S30V is it really that great over current stainless?

N

Nimravus Nut

Joined
Jan 17, 2003
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202
I have a few questions about s30v. From reading earlier posts, is s30v still experiencing chipping problems? Has anyone done edge flex test on their s30v to see that it's really as tough as vg-10 or aus-8 or maybe tougher? :)
 
I also have a question about which manufacturers make decent s30v fix blades around $100?

I'm looking at around 4 to 5 inch utility blade for my next purchase.
 
I still prefer 154CM, and now that Crucible has CPM154CM, you get all the benefits of a CPM steel (fine grain, flexibility, better finishing, etc.) in a great edge-holding steel that isn't such a bear to sharpen. I'm making some now out of the CPM154, and I really can't wait to see how they turn out. VG10 is great stuff, though. I wish custom makers could buy it on the open market.
 
It sounds like you want a Fallkniven F1: VG10 core between layers of 420J. Laminated blades are very strong, and the VG10 will stand up to quite a bit of abuse.
 
Nimravus Nut said:
I have a few questions about s30v. From reading earlier posts, is s30v still experiencing chipping problems? Has anyone done edge flex test on their s30v to see that it's really as tough as vg-10 or aus-8 or maybe tougher? :)
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VG-10 is about the same (in terms of toughness). AUS-8 is tougher, but won't hold an edge as well.

S30V's "toughness" has a whole lot more to do with a very successful marketing campaign than the composition of the steel. It's in the same general class of use as BG-42, D2 and the other highly abrasion-resistant steels that tend to run in the low 60s RC. Holds an edge very well in slicing and push cutting, but is not well suited for impact work (chopping/batoning) or prying.

It's a good steel, but you'd have a hard time telling a performance difference between it and the above steels or ATS-34/154CM (all of this is assuming that the heat treatments have been done well).
 
t1mpani said:
It's a good steel, but you'd have a hard time telling a performance difference between it and the above steels ...
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I have compared VG-10 and S30V slicing cardboard and they will separate fairly quickly. However they are near idential on push cutting cardboard, whitting woods and many other types of cutting. The main advantage of S30V is wear resistance and it seems to need slicing to bring this out, maybe an issue with carbides and edge formation.

-Cliff
 
Here is some info that might be of interest. 440-C steel has more chromium and is more stainless than s30v, fyi. Many of these steels are really a waste for knife use as they were originally designed for products like jet engine blades spinning at 100,000 rpm in hundreds/thousands of degrees of heat.

http://www.bladeforums.com/forums/showthread.php?t=368828
 
According to crucible S30V has the same corrosion resistance and better pitting resistance. There is much more to corrosion resistance than amount of Cr. How much of the Cr is actually free in the steel, and as well consider the effect of other elements on corrosion resistance like nitrogen which S30V has and 440C does not.

As for the steels being used for other things, many of the aspects translate well to knife use. Knives can for example easily become hot enough in use for the edge to readily burn human skin, the very thin edge of a knife has almost no ability to heat sink and thus in very acute profiles ability to take heat could be of benefit.

Though in general the specific hot work steels (H series) would not be good knife steels other steels which can do this well and either also have high hardness and wear resistance (M series) or shock (some S and A series) steels all make good knives.

-Cliff
 
Cliff Stamp said:
The main advantage of S30V is wear resistance and it seems to need slicing to bring this out, maybe an issue with carbides and edge formation.

-Cliff
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True, but how many makers are running its hardness so as to maximize its wear resistance? I would dearly love to see the "toughness" claims around this steel die, so that we could see it pull into the 61+ RC range where it belongs.

The difference you've found in slicing longevity between S30V and VG-10 surprises me given what I have found, but I suppose that could be due to the fact that what VG-10 I've used has been ground fully convex, while I'm pretty sure I haven't tried an S30V blade that was anything but flat ground. I may have been mistaking design-based edge durability for abrasion resistance.
 
t1mpani said:
I would dearly love to see the "toughness" claims around this steel die ...
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That is the major promotion hence its widespread use in tactical knives, extending to large chopping tools, I doubt it will change until Crucible replaces it with a new steel at which point it will become obvious of the problems with S30V and how the new steel fixes them.

The difference you've found in slicing longevity between S30V and VG-10 surprises me given what I have found ...
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As you noted geometry makes a huge difference, a slim convex grind will outcut a much thicker flat v-edge grind, irregardless of steel. Several S30V blades custom rehardened have also been found to be too soft, ~55HRC, so if you ran one of them against VG-10 at 59/60 HRC then the comparison won't reflect what I saw either.

-Cliff
 
Cliff Stamp said:
According to crucible S30V has the same corrosion resistance and better pitting resistance. There is much more to corrosion resistance than amount of Cr. How much of the Cr is actually free in the steel, and as well consider the effect of other elements on corrosion resistance like nitrogen which S30V has and 440C does not.

As for the steels being used for other things, many of the aspects translate well to knife use. Knives can for example easily become hot enough in use for the edge to readily burn human skin, the very thin edge of a knife has almost no ability to heat sink and thus in very acute profiles ability to take heat could be of benefit.

Though in general the specific hot work steels (H series) would not be good knife steels other steels which can do this well and either also have high hardness and wear resistance (M series) or shock (some S and A series) steels all make good knives.

