Sharpening high hardness and wear resistant steels

I dunno about that.The Crystalon fine side has handled every steel I've thrown at it including s110v.

It just doesn't do a very fine finish.
 
Maggot Brain said:
I would not classify the Crystolon anywhere near the SPSII stones in characteristics, excepting maybe the type of abrasive between the two (SiC). The SPS II have virtually no binder, which allows the abrasive to be released *trivially*… whereas the Crystolon is more or less an extremely hard bonded stone similar to glass fusing the abrasives together. The main difference would be that the Crystolon will give up the goat somewhere near S30V and up as far as the ability to keep cutting is concerned (glazing) whereas the SPSII should just keep chugging along for any of the common high carbide volume steel/processing.
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Haha, I see what you did there
 
Beyond the 240 grit, the Sigma 2 stones do not work well with high carbide steels. At 240, it doesn't blow the crystolon stones on a given steel. As far as binder, maggot is incorrect, there is no binder, it is sintered together and is basically pure abrasive.Crystolon will dish if not used properly and may need lapping to flatten them because they release so fast. As it comes loose the abrasive breaks into finer fresh particles. For true super steels I found these to be a rather expensive disappointment. 240, 1000, 3000 cost me about 200$ with my dmt and atoma plates, as well as many shapton stones, and the trusty coarse medium and fine crystolon, these were a waste of money. There was a thread a while back, and my opinion has not changed since then.
Don't take my word for it, buy them all, just don't lie about them after you try them out.

When guys are sneaking cliff stamp quotes in, I realize I may be wasting my time...

Russ
 
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DeadboxHero said:
Steel Drake,

I like the idea of the sigma stones, super charged Norton crystolon stones with more finishing options.

Could you give me a run down of the how the different grits behave? Feedback, speed, mud, dish, etc

Thanks man.
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Happy to to provide whatever information I can. All of the SPS-II stones that use SiC with minimal binder (that includes the 240, 1000, 3000, 6000, and 10000) all have very weak bonding and thus create a slurry very easily, dish much faster than something like a Chosera, but partially as a result of exposing fresh abrasive constantly and partially as a result of abrasive density and the hardness of SiC, they cut extremely fast. I personally prefer to use very little force when I sharpen and even with minimal force I have no problem keeping a slurry going on the SPS-IIs.

They provide good feedback, and the slurry they readily produce is nice for both burr minimization and producing a finer finish relative to the grit of the stone. To emphasize this property I permasoak my SPS-II stones and flatten them with an Atoma 140 prior to each use to get a slurry going before I even start.

The stones get a little harder, less muddy, and less prone to dishing as the grits increase. Feedback is good on all of them. Keep in mind that the 400, 1200 and 13000 are not the same type of stone as the other grits (they are actually part of the Sigma Power Ceramic line, use aluminum oxide abrasive and have a fair amount of binder in them).
 
Maybe it's just me but I can feel when the abrasive stops working or should I say has a very difficult time doing it's job. Even my Fine Norton Silicon Carbide shows issues with steels like S90V and 10V (I'm keeping with high Carbide volume examples).

I have used a King 1k on these steels too and even my ACE aluminum oxide stone on my Spyderco K2 in 10V steel. It all "worked" but it gave subpar results each time... just like sharpening a ceramic knife on a waterstone will yield subpar results. Sure it "worked" but it did not do its job correctly... look at the edge under a microscope and you will see.

I don't have the SPS II stones but have used most other waterstones including the Kohetsu 800 and 2k which are Aluminum Oxide and Silicon Carbide respectively. I can get a decent edge on steels like 10V with these waterstones but they just don't sharpen like diamond. It becomes very obvious as the apex starts to refine that the abrasive is not cutting the carbides, it will be sharp and even shave arm hair but is nowhere close to the results found with an abrasive of proper hardness.

I've heard "but it works" for years, and I will continue to say no, it does not.

BC, great thread btw, I love micrographs!
 
Jason,

Can you please elaborate on what you mean by subpar results?

I'm honestly very confused by comments like this because they are so different from my own experiences. I literally cannot tell the difference between shaping the edge bevel on my knives in CPM-M4 and HAP40 between using a King 1000 and an an SPS-II 1000. Off either stone I have no trouble getting an edge that will easily slice newsprint and pushcut it with the grain, with no apparent (to me) difference from the level of sharpness I would expect off those stones with any other steel.

