Why is 13C26 better?

[Larrin]

STR - can't vouch for how accurate all this is, but here's one description of AEB-L:

http://www.devinthomas.com/pages/faq.html

Sounds like a high quality cutlery steel to me.

That sure is an excellent link.

On the subject of the steel being a beater steel, I'm not sure what the issue is here. AEB-L/13C26 has very good toughness for a stainless steel, so it probably has a pretty good potential to be used in a beater knife. It also has a fine carbide size and it can get pretty hard too, so it could also be used for thinly ground, hard knives used for more fine cutting tasks.

 

[Cliff Stamp]

... it appears to be holding up quite well at the current hardness and tempering they currently use

Performance as always is relative, as I have stated, if the steel is compared to the higher carbide steels for the uses you describe then the steel will quickly get a reputation for poor performance and be relegated as simply another tough steel with poor edge retention. This isn't theory, it already happened, you are just encouraging history to repeat itself. Hopefully Spyderco will produce the optimal models and encourage sensible use of the knives to showcase the abilities of the steel.

It seems that your point is that you should be able to address what a person writes about without knowing anything about the writer and that this logically follows because it is what is written that is important, not who it comes from.

Yes.

Do you believe that everyone here is capable of understanding the details of what you write about?

Capable yes, the ideas are not overly complex. Some details/terms may be unknown so you ask. It is possible that people can choose to take a faith based responce to a speaker, however the speaker should never imply that it is mandatory.

... no matter how bent over backwards we get from discussing hypothetical heat treatments, suitable only for custom, small operations.

You really should be far more skeptical of what you are told by manufacturers. Benchmade is using AUS-8A at 60 HRC. 13C26 actually has an inherently higher hardness than AUS-8A, not a lower one. Cold treatments have been used in production cutlery for some time and there is a growing realization that use of aggressive quenchants on air hardening steels is of benefit. This is no different than any of the advancements in knives. Look for example at the massive refinements in the Endura series from Spyderco. The new model is definately one which takes more time/money so it is hardly absurd to propose that a similar interest should be put into refinement of heat treatment.

-Cliff

 

[STR]

For what its worth, my Storm II is one of my favorite less expensive knives.

I am not familar with the last time this steel was used that is referred to historically here. I am sure you are correct though Cliff but keep in mind that it is doubtful the heat treat methods incorporated into it then were the same as Kershaw is currently using today. I am certain that when Sandvik gave their recommendations to Kershaw about the H/T that they took into account the history you speak of.

I think it is also worth mentioning here that the last time this steel was used in knives that you speak of manufacturers did not have modern day machining and serrations as an option on the edge to aid performance on a beater you use hard. Nor was stainless looked at very favorably at all by anyone in those days. These things combined with the attitude change toward stainless today seem to be a match for a good performer overall and seem to indicate its a good steel for an EDC that should outperform the one it is replacing.

Time will tell how the steel will fair this time around and should it be discontinued from an early demise because of anything pointed out here today I'll be the first one to admit it Cliff. I do disagree with your view on this, and that is all. I don't claim to know it all by any stretch of the imagination.

By the way, I admire the way you dish it out and take it while keeping an even tone without emotion. This is something we should all strive to emulate and that I have learned from you over the time we have interacted because it was not always this way for me. It is very good for discussions so they can get intense without getting overly personal. I do feel that at times opinion is stated as fact deceptively though and that even though both of our posts are sometimes already lengthy that details of where info we post comes from should be added with statements of fact when possible.

STR

 

[Joshua J.]

Cliff, if I understand correctly. Your complaint is not so much with the way Kershaw is treating the steel (for use as an every day working steel), but that the steel in use is the wrong steel for this application altogether, and Kershaw should switch to another steel.
If the above statement is correct. What would you suggest for steel that can be manufactured at a similar price but give better performance? (In toughness and edge retention.)

And can we come to an agreement that even if not being used properly 13C26 is an improvement over 440-A?

 

[Larrin]

Time will tell how the steel will fair this time around and should it be discontinued from an early demise because of anything pointed out here today I'll be the first one to admit it Cliff. I do disagree with your view on this, and that is all. I don't claim to know it all by any stretch of the imagination.

AEB-L is pretty common in European custom knives, especially Sweden, of course. Also, it is not uncommon to see "Swedish stainless steel" on any number of knives, especially on Japanese factory kitchen knives that I've seen.

 

[RussG]

Performance as always is relative, as I have



Capable yes, the ideas are not overly complex. Some details/terms may be unknown so you ask. It is possible that people can choose to take a faith based responce to a speaker, however the speaker should never imply that it is mandatory.



