Mirror polished edges - Which steels are better (and worst) for taking them?

[Menipo]

Quite recently I have joined the CAMPE (Cult of Adorers of the Mirror Polished Edge) :D

Though I am buying and using the cheapest knives I can find to complete my learning curve, sooner or later, knives of my collection will start to be converted to the mirror polished edge true faith ...

As I am sure that many of you have been sharpening different steels for years, I turn to your experience. Is there any steel you would recommend not to sharpen (polish) to a mirror like point for any reason (I have Spydies with AUS-6, CPM-440V, ATS-55, VG-10, S30V, and S110V blades). And a Cara Cara with 8Cr13MoV.

Thanks in advance for your input!

[driftingfir]

Typically s110v has better edge retention with a coarser edge.

[Menipo]

Typically s110v has better edge retention with a coarser edge.

Thanks for the tip because, in fact, one of my S110V blades (PM2) was in the line of candidates to become a believer in the true faith ...

[vivi]

Easy to grind steels would be my first choice, since they'd take less time to achieve a true mirror polish.

As for which attributes to look for in a steel for optimal polished edge performance, edge stability is key. Hard steels that won't chip for your uses, steels with high toughness, etc.

Typically s110v has better edge retention with a coarser edge.

I've had this hold true for every steel I've tested it on. Which includes K390, H1 PE, H1 SE, A2, 1095, VG10, S30V, 204P, ZDP189, 440C, 8cr and others.

I used to run polished edges on everything, but over time I observed it was extra effort for less edge holding. Now I sharpen PE knives on 200-500 grit diamond stones typically.

[JRinFL]

Being lazy by nature (also my '90's hip hop name) I found the same thing, that a course edge works best for me, on my knives. I never go beyond the grey stones on the Sharpmaker. I do like the look of mirror edges, but only when others do the work. :D

[Menipo]

Easy to grind steels would be my first choice, since they'd take less time to achieve a true mirror polish.

As for which attributes to look for in a steel for optimal polished edge performance, edge stability is key. Hard steels that won't chip for your uses, steels with high toughness, etc.

Typically s110v has better edge retention with a coarser edge.

I've had this hold true for every steel I've tested it on. Which includes K390, H1 PE, H1 SE, A2, 1095, VG10, S30V, 204P, ZDP189, 440C, 8cr and others.

I used to run polished edges on everything, but over time I observed it was extra effort for less edge holding. Now I sharpen PE knives on 200-500 grit diamond stones typically.

Thanks for your detailed comment, Vivi. I have a dozen knives for EDC rotation and following your advide I will not run a polished edge on any of them. As to the rest of my collection, as they are not used (they only leave the showcases to be admired and get a film of Sentry Tuf-Glide from time to time, edge retention is not crucial, so a number of them may get their edge mirror polished.

[Menipo]

Being lazy by nature (also my '90's hip hop name) I found the same thing, that a course edge works best for me, on my knives. I never go beyond the grey stones on the Sharpmaker. I do like the look of mirror edges, but only when others do the work. :D

Send me your knives and I will take care of it. I need keep practicing before I put my own knives at stake :rolleyes:

[JD Spydo]

I'm not exactly sure if S30V would produce a "mirror polished edge" as you allude to. But I do remember the first two Spyderco models I got that had S30V blades I immediately noticed that the blades themselves did not take a nice polished look like VG-10 or AUS-8. Not sure how that equates in the performance of the steel but I've never gotten a mirror finish with S30V.
Now I don't own a Wicked Edge or Edge Pro system either one. I'm still not convinced which one is the best. Right now I'm leaning more toward the Edge Pro based on what a couple of guys have told me that use them.

Also the one Brother points out that S110V does slightly better with a "toothy" edge. I have indeed noticed that myself with my Para2 that has S110V. I guess I don't really care what they look like as long as I get superb performance from my knife blades.

[Menipo]

I'm not exactly sure if S30V would produce a "mirror polished edge" as you allude to. But I do remember the first two Spyderco models I got that had S30V blades I immediately noticed that the blades themselves did not take a nice polished look like VG-10 or AUS-8. Not sure how that equates in the performance of the steel but I've never gotten a mirror finish with S30V.
Now I don't own a Wicked Edge or Edge Pro system either one. I'm still not convinced which one is the best. Right now I'm leaning more toward the Edge Pro based on what a couple of guys have told me that use them.