You mentioned looking at the edge under a microscope, so I just did that and took some pictures:

First off, this is a picture of the millimeter scale on a ruler, showing that the 50x optical and 4x digital USB microscope shows about 2.2mm of the ruler at full zoom:


Here is one of the ~1000 grit stones I used:



Here is the second of the ~1000 grit stones I used:



Here is the third of the ~1000 grit stones I used:



Here is the last of the ~1000 grit stones I used:



Personally, I cannot tell the microscope images of the edges produced by those four ~1000 grit stones apart even though two are diamond plates and two are waterstones. I also was unable to detect any difference in the obtained sharpness compared to the results I would expect off those same stones if I'd been sharpening VG-10 or 1095, so again I am really confused as to why I am not noticing the issues others have raised?
 
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mycough said:
Beyond the 240 grit, the Sigma 2 stones do not work well with high carbide steels. At 240, it doesn't blow the crystolon stones on a given steel. As far as binder, maggot is incorrect, there is no binder, it is sintered together and is basically pure abrasive.Crystolon will dish if not used properly and may need lapping to flatten them because they release so fast. As it comes loose the abrasive breaks into finer fresh particles. For true super steels I found these to be a rather expensive disappointment. 240, 1000, 3000 cost me about 200$ with my dmt and atoma plates, as well as many shapton stones, and the trusty coarse medium and fine crystolon, these were a waste of money. There was a thread a while back, and my opinion has not changed since then.
Don't take my word for it, buy them all, just don't lie about them after you try them out.

When guys are sneaking cliff stamp quotes in, I realize I may be wasting my time...

Russ
Click to expand...


Ive always written off SiC stones. It wasnt until I read more here on this forum that my curiousity had been piqued.

Phil Wilson is like the godfather of high Vanadium steels

thats what he uses for s125v and 15v

so Idk

I havent used a norton Sic stone or 125v so I dont have an opinion.

I thought the SiC waterstone was awesome because there is more finishing options compared to the Crystolon stone

but I haven't tried it but am curious.

Nanwia diamond stones might be the best option I am waiting for a 800 and 3000 stone.

Ive played with the atoma and dmt stuff. I didn't like the edges I was producing or stones themselves, I like more polish and precision on my edges at the cost of endurance.
 
Steel_Drake said:
Happy to to provide whatever information I can. All of the SPS-II stones that use SiC with minimal binder (that includes the 240, 1000, 3000, 6000, and 10000) all have very weak bonding and thus create a slurry very easily, dish much faster than something like a Chosera, but partially as a result of exposing fresh abrasive constantly and partially as a result of abrasive density and the hardness of SiC, they cut extremely fast. I personally prefer to use very little force when I sharpen and even with minimal force I have no problem keeping a slurry going on the SPS-IIs.

They provide good feedback, and the slurry they readily produce is nice for both burr minimization and producing a finer finish relative to the grit of the stone. To emphasize this property I permasoak my SPS-II stones and flatten them with an Atoma 140 prior to each use to get a slurry going before I even start.

The stones get a little harder, less muddy, and less prone to dishing as the grits increase. Feedback is good on all of them. Keep in mind that the 400, 1200 and 13000 are not the same type of stone as the other grits (they are actually part of the Sigma Power Ceramic line, use aluminum oxide abrasive and have a fair amount of binder in them).
Click to expand...

Thanks man, what does the 3k sharpen like?

soft and muddy with good feedback and fast cutting but with a much coarser edge?

I have an Imanish 1200 that is more like an 800
 
Firstly, thank you all for a good discussion. I think both Jason and Steel Drake might be correct, in that one can detect the difference and the other not. The best would be for them to get together and compare notes directly.

If only I don't live so far away. :(

Jason, perhaps a video of comparing them will help us understand what you see? It won't convey what you sense through the trained perceptions, but perhaps what is audible can help?
 
DeadboxHero said:
Ive always written off SiC stones. It wasnt until I read more here on this forum that my curiousity had been piqued.

Phil Wilson is like the godfather of high Vanadium steels

thats what he uses for s125v and 15v

so Idk.

