Polished Edge: When, Why, What Steels??

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w3tnz
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Re: Polished Edge: When, Why, What Steels??

#21

Post by w3tnz »

Airlsee wrote:
Sun Jul 25, 2021 7:26 pm
I don't think 1500 grit is overly polished, in fact I do the same most times. I will sharpen up to ~1200-2000 then micro on the brown stones usually.
Yeah you are right that 1500 isn’t really polished, it’s the stropping that gives that mirror finish. I use the leather ones loaded with 3.5 and 5 mu compounds and you can still faintly see the scratch pattern from the stones.

I always planned to get the ceramic stones as an intermediate step between the stones and strops but haven’t found it necessary given what they cost.

I don’t have to do a lot of cutting with my current job so my edges last ages so I don’t have to reprofile often.
Using the brown stones micro bevel and touch up gives decent bite at the apex but I do like the mirror look on the bevel.
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Re: Polished Edge: When, Why, What Steels??

#22

Post by sbaker345 »

The Meat man wrote:
Sun Jul 25, 2021 9:21 pm
sbaker345 wrote:
Sun Jul 25, 2021 7:53 pm
I usually went for about 1,000 grit on knives I knew Id be sharpening a lot due to the high chance of them experiencing metal on metal contact. However I did always go for polished mirror or near mirror edges on less carried knives, it was for the challenge as much as anything. Try polishing s110v to a mirror finish, you'll be there a while. Some steels particularly high HRC steels seemed to take to a polished finish better, but really it was always some sort of minor edge damage that brought them back to the stones before true dullness, though in fact it felt like the more polished the edge, the more resistant it was to minor damage.
Excellent observation. It only makes sense, too. A coarse edge is, microscopically, very rough and uneven, with many individual "points" that protrude and may break off. It will not be as strong as the smooth, unified edge of a highly polished bevel.

This difference is no doubt exacerbated by the fact that the coarser the edge, the more skill it takes to completely remove any burr and leave a crisp apex.

The question then, is, would this difference be noticeable in daily use? In your case, it would seem so.
That was exactly my theory, to be fair I'm not sure if I would've noticed had I not been testing knives, and sometimes at varying level of edge finish, If I left a toothy edge carving up wood and thick plastic would inevitably take their toll on the results of the shave test, but frequently when I spent the time and effort to work up to a near perfect mirror finish, sometimes it would feel like the knife never dulled at all.
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Re: Polished Edge: When, Why, What Steels??

#23

Post by FK »

Polished = push cutting,,,, wood working, cardboard breakdown,, chopping for kitchen use,,, etc
Coarse = slicing, kitchen knives for some uses.
Some of my kitchen knives are polished and some are coarse,,, depends upon application.

This discussion carries over to the kitchen knife forums with some very expensive hard steel applications.

My general EDC preference is polished bevel for reduced friction drag in slicing and micro bevel at about 800-1,200 grit for nice slicing performance.

With diamond compounds like Gunny Juice on thin hard leather or hard felt,,, it only takes a few minuites to polish the main bevel and remove any burr. Then a DMT Extra Fine diamond for the micro bevel.

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Re: Polished Edge: When, Why, What Steels??

#24

Post by ZrowsN1s »

When? Always.
Why? Shiny edge is best.
What? Everything.
:D

Seriously though with rare exception I take everything to high refinement. Mirror polishing a bevel is an aesthetic choice. I will usually polish the bevels 'a little'. But my edges get ultrafine stone grits, and 1micron stropped.

Why?

For me there is nothing more satisfying than making a cut with a highly refined edge. Like a laser beam. I don't care if the edge retention isn't as good as coarse edges, or if it doesn't have as an aggressive bite. That smooth clean crispy cut is what has drawn me to knives my whole life.
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Albertaboyscott
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Re: Polished Edge: When, Why, What Steels??

#25

Post by Albertaboyscott »

I polish my edges whenever the urge strikes me for whatever steel. I use it for a while and maybe when I resharpen it, I go coarse. The next time I sharpen, maybe polished again. I'm not all freaky about a hard and fast rule for a steel, one way or the other. I've NEVER had an edge, coarse or polished, not last long enough till the next t/u. Just my experience/opinion. I like sharpening so whatever I feel like that day. They all cut just fine
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Re: Polished Edge: When, Why, What Steels??

#26

Post by Airlsee »

ZrowsN1s wrote:
Mon Jul 26, 2021 2:10 pm
When? Always.
Why? Shiny edge is best.
What? Everything.
:D

Seriously though with rare exception I take everything to high refinement. Mirror polishing a bevel is an aesthetic choice. I will usually polish the bevels 'a little'. But my edges get ultrafine stone grits, and 1micron stropped.

Why?

For me there is nothing more satisfying than making a cut with a highly refined edge. Like a laser beam. I don't care if the edge retention isn't as good as coarse edges, or if it doesn't have as an aggressive bite. That smooth clean crispy cut is what has drawn me to knives my whole life.

This is the ideal response I was looking for in this thread. There is no right or wrong, just why & when...
So it goes.
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Airlsee
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Re: Polished Edge: When, Why, What Steels??

