How sharp..is sharp?

[panama]

Question on Sharpeners - I use the spyderco sticks. Have always been able to obtain shaving sharp unless it is a real junk cheap knife. Will the edge pro or another system allow me to surpass this level of sharpness gotten with the spyderco sticks. Once bud nealy told me that is what he uses and he said was good enough for tactical applications. Comments welcome, please.

 

[Ankerson]

Question on Sharpeners - I use the spyderco sticks. Have always been able to obtain shaving sharp unless it is a real junk cheap knife. Will the edge pro or another system allow me to surpass this level of sharpness gotten with the spyderco sticks. Once bud nealy told me that is what he uses and he said was good enough for tactical applications. Comments welcome, please.

Yes the Edge Pro will do that easy.

 

[unit]

Question on Sharpeners - I use the spyderco sticks. Have always been able to obtain shaving sharp unless it is a real junk cheap knife. Will the edge pro or another system allow me to surpass this level of sharpness gotten with the spyderco sticks. Once bud nealy told me that is what he uses and he said was good enough for tactical applications. Comments welcome, please.

I suppose EP will allow for improvement, but so will UF sticks for the Sharpmaker.

Also understand that you can use the sticks freehand and get pretty sharp. Here is a video of the results of Spyderco UF sticks.

http://www.youtube.com/watch?v=yH12Cld6_sA

 

[Gadgetaholic]

The sharpest I have gotten was when I got a knife 'shaving sharp' with the DMT Aligner and polished smooth with the EEF stone, then spent hours (just idly stropping while watching TV) with green compound on a strop polishing it like a mirror. That is my cheap Ontario RAT-1 folder with AUS-8 steel - it can whittle hair, but I still can't 'tree top' with it.

How sharp is sharp? I used to think 'shaving sharp' was sharp, now that is just my starting point - I like to get most knives sharper than that. For my Khukuri I am happy enough with 'shaving sharp' but I like my smaller blades a bit sharper than that.

 

[singularity35]

I always hear "shaving sharp" but what does this mean? good enough to take off arm hair or good enough to shave your beard and mustache? I got my FFG ZDP Endura sharp enough to tree top. It took off some hair from my arm but not all by tree topping. It is sharp enough to split a 1 inch length of hair and to cut a single hair by running the hair across the edge but I can't shave my facial hair with it, does this mean it's still not "shaving sharp"?

 

[hardheart]

That's shaving sharp in this context. The trouble with hair is that it is not consistent from person to person, or even across your own body. One person's feats may seem impossible, but partly because you are cutting hair of a different thickness or stiffness. Some googling returns a range of thicknesses from 17 to 300 microns. Supposedly the male moustache houses the thickest hairs.

Also, shaving your facial hair is not just a test of edge finish, but also geometry. A straight razor can be many times more comfortable than a knife edge at a relatively coarser level of edge finish, due to the low angle and thin grind. It isn't just the edge radius, but your capability to present it to the skin/hair at the correct angle.

 

[Obsessed with Edges]

That's shaving sharp in this context. The trouble with hair is that it is not consistent from person to person, or even across your own body. One person's feats may seem impossible, but partly because you are cutting hair of a different thickness or stiffness. Some googling returns a range of thicknesses from 17 to 300 microns. Supposedly the male moustache houses the thickest hairs.

Hair even has varying cross-sectional shape, from circular to oval to almost flat (like a blade of grass). I've no doubt that influences how it cuts, too.

I wouldn't be at all surprised about the moustache having the coarsest hair. That's always been the toughest place for me to shave, always end up cutting myself right under my nose (and it bleeds, and bleeds, and bleeds... ).

I'm sporting a closely cropped goatee now. Much easier to live with.

 

[Jason B.]

This is almost a impossible question to answer because it will all depend on what you know as sharp. Your sharp may be my dull and my sharp may be a level you didn't even think was possible with a knife.

Blade thickness, blade grind, steel, and heat treat will all determine how sharp a knife will become or feel.

Saying a knife is shaving sharp is kinda a bad example of how sharp a knife is. The reason I say this is because I can have a clean shaving (arm hair) edge from a coarse 320 mesh diamond hone but you can also have the same from a edge stropped at 1 micron. Unfortunately the difference is hard to explain, there are several different finishes and levels of sharpness to each grit and the amount of pressure is a huge deciding factor in this. A example of this would be when I am finishing with my 8k diamond I can either have a slightly toothy clean shaving edge or if I use feather light pressure I can have a edge that feels polished smooth and will treetop and whittle hair like a well stropped edge. The diffference in pressure lessens the amount of plastic deformation and depth that the abrasive pushes into the steel, thus the reason when you have burr problems most will you to ease up on the pressure.

There is also ways to "fake" sharpness, factory edges are a good example of this. The coarse edge feels sharp because your finger can feel all the small teeth of the edge whereas a smooth polished edge is too fine for your fingers to feel and may often times feel dull, that is until you cut yourself or a object then the true sharpness shines through.

So what is sharp? its what ever you want it to be until you fully understand the sharpening proccess and how different abrasives effect different steels and the practical level of finish for that steel. Understanding sharpness is a long and involved process that can take many years to fully grasp and sift through all the variables. Once you have the tools and skill all that is left is to consistently make a edge as sharp as it can be, when you can do this is when sharpening and sharpness all start to make sense. The only problem is most will never invest the time or study to reach that level, its not something that's easy or quick.

 

[Alberta Ed]

Sharp is being able to pare the edges off the atoms of a molecule. Accept nothing less.

 

[oxbld]

If it shaves the hair off on arm with ease, the knife is sharp enough for my use. I have a lansky kit and a couple DMT diamond stones, but I use a turn-box set of lansky crock sticks more than anything. Five minutes or less on them and my knives are shaving again. The best 12.99 I have ever spent at Academy!

 

[Gadgetaholic]

Your sharp may be my dull and my sharp may be a level you didn't even think was possible with a knife.

From what I've seen here this seems VERY likely!