Above is a quote I copied but it isn't showing up as a quote. Sorry.

So I've talked with Phil Wilson quite a bit about HT and different steels. 15v and s125v have been the topic of discussion many times as well. S125v we talked about for me to get a knife made in this steel and 15v because in Cliff notes as well as a thread in Spyderco forum Cliff said that PW was making him a knife out of 15v. First mention was a test knife. I asked Phil if I could also have a test knife made of this steel as well. I don't know if he has a knife made by another maker of 15v but I know for sure he hasn't made one out of 15v himself. He said he had some 15v slabs under his workbench that had been sitting there so long that they had developed surface rust and collected dust. He said for him that 10v had plenty enough wear resistance/edge holding for him that he didn't see the need for the extra carbides with the trade off for toughness seen in 15v. He said he had no plans in making any 15v in the foreseeable future. My question is where a quote from Phil about 15v or its use could be found because from what I understand if he wants a little more carbide in a knife then s125v is as high as he goes and he doesn't even have plans of using it anymore as well. Just thought I'd throw that out there as a clarification or maybe someone could prove me wrong.




Sent from my iPhone using Tapatalk
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Steel_Drake,

If you cannot feel a difference between M4 and Hap40 then truly I'm not sure where to start. I can and have told the difference between many common steels, I can tell the difference between S30V and S35VN or 52100 and A2, Hap40 and M4 or S110V and 10V. S30V is a steel I know so well I can usually tell the maker by the slight differences in heat treatment. These are all things I feel through the sharpening and by touching the edge.

This "feel" has come from sharpening tens of thousands of knives and tools, from small traditional knives to Ice chipper blades there are very few steels, knives, and tools I have not sharpened.

I also spent a long time looking at micrographs of my own edges then feeling the edges and looking closely without visual aid. I learned a lot from that and my senses were highly refined after. It gave me a whole new perspective on sharpness and what an edge should feel like.

After that I kinda dove into abrasives and steels. Learning about the elements that make up the steel and their hardness compared to the sharpening media. This again, opened a window to the senses and allowed me to understand the feedback I was receiving from the interaction of steel and abrasive. I started to discern the difference between hardness and wear resistance and furthered that by noticing differences between carbides such as Chromium, Vanadium and Tungsten.

So, what is it I feel?

First it starts with the steel, it must have at a minimum 4% Vanadium for the carbide content of the steel to reach a high enough volume to inhibit sharpening by standard abrasives. Heat treatment must also be as specified by the foundry and be at optimal hardness. If these parameters are not met then anything is possible when it comes to sharpening.

Next, you have the carbide size vs the abrasive size. Up to about 1000 grit most any abrasive will grind most any steel, with good Aluminum Oxide based stones showing the best performance IMO. I feel Silicon carbide fractures and breaks down too quickly causing an excess of polishing by the abrasive especially as the Vanadium content starts reaching 9%-10%. The problem with this however, is that the abrasive is only digging out the hard carbides and surface polishing the ones it leaves behind. As you start to form the apex with finer stones the problem becomes the abrasive not being hard enough to shape the carbides at the edge apex and typically will have what I loosely call a burr that wont go away.

What I feel is this "burr" but I don't really get a sense of a burr to my fingers but an edge that is not complete. The roughness I feel at the edge equates to unshaped carbides due to inadequate abrasive hardness. So there you have it, that's how I describe the "subpar edge".

And while your pictures are very nice they are about 1000x too zoomed out to be of any use.
 
This is for the Jason mostly but also the rest of the people in the whole thread,

First off I don't have any thing intelligent to contribute on the topic of sharpening super steels (painfully obvious to some here) so I am lurking.

Jason thanks for the history of your journey. That made for good reading / understanding of what you do.

Another thing I want to say is today I finally got it, I think, when it comes to realizing just how hard vanadium carbides / edges heavily laced with vanadium carbides are. I had this idea stuck in my head that ceramic knives was the next step "up" but people didn't use them because they were so frail and hard to sharpen in the field.

What I think I finally understand is that ceramic is a step down and the vanadium edges are the pinnacle. I mean I don't know how many times I read ceramic stones were not hard enough to sharpen vanadium carbide and that pretty much the only thing that was going to shape the vc edges was diamond . . .
I read that over and over
but I still had this idea, hard to imagine looking back, that if the rope cutting were done with the ceramic knives that they would fair well or maybe better than 10V.

