Some comments on S30V (stainless CPM-3V) by Phil Wilson

Uhhhh... so what you're saying, Cliff, is you don't like S30V? Or do like it better than ATS-34? No?

I think I got lost somewhere... actually, I think in the second paragraph where you respond to "...3V ...marginally tougher than 30V..." by comparing the 30V to A2..... :confused:
 
Rockspyder, based on the promoted performance by Crucible of S30V, the general advantages of CPM steels, and the user feedback so far, if I had to pick between an ATS-34 blade and a S30V one, yes I would go with S30V. However in reality, this isn't a choice I would make as neither of those steels I would consider in the first place, for reasons stated in the above.

in the second paragraph where you respond to "...3V ...marginally tougher than 30V..." by comparing the 30V to A2.....
Click to expand...

S30V is supposed to be similar in toughness to A2, thus if CPM-3V is "marginally tougher" than S30V, it also follows that CPM-3V is only "marginally tougher" than A2, which I don't agree with for reasons stated in the above, and thus I don't accept the original statement as it leads to an incorrect conclusion.

-Cliff
 
Cliff, have you tried an S30-V blade?

I agree with a lot of your comments reguarding performance, but for those looking for a very well balanced stain resistant steel, this is looking pretty good so far. I always say, never judge a steel by its spec sheet, but by real field testing. (Which I havent really done much of yet)
 
Rob Simonich :

for those looking for a very well balanced stain resistant steel, this is looking pretty good so far.
Click to expand...

Yes, pretty much exactly.

never judge a steel by its spec sheet
Click to expand...

The base materials properties of course don't tell the whole performance, however it is hardly like they can be ignored, they were developed for a reason and well characterize the aspects they measure, just like hardness measures compaction resistance. There are literally thousands of cutlery grade steels, any maker (or user for that matter) who doesn't want to spend his entire life just moving from one steel to the other every few days has to use something to discriminate among the steels that they have not used in order to seperate the ones that are promising from those that are not and focus on the ones that look to give the most benefit, otherwise you would never get anywhere.

No, I have not used a S30V blade, the properties that Crucible have promoted are of no interest for me for reasons described in the above. I can easily list off over a dozen alloys now that for similar reasons have no interest to me, and I am sure that it would be trivial for others to do the same. If I hear that the properties of S30V are different as more blades are made out of it then yes my opinion might change. However I don't think it is reasonable for anything like that to happen as it would mean that it had either a toughness greater than 3V, or better low stress edge retention than S90V, or extreme corrosion resistance akin to 440A.

As for material properties, the way they are used correctly is not to simply to look at them as numbers on a piece of paper. They only become meaningful when you correlate them to actual experience with that material. It is the same thing with anything. For example once you know the properties of A2 and have worked with it quite a bit you then understand what those numbers mean in regards to such things as edge retention, edge durability etc. . They are no longer then just numbers on a sheet of paper but a way to quantify the performance that you have seen in use.

This by the way is something that everyone does in every day life. It is nothing more complicated than knowing that you like the taste of one tablespoon of sugar in your coffee. Once you have come to this conclusion you have now correlated a precise measured standard (one tablespoon) to a personally meaningful quantity (your desired sweetness). Thus when you order coffee you can specify a particular quantity of sugar, which is a rigerous standard, and not a judgement on sweetness which pretty much no one really understands but you. The material properties of steels allow the exact same types of decisions.

The complicated part about steels is the way that they intereact. For example edge retention is dependent on the impact toughness, ductility, hardness , wear resistance, and carbide structure. And what is even worse is that the dependancy is different depending on what is being cut. Chopping wood for example requires a very different set of properties that cutting fibreglass insulation. Decisions can still be made though once the various factors are considered. For example if someone asks you for a better knife for cutting the insulation that a 60 RC A2 blade they are using, you can provide once in D2 at 62 RC with confidence that the extra edge strength and wear resistance will give them the performance they need.

This is also obviously why Crucible went the way they did for the spec's relating the performance to well known steels instead of just stating numbers (toughness like A2 instead of -> a c-notch charpy value of ~40 fl.lbs) . However how to you think they determined that it had a toughness similar to A2, by a charpy test, same thing for wear resistance and corrosion resistance. There are well developed standards for measuring these quantities and they are vigeriously used in the development of steel alloys (and for lots of other ones as well including the non ferrous ones) and they allow a very rapid rate of progression in the development of alloys.

