Polished edges.

[Razorsharp-Travis]

I put coarser edges, around 14 microns on my low carbide steels so they bite and put a finer edge, around 5-7 microns on my higher carbide steels cause they still cut with a lot of bite with that edge . When I want to do a stupid fine edge for detail work, ill take a low carbide steel to about 0.5u

 

[REK Knives]

I don't really quite get this whole toothy vs polished, since I pretty much always take my edges as far as I can and I still haven't met a cutting task which my edges couldn't handle because they were polished.
I've cut plenty of rope with polished edges and I actually prefer the clean cuts they make, compared to the hint toward frayed ends I get with a very sharp coarse edge.
Cardboard isn't a problem either -- just that it dulls the edge and I therefor use box cutters for that. A polished edge goes through cardboard like butter though and a coarse edge does it very well too, but definitely not better.
I find that I must use more force with coarser edges than with polished edges, which I don't like. I want the knife to do the work instead of compensating with force and risking that I may slip.
If a polished edge is scary sharp then yes, it is easier to cut yourself with it than with a scary sharp coarse edge; by just barely touching it, but since it's packed with so much performance one can and should be more delicate with it.

There won't be any cutting task a truly sharp edge (i.e. ensured you reached a burr on both sides and then removed it) won't handle... the question is just how efficient will it be at any given task. The OP had it right on... a highly polished edge has very limited uses if you are going to use one efficiently (i.e. cutting hair, shaving, whittling/chopping) - although you CAN use it for anything. Most people will find that a courser, toothier edge is much more practical for almost anything they will use it for.

I will give you an example... when I have a knife I want a very precise edge on, I take it to my WEPS. HeavyHanded is correct in that now, I try to get the most highly polished toothy edge I can, so that way you get the best of both worlds. My favorite edge (at this point) is an edge finished on the 600 grit stock diamond stone on the WEPS. On the last sharpening of my Para2 I bumped the edge up to a 1k just to see how I liked it... it is a no go. While it will shave hair, slice newspaper, etc. cleanly, there is a noticeable difference in cutting performance. Seriously, try this next time when you are testing edge refinement w/ different grits... get you a piece of rope or webbing (larger is better), pull it taught in a horizontal line in front of you, and then use an equal amount of pressure as you slice the piece of rope with different edges. You will notice that (for example) a 600 grit diamond finish will slice through with ease whereas the 1k grit diamond finish will not really "slice"... you more of have to "push" the edge straight down through the rope. I can barely put any pressure on the edge while holding the knife and "saw" or "slice" it across the rope and it will really bite in and cut right through it.

The only reason you would need to use more force with a courser edge (that is properly sharpened) is that you are still trying to push through your cut with it instead of using it the way it is designed to be used and slicing through your cut.

Here, check this out for some pictures (and also a very interesting article) of different edges at 600x magnification... go to page 9 and you will see an edge at 220 grit, 600 grit, and 1000 grit (on a tru-hone). You should be able to see why a 220 grit edge will really bite in more than it's counter-parts. That is why you can set a mirror finished edge on your fingernail and slide the edge across it and it will slip right off... try that with a 220 grit edge and you will be hurting probably lol. If you want to try an experiment (which I have not been able to do yet), get a sharp toothy edge and then polish the grooves with a 1um pasted strop and see if it slices cleanly while still having a lot of bite just a thought!

 

[Robs92XJ]

That is why you can set a mirror finished edge on your fingernail and slide the edge across it and it will slip right off...

If that is how your mirror edges behave, you are doing something wrong.

That said, I've found course edges to be quite useful. An Opinel I left with a Course DMT (320 grit) edge was a slicing machine. Still, there's something about the way the finely polished edges cut that makes me want to spend the effort creating them.

 

[unit]

That is why you can set a mirror finished edge on your fingernail and slide the edge across it and it will slip right off...

Nothing against toothy edges...we all have preferences, but it appears from this statement that you have not experienced what some of us understand as a "polished edge". Until you have experienced truly exceptional examples of both toothy and polished edges, I suggest that you can not really declare a preference.

