What is your ultimate test for a sharp Knife

[BILLy]

Hi All,
Apologies if this has been asked before,
If not here goes.

What is your ultimate test for a sharp Knife?

I know the one about cutting a piece of A4 paper or any size come to that,
I use mine on my arm to see if it will shave the hairs of it.

thanks for your kind replies

 

[JimN]

Not realising I've cut myself until I see the blood normally works for me.

 

[Tadpole]

Hi All,
Apologies if this has been asked before,
If not here goes.

What is your ultimate test for a sharp Knife?

I know the one about cutting a piece of A4 paper or any size come to that,
I use mine on my arm to see if it will shave the hairs of it.

thanks for your kind replies

Does it cut what I want it to cut? will it carve what I want it to carve? if it does, then it's sharp enough. My knife is as likly to be use to chop wood, as it is to be use for chopping up a side of beef/pork. Both types of jobs have their needs, and a knife that is sharp enough to do both is all that I want from a knife.
Saying that my clipper is sharper than the butchers knife in use at my local Morrisons ( I know as I've seen them hacking for ages at a rack of belly pork)

 

[SMARTY]

Fully agree with Tadpole on this one. Dont worry about sharpness "party tricks" on bits of paper or shaving the hairs from your body. Get it sharp enough to do the required task. If you want to know if the edge is sharp enough to carve wood test it by carving wood. Also test the whole edge. A little often is better than a sharpening blitz is what i have found in the past.

Smarty

 

[John Fenna]

Sharp enough for the job in hand is a good measure in realworld terms - I tend to test mine after a stropping by slicing free hanging newspaper - if it will cleanly slice this along the length of the blade (the fibrous nature of the paper realy shows up any dead spots) then it is sharp.
This does away with the tedious necessity of taking wood or meat into my sharpening area (OK the spare bedroom/workroom) when getting things ready for a trip away.
If the blade dulls during a task then I will sharpen in situ, but normally I just strop (or work out any nicks and dull spots working from coarse to find diamond then strop) back at my work table - where a paper test is prefered to carving or meat prep by my other half

 

[VirusKiller]

I test my blade (carefully!) with my fingers. I feel along the whole blade to confirm it has a razor's edge and no burrs, though the latter can also be checked by looking along the edge of the blade for specks of reflected light.

 

[Hoodoo]

My favorite test is to cut a very thin slice across the end grain of a stick of basswood. A sharp knife will make a clean, shiny cut, with no scratches. This is a pretty standard way to test woodcarving knives but also a great way to test the edge of bushcraft and hunting knive.

 

[spamel]

I go by feel too, also I am no longer going for the completely zero ground bevel often referred to as a scandi grind, but am now putting on a micro secondary bevel with a small jasper stone. It can hardly be seen but the edge remains sharp longer and is more robust. If you look at all the traditional Scandinavian blades you will notice that micro bevel. Robin Wood did a thread a while back about it and he is absolutely right, the fine edge left by putting it over the stones leaves an incredibly sharp edge, but it is so fine that it can be damaged easily.

 

[sirex]

only once the blade can cut the fabric of space-time, is it ready.

 

[Tadpole]

only once the blade can cut the fabric of space-time, is it ready.

That would be a very subtle knife indeed

 

[BILLy]

[QUOTE ( I know as I've seen them hacking for ages at a rack of belly pork)[/QUOTE]

Maybe they did not do a test first to see if it was sharp enough for the said job.

 

[Nonsuch]

That would be a very subtle knife indeed

Spot the Dark Materials fan

NS

 

[sapper1]

When i can use it to cut corners it's sharp enough.

 

[Siberianfury]

my test only works with really sharp knives, i take a long hair and hold it loosley, then i swing my knife at the hair, if it cuts the loose hair its bloody sharp, the only knives ive been able to do this with are my opinel and puukko. if u try this dont get your fingers caught because its very easy to do so.

 

[Firebringer]

You mean everyone doesn't use the silk scarf dropped onto the blade test!

 

[Siberianfury]

You mean everyone doesn't use the silk scarf dropped onto the blade test!

i wish, can steel be that sharp?

 

[FGYT]

as said it has to do the job required and this varies

i usually check the edge by eye you can see most problems as a reflection of light between the 2 bevels

then you can start honing on sunlight

ATB

Duncan

 

[Chinkapin]

I grasp mine with the thumb and first two fingers, with the sharpened side of the blade upright. The blade is held more or less level with the floor. I then lean my head over to where it is about 15 cm. from the blade. At this point I give a short sharp blast of air directly at the blade.

If I can hear the screams of the tiny microbes as they are cut in two, I know it is sharp enough for my needs.

Of course it is axiomatic that this is nowhere near sharp enough to cut the very fabric of space/time.

 

[Javapuntnl]

Here's a good test; http://www.youtube.com/watch?v=aQPwHu4lxsQ

 

[Tadpole]

Doesn’t matter how sharp it is, if it can’t cut through 10 bottles of hard water it’s not a mans knife
http://www.youtube.com/watch?v=DMn8w15Wn38