Why s90v and all these other high carbide steels suck for knives

Wowbagger said:
Nah . . . Cliff Stamp and his ideas about shallow sharpening bevels . . . all that sucks.
Oh wait.
. . .
I'm lying again.
Funny vanadium carbides aside for a moment; when I started listening to his enthusiasm for edge geometry, shallow edge geometry and how it could get "lesser" steels (but still quality steel properly hardened) up to speed to cut like the higher end steels , for me, it was like coming home.

For a while there I thought I was crazy because I thought I had taken a Swiss Army Knife and actually got it to cut right and hold an edge after thinking for years and years that it was crap steel because it wouldn't hold an edge for a day with the factory grind. I shallowed the peas out of it and it suddenly became a magic long lasting saber. That just didn't make sense to me but I thought it was working that way so I must be crazy (right ?). Nope my main man Cliff says he's crazy that way too.

Now the below is kind of some where in between because he isn't a fan of vanadium carbides but here you go :

For me yesterday was a heavy knife day at work. Of course I was carrying the newly reprofiled little purple monster (Para 2 S110V reprofiled as shallow as I could get it and about 8 thou behind the edge).
Pallet straps; the yellow ones that feel like they may have some sort of abrasive fiber in them. I cut quite a few of these. Some of them I came at full edge across full width of the strap; I figured this was a bad idea but just went for it. (seemed like it might be particularly abrasive to the edge is what I am getting at).
Trimming hard rubber.
Cut up rubber coated cloth.
Cut up corrugated cardboard boxes.
Food and easy stuff.



There are zero chips or rough spots (carbide fall out etc.) zero rolls or flat spots.
Granted I am not attempting to cut bamboo chop sticks or pencils in half.

And there was a surprising bonus and part of the reason I reprofiled this little purple monster to da max :
Still easily shave sharp, both directions, shave sharp for the entire length of the edge. . . oh yes . . . very pleasingly shave sharp ! ! !

OhYahBaby :cool:

PS: there could be some hope for and place in the knife world yet for this funny Vanadium carbide stuff.
A year ago I would never have believed I would ever write that sentence.
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I reprofiled my s30v pm2 recently to a verry low angle with diamonds. Not sure what it is I just layed it way back, later added a small 15dps micro with spyderco stones.
It is going strong after some cardboard and bunch of plastics and lots of edge contact with hard plastic surfaces as I cut on them.
I am taking about it keeping it's shaving sharp edge not just a working edge. I think sandvik would loose this right away after the cardboard.
 
Can I conclude that spyderco's s110v is better maintained with a dmt extra extra fine diafold than the extra fine? I believe most everything cliff says, but don't have either his patience or skill, plus I already own what I own
 
I somewhat disagree with tool steels and carbides not being suitable for carry knives. For nearly twenty years I have made millions of notebooks on machinery using tool steel and carbide tipped "knives". When I say knives I mean blades ranging from three feet to six feet in length. Typically they are D2 and D2 with tungsten carbide tips. We have put on brand new knives and run 1.5 million books which means 500,000 cuts through at the least 70 sheets of 20 pound notebook paper including a cover and a chipboard back. Grab a 70 sheet notebook and imagine shearing through half a million times. Then we get them reground on a linear rail knife grinder and go again. Straight D2 knives get 30 degree chisel edges and the carbide we go 26-28 on. The carbide tends to cut cleaner but doesn't last as long. We average about a ten percent gain in D2 cuts per grind but the carbide do leave nicer edges on our books. Admittedly this is not apples to apples in terms of size and design, but materials are comparable. I might add that when we get them new and after regrinds these are sharper than any carry knife I have ever seen. I mean when you touch the edge, even feather lightly, you are cut. Apply these facts known to me to whatever knife steel choices you wish. Or just disregard this as a bunch of hooey. Semper Fi, that is all.
 
If ceramic does not remove metal from S90V, then why do my rods have metal on them after sharpening it? I have to clean it off and starting with clean rods , they become just as fouled with metal as any other steel I use them with. If metal was just being moved around, wouldn't it build up on the edge and give you a less than perfect job? I notice no difference at all, in my edge after using ceramic on S90V and other steels. They all look and sharpen the same.
 
jill jackson said:
If ceramic does not remove metal from S90V, then why do my rods have metal on them after sharpening it? I have to clean it off and starting with clean rods , they become just as fouled with metal as any other steel I use them with. If metal was just being moved around, wouldn't it build up on the edge and give you a less than perfect job? I notice no difference at all, in my edge after using ceramic on S90V and other steels. They all look and sharpen the same.
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I don't think they are saying the ceramic rods are not removing metal. I think they were saying ceramic cannot cut the vanadium carbides. This is based on the carbides being harder than the ceramic.

I don't know if it's true or not, that is to ask, if the carbides are harder will the ceramic never be able to cut them?
 
My Spyderco South Fork, sharpens up easy and keen on ceramics. No difference in the way it sharpens , than the lesser steels. What more could you ask?
 
I found this:

A material's hardness is determined by measuring the size of an indentation made by a sharp diamond pressed strongly onto a material specimen. The hardness of alumina ceramics is nearly three times that of stainless steel; silicon carbide is more than four times harder than stainless steel.
 
Yes it is harder than the stainless steel part (i find that misleading anyway as stainless steel can be many hardnesses)

However it is not harder than the vanadium carbides in the stainless steel.

Either way then sharpmaker aluminum oxide rod gets my knives plenty sharp. Just sucks to reprofle with.
 
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