-Cliff

Cliff,
it appears that you'd agree that not everyone on the forum is aware of the substance or details of what you write and that those that don't understand may not necessarily be incapable of understanding either but simply may not know of the underlying facts or principles in the first place. They may have to take the leap of faith that you suggest. Unfortunately without knowing any of the educational or experiential background and expertise of those writing, including you, how is anyone supposed to know whose opinion or information is accurate and/or valid?

 

[Jeff Clark]

You know this thread is like a microcosm of the knife industry. It just goes round-and-round. It is so easy to start one of these roundabouts it reminds me of these penguins: http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2003/01/16/MN175528.DTL&type=news

Back about 45 years ago guys who did serious on the job cutting carried something like these (nonstainless) carbon steel blades on their toolbelts and had something like a carbon steel stockman in their pocket:
http://www.dexterrussell.com/Search_result.asp?group_name=industrial.asp&Type=263

Notice that all these Dexter Russell industrial knives and utility blades are nonstainless steel. The common box opener "razor blades" (with reinforced back edges) 45 years ago were made of nonstainless steel as were shaving razor blades. Stainless steel was hardly seen outside of a kitchen, and there it was used more for salad tongs than for cutlery. The everyday cutlery steel was around 1075 to 1095 carbon steel and was tough and easily took a fine edge without premature breakdown.

Then Wilkinson introduced stainless steel razor blades and the public's love affair with stainless blades began. It was commonly discussed at the time that stainless blades did not get as sharp as carbon steel blades and that they were not as tough, but they provided smooth shaves much longer since they didn't rust. It turned out that edge rust is the primary dulling mechanism for shaving razors. The facts didn't matter, the public began to associate superior edges and edge holding with stainless steel and they began to demand it in their knives.

The knife industry adapted to give the public what it wanted, stainless steel blades. The knife industry was compelled to tell the public that they were getting what they expected, sharper, tougher knives that held their edges longer (when actually the opposite was true). At times they have given the public knives made of shaving razor quality alloys that get extremely sharp, but then the public complains if the knives don't hold edges like a higher carbon steel like 1095 or 440C. If they use a harder stainless the public complains of brittleness and difficulty sharpening. The compromises and the complaints go round-and-round.

If you aren't around a damp environment you would probably be better off with a multibladed carbon steel pocket knife as your beater. You are also better off with a replaceable bladed utility knife when you cut much carpet or linoleum. These blades are cheap to replace and work pretty well for their expense. They are not made of AEB-L or AUS-8 or 12C27 or 13C26--they are not made of stainless steel at all. They are made from simple carbon steel like SAE1074 or SK5.

When you have a broader sense of where the strengths and weaknesses are for various steels you get sensitive to the way that manufacturers over generalize the advantages of one steel over another. The public is still expecting magic stainless steel with no trade-offs and at throw away shaving razor blade costs. You may really approve of a manufacturer's selection of a steel and yet be uncomfortable when it is marketed as being all things to all people. It would be nicer if they could simply promote the parameters that are improved over the previous steel and remain silent about what was sacrificed in the process. The problem is that if you say todays' steel gets 50% sharper than last years steel you emphasize that last year's steel had second-rate sharpenability. You sure don't want to say that today's steel may dull faster than last year's alloy. You also don't want today's blades to be seen as more brittle than last year's.

So members of the cutlery industry based around stainless steel compares itself to other's in the same industry. This is an industry that tries to satisfy a delusional public by balancing the performance characteristics of their product towards the middle. Don't make the blades too hard or too soft or too brittle or too full of carbides... Try and make a general purpose blade even if you are using a special purpose steel. The public won't understand an optimized blade. They expect to have it all. They are also forced to assure the delusional public that they have not made any trade-offs; they have provided it all.

Cliff comes from a scientific background. People tend to think of scientific methods as ways to make great leaps in understanding the universe, but most of the scientific method is designed to provide quality control of measurements and models of the universe. Scientific methods are designed to tear down common wisdom that is built on faulty premises or traditions until you reach a provably sound foundation. You automatically reject any statement based on tradition or common practice as unreliable as a building block of the edifice of science. If you are trying to extend a science or technology of knife design you want to exorcise marketing claims, common practise, subjective customer impressions, and vague descriptions from discussions of the technical effects of materials, processes, and mechanical design of knives. You want to build up your knowledge base using regulation solid bricks.

