How to you know when it is Sharp?

W

wdtorque

Joined
May 29, 2010
Messages
1,441
What is your "proof" that your knife is sharp enough to stop sharpening?
What do you cut to judge it sharp?
I don't have enough hair on my arms and don't get a newspaper.
I have cut up a phone book, but don't know if that proves anything.:rolleyes:
Thanks for your input,
Dozier
 
I like to cut oranges when not using phonebook paper or hair. I also don't use leg or arm hair anymore, I use thigh hairs.
 
I don't know how to explain it but I kinda scrape my finger arcross the edge........and the paper cut dose prove a lot about sharpness in my opinon....
 
Shave some hair or cut some paper, or use ol'trusty, my thumb. If it feels sharp it probably is.
 
I use thin phone book paper, and then lightly drag the knife blade at an angle on the back of my head. If it hangs on the hair all along the blade, It passes the sharpness test. I also just bought a high output Halogen spot light that allows me to see the edge better. (Old eyes ain't what they used to be) It really helps see any missed or flat spots. Can even see dust on the edge if I don't clean it well.

Blessings,

Omar
 
I feel the edge with my finger, cut newspaper or phone book paper and see how easily it shaves hair. I always do all three.
 
Thanks all.
I'll stick with the phone book paper, will try to grap a few more before they are gone.
I've tried using my thumb, fingernail, and finger with no luck. Don't guess I know what I'm looking for or can't tell the difference between sharp and very sharp?

Omar, maybe I will get a light and a maginifier too? My eyes ain't too good.
And I take it you drag the blade across your hand? Not head?
Dozier
 
Jegs or Summit catalog paper, newspaper, -and / or- drag (with only the weight of the blade) across my thumbnail, if it doesnt 'slip' it's good.
 
I've heard the term "sticky sharp" passed around here before; to me, that means you've got an edge that bites into everything very easily whether it's receipt/phone book paper, finger tips/nails or the medium being cut. I'd consider that to be sharp!

Many knives that I have owned, received in trades/purchases etc. off of the exchange that would shave easily are still not quite at this level of sharpness FWIW.

I've upgraded all the bulbs in my knife "bunker" to high brightness, white CFL bulbs and that has definitely helped in terms of seeing what the edges on my blades really look like when I'm working on them.

My sharpening results have been pretty good so far, both knives WERE sticky frightningly sharp when finished but have faded a bit with use of course:

Spydie TUFF (received it sharpened on a WEPS system, I polished in on a slotted paper wheel a few times. :thumbup:)

IMAG0791_zps0d0bc125.jpg



Benchmade 581 Barrage (reprofiled by me on an Edge Pro, polished to 6k)

IMAG0403.jpg

IMAG0385.jpg
 
I do the three finger test , like Murray Carter. Lightly touch three fingers to the edge and begin to add pressure. Your finger will tell you when something is sharp. I get to the point where any more pressure and this will cut me, then I stop. Once you get a feel for sharp, you don't forget it. Also, set the edge on a thumbnail and try to scrape. You can feel it bite into the nail with just the blade weight if it is sharp. I try this all along the edge length. Keep in mind this is what I do for knives. We have tooling at work, paper processing knives from one foot to eight feet in length and when they are sharp just touching the edge cuts you. Good luck.
 
wdtorque said:
Thanks all.
I'll stick with the phone book paper, will try to grap a few more before they are gone.
I've tried using my thumb, fingernail, and finger with no luck. Don't guess I know what I'm looking for or can't tell the difference between sharp and very sharp?

Omar, maybe I will get a light and a maginifier too? My eyes ain't too good.
And I take it you drag the blade across your hand? Not head?
Dozier
Click to expand...

Actually I do mean my head, or more accurately, the hair on the back of my head/neck. Just light enough to feel the light pull of the blade digging into the hair. Similar to what ixer does with his thumb nail. Not hard enough to actually shave/cut the hair. You will feel the slight pulling when done properly. By the way, I wear my hair cut pretty short. (We called it a burr cut when I was a kid :) )

Blessings,

Omar
 
Paper cutting and shaving here, plus the fingernail test to know when an edge is sharp enough on a coarse stone to progress to finer stones.
 
I've got a few different ways to test. Whittling hair is my main way to tell if it's sharp enough. It doesn't necessarily have to whittle it perfectly but if it bites into the hair easily, I'm good. I also test with my finger tips. If it instantly "grabs" or "bites" into my finger (Not to the point where it bleeds, of course) it's good to go. cleanly slicing through phonebook paper is a good test, too.
 
Last edited:
Paper and shaving are fine but when I drag my thumb across the blade and can feel the edge catching or sticking on my fingerprints I'm satisfied.
 
I usually try to shave arm hair, and cut phone book paper. A lot of times my edges won't shave very good at all, but glide through phone book paper. Not sure what that means, but I am satisfied with it.
 
You must log in or register to reply here.
Back
Top