S30V Questions as Answered by the CRK Shop Foreman Himself...

[Professor]

S30V and General Sebenza-Related Questions Answered By The CRK Shop Foreman Himself…

In order to get some answers to the questions we’ve all been posing around here lately, I decided to go straight to the source. I called CRK today and spoke with Brian, the shop foreman, who was patient and forthcoming with answers to my questions. At the end of our conversation, I asked if he minded my sharing with others here at the forum, and he said "sure!" Brian, if I've mis-paraphrased or misinterpreted anything you told me in regard to S30V or anything else we discussed, please feel free to chime in here and set me straight!

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Question: Why are new S30V blades hardened to 57-59RC when the former BG42 blades were hardened to 60-61RC?

Answer: Because S30V doesn’t need to be hardened to that degree. At 57-59RC, it is incredibly tough by virtue of itself, yet significantly easier to sharpen than BG42 by the end user, using conventional methods such as ceramic rods, etc. The increased toughness of S30V is evident when grinding it (Brian stated that though he considers S30V a significantly better steel choice, he’d rather still be grinding BG42 blades!). Edge retention will remain close to that of BG42, but in an easier-to-sharpen format. Increased toughness, because of the inherent difference in the steel combined with the lesser RC hardness will make for a more chip-resistent edge and blade overall.

Question: Are there any concerns about what one might call a “softer” steel’s wear at the contact point on the blade tang with the titanium locking bar?

Answer: No. All noticeable wear with Sebenza’s has been historically on the titanium of the locking bar. Though not as “hard” as BG42, again the toughness of S30V will compensate and lock wear will remain isolated to the locking bar, and remain as negligible as in past years (the proof’s in the pudding: we don’t hear much about Sebenza’s wearing out or being sent back for new lock-side ti slabs; if it was that frequent, we’d be hearing about it at this forum to be sure!)

Question: I recently ordered several double-thumblugged small Sebenza’s with the new steel (not a new steel-related question per se), and wondered about retrofitting the lock-side ti slab with a recess for the new left-sided thumblug. The recess is cut into the locking bar, and then the locking bar is re-blasted. Is there any loss of lock-face surface when the lock-side slab is re-blasted?

Answer: No. The lock-face is carefully taped-off to prevent surface removal, which would result in effect a “worn” lock when the knife is reassembled.

____________________________________

Again, many thanks to Brian for taking the time to answer my questions. A year or so ago, I phoned CRK and spoke with Chris Reeve for over 40 minutes with all kinds of Sebenza-related questions. He too was patient and forthcoming with information, and both gentlemen genuinely seem to want their customers to understand the “in’s and out’s” of their products. Considering the tediousness and anal-retentive, perfection-driven nature of my line of questioning, the fact that my questions were not only answered but with experience-reinforced fact only augments my respect for this company.

While some of this info may be redundant to the good information others have shared lately, I hope you find it somewhat useful. I know I do.

Professor

 

[Danbo]

I'm not buying it. Heat treating S30V to that low of a rockwell is not getting the most out of the steel. Ease of sharpening and super toughness? That's not what this steel was designed for. This steel was designed to be super tough and to hold a great edge and be stainless at the same time. I imagine that the factor here is the ease of grinding and finishing it at 57 instead of having to grind and finish it at 61. Too bad, since a Sebenza with a properly heat treated S30V blade(60-61) would be something great. Sorry to sound bitter, but I imagine that I am not the only one who is disappointed with the decision to leave these blades at that low of a Rockwell. Reeve Knives needs to take a poll of its customers and listen to what they tell them.

 

[Professor]

And thus far my only contentment with the RC57-59 choice is what Brian has told me. I do not, however, believe that CRK is a company to cut corners for ease of production. The difficulty in grinding the new steel illustrates a level of commitment to us, the end users, in itself IMHO.

The only way we'll know for sure what we're dealing with in the new steel's composition and hardness will be use. And I will give them the benefit of the doubt until I get to try out my new Seb's due to arrive tomorrow or Friday. We can theorize the steel composition and RC choice to death, but it's not until we start cuttin' and resharpenin' that we'll really know!

Professor.

 

[ARtsig1]

.........thanks for taking the time and trouble to call! It seems like you are always able to get answers to the tougher questions. I have to think that CRK is not going to risk their reputation by delivering an inferior product, after all they are #1

Thanks again Professor.

 

[Professor]

Knives are a heck of a lot more fun than my work! Ahh, is that my boss coming?



Professor.

