When is a knife DULL?

[Lavan]

1. When it won't shave
2. When it doesn't drag on a fingernail
3. When it won't slice paper
4. When it won't cut a ripe banana
5. When it won't bite into wood
6. Always

 

[ARtsig1]

When it just sits there watching TV and never utters a word.

 

[Medic1210]

I'd have to say #2 since if the edge won't bite into the fingernail, then the edge bevels don't meet, or the very edge has worn away or rolled over. There are plenty of knives that won't shave, but still cut almost effortless. I have yet to see a knife that met #2 criteria that cut well.

Mike

 

[APM]

When it will not do the job it was intened for, end of story! All the tests are just that, a Test!

James

 

[pahl]

Originally posted by artsig1
When it just sits there watching TV and never utters a word.

ROFL

I would say # 2. When it doesn't drag on a fingernail.

 

[TheBadGuy]

3

 

[Alberta Ed]

When it won't cut molecules cleanly.

 

[Ebbtide]

When you have trouble with butter.

 

[Jin]

When my grandmother finds it a "good" knife...

 

[The General]

When you look at the edge under a light and see a white line which indicates dullness.

Or N3 if you insist as thats my min sharpness level before I get annoyed with it.

Part of the problem is, if you leave a knife to get properly dull, it takes a lot longer to sharpen, than frequent steeling and a couple of passes on the Sharpmaker from time to time.

 

[allenC]

When you're not afraid to hold the knife by the blade, it's dull.

Good luck,
Allen.

 

[VampyreWolf]

When it doesn't cut veggies cleanly. I work in a kitchen, and do food prep 75% of the time(when my dish pit is cleared of dishes).

Normally I touch up when they don't shave, and test on paper(free hanging paper, pushcut through, no tears). Just had to redo my 2 kitchen knives b/c they didn't want to slice paper.

 

[Jeff Clark]

Number 2. I consider push cutting meaningless for anything but a razor or chisel. An amazing variety of edges will slice paper with a draw cut. An edge that catches on the back of my thumbnail either has an edge that tapers to a fine edge or has some microserations that are digging into the nail. Either on will cut pretty well.

Not being dull is not the same thing as being sharp. I usually use shaving as the threshold of sharpness.

 

[VampyreWolf]

one point to make is that when I sharpen freehand, I form micro-serrations in the edge, angled toward the handle. Thus a pushcut at 90deg to edge works well.

 

[Roadrunner]

I actually trim my fingernails with my EDC, so I've found a good test to be how cleanly it will cut the nail itself. Fingernails require a fairly polished edge to be cut cleanly without chipping. When my EDC gets dull enough that a nail breaks off before the cut is completed, it's time to touch it up a little.