It can be frustrating at times to deal with quality control personel. I have worked on the design of things like missile launchers. I have been in general agreement with QA engineers when designing redundency in the fire control circuit and then have been ready to pull my hair out when the same standards are applied to circuits in a training simulator. If some idiot referenced a particular mil standard in the trainer specification the QA engineer will force compliance when it makes no practical sense. Sometimes Cliff applies scientific criticism to our discourse when we are not all in tune with the standards. For practical purposes we are quite willing to take advice from people with more experience or a more extensive background than we possess. Sometimes we have social reasons to promote opinions or behaviours that are more pressing than refining every nuance of product claims. For example I think it's more important to keep Thomas W and Sal G around listening and contributing to our forums than it is to critique their every statement for scientific rigour.

I have observed that it can be hard to engage people in these forums through criticism of their methods or products. I have found myself apologizing to people I respect for what I intended as constructive suggestions and which were taken as attacks on their intelligence or integrity. I think that often all Cliff intends is to make suggestions, but when his suggestions are criticised he will go to great lengths to defend his rationale. I have found that he is very receptive to practical suggestions of how he might improve his testing techniques. He expects others to be receptive to suggestions. I have found that a lot of manufacturers and makers are much more defensive than I think they need to be. They generally have a lot of respect here and they can afford to offer a bit more give and take in their discussions. For the most part we mean no harm, we just look to understand and to be understood.

 

[db]

I cann't find it so I'll just ask. Cliff what knife do you have or used that has this blade grind and heat treatment of 13c26 that you are promoting?

?

..
As for Thomas, he interjected himself into the discussion

In my opinion you have treated him far beyond disrespectful as you seem to do with most who disagree with you. You can disagree and discuss without being offensive but depending on who it is you choose not too. Your responses and there tone are definitely affected by the poster themselves.

By the way, I admire the way you dish it out and take it while keeping an even tone without emotion.

WOW! Are you serious? It’s funny how opinions are so different even when reading the very same posts.

Kershaw of course isn't selling the Storm and similar knives to be used in a similar manner, use it a little and then throw it out and buy a new knife and thus it is invalid to extrapolate as you have done .. .
the high carbon 19C steel that Sandvik makes
is much more suitable for extended cutting in abrasive materials like cardboard and carpet.
To be very clear, if Kershaw starts promoting that steel, 13C26 for that class of work, a beater knife used very harsh on abrasive material it will very
quickly destroy the reputation of that steel because it is not designed to do those tasks.. .
It will not compete with high carbide steels for such work and is significantly inferior.. .

Again, this is a highly focused steel which is designed to hold a very high polish at very acute edge angles. It has near optimal edge stability and should
be used accordingly. This is why it is simple to design for because it is so specific. This doesn't mean you can't use it in the wrong way, it simply means
it has a very narrow range of uses where it performs well.

I’m not sure that 13c26 is only good for such a narrowly designed knife, nor would it be my choice for such a specific single designed knife. I’d guess that very very few knives would be sold if Kershaw, or even Spyderco promoted a knife as such.
JoshuaJ good questions.

 

[STR]

db. Sure I'm serious. Most all the time Cliff's tone remains the same with very little if any change in the way he presents himself. Not always but pretty steady and we should all strive for something similar when we post. I rarely if ever have seen him actually take his comments to a personal level. Most always he deals with the facts presented and statements made and will comment on those regardless of who said it. This has been taken personal by all of us and perhaps easily enough, but when you stop to examine it closely you cannot deny that what he refers to was said and that he is basically sticking to the facts as he saw them presented.

I find it admirable because I often times find myself feeling it got personal until I look deep enough to see that it really wasn't. This does not mean that I don't feel Cliff gets overly critical because he certainly does. Maybe we all do at times for that matter. That in itself can be taken personal at times and is easy to get bent about. Its a fine line difference I know but its what I see most of the time.

For what its worth, I stand corrected on the majority of utility blades I have here. I didn't know how else to check them since none of them are labeled and I no longer have the boxes they came in. One batch is stainless. I can't say where they came from, Lowes I suspect. All the rest are non stainless. I got out my gun blue solution and a Q Tip and did some quick marking. The ones that turn black are obviously not stainless and just to set the record straight that was the majority.

STR

 

[Cliff Stamp]

On the subject of the steel being a beater steel, I'm not sure what the issue is here.

It is the same issue which already lead AEB-L to be wrote off as a low end cutlery steel because it had been reduced to such. While Verhoeven and Landes have done much work to illustrate the potential of low carbide steels for cutlery as focused on cutting performance, Devin really brought this steel into the public in a positive manner as a high end material as the public isn't as aware of the research done by Landes and Verhoeven.

