How sharp is sharp?

I many times hear people that they want their knives super sharp, and I always ask them how sharp is that? So I have decided to make a sharpness scale from ridiculous sharp that I give sharpness number 5 down to dull that I give number 0. Let’s start with sharpness 5 that is the hanging hair test (HHT).

Hanging hair test

Hanging hair test

As you see this old knife that I in my household call “The bacon slicer” doesn’t pass the test, because the hair is hanging on the edge. The pieces of cut off hair on the paper, came from that I had I little to much tension while trying to line the hair up. Next up is sharpness number 4, which is to smoothly slice a cigarette paper from heel to tip.

cigarette paper slicing

cigarette paper slicing

cigarette paper cutting with knife tip

cigarette paper cutting with knife tip

cigarette paper cutting with knife heel

cigarette paper cutting with knife heel

As you see the old knife passes this test, the only thing was that I felt a light resistance at the back and of the heel starting. Anyway, this is crazy sharp, it’s actually sharper than an ordinary surgical scalpel new out of the box, their are scalpels like the ones that are made for eye surgery that I’m sure would pass the test though, but I don’t have one. This is to sharp for any kitchen knife, except for maybe the most delicate fillet knives, and it wouldn’t last very long. Over to sharpness number 3, which is that it should be able to push-cut Para-cord without a problem from heel to tip and being able to shave arm hair.

Push cutting paracord easy 1

Push cutting paracord easy 1

Push cutting paracord easy 2

Push cutting paracord easy 2

Shaving hair

Shaving hair

These tests are passed easy; sharpness number 3 is a good sharpness for most thin kitchen knives like slicers, fillet knives and so on. Sharpness number 2 is to be able to slice magazine paper from heel to tip, slowly, smooth without any snagging.

Slicing magazine paper easy and smooth

Slicing magazine paper easy and smooth

This knife is almost too sharp for this test, I’m pretty sure the paper will dull it. Sharpness number 2 is good for most medium and heavy duty kitchen knifes and I think this is the sharpness most people are comfy with on their kitchen knives. Over to sharpness number 1, this is to be able to slice ordinary printing paper, cutting into the side of a tomato without slipping and slice paper thin slices of lemon.

Slicing lemon paper thin

Slicing lemon paper thin

Slicing printing paper smooth for heel to tip

Slicing printing paper smooth for heel to tip

Well this is still a good sharpness for your heavy duty kitchen knives and cleavers, but if you don’t pass sharpness number 1 test, your knife is dull and need sharpening. I call this sharpness number 0.

Sharpness:       Test:                                                    For:

5                      Hanging hair test                                 Straight razors

4                      Slicing cigarette paper                         Delicate slicing knives

3                      Push cut Para-cord, shaves                 Thin kitchen knives, fillet knives

2                      Slicing magazine paper                       Most medium kitchen knives

1                      Slicing printer paper smooth               Heavy kitchen knives and cleavers

Magnus Pettersson hand sharpener, now serving the whole Westside with free pickup and delivery: Santa Monica, Brentwood, Pacific Palisades, Venice, Marina Del Rey, Culver City and West LA.

For free pickup and delivery on the Westside, call/txt 310-486-6068 or email.



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