Your experience sharpening super steels?

[ATJ999]

3V, elmax, and s35vn are all great steels to sharpen. 3V is such an amazing steel, so easy to sharpen and gets razor sharp. I have it is a 3 inch folder all the way up to a 22 inch slimline machete and it works great in all of them! If you want a hard use knife, it is the way to go. I beat the crap out of my 3V fixed blades, and they take it! S110v I would stay away from, I only have one knife in S110v that has a good HT, and it is a fantastic knife. However, I have 2 others that are not great! S90V I prefer much more for some reason, never had a problem with. My S90v Hoback A10 is one of my top 3 favorite EDC folder, great grind and HT.
20CV, M390, and 204P are fantastic steels, very easy to sharpen, work great in fine and rough grit edges, and gets very sharp. Amazing all around low maintenance steels! If you like Elmax you will love them.
My new favorite steel is K390. Oh man! If you can find a knife you like in this steel I highly recommend it. Very similar to 10V, but I find it easier to sharpen and gets very very sharp with such little effort. I now have 3 more K390 knives on order ever since I bought my first. I am still in shock with how little effort it is to sharpen compared to how well it holds an edge. I can imagine reprofiling is not a walk in the park, but if you have proper tools, it won't be a problem. The only drawback is corrosion resistance, but I have yet to have any corrosion issues. I just remember to take care on wet days.

M4 has impressed me, but for me K390 is a step up.

So, right now, and probably forever since those last 3 knives on order are it for my knife buying. I got my perfect assortment now, and I am done. Anyways, right now my 5 favorite knives have these steels, in no order - 3V, K390, 20CV, S90V, and Stellite 6K(not steel but a favorite knife metal) And S90V is the hardest of those for me to sharpen. If I only had 5 knives in those 5 metals, I would not complain, they are fantastic. But, there are som many great steels out there right now, not saying they are the best by any means. They are my favorites, but everyone is different, and every knife is different with different HT, edge profiles, etc.

OH and as for my sharpening stones and whatnot. I use freehand spyderco ceramics(don't have a sharpmaker but the triangle stones freehand are great, especially on large fixed blades), I use black and trans. Arkansas stones, they work great for me on all the steels I mentioned, Diamond stones work wonders, and I use a belt grinder with a guided system which is amazing for reprofiling. That is pretty much all I use. Took a long ass time to get decent at sharpening, years, and only this year I really "got it", still learning though. It is an art for sure!!

Almost forgot CTS-PD#1 and Cruwear. One of the best all around steels. So easy to sharpen and gets razor sharp like 3V! So many great steels out there!

 

[Obsessed with Edges]

I see your point. If that is the case, as the "soft" steel surrounding the carbides is abraded away by the stone, won't it remove those carbides and expose new ones? Isn't this effectively sharpening the blade?

Up to a point, yes. The difference is, abrasives that are capable of cutting the carbides will do a much better job actually shaping the carbides at the edge, instead of just eroding the matrix steel supporting them, to the point the carbides just break away. That's what I meant earlier, in that there's a difference in how refined the edge will get, depending on whether the carbides get cut, shaped and thinned at the apex (more refined), or if they just break away due to lack of support, leaving voids in the apex where they used to be (less refined). In steels like 90V, 110V and others, a large percentage of the alloy (9% or more) is comprised of carbides that won't be shaped or sharpened at the edge if the abrasive used isn't hard enough to do it. Effectively, in that example, you're sharpening maybe 90% of the edge, and not getting the benefit of well-shaped and sharpened carbides as well.

Compare the steel with the carbides to a concrete floor with aggregate pebbles in it. You can grind the supporting cement (representing the 'matrix steel') with a less capable abrasive that isn't capable of actually abrading the much harder aggregate pebbles (the 'carbides'), leaving a rough finish on the surface and at the edges/corners, with the 'carbide' pebbles exposed proud of the surface, and some voids left by the pebbles that break away. Or you can use an abrasive that's also capable of grinding the pebbles themselves to be flush to the supporting cement, leaving a much more refined surface and sharper edges and corners.


