Edge Test

[FaithfulPastor]

One way I test the edge of a blade is to cut a piece of paper.
Nothing new there.
However, I have an old telephone book with really thin, flimsy paper.
Is my assumption correct? I assume that thinner paper is more likely to reveal a bad edge then thicker paper.

My thinking was that if there's a problem with the knife, the thin paper will tear, rather than be cut by a knife.

Am I off track with that line of thinking?

FP

[Wanimator]

Yes. Edge differences are more detectable this way. It's a common, if not standard test.

[FaithfulPastor]

Wanimator, thank you for your reply!

What do you think of me using thin paper as my test?

Thanks!!!
Michael

[Wanimator]

Wanimator, thank you for your reply!

What do you think of me using thin paper as my test?

Thanks!!!
Michael

It's more difficult to cut, especially push cutting. The coarser the edge the more difficulty you'll have.

[dplafoll]

I found that using multiple media tells me a lot about a knife as I'm sharpening. I use regular paper and phonebook paper as a general guide. Then, when I get towards the end of sharpening a knife, I use hair. I draw a hair up against the edge vertically to see if I can shave/split the hair lengthwise, and I also try to chop a hair held in one hand. I also do the standard self-shave test, but I use the hair on the top of my thighs instead of my arms as there is more of it for testing and it's less obvious when I'm done. :p

[Nate]

Hello again Michael,

I agree with the above. When I first learned to sharpen, cleanly slicing standard printer paper was my first benchmark, but I quickly learned that many would consider an edge that would only slice printer paper as actually fairly dull. Moving to phone book or receipt paper is a pretty logical next step as a test once you move up in proficiency.

Other common sharpness tests are things like tissue or toilet paper, shaving arm hair, catching hair above the skin or "tree-topping," cutting a hanging hair, or even hair-whittling. :eek:

You can go even further down the rabbit hole and start looking at different grit finishes to optimize sharpness for push-cutting vs. slicing depending on how you use your knives. I generally leave my edges fairly coarse and am happy with the sharpness once the blade will cleanly shave forearm hair, though sometimes I just go by receipt or phone book paper if I'm sharpening a lot of knives at once.

[Nate]

Nevermind, too silly. :)

[Doc Dan]

A sheet of toilet paper or a Kleenex will certainly show how sharp a knife is.