.... it is doubtful the heat treat methods incorporated into it then were the same as Kershaw is currently using today.

This isn't actually that relevant and those steels have actually been used in cutlery for a very long time. The Sandvik steels have a low wear resistance as their carbide volume is really low, heat treatment doesn't actually effect this significantly outside of extremes. What happened was quite simply that people looked at the low carbon value of the Sandvik steels and concluded they were "beaters". When they were compared to the high carbide steels for cutting abrasive media they were indeed found to be behind in performance and thus AEB-L was basically equated to 440B. This was done by some very well respected members of the knife community such as Engnath and unfortunately when one vocal maker/manufacturer states such an opinion it tends to become law very quickly because of the faith based perspective which is common in cutlery.

Now, quite frankly, could any custom maker sell knives out of AUS-6 as high performance blades - maybe, if you were someone of Cashen's status, but for most makers it would be a real problem. It actually is though, it is just behind AEB-L in edge stability, the hardness is just a point or two lower and the carbide volume and type similar. AUS-6 actually is on the same tie line as 440C and that means it has the same maximum hardness. But how are they perceived (radically different) and why are they perceived that way. Because manufacturers wanted a very cheap steel to use in cheap knives and the steel unfortunately became known as a cheap material which was "low end".

Now to make it clear, the sandivk steels are very tough, much more than the high carbon stainless, but if you use obtuse edge profiles you don't need a high toughness in the steels. So it isn't that the sandvik steels won't do well as beaters it is simply that the other steels will do better because you have created a biased comparison because your edge configuration removes the weakness of the high carbide steels and the strength of the sandvik steels. It is a really lopsided comparison which is what destroyed the reputation of those steels already on the NA market and favored the current promotion of high carbide stainless as "superior" because they actually are superior in really obtuse edge configurations.

What would you suggest for steel that can be manufactured at a similar price but give better performance?

In thicker edge profiles you would use a higher carbide steel to take advantage of the inherent edge stability (and toughness) of the cross section. Sandvik makes 19C27 for that type of edge. However the most logical steel to use would be CPM154 because you can take advantage of Crucible promotion of the steel and the wide acceptance of "quality" of those steels whereas with 19C27 you basically have to do all that promotion yourself.

And can we come to an agreement that even if not being used properly 13C26 is an improvement over 440-A?

In general this is like asking is a fillet knife an improvement over a paring knife. There is critical information being left out of that question which is what are the critical aspects of performance. 440A has a much higher carbide volume than 13C26 which gives it a large advantage in wear resistance but in cutlery it is limited by the fact it is usually really underhardened. It actually tops out with oil/cold at about 59 HRC, but is usually much softer so you end up with chunky carbides in an edge which tends to easily dent, roll and is aggravating to sharpen to a high sharpness unless you have jedi level skills. Pretty much another beater steel, but again not really the fault of the steel.

They may have to take the leap of faith that you suggest.

Sure, but I don't force it on anyone and that is a critical point. I'll explain my perspective right down to basics if you want in as much detail as you want. I won't force you to accept anything I say simply because I say it and I will give you the references so you can read them yourself. I have even sent many knives out to people so they could check what I was saying and evaluate the principles for themselves. I was doing passarounds before there was a pass around forum on bladeforums.

Unfortunately without knowing any of the educational or experiential background and expertise of those writing, including you, how is anyone supposed to know whose opinion or information is accurate and/or valid?

You get educated, people selling hype thrive on ignorance, people who seek the truth do not. Go over to Cashen's forum and find some point he has made and say something like :

"Cashen, you have stated XXX, that makes no sense to me and further it even seems absurd if you consider XXX. Do you have any data to support your viewpoint and independent published work which predicts that behavior from a fundamental level."

His answer will be basically :

"Yes, I have done XXX and you can read about the underlying materials science here XXX."

What he won't do is go on a rant about how great he is, why you should listed to him, how long he has been in the business, how much praise he receives from his customers, he has no need to justify what he says to you some pinhead newb poster, and encourage others to do the same to attempt to prevent such challenges. He knows why he does what he does and it is supported by facts and logic and he will tell you these facts and logic if you ask him.

Now if you don't have the time or inclination to get educated then there are still many things you can do. Immediately you disregard commentary from salesmen, you disregard anyone who has not shown the ability to be independent (they just repeat whatever is commonly accepted), you disregard people who won't explain their viewpoint, you disregard people who attack speakers and not the argument, and you disregard people who are inconsistent (apply one set of criteria to products they promote but another set to products they attack). If you do all of this you will find that very little contradiction remains.