#27

Post by Airlsee »

Albertaboyscott wrote:
Mon Jul 26, 2021 2:28 pm
They all cut just fine

So many internet arguments could have been headed off, if this were the stance of most blade afi's.

I suspect there are many here, that disagree with this stance.
So it goes.
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Re: Polished Edge: When, Why, What Steels??

#28

Post by Albertaboyscott »

Airlsee wrote:
Mon Jul 26, 2021 2:45 pm
Albertaboyscott wrote:
Mon Jul 26, 2021 2:28 pm
They all cut just fine

So many internet arguments could have been headed off, if this were the stance of most blade afi's.

I suspect there are many here, that disagree with this stance.
Yeah I'm sure there are many who would argue one way or the other. To each his own and respect each other's opinions/feelings is my take. No point in trying to convince anyone of anything if you disagree. We're all spydie fans in the end. Cheers
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Airlsee
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Re: Polished Edge: When, Why, What Steels??

#29

Post by Airlsee »

Albertaboyscott wrote:
Mon Jul 26, 2021 2:57 pm
Yeah I'm sure there are many who would argue one way or the other. To each his own and respect each other's opinions/feelings is my take. No point in trying to convince anyone of anything if you disagree. We're all spydie fans in the end. Cheers

Absolutely! We're all Spydie fans, and definitely over-analyzing things that in the end are pretty insignificant.

Cheers!
So it goes.
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Re: Polished Edge: When, Why, What Steels??

#30

Post by Wandering_About »

My preferred edge is 3000 grit stone with a quick finish for deburring on 1 micron diamond. It works well for me on pretty much everything. Sometimes I will just go to 800 or 1000, but most of the time I like a little finer edge. I've tried everything from coarse to polished over the years and that is just what I prefer. I don't really bother with different finishes for different steels or applications very often, unless I decide to do another experiment.
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metaphoricalsimile
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Re: Polished Edge: When, Why, What Steels??

#31

Post by metaphoricalsimile »

ZrowsN1s wrote:
Mon Jul 26, 2021 2:10 pm
When? Always.
Why? Shiny edge is best.
What? Everything.
:D

Seriously though with rare exception I take everything to high refinement. Mirror polishing a bevel is an aesthetic choice. I will usually polish the bevels 'a little'. But my edges get ultrafine stone grits, and 1micron stropped.

Why?

For me there is nothing more satisfying than making a cut with a highly refined edge. Like a laser beam. I don't care if the edge retention isn't as good as coarse edges, or if it doesn't have as an aggressive bite. That smooth clean crispy cut is what has drawn me to knives my whole life.
I think it's worth pointing out that the forum members here who claim better edge retention with coarse edges are making claims that contradict *many* other sharpeners/users.
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Re: Polished Edge: When, Why, What Steels??

#32

Post by TkoK83Spy »

metaphoricalsimile wrote:
Mon Jul 26, 2021 4:07 pm
I think it's worth pointing out that the forum members here who claim better edge retention with coarse edges are making claims that contradict *many* other sharpeners/users.
I dunno man, I use my knife for probably 3 hours or so a day of actual in hand use in a warehouse. I've tried quite a few different knives, steels and edge finishes over the past few years.

I can honestly say that I've noticed a fairly significant difference in the performance of my 52100 Manix after, granted reprofiling it and knocking off a few degrees...but left it with a 320 grit finish. Cutting a lot of the same materials daily, it's needed far less touchups or time touching up when needed after getting rid of the factory edge and finish.

Same goes for my M4 Para 3. There was a slight scratch on the side of the bevel and I decided just to give it a quick, new scratch pattern on my DMT Coarse stone. Since then, another noticeable difference in retention and overall performance in the warehouse.
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vivi
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Re: Polished Edge: When, Why, What Steels??

#33

Post by vivi »

metaphoricalsimile wrote:
Mon Jul 26, 2021 4:07 pm
I think it's worth pointing out that the forum members here who claim better edge retention with coarse edges are making claims that contradict *many* other sharpeners/users.
I'm not sure if you've seen this video:

https://youtube.com/watch?v=VbDHhIx-ZO4

It's not something I'm merely claiming. It's something I've demonstrated.

Many other posters here have experienced the same thing. We can go 2-4x as long between touch-ups by sharpening with a coarser finish and using thinner edge angles.

Of course that doesn't mean low grit edges are the end all be all. I'll still take a polished edge on certain knives and tools - they're superior for certain uses.
ZrowsN1s wrote:
Mon Jul 26, 2021 2:10 pm
For me there is nothing more satisfying than making a cut with a highly refined edge. Like a laser beam. I don't care if the edge retention isn't as good as coarse edges, or if it doesn't have as an aggressive bite. That smooth clean crispy cut is what has drawn me to knives my whole life.
I think the first time anyone tries a well sharpened polished edge it's an eye opening experience. Most people are used to terribly dull knives, where they have to saw back and forth vigorously to make any progress. Being able to effortlessly push cut through something is a night and day difference.
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Re: Polished Edge: When, Why, What Steels??