 

[Paul Work]

Thanks Professor. Let's not forget that CPM-440V shows the same general characteristics where hardness is concerned. I trust CRK to make the right call. They've done their research. I can't wait to try this new steel out.

Paul

 

[Barry H]

With all due respect to CRK, their heat treat of S30V has not been tested by the likes of any of us. There are some fairly current posts on some of the other sub-forums here at BF that illustrates some of the characteristics of S30V, including some extensive testing by Cliff Stamp as well as comments about the origin of this steel from a couple of gentlemen from Crucible.

I just recieved my large S30V yesterday, but have not had much of a chance to use it hard yet. So I will reserve judgement.

I would eventually like to see Cliff Stamp take an assortment of S30V hollow grind knives--CRK, Darrel Ralph, Kit Carson, J.W. Smith, Mike Obenauf--and "put it to it".

Regards, all.

Barry H

 

[Warriorsociologist]

Thanks Prof. for the effort and timely report!!! I will have to call Bridget and tell her that you've already answered most of the questions I just emailed her with...

 

[Cliff Stamp]

CRK Shop Foreman (second hand) :

Because S30V doesn?t need to be hardened to that degree. At 57-59RC, it is incredibly tough by virtue of itself ...

This implies that it would be tougher at the higher RC, but that extra toughness isn't really needed and thus you don't push it that far. This statement seems to be using toughness in an odd manner, I do not think it is impact toughness or stress/strain, more on this below.

... yet significantly easier to sharpen than BG42 by the end user, using conventional methods such as ceramic rods, etc.

High alloy steels want to be left very hard for ease of sharpening. If you put a lot of very hard carbides in a soft matrix then you get a gummy grinding action and it is very easy to get heavily burred edges. Unless you want to file the steel, or use very low grade hones (like a rock) lowering the hardness in general doesn't make sharpening easier. It does allow for much easier heavy stock removal (which could be an important production point as Danbo noted), but how many people do extensive reprofiling to thin out the edges on their Sebenza's?

The increased toughness of S30V is evident when grinding it

This seems to be using toughness to indicate a low machinability, as in "it is tough to grind". This isn't the same as the meaning of toughness as CPM is promoting for this steel, which is a high impact and stress/strain toughness, and as Danbo noted, the goal would be to get such toughness at a high RC.

Edge retention will remain close to that of BG42, but in an easier-to-sharpen format.

For a lot of cutting on many materials, hardness is the critical factor in edge retention and abrasion resistance makes little effect. Thus dropping ~4 RC will induce a significnt loss in edge retention on many materials because the steel will be weaker and thus roll easier, regardless of alloy content.

Increased toughness, because of the inherent difference in the steel combined with the lesser RC hardness will make for a more chip-resistent edge and blade overall.

The edge will also deform easier and have less resistance to compaction.

Danbo :

I imagine that the factor here is the ease of grinding and finishing it at 57 instead of having to grind and finish it at 61.

As well, getting the higher hardness after tempering on the other stainless CPM's requires a high soak temp and/or oil quenches, this may simply be too difficult to do.

For some reference information on a very similar topic, do some searches for reports on Spyderco's leaving S60V at 55 RC. There are many reports of poor edge retention when cutting harder materials that induce edge roll, and much easier indendation and deformation of the edge in general. The high vanadium content also requires sharp aggressive hones for optimum edges, regardless of the soft steel body.

-Cliff

 

[Professor]

We can theorize all day long. We'll see what we'll see!



Professor.

 

[Blade Santa Cruz]

After following this discussion, I'm a little surprised that more folks don't realize that Cliff is right on here.

A lower RC results in a "tougher" steel, which means it deforms more readily, has higher impact strength and is easier for the end-user to sharpen. This is probably just fine for the majority of users. The trade-off of RC is a gain in ease of sharpening and small loss of edge retention (compared to the last generation material) at the expense of far superior edge holding and outstanding cutting ability.

However, a higher RC means a harder steel more resistant to deformation. It may snap or chip more readily when abused, but it takes a far better edge (and so cuts a lot better) and it holds it far longer. So if you limit the knife to being a cutting tool, it's a lot better cutting tool at the higher numbers. Of course, the heat treatment is more difficult and requires better equipment and the blades chew up belts when you grind them. Both of these cause problems for the manufacturer and knives made with hard, high-performance steel do not lend themselves to semi-mass production.