No offense.

 

[pwet]

as other said, the behavior you describe for your polished edges doesn't match my experience, 1k grit shouldn't struggle on rope or whatever.

most of my EDC routine is cardboard cutting, rope i don't do much. so i'll comment on what i know. and from my experience a 600 grit edge will always be outperformed by a more polished edge. my usual technique is cutting on a bias, the edge at 45° to the cardboard. this is more of a slicing motion and i still prefer a more polished edge. it'll last longer by a fair amount, will cut smoother, with less force ... if the correct technique for a "coarse" edge is back and forth with no downward pressure i just don't want that...

 

[stoffi]

razor-edge-knives,

I hear what you're saying, but I'm not a beginner (no expert either!). OK, the fact that a toothier edge has more grip doesn't make it the best all-round edge. It is widely known that a toothy edge has more grip and therefor is well suited for shearing rope and cloth, for instance. Look at rescue knives, they're all serrated for a reason. It is also very easy to set a toothy scary-sharp edge with minimal effort vs a polished one, hence why most people have toothy edges. It takes very little time and effort, yet yields pretty much the same results as a polished edge, in all practical terms. If you get a scary sharp mirror polished edge however, (heck polish the whole blade for even less friction!) then you'll see why many of the ones who use them insist that there is a difference in... well, perhaps not so much in its performance, as in its character.

 

[REK Knives]

Nothing against toothy edges...we all have preferences, but it appears from this statement that you have not experienced what some of us understand as a "polished edge". Until you have experienced truly exceptional examples of both toothy and polished edges, I suggest that you can not really declare a preference.

No offense.

None taken. But if I don't know what a polished edge is, then please enlighten me.... Below is one that I sharpened that will pass the HHT with no issues... over 1500 passes reversing strokes w/ each grit on the WEPS done under a 230x microscope progression. Is this not the type of edge you are speaking about? It makes perfect sense to me: the explanation between the design and purpose of a polished edge vs. a toothy edge...

Both are taken in the same spot on the paper, one is just lifted up a little bit.

finished on .5um pasted strop.

 

[REK Knives]

as other said, the behavior you describe for your polished edges doesn't match my experience, 1k grit shouldn't struggle on rope or whatever.

most of my EDC routine is cardboard cutting, rope i don't do much. so i'll comment on what i know. and from my experience a 600 grit edge will always be outperformed by a more polished edge. my usual technique is cutting on a bias, the edge at 45° to the cardboard. this is more of a slicing motion and i still prefer a more polished edge. it'll last longer by a fair amount, will cut smoother, with less force ... if the correct technique for a "coarse" edge is back and forth with no downward pressure i just don't want that...

I am not saying it really struggles, but it is noticeably different... Different grits have different purposes: a toothy edge for a tomatoe may not be as effective of a "toothy edge" for rope. I appreciate your honesty in that you mostly do cardboard... for for that , I would agree (although I do not have tons of experience w/ cardboard) that a polished edge is better. And it is not "no downward pressure," just noticeably less than a highly polished edge.

 

[unit]

None taken. But if I don't know what a polished edge is, then please enlighten me.... Below is one that I sharpened that will pass the HHT with no issues... over 1500 passes reversing strokes w/ each grit on the WEPS done under a 230x microscope progression. Is this not the type of edge you are speaking about? It makes perfect sense to me: the explanation between the design and purpose of a polished edge vs. a toothy edge...

Both are taken in the same spot on the paper, one is just lifted up a little bit.

finished on .5um pasted strop.

The process sounds good and the result looks nice but the performance sounds remarkably different to what I have experienced.

If I delicately place a polished edge on my thumbnail it will not slide off even at low angles. If I then drag the knife under its own weight I can feel the edge cut deeper into the finger nail. Slow or fast makes no difference the edge cuts deeper into the nail. Under no circumstances doe the edge slide off.