David

 

[David Martin]

And we're not really sure this ^ Is happening. DM

 

[David Martin]

Personally I'm with you 95%.

I've seen some of Ankerson's testing numbers and some of my own limited testing indicates potential multiples of "passes" before notable dulling on a standard cutting media. There's no doubt in my mind that some steels hold a functional edge for a looong time (D2 for example) and that factor is a function of the carbide content, whatever it happens to be.
Ok, most of this I agree with. Yet, some steels without vanadium hold an edge longer than those with vanadium. S30V and CPM154 come to mind. Plus, the later is easier to sharpen. (not requiring special sharpening stones) So, first off you don't have to have a high V steel to get several thousand cuts on sisal rope. Then there is the expense of the high V steel. Makers don't care to grind those for cheap for a reason. No, doubt they cut until the cows come home but will they match 2 blades of say ATS-34? No, but they will cost over that much. These are some items to consider when purchasing the in vogue steels. DM

 

[HeavyHanded]

Personally I'm with you 95%.

I've seen some of Ankerson's testing numbers and some of my own limited testing indicates potential multiples of "passes" before notable dulling on a standard cutting media. There's no doubt in my mind that some steels hold a functional edge for a looong time (D2 for example) and that factor is a function of the carbide content, whatever it happens to be.

Ok, most of this I agree with. Yet, some steels without vanadium hold an edge longer than those with vanadium. S30V and CPM154 come to mind. Plus, the later is easier to sharpen. (not requiring special sharpening stones) So, first off you don't have to have a high V steel to get several thousand cuts on sisal rope. Then there is the expense of the high V steel. Makers don't care to grind those for cheap for a reason. No, doubt they cut until the cows come home but will they match 2 blades of say ATS-34? No, but they will cost over that much. These are some items to consider when purchasing the in vogue steels. DM

This is all true, that's why I mentioned "carbide content" and not specifically Vanadium carbides. Even steels with high cementite content tend to outperform those with lower, and HSS makes very nice knife stock from my experience. And even then, steels with lower edge retention - lower wear resistance will almost by definition be many times faster to regrind an edge and capable of being worked on a huge variety of abrasives right down to the underside of a coffee cup.

One thing I never tested when cutting rope was a full on endurance routine where once the edge began to fail I include resharpening time along with other metrics. So if a steel cuts 3x more than another but takes 4x as long to resharpen that's another factor. And as you mention, the cost might well be 4x that of the same knife in regular steel. Using your example, what if we took a dollar value and compared the three or four knives to the one to see how much rope our money cost.

 

[David Martin]

Exactly. How much does it cost to chase this trend? I think one end of the scale is heavy with dollar cost. While the other end is heavy with cutting more rope. And we're off of this gentleman's topic. DM

 

[Jamesh Bond]

Personally I'm with you 95%.

I've seen some of Ankerson's testing numbers and some of my own limited testing indicates potential multiples of "passes" before notable dulling on a standard cutting media. There's no doubt in my mind that some steels hold a functional edge for a looong time (D2 for example) and that factor is a function of the carbide content, whatever it happens to be.

However the steels that perform so, all seem to have idiosyncrasies in the type of finish they prefer, edge angle, certainly the type of abrasive used.

Whereas stuff like carbon steel at 1070 or higher, or fine grained stainless all take pretty much whatever edge finish you care to apply, and hold it for...a few - as in 'long enough' that re-sharpening isn't a hassle and I don't have to sweat it if the edge turns on something my edge shouldn't have slammed into. Its far easier to me to just have easy means of keeping my edges sharp rather than rely on inherent and pricey qualities of the steel itself. Truth be told I no longer even bring sharpening media with me when camping/backpacking as all my choppers and camp knives are low carbide stainless or carbon steel and can be touched up with improvised means right back to shaving sharp.

