way and not getting fooled by a possible burr the way you can if you drag your fingers across. Anyway, try it and with your seven remaining fingers, give us a report on how you like to test sharpness.

-M


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## Lefty (Sep 21, 2011)

I do the three finger test, the Morimoto thumb nail test, and slice red peppers with the skin up. It seems to be the best way.
Oh, Michael, sorry but my paper airplane throwing dragon said he'll only do it for you (like he does for my fiery steel airplanes) if you send me the knife you are testing immediately afterwards. Do you still want to test it that way? I'm cool if you do


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## Dave Martell (Sep 21, 2011)

The 3-finger test is one good test to use but is not a way to test sharpness all on it's own as it's flawed because a wire edge or extremely coarse straightened out/aligned burr passes this test with flying colors while a convex edge fails this test everytime. I do use the 3 finger test myself all of the time but only as one piece of the puzzle. What's the rest of the pieces? Well, one is my trusty leather belt test to ensure a wire free edge and then copy paper cutting both slice and push cutting but most importantly is knowing that I've followed my time tested procedures to ensure that my edge is indeed sharp before I ever get to the point of testing. This last part is the most important because it allows me to reasonably assume that I'm passing along a good to go kitchen knife edge without having to test each and every edge on food products. As a pro sharpener you can see why that's important for me.


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## Dave Martell (Sep 21, 2011)

Michael Rader said:


> That paper airplane test was fun. Going to have to play with that myself, but MY plane will be made out of steel AND it will be on fire... AND thrown by a dragon...




LOL


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## Eamon Burke (Sep 21, 2011)

G-rat said:


> I just make sure I have at least some piece of produce I can cut after I'm done sharpening. Usually an onion or tater. That way I'm testing on what I would need the edge for anyway. But I always also basically shave my left arm half bare and giggle the whole time like a mad man. Then I cut paper into shreds and leave it all over the house like a weirdo and as it piles up make my wife angry....She's pretty awesome though and loves a sharp ass knife.


 
Story of my life.


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## JMJones (Sep 21, 2011)

I like to push and slice cut phone book paper. Since the internet, that is the only thing that book is good for anyway.


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## Lefty (Sep 21, 2011)

Hey, that's not entirely true. You can strop on phonebook paper too. Other than that, though....


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## tk59 (Sep 21, 2011)

Lefty said:


> Hey, that's not entirely true. You can strop on phonebook paper too. Other than that, though....


 haha. +1. I used to do a lot of sharpness tests. Sometimes I still do but at this point, I touch the edge for stickiness and make sure it shaves the same way in both directions as I'm working through my progression. When I'm done, I use a tomato to make sure I have the desired effect, whatever that may be.


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## JohnnyChance (Sep 21, 2011)

scrap paper and 3 finger for me.


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## memorael (Sep 22, 2011)

chazmtb said:


> I run the edge accross my fingers.


 
Krikey...

The flying dart thing is ultra cool. Anyone ever tried doing the whole silk thing? I tried searching youtube for it and it didn't appear anywhere that I could find, now THAT would be really cool. I once tried the dropping a paper over a blade test and managed to get about halfway through, scared the crap out of me since about 100 tries in you develop a kinda rhythm and sooner or later you start doing stuff you shouldn't... like coming extremely close to the edge of a very sharp knife with your face.


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## Justin0505 (Sep 22, 2011)

Vertigo said:


> This. I'm pretty happy as long as it cleanly shaves a patch of hair off my left arm, and whips through whatever paper I have nearby. After a few knives, it looks like I had a ticker tape parade celebrating my recent battle with mange, but whatever.


 
HAHA! I laughed out loud on this one... often had a similar thought, but never put it all together like that. 

I also do a few different test: thumb nail, thumb pad, 3 finger, hanging paper push and slice, arm shave.

If I'm really going for a stupid sharp edge, I'll pass the edge though my arm hair, but above the skin. If I can feel hairs catch and drag, its very sharp, if hairs start popping off the edge / fleeing from my arm, then it's stupid sharp. 

I've done the Niloc "free standing folded receipt paper push cut" test a few times, and it's really difficult to get and edge to that level (I think that not all are capable) but I don't have access to fresh, crisp receipts all that often.


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## JohnnyChance (Sep 22, 2011)

I shave my forearm sometimes as well, but I don't really use it as a judge of my edge's quality. It doesn't really tell me anything I don't already know. More so to show off at work.


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## DrNaka (Sep 25, 2011)

Does nobody use the sun (or reflection of sunlight) to see if you have burr or not?


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## SpikeC (Sep 25, 2011)

I always use a strong light source to monitor my progress as well as the ongoing condition of the edge.


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## tk59 (Sep 25, 2011)

DrNaka said:


> Does nobody use the sun (or reflection of sunlight) to see if you have burr or not?


 Of course. I don't know that I'd really call it a "sharpness test."


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## unkajonet (Sep 25, 2011)

C'mon tk, you know that one of your tests is to cut photons in half...then it's almost sharp enough for you...


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## mr drinky (Sep 25, 2011)

I cut photos of my ex-wife.

k.


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## Eamon Burke (Sep 25, 2011)

mr drinky said:


> I cut photos of my ex-wife.
> 
> k.


 
:rofl:



To Dr. Naka:
Yes I do, but only at the 1k level to make sure the burr is built up evenly and any chipping or uneven grinding is worked out. If I still see light reflecting off the edge after deburring off a 1k, I am not done on the 1k. After that, I don't see any reflected light at all...If I do, I built up too big a burr or hit it against the granite counter when reaching for a beer.


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