-Cliff
 
I just finished reading this entire thread, and realized how little I know about knives and steel!!!

Me feel stupid, so me go now and play with sharp,pointy metal things.:confused:

Jet
 
Dont' worry about it, JtJ. I've come to the conclusion that the numbers don't mean ****. Or at least, they mean very little ****. 440V was supposed to be the best steel down the pipe in production, but while it is workable, I'll take 440C over it any day. It all depends on the shape of the blade, the blade geometry, and what the man shaping/treating the steel does with it. For 99.9% of the users 99.99999% of the time, it just doesn't matter. :rolleyes:

Just give me a good knifemaker/craftsman, a good treater/treat, and I'll go with whatever. But it is fun to read the threads, ain't it. :D
 
rockspyder :

440V was supposed to be the best steel down the pipe in production, but while it is workable, I'll take 440C over it any day.
Click to expand...

The problem with the perception of 440V is often that it is based on Spyderco's use of that steel at ~55 RC. They found that at a high RC the steel chipped too readily and thus they softened it. The problem was that the blades were not suitable for the steel and they would have been much better off switching to another steel. CPM-440V (S60V) is designed as a light use, very wear resistant steel. If you run it soft that counteracts the very purpose of its existance and you end up with an edge that is weak, rolls easily and likewise has poor resistance to indendation. Thus on cutting hard materials you will get lower edge retention that something like 154CM at 59/60 RC, and you will see greater damage on the odd mishap (staple hit) and on top of that a steel which has a much greater tendancy to burr when sharpening. However this is not indicative of a "poor" steel, simply a material being used for something that it should not be. If you really want to see the stainless CPM's S60V/S90V perform at their best, get a custom maker who runs them hard, in blades that are designed for low stress cutting. In those knives S60V/S90V will readily outshine steels like 440C / ATS-34 etc. .

-Cliff
 
Now you're starting to talk like you get it, Cliff, almost.

There are no "problems with" 440V, whatsoever. 440V does what it's designer meant for it to do. The quality is constant. The problem is that most people don't know what they think they know, or what they don't know. The adaption of these modern tool steels has only exacerbated the core misunderstanding. To wit:

Heat treatment is the single most important factor to consider in the construction of a knife, or any tool for that matter. Its importance cannot be overemphasized. It is complicated, and not to be guessed at. More than any other single thing, heat treament determines whether you just bought a fine handmade knife that possesses all the qualities the maker says it does, or a $500 paperweight.

Furthermore...

With the possible exceptions of 440C, and Sandvik 12c27**, none of the steels used in knives over the past 100 years was <i>specifically</i> designed to be made into hand-held knife blades. These are industrial tool steels, with complicated chemistries. In alloys this complex, it is a fool's gambit to try to <i>precisely</i> predict all the ultimate effects such a combination of alloying elements will produce. S30V's potential as a knife blade alloy still must be discovered through trial and error, IN KNIFE BLADES!

That range of processes which we call "heat-treatment" can be (and very often is) tailored to produce astonishingly different results in each and every steel. You can make the same alloy more or less stainless, hardenable, tough, abrasion resistant or whatever you wish, by different heat treatments. You just can't do all of those at the same time. Witness the amount of bandwith wasted here each year arguing about whether or not ATS-34 is the best alloy. You know this, as well as I, and I am stopping here because this is becoming a soliloquy, and that is your specialty not my own.

S30V is unique in that it was designed directly for hand-held knife blades. It is an important contribution to the field. People are just testing it now. I think that less than twenty people are qualified to speak about S30V - AS A BLADE STEEL ALLOY - right now. Give it a rest, for now.


** I know that this statement is not entirely complete, but it's close enough for this thread.
 
Well, the S30V arrived, and the first two chisel ground blades are going to be finished up this weekend.
So far, I like the steel. It heat treats very nicely, real "snappy". By that I mean that the steel responds well to the cycle. Consistent and predictable, not sluggish like some steels.
And, although neither blade had been full sharpened yet, I like very much the way the blade feels when it's being re-ground. This stuff just feels good on the belt-like it is going to be tough and wear resistant. Yeah, I know-Where's the data, RJ?
No hard data yet, but, I'm tellin'ya, this stuff is gonna work out well. Them Boys from Crucible are sharp.