Not to mention the super steels all have a super duper price tag...they are pretty neat though, and that's the 5% I like about them. Several hundred passes through manila rope and still shave arm hair and slice thin paper - my regular cutlery can't touch that and the really cheap stuff can only dream about that level of edge retention.

Very well stated. Agreed on all. I too enjoy touching up my knives on things I find while out and about!

 

[Jens Schuetz]

If it's really about touching it up as often as possible a naughty person might suggest an aluminum or magnesium blade, copper or brass would work too.


Some really want to touch it up as little as possible or not at all and if they have to take it for sharpening 10 times a year or only once makes a big difference in cost and time and how long it takes until the knife is totally ground to dust.

Then there's a wide range in between.

I myself like supersteels because I don't have to worry much about touching them up to often. Having two luthersteel blades for the same price makes sense especially at home where one doesnt need to carry the backup but still it doesn't feel right, a bit of a waste.
I also like sharpening and thus can deal with luthersteels if I have to, but I prefer to do it whenever it fits my time frame and not when an edge decides to be dull that day when I have other things to do.
A super steel degrading slower simply gives me more flexibility on when to touch it up. OK the supersteel is starting to get less sharp but I still have a few weeks before its completely useless while with the luthersteel I might have only a few days of useful sharpness left.

 

[mycough]

I like them all and can put respectable edge on every steel I have run into. I also would never presume to tell a fellow enthusiast he was wrong to buy what he wants. I can also get by with SiO2 but enjoy a good rub on a dmt/atoma, or if I am messing with my work knives, a shapton.
Just my thoughts, Carry on Montesquieu...

Russ

 

[pathwinder14]

Up to a point, yes. The difference is, abrasives that are capable of cutting the carbides will do a much better job actually shaping the carbides at the edge, instead of just eroding the matrix steel supporting them, to the point the carbides just break away. That's what I meant earlier, in that there's a difference in how refined the edge will get, depending on whether the carbides get cut, shaped and thinned at the apex (more refined), or if they just break away due to lack of support, leaving voids in the apex where they used to be (less refined). In steels like 90V, 110V and others, a large percentage of the alloy (9% or more) is comprised of carbides that won't be shaped or sharpened at the edge if the abrasive used isn't hard enough to do it. Effectively, in that example, you're sharpening maybe 90% of the edge, and not getting the benefit of well-shaped and sharpened carbides as well.

Compare the steel with the carbides to a concrete floor with aggregate pebbles in it. You can grind the supporting cement (representing the 'matrix steel') with a less capable abrasive that isn't capable of actually abrading the much harder aggregate pebbles (the 'carbides'), leaving a rough finish on the surface and at the edges/corners, with the 'carbide' pebbles exposed proud of the surface, and some voids left by the pebbles that break away. Or you can use an abrasive that's also capable of grinding the pebbles themselves to be flush to the supporting cement, leaving a much more refined surface and sharper edges and corners.


David

Ahh...now I see what you mean. Since the carbides won't be abrasively altered, wouldn't the friction/heat build up from the stone alter them?

 

[Obsessed with Edges]

Ahh...now I see what you mean. Since the carbides won't be abrasively altered, wouldn't the friction/heat build up from the stone alter them?

There'll never be enough heat generated in hand sharpening to make that kind of difference. Powered grinding might generate enough heat to do it, but who knows. If they are altered, there's also the question of how(?) will they be altered (harder or softer?). And most powered grinding applications are at much coarser grit, which will just plow the carbides out of the matrix anyway, whether it's able to cut or alter the carbides or not.


David

 

[jrawk]

Good read. I love following along on these discussions.

I'm going to approach the OP more practically/realistically. Since learning freehand on diamond stones, the only noticeable difference in degree of difficulty sharpening various supersteels, for me, is how thick the blade is behind the edge. The thicker the primary grind terminates, the more time it takes to sharpen the secondary bevel.