Also the one Brother points out that S110V does slightly better with a "toothy" edge. I have indeed noticed that myself with my Para2 that has S110V. I guess I don't really care what they look like as long as I get superb performance from my knife blades.

Thanks! I bought last week a KME system (once I got some practice with the Lansky) but had no time to try it. Maybe during the coming weekend ...

[vivi]

I think you should take one of your carry knives to a mirror polish and test for yourself if what I experienced holds true for you as well. Especially if you have multiples of the same model, its a fun project.

Right now I have 3 PE Police folders. One sharpened at 300 grit on diamonds, one sharpened at 600 grit on diamonds, and one sharpened on a fine Spyderco ceramic stone. They all cut well but I find I prefer using the first. Maybe you'll find the same is true for you, or maybe you'll prefer something else.

[JuPaul]

I also have a KME and I think it's pretty fun to take steels to a high level of polish, and I've played around with mirror edges on lots of steels from 8cr to s30v to cruwear and 4v. I've yet to put a highly polished edge on k390 or rex45, but I plan to, mostly just to see what will happen. I agree it doesn't help with edge retention, and it won't give you a "grippy edge" for rope or fibrous materials. But it sure feels extra slicey and it looks purdy! I like my mushroom hunting knives to have polished edges, but I'm finding I like a lower grit finish - or even a serrated edge blade - for lots of other outdoor tasks.

[Albatross]

Any steel can take a polish, but as a general rule of thumb, high carbide steels don't perform as well with a polished edge. The carbides act as micro serrations with high edge retention, so polishing smooths over the carbides, making them far less effective.

S30V will take a polish, but not as well as VG10, CTS XHP, BD1N, or other similar steels. Rex 45 works with a polish and so does M390/204P/20CV, but that's because of the lower vanadium content. In fact, M390 actually has more vanadium content than Rex 45, even if it's only by a very small amount. I usually finish my Rex 45 knives with a 1500 grit stone, then diamond spray/paste strops in 1, .5, and .25 microns. If I'm sharpening just for sharpness, the edge wont end up with a polish, but if I'm setting out to polish it, all it takes is a little more effort with the same grits.

Ive heard that anything over 4% vanadium requires diamond stones for sharpening, and should be sharpened to a lower grit finish, such as 400-600 grit. I'm not sure what that is based on, but it seems like the 4% cutoff works well (at least from what I've seen) as criteria for polished edges.

[Menipo]

I think you should take one of your carry knives to a mirror polish and test for yourself if what I experienced holds true for you as well. Especially if you have multiples of the same model, its a fun project.

Right now I have 3 PE Police folders. One sharpened at 300 grit on diamonds, one sharpened at 600 grit on diamonds, and one sharpened on a fine Spyderco ceramic stone. They all cut well but I find I prefer using the first. Maybe you'll find the same is true for you, or maybe you'll prefer something else.

I have taken to a mirror polish one of my EDCs (A Gerber SLG 3.25 ATS-34) with the Lansky and carried it for two full weeks. It is keeping its edge quite well. ATS-34 is the "best" steel that I have sharpened to that point so far.



I will follow your advice and will test it by my self. Many thanks, Vivi!

[Menipo]

I also have a KME and I think it's pretty fun to take steels to a high level of polish, and I've played around with mirror edges on lots of steels from 8cr to s30v to cruwear and 4v. I've yet to put a highly polished edge on k390 or rex45, but I plan to, mostly just to see what will happen. I agree it doesn't help with edge retention, and it won't give you a "grippy edge" for rope or fibrous materials. But it sure feels extra slicey and it looks purdy! I like my mushroom hunting knives to have polished edges, but I'm finding I like a lower grit finish - or even a serrated edge blade - for lots of other outdoor tasks.

I moved from the Lansky to the KME because when putting a mirror edge, I managed to scratch the blades.






Don't ask me how I did it (because I thought that this was impossible with guided systems as the stone is supposed to have contact with the blade only at the edge which it is generating) but it happened. So I hope that the KME will allow me to put mirror edges ... without the Lansky side effects :D

[Menipo]

Any steel can take a polish, but as a general rule of thumb, high carbide steels don't perform as well with a polished edge. The carbides act as micro serrations with high edge retention, so polishing smooths over the carbides, making them far less effective.

