Rethinking S30V

snowbrow said:
I have a Kershaw Avalanche and thought it was unbreakable.
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Sorry, Avalance has CPM S60V - which was CPM 440V. It does not tough as CPM S30V but CPM S90V (former CPM 420V) is different bird and it tough as CPM S30V but much more wear resistant even more then CPM S60V.

Thanks, Vassili.
 
I’ve read that S90V is very difficult to cut, grind, and finish, and that it takes a lot of time and expertise to work with it. This combination of factors probably explains why no large manufacturer is interested in producing knives out of S90V. The cost and complexity of the task is just too great.
 
I grind it myself without too much troble.

CPMS90V-Pair-13.jpg


Not so far ago when CPM 440V was on the top of food chain, almost any manufacturers makes some knives out of it and wear resistance was similar, so cost and complexity probably similar too. And price for CPM 440V knives does not too much different from CPM S30V knives - best example Spyderco Military which was produced with both steels and cost same price. So it should not be much bigger for CPM S90V.

I may expect some problem with HT - when I ask Paul Bos to harden CPM S90V for me he refuse, because of too high temperature for his owen. However Benchmade manage to HT M2 steel and it has even higher temperature for HT.

I hope somebody will make nice folder from this steel (fixed blade anybody can make himself).

Thanks, Vassili.
 
While I'm starting to learn that first hand experience and what the spec sheets say are often two very different things... S60V & S90V have more than 2% carbon content. I highly doubt that either one will be very durable under any circumstance.
(I LOVE the 24hrs of Le Mans!)
 
Just a little personal experience with CRK. I've been very impressed with the edges on all of my CRK knives, so far. Very sharp, long lasting edges in every case. Not too tough to keep sharp or bring back to sharp either. One day at work I had my Mnandi out cutting something mundane like an envelope or something, and got all "fumbly" and dropped it onto the floor. This particular floor was a very hard tile and when I saw it go down I cringed, especially when I saw the knife hit the floor tip first. "Aw crap" I was thinking, "the tip's going to be broken for sure." Not the case. On inspection, what I had was the very tip, less than a millimeter, was just slightly bent over a bit.

I'm not a steel expert, but that said to me tough rather than brittle. Am I correct in my assessment?
 
Being only semi-stainless may explain the toughness of D-2.
But like I said, if someone has first hand experience that says otherwise, I won't argue.
 
GarageBoy said:
Hmm..S30V should have a VERY fine grain structure due to the CPM process
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Better call that a *reasonably fine* grain structure. The carbides that give S30V its wear resistence aren't exactly small AFAIK. Most carbon steels have a much finer grain structure, and that's why they also take a much keener edge.

Hans
 
D2 and S30V have similar carbon content. But D2 is tougher although both steels have proven to be susceptible to tip breaks. I think proper heat treatment can certainly be a factor here but even on some that are heat treated perfectly the thinness of the steel can sometimes be more at fault. Many of the D2 knives I get for sharpening have very thin and acute tips and edge profiles as well as thin primary grinds. (One of the benefits of using such a tough steel is being able to make it that thin I think.)

On the S30V blades I've seen that were chipped or broken they don't have this thin profile to use as an excuse. In fact some of them are rather thick and look like they should be tougher than they are. So, from my point of view a D2 blade as thick as say a Manix with the same grind and blade shape would be incredible in toughness.
 
Lynn Thompson called out crucible almost 10 years ago claiming they made brittle steels not suited for tactical knives ;) sorry for the pun, couldn't resist
 
nozh2002 said:
CPM S90V according to Crucible data sheet way better then CPM S30V ...
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When S30V first came out it was promoted mainly as being cheaper than S90V. It was not intended to be a direct replacement, just a step up from ATS-34 class steels without jumping way up to S90V, simply a middle ground. Of course then the hype engine started and the incredible toughness claims started being made, and S90V was lost in the backwash.

nozh2002 said:
I may expect some problem with HT - when I ask Paul Bos to harden CPM S90V for me he refuse...
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Yes and look at how many custom makers use Bos for hardening.

-Cliff
 
Bad technique can also cause chips in blades. I once chipped an ax. It was a glancing swing off a branch.
 
Chuck Bybee said:
Bad technique can also cause chips in blades. I once chipped an ax. It was a glancing swing off a branch.
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You can't get those kinds of chips like that, a bad lateral stress on an axe can deform the edge however you can't get highly localized stresses which would cause sub-mm chips. Plus that wood is soft and the folder light, you should be able to hack at it randomally and not have it be damaged assuming the angle is 15+ degrees per side. If you have it reprofiled down to ~5 the you could bent it on a cross hit.

-Cliff
 
I think, the point is, that the carbides in S30V are not that small and well destirbuted as promoted by CS.

I saw my S30V blade getting a chip by nothing. I mean i did a fresh sharpening and edc-ed it over a week and didn´t do anything than opening letters and that stuff and all of a sudden there was a little chip in the edge. No kidding. It didn´t took much to get the edge back but for me there is no doubt, that Crucibles PM steels are not that fine. They seem to be pretty rough for wear resistance.

Experiences may vary as we talk steel. Steel can´t be the same from production run to run.

But, looking at my blades, i found RWL 34, a powder steel based on ATS 34, to be much finer and stronger at the edge than S30V. But this may vary from blade to blade as on S30V. Some ppl. don´t like RWL 34.
 
After using the Spyderco Native with S30V and the Native III with VG-10, I prefer the VG-10.

Admittedly, I don't chop with such a small blade, but I can get the VG-10 blade sharper and it seems to hold an edge just as long as the S30V with equal useage.

Good luck,
Allen.
 
Blop said:
I think, the point is, that the carbides in S30V are not that small and well destirbuted as promoted by CS.
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The interesting thing is that the main advantage, or one of them is the supposed consistency of the steel and the ease of heat treatment, with respect to S30V, so experiences should be more uniform than with other steels not less.

-Cliff
 
Alot of what happens with S30V seems to depend on the heat treat. Some of the early knives with it would chip, but then most people usning it adjusted to compensate for that, with the best being Bos.

Of course, I am really looking forward to the new CPM154.
 
When I was in school, powdered metal steels (as opposed to tungsten carbide and hard metals) were a relatively new technology. I find it fascinating that these alloys can be made tough and strong. Although I believe it, I also take it with a grain of salt.
 
I always thought that the general consensus was that powered steels performed better when laminated making the powdered steel the central core but I guess new techniques or improvements have made that school of though obsolete with some of them. Still, I vaguely remember a write up about the S30V before it came out suggesting that it was going to be laminated with 420HC or some such steel but I am not sure that ever happened.
 
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