 

[Jamesh Bond]

If it's really about touching it up as often as possible a naughty person might suggest an aluminum or magnesium blade, copper or brass would work too.


Some really want to touch it up as little as possible or not at all and if they have to take it for sharpening 10 times a year or only once makes a big difference in cost and time and how long it takes until the knife is totally ground to dust.

Then there's a wide range in between.

I myself like supersteels because I don't have to worry much about touching them up to often. Having two luthersteel blades for the same price makes sense especially at home where one doesnt need to carry the backup but still it doesn't feel right, a bit of a waste.
I also like sharpening and thus can deal with luthersteels if I have to, but I prefer to do it whenever it fits my time frame and not when an edge decides to be dull that day when I have other things to do.
A super steel degrading slower simply gives me more flexibility on when to touch it up. OK the supersteel is starting to get less sharp but I still have a few weeks before its completely useless while with the luthersteel I might have only a few days of useful sharpness left.

Nice.

A very logical line of reasoning. I can actually understand your preference, even if it's not mine.


Now, THAT's good discussion!

 

[pathwinder14]

There'll never be enough heat generated in hand sharpening to make that kind of difference. Powered grinding might generate enough heat to do it, but who knows. If they are altered, there's also the question of how(?) will they be altered (harder or softer?). And most powered grinding applications are at much coarser grit, which will just plow the carbides out of the matrix anyway, whether it's able to cut or alter the carbides or not.


David

AKA if there's enough heat to alter the shape of the carbides there is also more than enough heat to alter the matrix steel they sit in?

 

[Obsessed with Edges]

AKA if there's enough heat to alter the shape of the carbides there is also more than enough heat to alter the matrix steel they sit in?

The heat needed to damage the matrix steel, i.e., ruin the temper, is at a much lower temperature (300°-400°F for many steels) than anything that might significantly alter the carbides themselves. The carbides are first formed at much higher temperatures during the steel's manufacture. Vanadium carbide has a melting temperature over 5000°F, and chromium carbide's melting temperature is over 3400°F, for some perspective.


David

 

[Megawatt308]

Thx ATJ999 for that reply.

And to everyone that has contributed from the scientific to the quick and easy answers. Some of these steels I have never heard of much less seen on a blade. I got lots more to experience.

 

[pathwinder14]

The heat needed to damage the matrix steel, i.e., ruin the temper, is at a much lower temperature (300°-400°F for many steels) than anything that might significantly alter the carbides themselves. The carbides are first formed at much higher temperatures during the steel's manufacture. Vanadium carbide has a melting temperature over 5000°F, and chromium carbide's melting temperature is over 3400°F, for some perspective.


David

Ahh...now I understand. Thank you for the details I was missing.

 

[Wowbagger]

A more meaningful hardness comparison, for reference:

Basic, hardened cutlery steel w/no hard carbides: ~600-800 Knoop
Novaculite (Arkansas stones): ~825 Knoop
Chromium carbide (D2, ZDP-189 are very heavy in it): ~1300 Knoop
Tungsten carbide (carbide pull-through sharpeners, also found in some cutlery steels): ~1400 Knoop
Aluminum oxide ('corundum' or 'Alumina'; Norton 'India' stones, and most ceramics of alumina): ~2100 Knoop
Silicon carbide ('carborundum'; Norton 'Crystolon' stones, wet/dry sandpaper): ~2600 Knoop
Vanadium carbide (significant in S30V/90V/110V steels and many others like them): ~2800 Knoop
CBN ('Cubic Boron Nitride'): ~4500 Knoop
Diamond: 7000 Knoop

This was EXTREAMLY useful !
THANK YOU !

I have remained silent until now just lurking.
Due to my extremely erratic experience with S110V I feel I have no positive rock solid input to add on “SUPER” steels. For the one or two who may have missed my dead horse beating of my experience with one sample of S110V : Shapton and or diamond free hand to shave sharp and or hair whittling only to have the blade dull in a day of fairly tame use. All my other super steels were . . . super . . . for days if not a week or more.