As has been pointed out, if you want to develop the superior cutting properties of a super steel, you have to harden it optimally. From what I can gather, this means 61-63 for S30V, not 57-58. Sure, the lower numbers make the knives easier for the average owner to sharpen (he'll need to sharpen them a lot more often) and they'll be tougher (maybe not be such bad screwdrivers or pry-bars), but they certainly won't take a super edge nor hold a decent edge very long. But they will be a lot easier and less expensive to manufacture.

 

[stjames]

I was under the impression that most stock removal blades are ground before the final heat treatment. If that is the case then the final harness doesn't affect that stage of manufacturing. The difficulty in grinding the steel would be a property of the un-annealed steel, even if you never took it to a hardness suitable for cutting.

Just more theory, anyway.

 

[Professor]

...and the way it ate up belts. He said that BG42 was easier to grind, and that S30V, even in its untreated form, was tough on belts, tough to grind, and tough in general.

I received my S30V small Sebs today, so I'll be testing it out. Hope others will be doing the same.

Professor.

 

[JoHnYKwSt]

I have to agree with Cliff and Blade Santa Cruz on this one. The way I see it S90V at 60RC will already be tougher than BG42. Leaving it at 58-59RC may increase toughness even more but why? Unless CRK was going to thin the edges on the blades even more I don't really see the point. This is a folder and toughness is not a huge deal as with larger blades. What is worse than all of this is the softer edge will more readily deform which means it would lose it's initial edge sharpness much quicker, not to mention dull quicker cutting some materials. Again, theory; we will just have to wait and see.

 

[Big D1]

This change in blade steels is really troubling me. As another poster mentioned, they were already #1. Why fix something that aint broke??? There is more to it than meets the eye. Big D1

 

[rdangerer]

First, thanks to Professor for taking time to call, question, and then post. Much appreciated.

Unfortunately, I'm w/ Danbo and Cliff, Santa Cruz, and Johnnyqwst on this one. And I must say that so far the answers leave me a bit disappointed. The logic for a change to S30V simply hasn't been articulated. In fact, a bit towards the opposite in my opinion.

Originally posted by Professor quoting CRK Shop Foreman
S30V doesn’t need to be hardened to that degree. At 57-59RC, it is incredibly tough by virtue of itself, yet significantly easier to sharpen than BG42 by the end user, using conventional methods such as ceramic rods, etc.

Cliff responded to CRK's foreman's (Brian) statements very adequately, so I won't repeat his thoughts.

If CRK wanted easier to sharpen, by this logic they could have softened up BG-42, but they didn't. It could be argued that BG-42 doesn't hold it's edge nearly as well as S30V at Rc57-58, but at this soft level, neither is at it's optimum from what I have learned from reading and from using.

Originally posted by Professor quoting CRK Shop Foreman
The increased toughness of S30V is evident when grinding it (Brian stated that though he considers S30V a significantly better steel choice, he’d rather still be grinding BG42 blades!). Edge retention will remain close to that of BG42, but in an easier-to-sharpen format.

I would say that wear resistance is what is evident based on difficulty in grinding S30V. Also, here we have a near admission that edge retention was sacrificed for ease of sharpening, which sounds like the same story as on the one piece line with A2.

I won't pretend to completely understand the marketing niche envisioned for the Sebbie. It is about the most precision made high-end production folder going, and the price is well past the top end of Spydie's and BM's line, so I figure the Sebbie user base is a moderately educated client, wanted more than "pretty close" (e.g. the BM Pinnacle is arguably 70% of the knife for 30% of the price). Such users would not be lamenting the difficulty in sharpening I woulnd't think, but then again I don't field the phone calls at CRK either.

Originally posted by Professor quoting CRK Shop Foreman
Increased toughness, because of the inherent difference in the steel combined with the lesser RC hardness will make for a more chip-resistent edge and blade overall.

Sure, very true. However, this move to deliver S30V in a softer form implies that the BG-42 blades that CRK delivered for those years was in fact too brittle. I'm not sure I ever heard that complaint on the forums, but it may have been mentioned. So now, they are not only going to a steel S30V that is notably tougher than BG-42 at Rc60, but they are dropping down in the hardness range for an even tougher steel?

So far, I don't get it.

I still suspect that there is either...
1. ... enough finish work to do after heat treat that they had to take S30V down to Rc57-58 or whatever to get this work done given their current production machinery
2. ... or they have some issue with heat treating where they can't get a fast enough quench to get the hardness up such that it comes back to Rc60-61 after temper.

