S30V disadvantages?

[Cliff Stamp]

... real world use would destroy a knife that hard

Depends on what you are doing with it, you can't chop or impact it, but you don't want to do this with D2 either. I have several really hard blades, I use them all the time, and I don't baby them, I don't pry with them, and don't torque on them, but I will cut most anything.

You don't need to go as extreme as the ones I listed however, that is just how I would run them for cutting blades, if you want to take about digging, prying, chopping, metal/bone cutting, and so on, then yes, stainless starts to become really problematic.

...and how many hours would it take to sharpen it after a suffering a chipped edge or one that is simply worn?

Less than five minutes with benchstones and a Sharpmaker to remove visible size chips if the edges needed to be actually reset. The ones I have are really easy to sharpen due to the way they are ground.

Most sharpening problems come from starting with too fine a hone, I use a 220 grit SiC waterstone. It chews into steel fast, you can make a much more aggressive one from a 80 grit AO belt and a stick of hardwood.

If corrosion/rust resistance isn't an issue, there is no reason to go stainless.

I agree there, you can easily find better carbon than stainless, I would not argue that, but not all carbon is better than all stainless.

Your comments about 52100...are you talking stock removal knives or forged?

Both.

I would think a forged and differentially treated knife of 52100 would be able to survive almost anything.

Consider the forging more of a shaping process than anything else. It has other effects, mainly on grain refinement through dislocation density increases, but this isn't the only factor in steel performance, much of the performance will come from how it is hardened after the forging.

-Cliff

 

[Cliff Stamp]

The term insolent does not apply to the word nonsense.

It is one of the definations, such as when a child is misbehaving and you say "Stop that nonsense right now."

I was stating my experience ...

You also attempted to devalue the experience of others. Your experience by the way mirrors mine it isn't in opposition to it.

I think the word you want is 'undermine,'

Yes, the post was first along the lines of "underwrite the hype", which I shifted in perspective on a rewrite and didn't fix it completely. I got most of the spelling mistakes though.

And I've noticed you seem to so often find fault with certain products more than others. This is curious.

Yes because not all products are at the the same quality and performance level.

If someone has had such positive, flawless experiences from certain products or makers shouldn't those experiences be part of the mix?

No product/steel is perfect, they all have weakpoints and drawbacks, some large some small. If all you have to say is positive your position is weakened because you have not shown the ability to actually notice or at least present the problems.

Lets say you are reading movie reviews and the guy likes every movie, they always get 5 out of 5 stars. How long does it take you to not really pay attention to what he is saying. Similar if every steel is tough, then obviously that assertion ceases to have meaning.

You also said the statement "S30V's performance can vary widely depending on the heat treat" is nonsense and inflammatory.

Yes because this is true of any steel in general, and should be less of an issue for S30V based on how it was promoted, not more. The only way this would be informative was if you were to argue that it was harder to heat treat and get consistent which is the exact opposite way it was promoted.

-Cliff

 

[nenofury]

Consider the forging more of a shaping process than anything else. It has other effects, mainly on grain refinement through dislocation density increases, but this isn't the only factor in steel performance, much of the performance will come from how it is hardened after the forging.

-Cliff

Granted, but it's my understanding that 52100 does benefit from hammer forging. Also, it has to have multiple hardening and tempering treatments. Many bladesmiths regard it as the ultimate knife steel in terms of toughness and edge holding. It is very difficult to work with and requires more time and care to finish properly so it's relatively unpopular. But I wouldn't hesitate to put it up against any other quality made blade.

 

[Cliff Stamp]

Many bladesmiths regard it as the ultimate knife steel in terms of toughness and edge holding.

That is wild exaggeration, now you can argue that it has solid performance in both areas, but it is readily exceeded in both areas by other steels. As for its forging benefits, find a comparison which takes one of those blades and compares it to a 52100 blade with a high quality stock ground heat treatment including full cryo and it has better toughness and edge retention. In regards to multiple quenchings, this can refine the grain of any steel, it isn't specific to 52100, there are material journal articles on this, including cryo treatment which are more than 20 years old.

-Cliff

 

[nenofury]

That is wild exaggeration, now you can argue that it has solid performance in both areas, but it is readily exceeded in both areas by other steels. As for its forging benefits, find a comparison which takes one of those blades and compares it to a 52100 blade with a high quality stock ground heat treatment including full cryo and it has better toughness and edge retention. In regards to multiple quenchings, this can refine the grain of any steel, it isn't specific to 52100, there are material journal articles on this, including cryo treatment which are more than 20 years old.