Perhaps you are rounding the edge slightly on the strop? Perhaps you have a wire? I have seen (numerous times) edges that look marvelous and were reported to have taken great deals of time and equipment to produce...but they performed very poorly. I am not suggesting anything derogatory, simply stating that looks and HHT are not everything. A beautifully polished wire edge will nail the HHT and disappoint on other tests (thumb nail )for example.

 

[REK Knives]

razor-edge-knives,

I hear what you're saying, but I'm not a beginner (no expert either!). OK, the fact that a toothier edge has more grip doesn't make it the best all-round edge. It is widely known that a toothy edge has more grip and therefor is well suited for shearing rope and cloth, for instance. Look at rescue knives, they're all serrated for a reason. It is also very easy to set a toothy scary-sharp edge with minimal effort vs a polished one, hence why most people have toothy edges. It takes very little time and effort, yet yields pretty much the same results as a polished edge, in all practical terms. If you get a scary sharp mirror polished edge however, (heck polish the whole blade for even less friction!) then you'll see why many of the ones who use them insist that there is a difference in... well, perhaps not so much in its performance, as in its character.

"perhaps not so much in its performance, as in its character."

right on! I'm not saying that its stupid to polish your edge to this point... I think it is beautiful! I just feel as if it has specific purposes just as the toothy edge does. And of course it doesn't make it the best all around edge for everyone... It just happens to be the best one for me due to what I cut, and I believe, for most people that EDC a knife for cutting anything that may come up. They both have their specific purposes and excel at each.

 

[REK Knives]

The process sounds good and the result looks nice but the performance sounds remarkably different to what I have experienced.

If I delicately place a polished edge on my thumbnail it will not slide off even at low angles. If I then drag the knife under its own weight I can feel the edge cut deeper into the finger nail. Slow or fast makes no difference the edge cuts deeper into the nail. Under no circumstances doe the edge slide off.

Perhaps you are rounding the edge slightly on the strop? Perhaps you have a wire? I have seen (numerous times) edges that look marvelous and were reported to have taken great deals of time and equipment to produce...but they performed very poorly. I am not suggesting anything derogatory, simply stating that looks and HHT are not everything. A beautifully polished wire edge will nail the HHT and disappoint on other tests (thumb nail )for example.

Thanks No, I have looked at the edge (both sides) under the 'scope and can't see any burr on either side... plus I have hit it up for around 100 passes/side on plain leather after the .5um paste. By "sliding off" I am not saying that it will do so at low angles... that's not the type of sliding off I am talking about. I am rather speaking of your second proposition, that when I drag it across my fingernail, it doesn't seem like it bites in nearly as deeply as a 600 grit finish would (although I haven't done this with a fingernail specifically, just on rope and that is my experience). I did, however, just take the photographed edge and do this on my fingernail.... and if I apply pressure, sure it would cut right in, but if I use only light pressure, it doesn't "bite" much. But that's not what its designed to do. Ah well, I guess its as if everyone says.... each has his preference to what works for him

 

[unit]

Thanks No, I have looked at the edge (both sides) under the 'scope and can't see any burr on either side... plus I have hit it up for around 100 passes/side on plain leather after the .5um paste. By "sliding off" I am not saying that it will do so at low angles... that's not the type of sliding off I am talking about. I am rather speaking of your second proposition, that when I drag it across my fingernail, it doesn't seem like it bites in nearly as deeply as a 600 grit finish would (although I haven't done this with a fingernail specifically, just on rope and that is my experience). I did, however, just take the photographed edge and do this on my fingernail.... and if I apply pressure, sure it would cut right in, but if I use only light pressure, it doesn't "bite" much. But that's not what its designed to do. Ah well, I guess its as if everyone says.... each has his preference to what works for him

I would agree entirely with that statement.

The truth is, most of us technically are using "polished edges" if you consider that once you join the bevels and remove the burr, everything beyond that is polishing the edge...and it seems most people probably use more than one stone around here. The real question is "how polished?"...and that probably has a pretty variable answer. In the end, why debate preferences?