-Cliff
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Where is the report showing that s30v has more corrosion resistence? Has anyone ever seen a research report on this topic? If so I'd like to get a copy of it for my knife records.
 
Cliff Stamp said:
That is the major promotion hence its widespread use in tactical knives, extending to large chopping tools, I doubt it will change until Crucible replaces it with a new steel at which point it will become obvious of the problems with S30V and how the new steel fixes them.
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I can't figure why they haven't spend more time promoting 3V. Everybody seems to KNOW it's a great steel, but very very few makers are offering it. Yes there's Fehrman, and Bill Siegle has turned out a couple of great pieces for me in 3V, so I'm not saying it's UNavailable, but it doesn't get a tenth of the press S30V gets, and as far as I can tell the only area it's NOT superior in is corrosion resistance. Given the widespread use of teflon/boron/polymer/etc. coatings out there that isn't even a really serious issue. Yes the edge and any exposed parts would need occasional attention, but I'd hope anybody spending three figures for a knife would be willing to give it twenty seconds of their time at the end of use.

As you noted geometry makes a huge difference, a slim convex grind will outcut a much thicker flat v-edge grind, irregardless of steel. Several S30V blades custom rehardened have also been found to be too soft, ~55HRC, so if you ran one of them against VG-10 at 59/60 HRC then the comparison won't reflect what I saw either.
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I almost always reset edges to thinner than how they came (except on really big heavy stuff) so the V-grinds in question are pretty slim, but think the basic shape of a convex edge--where lateral/crushing force applied to it is spread out along a curve rather than a flat plane--slows edge degredation. Even when doing non-impact work that thin little strip of steel still has, psi, a lot of pressure on it, and will tend to blunt and misalign as it is used. Sometimes this is so slight as to not be readily visible, but shows up quick under magnification. I may either sacrifice a Fallkniven (meaning, turn it into a V-grind) or convex a little S30V utility knife I have that needs to be thinned down--by some method--anyway, and run them off together. Not a matter of doubting your results, just curious to see how much difference there is.
 
t1mpani said:
I can't figure why they haven't spend more time promoting 3V.
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It was promoted strongly initially, very heavily by a few makers, but it was replaced by S30V which was promoted to have extreme levels of toughness, initially put up in the same class as A2.

... the basic shape of a convex edge--where lateral/crushing force applied to it is spread out along a curve rather than a flat plane--slows edge degredation.
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It is amusing the things you don't see but which become obvious when someone else mentions them. I did a pile of work a few years back comparing v/hollow/convex grinds on harder work, mainly looking at primary grinds and found the exact same thing, but never thought about the very edge with the same perspective, not significantly anyway.

However I would caution a direct link because the typical edge deformation from cutting (not chopping) is usually really shallow as in about 10-100 microns. Now if you look at the steel on this scale there essentially is no curvature, it is too long since I did pure math, but basically any curve, no matter how funky will essentially be a straight line between two close points.

However there could be issues on a more macroscopic scale due to control in a cut, and similar. I switched from full convex to v-micro bevels years back simply due to sharpening time. I can do a micro bevel on a small blade in 2-3 minutes from extremely dull to push newsprint sharp, it takes about ten times as long if I do a full freehand polish, too long when I am running comparisons on blades.

Not a matter of doubting your results ...
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I do all the time. I even have other people do partial cutting for me so I can do trials where I don't know how much material I have cut just to check that I am not unintentionally biasing the results somehow. Most people interested in information don't mind being doubted, I would encourage it if anything. The best thing that can happen is that someone corrects you and now you know more than you did before. The only people that are bothered by people doubting them are those that are selling something.

-Cliff
 
Not Cliff, but he means shaving newsprint off of a newspaper without damaging the paper underneath. :)

Cliff Stamp said:
However I would caution a direct link because the typical edge deformation from cutting (not chopping) is usually really shallow as in about 10-100 microns. Now if you look at the steel on this scale there essentially is no curvature, it is too long since I did pure math, but basically any curve, no matter how funky will essentially be a straight line between two close points.
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True, but you can also have edge deformation in the guise of misalignment--where it starts wobbling outwards along its length like the pitch of a saw. It's possible that this is what I've notice more than actual blunting--but it seems to me that convex grinds seem less prone to this, in that I have to steel/burnish them less often than V-grinds of similar thickness (during extensive skinning, etc). I wonder if the curve still would apply since it is lending strength to the steel below it. I don't know though---could be purely the result of technique or differences in the knives I've happened to use in either case. Like I said, at some point I'll put a V on a Fallkniven and see what's what.
 
t1mpani said:
... he means shaving newsprint off of a newspaper without damaging the paper underneath.
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Generally I aim for a smooth push cut at 90 degrees to the paper with *no* draw, but when it can achieve this it can slice the print of paper as well, which tends to require more technique. I generally hold on to the newsprint, there is a much higher standard which is to just fold it, and leave a strip standing and just push the knife down into that with no support.

I wonder if the curve still would apply since it is lending strength to the steel below it.
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I think there might be an effect there in regards to stability of the cut, what are we talking about exactly in regards to profiles in particular are the very edge angles (the last 0.1 mm) the same? Are the same abrasives used?

-Cliff
 
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