-Cliff

Wild exaggeration?? Ok, than all those forgers are wrong? Sure M2 is better at edge retention and 5160 is tougher, but neither one exceeds 52100 in both areas. Is there a steel that does?

 

[Cliff Stamp]

Sure M2 is better at edge retention and 5160 is tougher, but neither one exceeds 52100 in both areas. Is there a steel that does?

You would need to get really specific about what you mean by edge retention and toughness. D2 has better edge retention than 420HC in carving woods, however in the kitchen in cutting vegetables 420HC can easily pull ahead due to corrosion of the edge of D2.

Even in just normal cutting, how and what you are doing makes a difference. A M2 blade at 65 HRC will resist deformation much longer than a 52100 blade at 60 HRC, and the edge will stay sharper a lot longer cutting cardboard, plastics and even carving bone. It won't flex very far, or take being hit by a hammer well though.

5160 would have a better combination of toughness and edge retention if you moved into really heavy work which required more impact toughness and less wear resistance. S7 would be even more so along the same lines. Of course anyone is free to draw the line where they want. Consider other well balanced steels like 3V and INFI.

You can easily say 1095 at 65/66 HRC has the best combination of edge retention and toughness for a broad class of cutting because it has enough durability to cut plastics, foods, cardboard, wood, foods, bone (cut not chop), without damage and it will stay sharp a long time.

As for "them all being wrong", yes lots of people really like 52100 and hold it as the ultimate, lots of others will say the same about other steels, it isn't like every forger uses 52100 over everything else and feels it makes the best knife - or will even claim that it is better than the better stock removal knives.

Is it a good steel, yes, I have used, and continue to use it in many knives. The Swamp Rat line uses SR101 which is a modified version of 52100 and it does very well and lots of people are pleased with it. I have used a number of 52100 blades, custom and production. I have a really nice fully convex one by Ed Caffrey.

However I would not argue that if I got a 52100 stock removal blade made of the exact same shape, and heat treated by Phil Wilson, that the Caffrey blade would be tougher or have better edge retention. I would be curious to see if any maker would actually support that claim.

-Cliff

 

[nenofury]

Even in just normal cutting, how and what you are doing makes a difference.

Good point and I think we agree. You are just after more specifics and I was speaking very generally. I guess for a really fair comparison what you are cutting and exactly how you are doing it should be the deciding factor when choosing or evaluationg a steel. For instance, I would never bother with anything but 420 or 440 in the kitchen. But wouldn't do anything in the woods without 5160. What's "best" changes in each situation. You mentioned INFI after 5160. Is that the steel it's closest to in makeup? I don't know anything about it. Thought Jerry Busse was keeping it a secret.

 

[Cliff Stamp]

Yeah, 5160 makes a nice large blade, I have a custom parang in it, really nice. INFI's composition has been published publically, it has been listed all over the forum, it is even in Busse's forum.

-Cliff

 

[conan]

It is time to clear up one important point about CPM S30V. Crucible DID NOT promote CPM S30V as a premium stainless knife steel that is easy to heat treat or for its ease of heat treatment. Crucible promotes CPM S30V as:
"a martensitic stainless steel designed to offer the best combination of toughness, wear resistance and corrosion resistance. Its chemistry has been specifically balanced to promote the formation of vanadium carbides which are harder and more effective than chromium carbides in providing wear resistance. CPM S30V offers substantial improvement in toughness over other high hardness steels such as 440C and D2, and its corrosion resistance is equal to or better than 440C in various environments."

If this is helpful, CPM S30V is easier to heat treat than higher alloyed steels such as CPM S90V, M 2, and CPM M4 but more difficult to heat treat than steels like D 2, A 2, and 440C.

If there are custom makers out there who have stated that
CPM S30V is easy to heat treat that is great but Crucible did not promote ease of heat treatment as one of CPM S30Vs' prominent features.

I learn alot from reading many of the posts here on Bladeforums. It is true that with proper heat treatment CPM S30V should perform well although blade and edge geometry are also critical factors in blade performance. CPM S30V was developed specifically for the cutlery business but like all steels CPM S30V has its limitations. Also, we at Crucible never rule out the possibility that a bad piece of steel could ultimately be the problem with the tool or blade. However, if a tool or blade is not performing up to expectations or fails prematurely we do want to investigate to determine the reason for the problem. If the steel is at fault we accept that finding but more importantly we try to address the problem so it will not repeat.

