Best way to test sharpness

I just use my arm . But after a good sharpening session I'm as bald as a fresh shorn lamb.:banghead:

I've collected knives for years - hso is exactly right.

+1 nail

in sunlight you can see a little bright spot on burs or missed areas on sharpened blade, but a light drag over fingernail is far more precise for feeling little burs and bumps WTG. . . one guy I know shaves words off a page of paper without cutting through paper
ST

hso,
Is correct !

Collector grade knives don't need to be sharp. Knives used as tools do, but a collection of knives don't need to be sharp.

Collector grade knives don't need to be sharp. Knives used as tools do, but a collection of knives don't need to be sharp.

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Now don't string me up here, but I've heard knives are worth more unsharpened. To collectors anyway.

I just hold a piece of printer paper with one hand, and the knife should cut through it like butter without tearing or ripping the paper on its way through.

If you want a sharp edge from the factory, try a Becker - they're the sharpest retail out-of-the-box that I've seen.

Many years ago, a guy named John Juranitch invented a pencil-like thing to use instead of your thumb-nail. I never tried it myself, but heard reports that it was effective to use.

three ways i test my knife before it goes in my pocket:

1) i gently place my thumb 90 degrees to the edge and lightly drag across. if it catches, it passes.

2) i see if i can shave hair from my arm. it dosn't have to do it really well, just take off a few hairs.

3) i hold a piece of paper in the air, and stick the knife in. then i push the knife foward to cut the paper, wiggling the blade to cut a SQUIGGLY line [not straight - squiggly needs a sharper edge than straight].

if it passes those three, in the pocket it goes.

~tmm

Paper dulls an edge quickly, and leads to a "feather" so I don;t test sharpness that way anymore. I use a leather strap, about 6inches wide, non taned and try to shave a peice off at an angle. This really lets you knw about sharpness, and how consistant the edge is. As for sharpening, I use a crock stick for maintaining an edge, a medium diamond hone for fixing a dull knife.

When you can cleave post-it note in midair, grasshopper, your knife sharp.

Currently only my Paul Chen and my Morpho 32 are capable of this feat (do it carefully, swinging that knife around) but boy does it impress people.

I test my kitchen cutlery with tomatoes. The knife should do all the work when slicing. If you have to "saw" or press hard, it needs honing. I have a boning knife that can slice veggies into paper thin slices. As a side note, you are more apt to injure yourself with a dull knife than a sharp one. If you have to force a dull blade, it will get you!

I recall a fishhook package stating that the thumbnail test is not an accurate means of determining sharpness. Ostensibly, I continue to use that test.

I like to be able to slice a free standing tube of phone book papar cleanly with a easy swipe of the blade. It takes a sharp knife.... and its fun

You should avoid touching any blade with your fingers. Oils, acids, salts on skil can lead to amazing rust formation. I've got a buddy that was in the knife industry and even after washing and drying his hands he would leave fingerprints of rust on "stainless" steel.

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You've got to be kidding. Any knife that precious is practically useless. If a knife can't survive merely being touched by human hands, it'll never survive actual use.

The nail test is generally useful. I sometimes slice newsprint the full length of the edge to find small nicks or dull spots. Push cutting (as opposed to slicing) newsprint can also indicate how sharp a blade is. An interesting thing is that paper often acts as if it has a "grain" in one direction. Cutting with it is easier than cutting against it.

Another test I use on some knives is looking at the edge straight on in direct sunlight. dull spots can often be seen reflecting light. this doesn't necessarily tell you if you have a sharp blade, but it will tell you if you have a dull blade, and where it is dull.

It should be noted that these tests can sometimes be misleading. A wire edge, for example, can be very sharp and perform these tests well, but in more vigorous use will roll or break, the result being dull blade. Perhaps shaving a harder material, such as a birch dowel, or making a "feather stick", might be a better test. However, such tests take more effort.

I like to hang the blade over the edge of a table, sharp side up. I then take a piece of silk and hold it parallel to the ground over the blade and drop it. If the knife can slice the silk in half before it hits the ground, then it is sharp enough for EDC.



Obviously, I don't have any knives sharp enough to EDC.

I actually just try to push cut notebook paper. I used to shave the hair off my arm, but you get funny looks when you only have one or two patches of hair left on your arm. I'm afraid I'd slice my finger off if I tried to test it on my fingernail.

stdlrf11

Well, I sharpened my KABAR TDI today. I started playing around testing the sharpness with a sheet of paper. My wife thought it was cool and took a video.

After I took the video, I fixed the rough spots.

http://s56.photobucket.com/albums/g197/stdlrf11/?action=view&current=knifesharp2.flv

stdlrf11

Tip of the toungue

Loan knife to someone to slice a tomato.

I loaned my Yellow Handled Case Barehead Trapper with CV blade to someone to slice a tomato. I mentioned it was sharp - thrice.

Four Rules always apply:

1. All knives are sharp
2. Always keep a knife pointed in a safe direction.
3. Keep your body away from sharp edges and points.
4. Always be sure of your target and know what is behind it along the blades trajectory.


Basically the knife cut to the bone and person better understands Four Rules and the word "sharp" now.


Use Enough Knife

A lot of the public does not understand how sharp a truly sharp knife is; sm your story reminds me of several of my own stories.

After that happened to me a couple of times I have just decided, If I don't know you, then I don't have a knife you can borrow. I am sorry, but I just don't wan't someone to cut them self on a knife I own.

I had a gentleman ask to look at one of my knives, he decided to see if it really was sharp, (I had told him it was very sharp) he pressed down a little to hard when shaving and took of a layer of skin on his arm. I was impressed that someone would cut a skin graft of without anesthesia. I am sure it hurt a lot after he realized how bad he had cut himself.

Two general rules for me.

I don't loan out my knife.

Off topic.

If I don't know you, you will dry fire my rifle once (get used to a really good trigger) with me watching before I hand you a round to shoot.