Scary sharp blade really worth it?

nice example, your videos are great for demonstrating things.

This I think is what most expect from the toothy edges. You can perform a quick swipe on an unsupported material and have the blade sail through it. If it's some gross motor skill, repetitive motion type cutting, this does fine with a longish blade.
 
I agree with HH, Nozh you make really nice videos. Nozh, now just try and find the perfect grit for a balance between draw and push cutting. :)
Isn't being a sharpening nut fun? I've found that the perfect grit is so dependable on what and how you are cutting that there is no perfect grit for everything. Should we carry 3 knives one sharpened coarse, one med and one polished? Maybe a stockman. :) I've pretty much settled on a medium to fine finish for a pocket knife. However the edge best for someone else could surely be something very different.
 
Scary sharp in itself may or may not be too important for the average guy. Of course, it depends on your definition of "scary sharp". But I've found that ability to get your knife scary sharp is very important. I have the choice to bring my edges to what ever sharpness level I want to get the job done however I choose. That was worth the work for me.
 
I can not understand why super -sharp edge will not perform slice? All my knifes perform slices very well much better then serration. Cut is very clean and it take much less force to go though target.

Especially it is noticable on ropes - I need to apply more force to slice manila rope wit serration than with super sharp-edge.

Actually all my tests if you see video have slice move not push - it is limited to 1" but it is not push cut.

Thanks, Vassili.

Vassili,

I've thought about that. I doubt neither of the validity of your reports nor of mines. If i well remember, in an other thread, you explained your sharpening process and what had surprised me is you begin by strokes on a xx coarse grit and then decrease the grit gradually to fine or extra fine. This way it's possible that your edge is hightly polished but still remain regular and well aligned micro teeth. I've tried the same process on an edge thought i'm not as well equipped as you are, i've carefully insisted on the polish process and yes it works but under a x20 magnification i still can see tiny teeth. Comparison is not reason but what do you think about that explanation?

Best regards.

dantzk.
 
This way it's possible that your edge is hightly polished but still remain regular and well aligned micro teeth.

So any edge have micro teeth, polished has smaller, rough has bigger.

It is hard to get and, I think, many people did not really polish edge up to this state but rolled it out during polishing (especially with felt wheels, but on soft leather with high pressure too) so they loose angle on very edge and do not has teeth - but this is dull edge to my opinion.

I my experiment, polished edge cut rolled paper too - less then rough edge, but as I remember, I was told that polished edge not suppose to cut it at all.

So of course polished edge has teeth, otherwise it is not polished but dulled.

After thinking a bit - real cut usually combination of draw and push, so it is not clear to me, even micro saw effect is seen very well, from what practical use will benefit more from better push cut or from better draw cut?

Thanks, Vassili.
 
I think after reading you guys post. They way I cut I like push cut. I love seeing a knife just slice right through a plastic clamshell package, or anything else your cutting. Now if I can just learn to get my knife that sharp i'll be doing really good.
 
It is hard to get and, I think, many people did not really polish edge up to this state but rolled it out during polishing (especially with felt wheels, but on soft leather with high pressure too) so they loose angle on very edge and do not has teeth - but this is dull edge to my opinion.

I agree, i have often somes troubles with stropping on soft stuff and i prefer now polish by light strokes on a very fine ceramic stone. Like for sharpening convex edges or grinds, the mouse pad doesn't work for me.

After thinking a bit - real cut usually combination of draw and push, so it is not clear to me, even micro saw effect is seen very well, from what practical use will benefit more from better push cut or from better draw cut?

That's the right question. For a all purpose knife it's an issue, find the edge which will draw cut a ripe tomato and push cut a seasoned hard wood and push cut a ripe tomato and draw cut seasoned hard wood, that's the quest!

best regards

dantzk.
 
After thinking a bit - real cut usually combination of draw and push, so it is not clear to me, even micro saw effect is seen very well, from what practical use will benefit more from better push cut or from better draw cut?
I think your video example is interesting(as all your video's) , but not necessarily a real world example, as you will almost always put pressure on your edge downwards normally.

The reason the coarser edge sliced better, is in my logic that it grips into the "cuttingobject", and hooks behind the microparticles, thus causing the knife to go downwards into the object, gripping into other microparticles/fibers, and so on. The polished edge will do the same the slicing motion with much lesser force required to move the blade, as an ice-skate sliding over the ice. So the total force applied by you on the two knives isn't the same.

