Sharpeness tests

[aguijonmagico]

Hi.
I was wandering about this.
There are fairly known quick and easy tests for testing the sharpeness of a knife.

-Shaving hair from arms, legs, etc
-push cutting paper.

Those two are the ones I regard as "basic". Any knife of mine should shave hair and push cut paper.

Ok.

Also, using your thumb to feel the edga, and seeing if the edge would bite a finger nail upon only putting the knife edge on the nail.
But those test don't tell you "how" sharp the knife is. you now there is a edge, but not how keen.

Then, there is push cutting "thinner than average" paper, like phone book paper or catalog paper.

Recently, I learned about "paper towel cutting", cutting a paper towel without ripping it.

Those two test would tell me that the knife is sharper than shaving hair.

Finally, Soleiman the Muslim Sultan used to throw a silken hanky to air and let it float down to the edge of his scimitar, and the hanky would split cleanly in two upon touching the edge

What other quick and easy to do test are out there to know how sharp a knife is?

 

[Gunsnknives]

Try tree topping hairs off your arm. If your knife can do that, it's pretty sharp.

 

[aguijonmagico]

ok, subtle one!
because one thing it's to shave, another to "tree topping". Jajaja good. You just made my day.

Thanks!

 

[Jason B.]

It's sharp enough when it makes you smile.

 

[aguijonmagico]

wow, that was like a taoist reply n

 

[Mack]

When I got my knives from Richard J he cut the fingers off of a kevlar glove to ensure it was sharp enough and the edge was tough enough. It still treetopped hair afterward so I was satisfied.

 

[UffDa]

When I got my knives from Richard J he cut the fingers off of a kevlar glove to ensure it was sharp enough and the edge was tough enough. It still treetopped hair afterward so I was satisfied.

You can always believe protourist. He never lies..........never!


IMHO, a knife is sharp enough when it cuts what you want it to cut.

You can also try the rubber band test. Search for it.

 

[jobasha11]

I use the "three finger sticky" test. Carefully run you fingers along the edge and feel how it bites into your skin.

 

[gadgetgeek]

I feel for burrs, and then look fro shiny spots on the apex of the edge, then I gently feel for the grip of the edge. Other than that, it just has to cut.

 

[Amos Iron Wolf]

I do the phone book and catalog paper test to check for tiny burrs and such and a general indication. But, along the lines of what UffDa says, I test on things that represent what I might want to cut and see how it cuts them. Bits of leather, paracord, jute twine, 1/4 in rolls of old jeans material. That sort of presents a cross section of the kinds of cutting an average pocket or field knife might be expected to cut.

So as I cut I take note of not only does the blade cut, but how does it cut them. Do I need much pressure? Does it take much movement or slicing to make a cut? Can I lightly press cut most of my test media and get clean cuts? Things like that.

I've had knives that would shave arm hair yet would pop right through 550 and jute cord and slice neatly through leather. I'll take the later over the former anytime. Both is nice, but if the knife cuts well on the types of materials it will most likely encounter AND not roll over or chip the first time or so out, I can handle that. I still like to go for super sharp, but also recognize that performance to the purpose is the goal.