Damn. Another 'polished vs toothy' thread...

Or maybe there was a wire edge and the steak broke it off leaving the knife dull.
 
jasonbroni said:
My girlfriend actually let me use my EDC on it.
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Blues Bender said:
You need permission?:confused:
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That was my thought. Knife dulling might be the least of your concerns. Happy or not, folks who care negatively about the cutlery I use while eating can take a hike.

I use my Seb on steaks out all the time. Stuff gets dull if you use it. Sharpen it back up and move on. No need to get pissed at an inanimate object.
 
FortyTwoBlades said:
Not exactly....a toothy edge is more like just the spread fingers of one hand. Even folks like the infamous Cliff Stamp will tell you that a properly apexed (burr-free) low grit edge will have increased slicing aggression than a high grit edge, as well as increased edge retention on slicing tasks.
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This. There are reasons to go toothy or polished, but I am deeply skeptical of claims that either is objectively superior unless we're discussing specific tasks.
 
A.L. said:
I dulled my professional soldier's S35VN blade by breathing on it
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H7VNKDX.jpg
 
jasonbroni said:
Ok. So I've posted about this before, but ran in to a problem the other night. I prefer a toothy edge over a polished one. I got a huge New York strip and the knife they gave me was so dull it basically didn't work. My girlfriend actually let me use my EDC on it. It cut through like the steak was air. I know better than to drag it on the plate. Either way - the blade was noticeably duller afterwards. Duller after cutting steak?!? What the hell? It's a small sebenza?!? Do you guys think it's the whole 'toothy edge' thing? Bad heat treat? (probably not).. what ever the reason - I'm pretty pissed and don't understand how a steak can dull a knife. Please help! (oh yeah - I'm running 17 DPS on it - figured that's fine?)
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The 'teeth' scrubbing off that easily in a steak, assuming the plate wasn't touched, is characteristic of toothy burrs (i.e., weakened steel) being scrubbed off or folded over. Chances are, the edge wasn't sufficiently cleaned up of burrs, wires and any other weakened steel after sharpening. A lot of poorly-done coarse factory edges on knives will behave this way, when the edge is created on a coarse belt and not adequately buffed (or stropped) to get rid of the weak burrs masquerading as 'teeth' on the edge. The weak 'burr-teeth' go away with the first use of the blade, usually leaving behind a thickish and functionally useless edge.

Combined with somewhat thickish geometry (17 dps / 34° inclusive), once the toothy burrs are removed from the edge, the geometry left behind isn't really ideal for slicing.

I don't believe this has anything to do with 'toothy vs polished' anyway. More an issue of a weak edge (burrs/wires) and thick geometry behind it. A thinner slicing edge at 30° inclusive (15°/side) or lower will do well at either finish, for slicing a steak. When I got heavily into sharpening my own knives, my first favorite 'steak knife' was a traditional pocketknife (clip blade), finished to 1000+ (near mirror) on a ceramic, at something around 28° inclusive. Went through a steak like a laser beam; almost effortless slicing. This isn't to say polished is any better at it, but that the underlying geometry and the cleanness & strength of the finished edge will make more difference than whether it's toothy or not.


David
 
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Wash the edge off and dry it good, strop a few passes on plain paper and retest. If it really did dull I cannot imagine a steak making it happen, maybe it was dropping off prior to the steak and after is when you noticed.

I've noticed in the kitchen my utility and paring knives (sharpened toothy and extra toothy) will sometimes feel a bit dull when everything is wet, including my fingers. Wipe it off and put it back on the magnet, next time I go to use it I'll check it first with dry fingers and blade, and 9/10 it is still plenty sharp.
 
The edge retention of the blade is based mainly on the steel alloy and its thickness behind the cutting bevel.

When testing with a consistent media the edge will have a curve to its edge retention. It looks a bit like a horsepower/torque graph from a dyno but backwards. The edge has its greatest ability right out the gate and gradually declines until it cannot cut. The graph of a polished edge starts very high but has a rapid decline rate that's like the slope of a mountain. The graph of a coarse edge looks more like a plateau with a rapid drop off at the very end. While both edges cut similar amounts of media the coarser edge maintains a consistent sharpness over a longer period of time. This gives more perceived edge retention to the user.

Beyond that it become task specific where some objects to be cut will prefer a coarse or fine edge.
 