Your feedback is extremely important. We do hear your feedback and concerns and try to address any problems that are steel related.

Thanks.

 

[Cliff Stamp]

...more difficult to heat treat than steels like D 2

In what way is it more difficult to heat treat than D2 which has a tendancy for carbide segregation and large amounts of retained austenite requiring multiple tempers and/or deep cryo?

This perspective certaily differs from how many makers commented on it during its early use, both on the forums and in magazines articles, which were never contended by Crucible.

But in any case the recipes for its heat treat are available from many makers who will be open about what they do and are getting very good results from it.

I certainly heard nothing from them with complaints in regard to heat treating, and in fact all are uniformly positive about its responce and its rehardenability.

So anyway difficulty of heat treat would include issues like :

-really high soak temperature
-really short soak time with a very short overburn time
-really short quench to temper tolerance
-really steep temperature/temper responce
-requires liquid quench
-requires multiple tempers/cryo
-requires a differential hardening
-aggregates cause large variances

there are others, but these are common ones, but anyway some more detail on how S30V is harder to get consistent results than the other steels mentioned here would be of benefit, D2, ATS-34, BG-42 and VG-10.

Note some of the knives it is being compared to, like Queen's D2 are very inexpensive, so it is really hard to stretch performance based on heat treating tolerances from that perspective.

-Cliff

 

[Carl64]

A Dogs Best Friend said:

I think you have a problem with my having simply disagreed with your self-vaunted opinion. Perhaps you thought I was being insolent by simply disaggreeing with you.

I read a statement by you in this thread which was very general, lacking in detail, and included the claim that any disagreement with you is "non-sense."

Surely that post warranted a comment from others?

Second, I think the word you want is 'undermine,' not underwrite. You ought to make sure you understand your terms before you use them so freely and often.

I am sure he appreciates your advice.

And I've noticed you seem to so often find fault with certain products more than others. This is curious.

It seems he finds fault with products that have faults. Perhaps you could be more specific.

Also, who, besides yourself, declared you to be such an expert?

That's a useless question. Are you here to make logical arguments about the subject of the thread, or check everyone's credentials?

You said to remove all comments from any person who has never had a problem. Or any person who has never found fault with a particular manufacturer. Very curious, again. Why should we ignore those experiences?

Because virtually every product is imperfect in some way, though some very good products have very minimal imperfections. Someone who never finds any imperfections in any product probably isn't looking very hard or putting the product to much use. Therefore, their not finding any problems with a new specific product could easily be due to their lack of ability rather than the greatness of the product. I sort of can't believe this had to be explained.

If someone has had such positive, flawless experiences from certain products or makers shouldn't those experiences be part of the mix?

Your statement is less specific than the statement Cliff made. He addressed people that never have any problems with ANYTHING, and people that never have problems with a specific manufacturer. This eliminates blunt people and brand fanatics.

You also said the statement "S30V's performance can vary widely depending on the heat treat" is nonsense and inflammatory. How so, when this statement just presents a general fact about this material. Is it untrue? If so, then how is it untrue?

He said the *argument* based on that is nonsense. You have mislabeled the quote. An argument can be completely stupid even if it contains facts.

By the way, he even SAID it was true, so why are you asking him how it is untrue?

Using the fact that performance varies with heat treating as an argument is stupid because the same could be said of the other blade. It also implies that you think we were starting with a poorly treated blade. If you think that, say so, but it's not a useful argument against the whole subject of s30v performance. Besides, it is quite obvious that more than one specific blade or model is in question.

I am sure everyone would be open to hearing which knife is done better than the ones we have used and should therefore improve performance.

 

[A Dogs Best Friend]

It is one of the definations...
-Cliff

Changed my mind. I still disagree with you and your attitude.

