Shapton stones and vanadium

[Ben Dover]

I need the benefit of your experience.

A member recently posted that Shapton stones caused vanadium tear out on high grade steels.

This is new to me. Has anyone had experience with this phenomenum?

 

[Blues]

Here's a couple of quotes excerpted from a discussion I was having with @Jason B. via PM regarding my sharpening arsenal and adding Shapton Glass stones to the mix, which he was in favor of:

The 500 double thick and 2000 are simply awesome stones and because they are hard and made of fast cutting ceramic abrasive they are ideal for folding knives. The 4% Vanadium rule still applies because ceramic is still softer than Vanadium but I will say they don't have too much issue sharpening steels like S30V. Higher grade steels like S110V will be too much for them though.

For the DMT stones I wouldn't change anything. It's rare I go beyond a Coarse DMT as I have found it to produce the most useful and arguably the sharpest edge of all the diamond stones. For a lot of high alloy steels a DMT Coarse and a strop with 1-3 micron diamond compound is all I use. Sometimes I will use a spyderco UF ceramic to help with deburring before stropping but this is just a feather light pass just to remove the burr and not to disrupt the Coarse scratch pattern.

We didn't delve specifically into the topic of carbide "tear out", however. Hope it's useful nonetheless.

You may also find this thread I started in the Spyderco forum of interest. It deals specifically with using ceramic hones and the potential for "carbide tear out" on Maxamet and high Vanadium carbide steels. So far, the replies are favorable to the usage of ceramic (aluminum oxide) for maintenance / finishing. Not enough data to call it definitive, however.

 

[JD Spydo]

Pardon my ignorance fellows but I'm still learning a lot about all these different blade steels. But I just learned a new term called "carbide tear out" and I assume that it refers to something not good during a sharpening process? And I also gathered by the context of the conversation that certain abrasives do that to some of the more premium blade steels and thus have results that are undesirable. I've mostly been using Spyderco's great ceramic stones for the most part in the past few months since I moved to my new residence ( because that's basically all I took with me at the time). I've never had anyting but great results using my Spyderco ceramic stones. The only gripe I have against them is that they need thorough cleaning pretty often to keep them performing at their best. But I have a wide selection of different sharpening stones and I've never noticed any of them doing anything bad to any of my Spyderco, Benchmade, Boker or any of the other premium blades I own. And I own all types of supersteels like M390, S110V, ZDP-189 ect, ect. And so far I've not encountered anything bad with my stones.

But I do want to know more about this "Carbide Tear Out" term and I want to know the types of stones that tend to do that. I put that on this thread because I want to get some of those Shapton stones soon myself and I've been told they are super high quality stones. I hope I'm not barking up the wrong tree???

 

[DeadboxHero]

Those stones just don't have the "giddy up" to cut steels with a combined high Vanadium and high hardness.

Not so much s90v at 59rc or white steel at 65rc
But if you take 4V to 64rc or k390 to 65rc or Rex121 to 70rc you'll start to have problems.

It doesn't mean they don't work at all, everything isn't so black and white. They will still have a polishing effect due to burnishing the metal but you'll notice a glassy feel and reduced feedback, also you'll notice less swarf and metal filings (if any) being generated.

The edge will come up smoother (less crisp)

This is why it's better to use a harder abrasive like diamond, CBN or Boron Carbide, which will cut the those steels better and make crisper edges and cut the steel faster and clean with more efficiency (less dishing and stone wear too)
Problem is it will hurt the wallet more

Keep in mind, Even Silicon Carbide works due to it being a sharper abrasive then the alumina and it consistently refreshs sharp points when the abrasive grains fracture in use due to its high friablilty which is both good and bad. SiC stones wear away and dish very quickly due to the nature of the abrasive not being very tough. Also in my experience the "cut" isn't as clean as diamond and CBN.
However SiC is considerably cheaper if you sharpen infrequently.

I'd say use your stuff, don't worry about it.
Unless you start craving more intense steels and performance.

 

[PeterS84]

I've been interested in this also so I did a little "experiment" (using that term loosely)... I took my Manix 2 in Maxamet and sharpened it on the Edge Pro using Gritomatic SiC stones up to 2500 grit (dry). Edge was screaming sharp and had a near-mirror finish but the apex felt a little less "crisp" than I'm used to. Decided to strop with 4 micron CBN followed by 1 micron diamond and the apex crisped up beautifully. My theory at this point is that the higher vanadium alloys can be effectively sharpened with non-diamond abrasives up to 2-4 microns and then finished with fine diamond or CBN and you end up with a similar level of keenness as if you had sharpened entirely with diamonds from start to finish. Short version of my theory: if you like course finishes, the Shaptons will be fine. If you're looking to mirror polish and get that highly refined apex, finish with CBN or diamond when you hit about the 4 micron abrasive size in your sharpening routine. YMMV of course.

 

[Ben Dover]

Thank you for your responses, gentlemen.

 

[Wowbagger]

But I just learned a new term called "carbide tear out" and I assume that it refers to something not good during a sharpening process?

I don't know . . . I suppose you could spend some time over on The Science of Sharp web site and see actual edges sharpened with diamond and with other media.

What I dang sure know is :

• I can easily get high vanadium alloys (S30V, S90V, S110V) extremely sharp with my Edge Pro Shapton Glass stones. Easily hair whittling and only going up to the 4,000 stone. No strops at all and it is a stellar edge.

BUT

• The edges do not hold up. It is as if the metal around the vanadium carbide has been burnished and or extruded around the vanadium carbides and they are down in there some where (or they are torn out) and then that softer metal doesn't hold up and gets flattened back and the edge sucks

THEN

• I take those very same knives and resharpen them with my DMT Aligner diamond stones on my Edge Pro to the same level of sharp (fairly polished and hair whittling) and the edges loose a little of the whittling and go to just shave sharp but stay there for a good long time and the edges hold up to challenging materials being cut and all is right with the world.

Call it what you will . . . that is the dif.

 

[eKretz]

I posted some photos of this some time ago, lookie here:

https://www.bladeforums.com/threads...t-steels-s30v-s90v-cts204p-etc.1372633/page-2

TLDR: If you try to do bevel setting with Shapton, you're going to get tear-out. Probably be fine for a quick finish after shaping the bevel with diamond hone, but in my experience, do too much with non-diamond (other than CBN, BC) and you'll get a sub-par edge with poor longevity.