I like toothy edges, that are very aggressive and cut like crazy.After sharpening on a coarse stone or any type of sharpener, I give it few light strokes on fine stone,strop or leather, and this way they shave hair too while having plenty of aggression.The edges I get are toothy and yet most times they can whittle hair too(that is not my goal ,but a byproduct of properly apexed edge and light controlled strokes).My dmt folding coarse sharpener was the only thing used for last few months.Few light strokes and stroping of back of my palm was all that was used.Excellent toothy edges that last long time.Thin edge geometry was another factor that's important!Knives get dull easily on plates,ceramics can dull or sharpen !
 
Obsessed with Edges beat me to it, I think that is what is going on the knife wasn't fully sharpened and when the wire edge was removed it revealed the not so apexed edge behind it.

I use cheap dollar store knives to experiment on and for dinner quite a lot as they tend to be sharper than the normal kitchenware I have most times (these tend to not want to take an edge, not want to hold it, bad geometry) and they are set from 15-25dps with various levels of finish. Trust me when I say this a steak will not dull a Sebenza unless it was improperly sharpened, or bad cutting technique by cutting into the plate or constantly trying to cut through the bone aggressively.
 
Put the sebenza on belt sander little:),to thin out the edge,and then raise angle just little bit and give it few strokes on diamond rod,stone or whatever.That should solve problem,most knives are not properly apexed,or are too thick behind the edge.
 
I used to do the xc, c, f, ef diamond and 2000 sand paper followed by stropping. It made beautiful hair whittling edges. However, certain materials were immune to such edge refinement. Now I agree about aggressive edges. Right off the 600 grit fine DMT and just a few very light passes on stropman white. Time to cut!
 
Honed_Edge said:
I used to do the xc, c, f, ef diamond and 2000 sand paper followed by stropping. It made beautiful hair whittling edges. However, certain materials were immune to such edge refinement. Now I agree about aggressive edges. Right off the 600 grit fine DMT and just a few very light passes on stropman white. Time to cut!
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Yea...what he said
 
ursamajor said:
The knife isn't even dull. It just needs to be honed on either a strop or a Steel. A "toothy" edge is an unaligned edge. Take your hands and interlock your fingers with them sticking out.

Like this

6a00e550bbaeb3883401287620273b970c-250wi


This is a what a Toothy edge looks like if you are lucky. Most likely, half ass sharpening a blade will leave a wire burr.

The "teeth" need to be aligned-by either a Steel or a strop. Skip that step after the stone, and you are going to end up with fools gold for the edge. It will seem sharp, but its really isn't.
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Not if you know how to properly finish on a stone.
 
walleyeguy7 said:
Sebenzas are definitely not known for their edge holding, but toothy is dull bullshit. Polished is just sharper and better. A perfect mirror is the best.
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ursamajor said:
The knife isn't even dull. It just needs to be honed on either a strop or a Steel. A "toothy" edge is an unaligned edge.
[...]
The "teeth" need to be aligned-by either a Steel or a strop. Skip that step after the stone, and you are going to end up with fools gold for the edge. It will seem sharp, but its really isn't.
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We might have a terminology problem here. Most people here say "toothy" when they mean a coarse edge. That is, an edge that has been sharpened with a relatively coarse stone, and apexed properly, and had the burr totally removed. You can do this at 80 grit, 100, 400, or 600.

The result is an edge that is truly sharp in that it has a consistent apex and no dull spots. It's also not "false sharp" because the burr is gone. The "toothy" part is simply that the edge has furrows in it left by the coarse stone. How deep and wide these furrows are depend on what kind/grit stone you stopped at.

I can tell you from personal experience that coarse edges absolutely cut like crazy and can cut for longer in some media compared to a polished edge. You might also be surprised at how incredibly sharp a coarse edge can be. Straight off of a DMT coarse stone (45 micron, ~320 grit), I've made edges that easily shave arm hair, without much resistance.

These types of edges feel more sticky when doing the 3 finger test of sharpness. They dig into media more easily because of the furrows in the edge. In a way they are micro-serrated. Here's master knife maker / sharpener Murray Carter on the 3 finger test:

[video=youtube;2k1o70tMHYM]https://www.youtube.com/watch?v=2k1o70tMHYM[/video]

Brian.
 
bgentry said:
We might have a terminology problem here. Most people here say "toothy" when they mean a coarse edge. That is, an edge that has been sharpened with a relatively coarse stone, and apexed properly, and had the burr totally removed. You can do this at 80 grit, 100, 400, or 600 ... no burr .. easily shave arm hair, without much resistance
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Hi,
You can even go lower, like extra coarse macro grits
Check it out
just newspaper slicing Extreme low grit sharpening : 24 grit nubatama - Cliff Stamp
actual arm hair shaving in this one Knife sharpening : 36 grit dressing stone - Cliff Stamp
 
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