I am getting a sense of just how WRONG that idea was.

Finally Jason,

I am fooling around with paper wheels (bought one; will probably buy more) but was wondering how hard felt wheels work in comparison . . . for using diamond paste / diamond grit and wax.

any thoughts ?
 
Here's a fact sheet I came across and recently shared in another conversation with a friend about VC rich steels, thought it was very interesting.

http://www.tool-dynamics.com/literature/papers/000.php

The difference in tool life with VC coating compared to others is impressive, amazing actually. Keeping in mind this is relative to vapor deposition of a uniform surface coating.

Whether VC laced steel is the ultimate overall for edged hand tools is debatable, but for wear resistance in tooling applications is in a league of its own.
 
Jason B. said:
If you cannot feel a difference between M4 and Hap40 then truly I'm not sure where to start.
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If it were possible to subjectively distinguish steels as similar as M4 and HAP40, then edge retention testing would not require the substantial rigor it does to be able to reliably distinguish between the performance of different steels. People like Ankerson go to rather a large amount of trouble in testing edge retention precisely because of how difficult it is to reliably distinguish the edge retention of different steels. I don't think anyone who does that kind of work would be likely to agree that anyone could reliably distinguish steels as similar as M4 and HAP40 in a double blind test.

Up to about 1000 grit most any abrasive will grind most any steel
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Okay, now I am really confused. Most people start with a stone of 1000 grit or less when sharpening their knives and reach an apex on the first stone before moving to higher grit stones to raise the level of polish. So if a 1000 grit stone (or less, I presume) will work on any steel, then why did you disagree that a King 1000 or SPS-II 1000 will work just fine on M4? Hell, since I usually only go up to 1k on my edge bevels, how would I even have noticed this issue if it doesn't occur until stones above 1k?

The problem with this however, is that the abrasive is only digging out the hard carbides and surface polishing the ones it leaves behind. As you start to form the apex with finer stones the problem becomes the abrasive not being hard enough to shape the carbides at the edge apex and typically will have what I loosely call a burr that wont go away.

What I feel is this "burr" but I don't really get a sense of a burr to my fingers but an edge that is not complete. The roughness I feel at the edge equates to unshaped carbides due to inadequate abrasive hardness. So there you have it, that's how I describe the "subpar edge".
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Firstly, to clarify, in my own day to day sharpening I would not notice if this was occurring because I only use waterstones to shape my edge bevels and then apply a microbevel to set the apex using non-friable abrasives like diamond plates, solid sintered ceramic stones, or coarse particulate abrasive strops. I do this to avoid any apex rounding from ploughing into the slurry on a waterstone with edge leading strokes, and because waterstones are in general not very good choices for creating or maintaining microbevels.

As a result of that, even if I choose to sharpen the edge bevels on my knives to grits above 1000 on stones you believe cause this steel matrix ploughing effect to occur, the effect would be eliminated once I created a microbevel anyway.

Now, leaving that aside, once I receive the maxamet mule I want to do some testing on in to try and reveal whether this effect occurs and what its implications are. Towards that end, I plan to sharpen the mule on a couple of different types of stones (apexing directly on that stone rather than microbeveling), doing some corrugated cardboard cutting with them, and then test their sharpness afterwards.

My thinking is that if metal matrix ploughing occurs and has a negative effect on apex strength, the effect should show itself fairly quickly in high sharpness edge retention, and corrugated cardboard should be abrasive enough to cause carbide tear out fairly quickly.

My question is this: If you believe that up to 1000 grit, any stone will work on any steel, then how high a grit will I need to go to for the purposes of this comparison to demonstrate whether this effect occurs and how severe its consequences are?

I am somewhat limited here in that there are not really any diamond plates between the ~JIS 1000 equivalent of an Atoma 1200, the ~JIS 1750 equivalent of a DMT EF and the ~JIS 4000 equivalent of a DMT EEF, so ideally I'd have to conduct the comparison around one of those three grits.

And while your pictures are very nice they are about 1000x too zoomed out to be of any use.
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What optical power of magnification would be necessary to demonstrate the effect you are talking about? Could you link some photos of the effect you are referring to?
 