 

[conan]

Cliff -

#1. Crucible did not promote CPM S30V as easy to heat treat. Key word - PROMOTE
#2. If D-2 is heat treated correctly(correct austenitizing temperature and holding time at temp) carbide segregation is not a problem. Also, retained austenite is not a problem if the quench is done corectly and two tempers are used. Deep freezing is only necessary when austenitzing - quenching - and tempering are not done correctly and/or if minimal retained austenite is necessary to promote better stability for applications like fine blanking.
#3. No need to contend makers comments - if they are getting good results with their methods -which most were - keep going. Makers who had problems usually called us and we helped them through the problems.
#4. The so-called recipes from the makers are also readily available from Crucible which is where the makers obtained the recipes.
#5. No need to address difficulty of heat treat issues because most of these do not apply to CPM S30V and no need to address how CPM S30V is harder to get consistent results than the other grades becuase that is not the case- very simply Crucible did not promote ease of heat treat with CPM S30V - again key word PROMOTE.

#6. I don't understand the Queen's D-2 comment so I won't comment.

Several of the people who have posted mention heat treat as the possible problem related to chipping. You respond by saying that heat treat should not be the problem leading to chipping since Crucible promoted CPM S30V as easy to heat treat. This is not a valid response. Regardless of the difficulty or ease of heat treatment - if the heat treat is done correctly then we need to look elsewhere for the chipping problem - like the steel, or edge geometry, or grinding & sharpening practice.

Lastly, we are curently investigating CPM S30V blades that have chipped. When we determine the cause of this chipping we will make the information available.

Thanks for your comments - they are always very informative and constructive.

 

[conan]

Sorry, I meant to sign off

Scott Devanna
Crucible Service Centers
Metallurgist

 

[thombrogan]

Lastly, we are curently investigating CPM S30V blades that have chipped. When we determine the cause of this chipping we will make the information available.

Mine chipped because they were either too soft or the edges were too thin. Usually softness was the culprit. When they were re-heated and rehardened, the only chipping came from my ambitious cutting with very fine edges. The chipping looked different, too. The softer S30V looks more like it smeared and the harder S30V looks more like it out right chipped. That's not a fault of the steel; more a fault of my enjoyment of thin edges.

 

[Manila Folder]

S30V kinda gives me bad vibes.. you know, something you just can't put your finger on. Never really had a problem with it, other than I do find it somewhat difficult to sharpen. D2 is much more forgiving, at least to me. Rock on Bro!

 

[Cliff Stamp]

If D-2 is heat treated correctly (correct austenitizing temperature and holding time at temp) carbide segregation is not a problem. Also, retained austenite is not a problem if the quench is done corectly and two tempers are used. Deep freezing is only necessary when austenitzing - quenching - and tempering are not done correctly and/or if minimal retained austenite is necessary to promote better stability for applications like fine blanking.

Minimal retained austenite would be *very* important for knife edges, as for the other benefits, there are makers who would contend that, but that has already been said in other threads. But you just repeated my arguement in regards to heat treating, of course you can get good results with any steel however not all steels need to even address retained austenite, have secondary hardening zones, can produce huge carbide aggregates, have to deal with temper embrittlement, require differential hardening, etc. . Of course there are ways to deal with these issues and they are what makes the heat treat more involved / difficult.

No need to contend makers comments

You would if they were misrepresentative.

The so-called recipes from the makers are also readily available from Crucible which is where the makers obtained the recipes.

Every maker heat treating CPM steels uses your schedules, no one actually developed their own through R&D?

.. and no need to address how CPM S30V is harder to get consistent results than the other grades becuase that is not the case

You said it was harder to heat treat that D2, A2, etc. This I don't see because from a very basic perspective just considering that you promote a high quality steel in terms of consistency of method and composition and a very high elemental dispersion rate, and a clear recipe, what difficulty does the customer have in heat treating?

It seems to be very positive in many respects with a clear starting point and improvement of heat treat made easier because when refining experimental techniques you are always considering the dual effect of changes in method and sample, if you can reduce the sample variance you can refine methods much faster.

Crucible is very clear on this and does promote several aspects of CPM which makes heat treating easier directly on their website :

• Consistent Heat Treat Response
• Predictable Size Change on Heat Treat

and as noted S30V is easier to heat treat than some of the other stainless grades you offer such as S90V due to lower soak temperatures. Clarification would be appreciated on where the difficulty is arising.

-Cliff

 

[mete]

" Grain refinement through dislocation density increases' NO it doesn't happen. Cryo does not refine grain either !! If you come over to the knife makers section we'll teach you something about metallurgy !

 

[C Ben Susrool]

Do appreciate your input Conan

 

[Walt2]

find a comparison which takes one of those blades and compares it to a 52100 blade with a high quality stock ground heat treatment including full cryo and it has better toughness and edge retention.


Ed Caffery says that he has done this himself.