I will say I have had no problem sharpening : ZDP-189, CPM-S30V, CPM-3V, CTS-XHP, M390

I got S110V hair whittling but it petered out in a day. Must be magic. Evil magic. Evil, sucky, magic that . . . sucks.

For best results (mind blowing hair whittling that digs into my finger nail in a scary and sickening way) I found it best to either go with Shapton glass 500 up through 4000 using a small secondary bevel. Then if I needed to cut back the secondary bevel to the main sharpening bevel I would use a Shapton glass 120 then 220.

Always on an Edge Pro if at all possible. Can take a lot of strokes for the wider bevel and to try to do this free hand is pretty much wasting strokes (the ones that miss the edge) and wearing the stones unnecessarily.

. . . wait . . . I can't ignore it any longer
I find the comment about cutting food on a ceramic plate makes me want to go bang my head against a wall. Taking a soft steel and instantly dulling it against a plate and being enthusiastic about it and how easy it is to sharpen it only to instantly dull it again is . . .
well . . . most of the terms that come to mind are clinical descriptions or very rude.

Cutting food on a ceramic plate is the only use I have for serrated knives by the way; the points keep the swoopy sharp areas off the plate and since the food is soft it can mush up into the scallops.

Hold on . . . I am having another episode of unspeakable, beside my self confusion as to the whole sharp edge on a ceramic surface . . . or as some use . . . a marble “cutting board” which also creeps me out to distraction . . .
I will just bang my head against the wall here for a little while until . . .
BANG
BANG
BANG
BANG

There !

I have completely forgotten why I was banging my head against the wall and can now continue . . .

natural stones and no problems with supersteels.
In emgineering they said any abrasive works, you might just need a bit more of some.

Moving on here is a photo of what an A-2 blade does to a very high quality translucent Arkansas stone. The blade had been sharpened to hair whittling on a series of Shapton Pro stones but had some slight, super thin, foily, wire edge and I was just attempting to take that off on the hard Ark. I tend to jig sharpen these blades with exclusively an edge trailing method unless I am hogging off a lot of metal on diamond plates then I go both directions. On the hard Ark I was using a sharpening jig and going both directions because the stone was so wear resistant that I knew I would not be taking the stone out of flat.





There was absolutely no sharpening effect other than, perhaps, a slight burnishing effect which was the opposite of what I wanted since part of the reason I had this wire edge was the burnishing / extruding effect of my edge trailing technique on the other stones.

I know there was no sharpening going on because I looked very closely at the pores of the stone with a hand held microscope; shown. There was no black metal imbedded in the stone. With the same sharpening of 1095 there is a good deal of black swarf left on the stone easily detectable even to the naked eye.



When I began, the stone was pretty much brand new and matt looking to the eye. In a matter of a couple of minutes the stone had been . . . basically . . . polished / burnished by the A-2 blade. I had trouble photographing the surface but from the photos you can see that since I used the whole surface of the stone . . . in the end . . . the whole surface of the stone was made shiny and ineffective for sharpening basic high carbon steels like 1095.

After the photos I refreshed the surface of the hard Ark with my diamond plate.

Lesson learned. Stick to Shaptons for the A-2

Any natural stone works for the high alloy steels ? ? ? ?
Nah dude, nah.
Maybe they mean the same abrasive material in a friable man made matrix but not a stone quarried .

 

[Megawatt308]

My first attempt at polishing. I used what I have for the progression, do I need another in between step?

100
200
400
600
800
1000
1200 ceramic
1600 ceramic
1mu paste on leather
.5mu paste on leather

 

[mycough]

My first attempt at polishing. I used what I have for the progression, do I need another in between step?

100
200
400
600
800
1000
1200 ceramic
1600 ceramic
1mu paste on leather
.5mu paste on leather

Looks great Man, you could probably skip a couple of those grits and still be successful.

Russ