RJ Martin
 
Jeez, Sam. Talk about giving it a rest! You rambled on for several paragraphs, and as far as I can tell, you made three points.

One, 440V is fine if you’re looking for what the designer had in mind when he designed it. Wow.

Two, that “heat treatment is the single most important factor to consider in the construction of a knife”, which is just a gross, if convenient, oversimplification. Obviously, it’s not nearly as important as geometry, for example. You can cut just fine with a serrated plastic knife, which is well-designed for its purpose--or certainly with a Haynes alloy that doesn’t even respond to heat treat--but I’ll “give it a rest” if you will.

And point three, that the steels used in cutlery originally were invented for other uses. What is that, “Sam on Cutlery 101?” Talk about stating the obvious.

Next time you decide to hold forth as if we’re kindergarten students, maybe you could rummage around for some illuminating material first. Comedic value goes only so far.

-w
 
RJ, so far my experiance with S30-V is very much like yours. I heat treated the third batch of blades today and the more I like work this steel the better I like it. I had one knife hollow ground very thin, .010 befroe sharpening and had great tip flex and the edge flexes very nicely over a steel rod, at 61Rc. It cuts like mad! I like it. I dont think I will even bother with S90-V anymore as the slight increase in edgeholding with S90-V isnt worth the toughness difference in my opinion.

Cliff, I certainly dont care if you give it your "Stamp" of approval. And although I dont agree with all your statements, I always find something to think about in your comments.
 
Originally posted by samwereb

Furthermore...

With the possible exceptions of 440C, and Sandvik 12c27**, none of the steels used in knives over the past 100 years was <i>specifically</i> designed to be made into hand-held knife blades.

Click to expand...

I'm pretty sure that vg-10 was developed for plant grafting knives.

that would be a hand held knife in my book.
 
I agree with RJ and Rob. It looks like it's going to be a great steel. The grain structure is extremely fine, especially considering it's stainless. Etched, it's almost as smooth grained as 3V.

I do have to say that taking it to a fine brushed finish is not much fun though, especially in a large knife. In fact I've found it more difficult than 3V. I finished a couple 154CM blades in the middle of working with some S30V blades, and it was like taking a break. This steel just might drive me to bead blasting. :)
 
Can someone compare it to D2? I like D2 and its edge holding, and the 30V sounds similiar to it, but tougher and more stainless. Can someone who has used D2 and the 30V comment with a comparision? I know its CPM to tool steel, etc, but im mainly interested in the edge it takes and edge holding of the 2 steels.

RJ, have u heard from Ed Schott lately?????
 
Well, immediately after posting, I wnet out to the shop and sharpened up a blade. VERY NICE EDGE. VERY TOUGH. NOT CHIPPY.
I am pushing this steel hard-62 Rc, with 3 tempers. I did some stuff with it that would have slightly damaged 3V at Rc59, and A2 at Rc60.
did some edge flexing on a 1/8" drill bit, and the stuff comes right back with much less deformation than A2-this is key on a zero thickness chisel grind.
AND, it's stainless!

Boys, it's a no brainer so far. Glad I ordered $1200 worth of the stuff!

Rope testing is next, soon as I get some.

RJ Martin
 
Taz, so far edgeholding seems to at least as good as properly heat treated D-2, maybe better, and certainly tougher.
 
Hey, if Rob or Jerry uses the S30V, and I can get one of their knives made with it, then it's a no-brainer for me, too.

But I think even from them, I'd pass on S60V, Cliff. I've had enough of that stuff.
 
For what its worth. S30V tested better than we thought it would on the CATRA tester. abrasion resistance ran in the same neighborhood as S60V, less than S90V. Test was done at Rc60. The mules are going to "Q"-fog in the next batch.

sal
 
Good info Sal, and pretty much where I am at with it at this time. Do you have CATRA numbers that would compare it to D-2 and 3-V? In my very limited testing, I think it is above D-2 and very close to 3-V in wear resistance. Impressive steel so far.
 
You must log in or register to reply here.
Back
Top