Steel_Drake said:
I am somewhat limited here in that there are not really any diamond plates between the ~JIS 1000 equivalent of an Atoma 1200, the ~JIS 1750 equivalent of a DMT EF and the ~JIS 4000 equivalent of a DMT EEF, so ideally I'd have to conduct the comparison around one of those three grits.
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I'm sure there probably are, but I guess not with the companies popular on this forum.
 
HeavyHanded,

Cool stuff ! 5000% improvement in tool performance. I'd say that's pretty significant for dies and stuff.

Whether VC laced steel is the ultimate overall for edged hand tools is debatable
Click to expand...

Thank you for saying that.
 
Steel_Drake said:
If it were possible to subjectively distinguish steels as similar as M4 and HAP40, then edge retention testing would not require the substantial rigor it does to be able to reliably distinguish between the performance of different steels. People like Ankerson go to rather a large amount of trouble in testing edge retention precisely because of how difficult it is to reliably distinguish the edge retention of different steels. I don't think anyone who does that kind of work would be likely to agree that anyone could reliably distinguish steels as similar as M4 and HAP40 in a double blind test.

Testing edge retention has nothing to do with it, this is about the feel I get from the stone when I am sharpening. Again, you may not be able to sense it but I can. I have also performed CATRA testing so I am no strange to what it takes to get consistent edge retention data.



Okay, now I am really confused. Most people start with a stone of 1000 grit or less when sharpening their knives and reach an apex on the first stone before moving to higher grit stones to raise the level of polish. So if a 1000 grit stone (or less, I presume) will work on any steel, then why did you disagree that a King 1000 or SPS-II 1000 will work just fine on M4? Hell, since I usually only go up to 1k on my edge bevels, how would I even have noticed this issue if it doesn't occur until stones above 1k?

I probably should have said that most will not notice it until just beyond 1000 grit. It's not that it's not occurring its that the abrasive is still large enough to scoop out the carbides on most steels. It's not until the abrasive size becomes closer too or smaller than the carbides themselves that the harder object starts to win. I imagine the negative side effect to a smaller carbides within the steel would then be the concentration of the carbides. With ever decreasing carbide size and increasing volume of Vanadium the percentage of carbides being contacted by abrasive would increase and the cutting ability of the stone would decrease. In such a case all grit levels would be affected, 10v proves this point well.



Firstly, to clarify, in my own day to day sharpening I would not notice if this was occurring because I only use waterstones to shape my edge bevels and then apply a microbevel to set the apex using non-friable abrasives like diamond plates, solid sintered ceramic stones, or coarse particulate abrasive strops. I do this to avoid any apex rounding from ploughing into the slurry on a waterstone with edge leading strokes, and because waterstones are in general not very good choices for creating or maintaining microbevels.

I use edge trailing strokes on waterstones, produces a sharper edge and is the recommended method sense forever. I can apply microlevels with waterstones without issue so I'm not sure what you even mean by that.

As a result of that, even if I choose to sharpen the edge bevels on my knives to grits above 1000 on stones you believe cause this steel matrix ploughing effect to occur, the effect would be eliminated once I created a microbevel anyway.

There is no steel matrix ploughing effect. The abrasive simply cannot cut the individual carbide so it either scoops it out or the abrasive itself is dulled and polished by the carbide. This is where grit size play its part.


My thinking is that if metal matrix ploughing occurs and has a negative effect on apex strength, the effect should show itself fairly quickly in high sharpness edge retention, and corrugated cardboard should be abrasive enough to cause carbide tear out fairly quickly.

I don't even know where you are getting this metal matrix ploughing theory but it has no relevance here.

My question is this: If you believe that up to 1000 grit, any stone will work on any steel, then how high a grit will I need to go to for the purposes of this comparison to demonstrate whether this effect occurs and how severe its consequences are?

1k to 4k would do.


What optical power of magnification would be necessary to demonstrate the effect you are talking about? Could you link some photos of the effect you are referring to?

You would probably need to etch the carbides and take it up to about 10,000x on an electron microscope. Optical microscopes have a limited depth of field and cannot show the detail needed.
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My answers in bold.
 
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