Until I hear a lot more on the logic of this decision, I'm pretty disappointed. At this point, I'd have to stick with BG-42 at Rc60 as a better choice, albeit a semi-close call, and wonder why they bothered to change before they could tackle S30V at Rc60.

 

[UW Mitch]

Who's to say that 60-61 is optimal? If CRK says 57ish is optimal, then maybe it is. Crap, for someone to say that a higher rockwell is going to be tougher/better or whatever symmantics you want to use, you could just argue that the blade should not be tempered at all and left full hard.

CRK has consistently shown their dedication to making the best knife they could. A while back they switched from ATS-34 to BG42 because it was the next evolution. They are now switching from BG42 to S30V because it is the new evolution.

I have a feeling that people are aruging because of a resistance to change rather than factual data and testing. I'll leave it up to CRK to decide what is best for their knives - I just use 'em.

~Mitch

 

[rdangerer]

Originally posted by UW Mitch
Who's to say that 60-61 is optimal? If CRK says 57ish is optimal, then maybe it is. Crap, for someone to say that a higher rockwell is going to be tougher/better or whatever symmantics you want to use...

Optimal for what? Toughess and ease of sharpening are what has been somewhat improved vs. BG-42, apparently, according to the comments by CRK's shop foreman. See my previous post.

Nobody suggested S30V was tougher at a higher Rockwell. I doubt that it is. Go back and read the thread again.

I assume you meant "semantics".

Originally posted by UW Mitch
...you could just argue that the blade should not be tempered at all and left full hard.

Well, I wouldn't argue with that flawed logic. That comment is just void of logic and understanding. In fact, enough so for==>

Originally posted by UW Mitch
CRK has consistently shown their dedication to making the best knife they could.

Indeed, and agreed. Money-where-my-mouth-is: all 4 of my Sebbie's are gems, super folders for what they represent, a triumph of precision and high-end production quality in folders. In fact, that is why those posting with questions on S30V at ~Rc57-58 are wondering why CRK bothered to change if they couldn't get the blades out near Rc60... it seems like a step backwards rather than forward.

Originally posted by UW Mitch
A while back they switched from ATS-34 to BG42 because it was the next evolution. They are now switching from BG42 to S30V because it is the new evolution.

True. In fact, S30V has the potential, given a proper heat treat, to be a bigger step forward vs. BG-42 than was BG-42's small step past ATS-34.

Originally posted by UW Mitch
I have a feeling that people are aruging because of a resistance to change rather than factual data and testing. I'll leave it up to CRK to decide what is best for their knives - I just use 'em.
~Mitch

Again, you are far off base, so far that it suggests that you have read few comments across these forums by myself, Danbo, Cliff and others on S30V. Use the search engine. See comments by RJ Martin, Hossum and others.

S30V is really a step forward for stainless knife steels. Just not at Rc57-58.

 

[stjames]

This has been reduced to the level of pointless bickering. I’m sure it will continue since many enjoy being argumentative. If you can’t make your point without being rude then it isn’t worth making, and try not to take things so personally.

I do find it amusing that the first negative comments about CRK’s use of this steel on these forums was that it might be too hard to sharpen and maintain and thus not worth the change. Now it seems that the move to keep the blade user serviceable is meeting resistance because it might keep the steel from performing optimally, and thus is not worth the change.

It seems you can’t make everybody happy all the time. Good thing I’m not learning this for the first time. I’ll save my disappointment until I actually have cause.

 

[Professor]

FYI... When I opened my new S30V small Seb's that I received yesterday, the card enclosed read "58RC." Not "57-59RC" as I've seen some Mnandi's for sale having read, card having been posted in the pics.

Please don't slap the messenger! I love all you guys dearly (ok, maybe not Cliff so much ), and while I may have mis-paraphrased a sentence here or there, I think I captured the essense of what Brian was saying.

My personal take on the steel hardening choice is this: We are the "knife-elite," and the "average" end user was having a hard time re-sharpening their BG42-bladed Seb's. CRK was probably seeing a lot of Seb's returned for resharpening, or worse, having been used as screwdrivers, there were likely divots in the edge. "Softening up" a bit, as it were, was likely the decision aimed at the total market of CRK purchasers. Kinda like Benchmade's coating of D2 steel; while semi-stainless, the average end user will not properly care for the steel. Again, while I'd love for CRK to enclose a knife fighting manual with every purchase, I don't think that's good for the people as a whole.

Again, theorizing, I stand down. It's time for Chris to clarify, if he would. In the meantime, let's avoid another "trial by internet" if at all possible!



Professor.