S30V will take a polish, but not as well as VG10, CTS XHP, BD1N, or other similar steels. Rex 45 works with a polish and so does M390/204P/20CV, but that's because of the lower vanadium content. In fact, M390 actually has more vanadium content than Rex 45, even if it's only by a very small amount. I usually finish my Rex 45 knives with a 1500 grit stone, then diamond spray/paste strops in 1, .5, and .25 microns. If I'm sharpening just for sharpness, the edge wont end up with a polish, but if I'm setting out to polish it, all it takes is a little more effort with the same grits.

Ive heard that anything over 4% vanadium requires diamond stones for sharpening, and should be sharpened to a lower grit finish, such as 400-600 grit. I'm not sure what that is based on, but it seems like the 4% cutoff works well (at least from what I've seen) as criteria for polished edges.

Thanks, Albatross! Really impressive.

I only use diamond stones and try to avoid steels with "an inclination to rust". I have two ATS-55 Spydies (a Dyad -the big one- and a Civilian) and though they are not in the EDC rotation and never leave the showcase (dry environment) I have to keep an eye always on them ...

[nerdlock]

I also have a KME and I think it's pretty fun to take steels to a high level of polish, and I've played around with mirror edges on lots of steels from 8cr to s30v to cruwear and 4v. I've yet to put a highly polished edge on k390 or rex45, but I plan to, mostly just to see what will happen. I agree it doesn't help with edge retention, and it won't give you a "grippy edge" for rope or fibrous materials. But it sure feels extra slicey and it looks purdy! I like my mushroom hunting knives to have polished edges, but I'm finding I like a lower grit finish - or even a serrated edge blade - for lots of other outdoor tasks.

I moved from the Lansky to the KME because when putting a mirror edge, I managed to scratch the blades.





Don't ask me how I did it (because I thought that this was impossible with guided systems as the stone is supposed to have contact with the blade only at the edge which it is generating) but it happened. So I hope that the KME will allow me to put mirror edges ... without the Lansky side effects :D

I've seen photos and videos of several Spyderco enthusiasts putting mirror edges on their PM2s with the Lansky system, all without your side-effect of scratching the blade...maybe you should try taping the blade and leaving only the edge/near-edge part for sharpening and polishing?

[Cambertree]

AEB-L and LC200N take a polished edge very easily. So would H1, I suppose, although I’ve never tried it on that steel, and the utility of that kind of edge on H1 would be debatable.

In the higher carbide steels, I’ve found steels with predominantly chromium carbides, like CTS-XHP, M390 and ZDP189 to all take a good polish.

Diamonds and CBN compounds are your friend.

Generally, I prefer some bite to my edges, with some very slight stropping refinement to aid push cutting ability.

While mirror polishing your edges can be a useful exercise in developing your sharpening skills, generally I try to customise edge finishes to the particular steel and intended purpose of a knife. Usually I only use that kind of edge for some kitchen knives.

Menipo - So what’s happening with those scratches, is when you grind at an angle where the grind lines are not exactly perpendicular to the curve of edge, your effective edge angle is reduced, which brings the stones closer to the flats.

I suppose you could adjust this by changing your clamp positioning.

Also, taping up the flats, as Nerdlock said, will help - but I’d aim to make sure the grind lines are perpendicular to the edge first, all the way up to the tip.

Changing the angle of the grind lines, so they face slightly forward or back on different parts of the edge is certainly a valid and useful technique, but that method is probably something for a separate discussion. :)

[jpm2]

It seems to me the harder steels are more resistant to scratching, where a softer (or no carbide) steel will scratch deeper with a given abrasive. The result should mean a harder steel is more difficult to polish, but is capable of a higher quality polish.
This should also mean, given equal polish, the harder, or higher carbide steel should hold that polished sharp edge longer.

[JuPaul]

Reading these sharpening threads always reminds me of how much I have to learn! It's a very humbling experience. :o

[bbturbodad]

I like clean push cutting blades so I've taken a good number of steels to a polished edge. Surprisingly I've found Maxamet and PMA 11 (similar to 10V) take great polished edges.