#34

Post by Sharp Guy »

w3tnz wrote:
Sun Jul 25, 2021 7:06 pm
Always, looks cool, micro bevel at 20dps with brown rods to give some bite and maintain sharpness.

I go up to 1500 15dps on stones and strop to mirror finish, there are still some lines if you look really closely.
That's pretty much what I was going to post. Except I use polishing tapes instead of the strop

When I reprofile I pretty much go through the whole progression. I sometimes plan on stopping but usually end up going all the way to mirror. It doesn't really take much longer and I think it looks great. I'm not out cutting a bunch of rope and things that are easier to cut with a coarse edge. My pocket knives are primarily used for regular edc stuff. Nothing special. When it's time to touch up the edge I create a micro-bevel on the SM brown rods and that's basically what I use until it's time to reprofile again.
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Re: Polished Edge: When, Why, What Steels??

#35

Post by metaphoricalsimile »

vivi wrote:
Mon Jul 26, 2021 5:19 pm
metaphoricalsimile wrote:
Mon Jul 26, 2021 4:07 pm
I think it's worth pointing out that the forum members here who claim better edge retention with coarse edges are making claims that contradict *many* other sharpeners/users.
I'm not sure if you've seen this video:

https://youtube.com/watch?v=VbDHhIx-ZO4

It's not something I'm merely claiming. It's something I've demonstrated.

Many other posters here have experienced the same thing. We can go 2-4x as long between touch-ups by sharpening with a coarser finish and using thinner edge angles.

Of course that doesn't mean low grit edges are the end all be all. I'll still take a polished edge on certain knives and tools - they're superior for certain uses.
ZrowsN1s wrote:
Mon Jul 26, 2021 2:10 pm
For me there is nothing more satisfying than making a cut with a highly refined edge. Like a laser beam. I don't care if the edge retention isn't as good as coarse edges, or if it doesn't have as an aggressive bite. That smooth clean crispy cut is what has drawn me to knives my whole life.
I think the first time anyone tries a well sharpened polished edge it's an eye opening experience. Most people are used to terribly dull knives, where they have to saw back and forth vigorously to make any progress. Being able to effortlessly push cut through something is a night and day difference.
I'm an R&D engineer by trade, and I've pointed out issues with your methodology in the past and you haven't seemed particularly interested in that feedback.

Edit: I also want to point out that I'm not flat-out claiming that you're *wrong* just that I don't think you've done a sufficient job demonstrating evidence for your claims, mostly due to not controlling for multiple different factors at once and also due to not recording numerical factors.
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Re: Polished Edge: When, Why, What Steels??

#36

Post by Kevinim82 »

@ metaphoricalsmile, which commentor are you addressing, you copied the course edge and polished edge forum member… please clarify your stance and data point.
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Re: Polished Edge: When, Why, What Steels??

#37

Post by metaphoricalsimile »

Kevinim82 wrote:
Mon Jul 26, 2021 8:17 pm
@ metaphoricalsmile, which commentor are you addressing, you copied the course edge and polished edge forum member… please clarify your stance and data point.
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Re: Polished Edge: When, Why, What Steels??

#38

Post by Vaugith »

I've personally been continually experimenting with the finishes left by different stones on different steels for different tasks. I don't do any controlled repeatable experiments though so I'll leave the real thunder to the folks who have the energy to do those. I have found a polished edge to do well in the kitchen and on my outside of work knives that only see light use. My work knives I prefer a mirror polish bevel set followed by a sharpmaker medium microbevel. But I'm still trying new things.

Now if anyone cares to go past things that we can all test in the real world and think about theory: Wouldn't one of the main reasons to work up a grit progression to a polished edge be to reduce subsurface damage to as shallow of an area as possible? This would explain anyone's feelings that polished edges seemed more durable, as well as having a more consistent texture and therefore less crack initiation points. Hence polishing and then following with a coarse microbevel.
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Re: Polished Edge: When, Why, What Steels??

#39

Post by Sharp Guy »

Some of you guys get way too deep into this stuff for me :D I try to keep it simple, I sharpen my knives until I feel it's as sharp as I want it. Then I cut the things I need to cut and continue doing so until the knife doesn't cut how I like anymore. Then I repeat. I like science and all but it I really don't want to get a headache overthinking how to sharpen a knife lol

I think it's BFK that has Sal's quote in his tag line. Something about edge Junkies just being nuts! Spot on haha :)
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Re: Polished Edge: When, Why, What Steels??

#40

Post by vivi »

Sharp Guy wrote:
Mon Jul 26, 2021 10:18 pm
Some of you guys get way too deep into this stuff for me :D I try to keep it simple, I sharpen my knives until I feel it's as sharp as I want it. Then I cut the things I need to cut and continue doing so until the knife doesn't cut how I like anymore. Then I repeat. I like science and all but it I really don't want to get a headache overthinking how to sharpen a knife lol

I think it's BFK that has Sal's quote in his tag line. Something about edge Junkies just being nuts! Spot on haha :)
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