With regard to sliding off. I completely misunderstood you. Sounds like you are experiencing similar results to what I would expect

 

[HeavyHanded]

as other said, the behavior you describe for your polished edges doesn't match my experience, 1k grit shouldn't struggle on rope or whatever.

most of my EDC routine is cardboard cutting, rope i don't do much. so i'll comment on what i know. and from my experience a 600 grit edge will always be outperformed by a more polished edge. my usual technique is cutting on a bias, the edge at 45° to the cardboard. this is more of a slicing motion and i still prefer a more polished edge. it'll last longer by a fair amount, will cut smoother, with less force ... if the correct technique for a "coarse" edge is back and forth with no downward pressure i just don't want that...

A polished edge (not sure what this means across the board, but to me this implies an edge above 1000 grit CAMI or 1200-2000 grit JiS) will cut cardboard with much greater ease. To me the coarse edge excels in longevity on really tough items. I discovered this at my work - printing by trade, and at one point I was cutting large amounts of coated cover stock - similar to a playing card in rigidity - and my polished edges were croaking in days on this stuff. Found that a very coarse edge held at a very steep angle to the surface to be cut could be used as a push cut (the edge didn't need to saw back and forth through the material, or even accommodate a long pulling draw ) with very long lasting utility - several weeks to a month as opposed to days with a polished edge. I'm very confident in my results, the blades on our large clamping cutters are polished to just short of a mirror edge - probably comparable to 2000 grit CAMI - and they can only tolerate stock like that for a day or two of heavy cutting and they croak. On uncoated stocks they can run for weeks. In general I prefer a bit of tooth on my EDU knives because I find it cuts more predictably and lasts a bit longer. On my choppers - machetes and hatchets - I prefer a more polished edge. It chops with far less resistance, and I find I don't do much draw cutting with a big knife or hatchet, no advantage to extra edge formations. I still feel that a toothy edge lasts longer if used with a draw cut, and a polished edge lasts longer if used with a press cut. Using a toothy edge for pressure cutting, or a polished edge for draw cutting will prematurely dull either. I have no proof of this, just a nagging suspicion.
So many variables...

 

[unit]

So many variables...

Lots and lots!

 

[Jason B.]

A polished edge (not sure what this means across the board, but to me this implies an edge above 1000 grit CAMI or 1200-2000 grit JiS) will cut cardboard with much greater ease. To me the coarse edge excels in longevity on really tough items. I discovered this at my work - printing by trade, and at one point I was cutting large amounts of coated cover stock - similar to a playing card in rigidity - and my polished edges were croaking in days on this stuff. Found that a very coarse edge held at a very steep angle to the surface to be cut could be used as a push cut (the edge didn't need to saw back and forth through the material, or even accommodate a long pulling draw ) with very long lasting utility - several weeks to a month as opposed to days with a polished edge. I'm very confident in my results, the blades on our large clamping cutters are polished to just short of a mirror edge - probably comparable to 2000 grit CAMI - and they can only tolerate stock like that for a day or two of heavy cutting and they croak. On uncoated stocks they can run for weeks. In general I prefer a bit of tooth on my EDU knives because I find it cuts more predictably and lasts a bit longer. On my choppers - machetes and hatchets - I prefer a more polished edge. It chops with far less resistance, and I find I don't do much draw cutting with a big knife or hatchet, no advantage to extra edge formations. I still feel that a toothy edge lasts longer if used with a draw cut, and a polished edge lasts longer if used with a press cut. Using a toothy edge for pressure cutting, or a polished edge for draw cutting will prematurely dull either. I have no proof of this, just a nagging suspicion.
So many variables...

I have no proof either but now I know I'm not alone in that thought

 

[singularity35]

I like the look of a polished bevel but I maintain the edge on a 14u strop. Gives the mirror bevels a bit of a bite without marring the finish. I also don't like the look of a microbevel from the stones so I just polish it up on the 14u strop.