It is in essence the principle of a normal big wood saw I think, that is designed only to push and pull with it, and not really to put much pressure against the object.
When you try to saw a tree with a gigantic shaving sharp, polished blade, I think it will take many many times longer to go thru it when doing the same movement.

That's why there are tools like axes, which are designed to push a strong polished blade with big pressure into the object.

The question could be: what requires the lesser total force to get your object cut. But it isn't maybe that easy, because some ways of putting pressure are more comfortable and easy for a human than others.(because our biceps are stronger, pushing is mostly considered easier than pulling I think)

So in the end it indeed all depends on the way of cutting, and the object you use for it, to choose the size of your (micro)tooth’s on that object .

And it also depends on which material you want to cut. A hanging rope will be better cut when sliced with a coarser edge, because it is very flexible and will move away from the edge, or around it when you only push against it. And other materials benefit from a more polished edge, like when you peel an apple.(pushing motion).

DISCLAIMER: my opinions are only based on own logical thinking, and not on my level of experience. I'm not as good in sharpening as many of you are, as I've only been able to sharpen a knife to hanging hair splitting ability once, and that was mostly by pure luck.:D
 
But not as many cuts as the one with the working edge!

Could you explain how this is possible? I've noticed the opposite myself. My dulll blades requires more force and start tearing through it rather than cutting quicker than my really sharp knives.
 
I have gotten knives from custom makers that were sharpened on a 120 belt that would pop hair. I reprofiled a CPM154 custom necker, and I made sure it would shave after I set the bevel with my D8XX. I sharpened an Old Hickory to shaving sharpness with a 60 grit aluminum oxide stone. OTOH, I could polish the bevels of a dull knife with an 8000 grit waterstone, and it still won't shave. I have gotten knives to shave with included angles from 50 to 20 degrees.

I'm not sure what a non-shaving working edge is.
 
I'm not sure what a non-shaving working edge is.

Exactly my thoughts. The DMT XX Coarse (120 grit) can put a shaving edge on a knife, and Tom Krein's 120 grit edges tree top arm hair. With attention to technique you can get very coarse edges that shave and then slice a really long time. The better a knife push cuts at a given grit the better the edge will last. To think that just because you formed a good edge at 120 grit that shaves it won't last is just wrong. Again, ask anyone who has used a Tom Krein sharpened blade, they last a long time and they sure as heck shave nicely to start with. I have sharpening OCD and usually go to a higher polish than required, but I have definately seen impressive performance from coarse shaving edges for extended slicing sessions.

Mike
 
Now I am not saying this applies to everyone. But everybody I know that says they prefer a "working edge" just doesn't have the patience, or perhaps the skill, to get a "scary sharp" edge.

In my personal experience, a very well refined, highly polished edge will outperform a "toothy" edge every time. At least that's my experience, yours might vary.
 
My working edges are the quick to apply ones. When working, which to me has meant manual labor, edge damage comes quick and easy. So, an edge quick to restore from chips and rolls is good. I don't go from final steps of 3, 1, 1/2, and 1/3 micron like I do for my 'scary' edges, but I at least make sure it shaves even at rougher grit, which might be rougher than 25 micron, possibly much more.
 
Alright guys I have another question. I hear people talk about getting their knives so sharp that they can cut free hanging hair, slice toilet paper, tree top hair, w/e other ones you want to add to it that says a knife really is scary sharp. I also read people saying that the edge is actually not useful in real life situations. Cutting cardboard, zip ties, plastic tie straps so on and so forth, that once you try and use that edge on these things that it just rolls over and the edge is no where near as sharp. Is this true, or not??

Fallkniven U2 is the sharpest knife I ever came across.It's literally like a razorblade.How do they do it?:confused:
 
A working blade should stay sharp for as long as is possible and is what is best for the average guy's knife or whatever is being sharpened. Scary sharp does not last.

For many of us on this forum however, sharpening blades is a hobby or a business. We therefore have the option of putting what maybe an impractical edge on a blade.

Even if it is just for the fun of it and has to be redone regularly.
 
Hmmm, thats weird to me that some people say a scary sharp edge last longer than a working edge. And others say that it doesnt. Too me it only makes sense that if you actually have a scary sharp edge and not just a burr straightened out that it would last longer. Naturally as you use a blade the sharpness degrades no matter what you cut with it, and just keeps going down everytime you use it. So I would think that the sharper it is the longer it would take to get dull again. Or am I just confused??
 
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