I rarely if ever have seen him actually take his comments to a personal level.

People have characteristics, characteristics determine actions, it makes as much sense to get angry at insecure people for lashing out as it does to complain that rain makes you wet. If you go out side in the rain then wear a coat, if you point out hype and misinformation, especially by someone selling something, then prepare for a character backlash. No it isn't ideal behavior and no you should not have to tolerate it but it is reality, especially if you are contending a well entrenched falsehood. The most you can do is represent the type of behavior you would wish to be reflected at yourself. If it really bothers you and you have difficulty in separating the criticism from yourself then create an identity and post under that which you can defend via a third person argument.

-Cliff

 

[Kohai999]

In thicker edge profiles you would use a higher carbide steel to take advantage of the inherent edge stability (and toughness) of the cross section. Sandvik makes 19C27 for that type of edge. However the most logical steel to use would be CPM154 because you can take advantage of Crucible promotion of the steel and the wide acceptance of "quality" of those steels whereas with 19C27 you basically have to do all that promotion yourself.

In general this is like asking is a fillet knife an improvement over a paring knife. There is critical information being left out of that question which is what are the critical aspects of performance. 440A has a much higher carbide volume than 13C26 which gives it a large advantage in wear resistance but in cutlery it is limited by the fact it is usually really underhardened. It actually tops out with oil/cold at about 59 HRC, but is usually much softer so you end up with chunky carbides in an edge which tends to easily dent, roll and is aggravating to sharpen to a high sharpness unless you have jedi level skills. Pretty much another beater steel, but again not really the fault of the steel.

.......pinhead newb poster, etc. . He knows why he does what he does and it is supported by facts and logic and he will tell you these facts and logic if you ask him.

Now if you don't have the time or inclination to get educated then there are still many things you can do. Immediately you disregard commentary from salesmen, you disregard anyone who has not shown the ability to be independent (i.e., just repeat whatever is accepted), you disregard people who won't explain their viewpoint, you disregard people who attack speakers and not arguements, and you disregard people who are inconsistent (apply one set of criteria to products they promote but another set to products they attack). If you do all of this you will find that very little contradiction remains.
-Cliff

1. Mention of the steels that you named are not fine-blankable, which is what I am pretty sure Kershaw wants to do with these blades.

2. 440-A is getting scarce, not too many steel manufacturers want to make it any more, for a variety of reasons.

3. Kevin Cashen is patient, but if you push him too far, he will call you names, might even throw a hammer. I have personally seen it.

4. STR congratulates you on your even tempered qualities, but completely discounts the fact that when other posters have you pinned to the floor with counterpoints or relevant facts that you are not willing to directly face, you slither away like a bug, and don't rise to the challenge.

5. If you discount everyone that might disagree with you, you have no discussion, it is more of a sermon. Which you specialize in.

Again, Happy Holidays, ESAD MF

STeven Garsson

 

[STR]

Steve I appreciate your honest feelings. I can't say I recall when or what you are referring to as I don't recall many times when I've been 'pinned to the floor" as you speak of. I'm sure you have some reference. I know I post a lot and often times don't remember to go back to some if another has my attention.

If I get into something over my head I will politely back out for the experts once I realize it. Granted sometimes I'm slow, but I think that comes from just being stubborn enough to continue at times when I probably should have backed out earlier. Whatever the case may be. Like everyone that gets acclimated to these forums I have had a long learning and growing experience from a lot of different avenues and angles and gone through some skin thickening as well as education.

I try hard to maintain an honor and integrity and though I make mistakes and taste my foot, and whole leg on ocassion too I make a lot of friends here and usually get a little respect if not thanks for my input and services. If at times it was not enough for you then tough luck I guess. Even still your opinion of me is not as important or as credible to me as your knife input which is certainly good enough and I've enjoyed your posts regardless of your feelings or thoughts about me personally. I was not meaning to discount others that disagree with me about my input on knives or what I know about them. I do however tend to discount personal posts about being a bug slithering away though. Have a great Christmas.

Again I must be slow. What does ESAD MF mean?

STR

 

[Kohai999]

..... I was not meaning to discount others that disagree with me about my input on knives or what I know about them. I do however tend to discount personal posts about being a bug slithering away though. Have a great Christmas.

Again I must be slow. What does ESAD MF mean?

STR

Yeah, STR, you MUST be a little slow, as my entire diatribe up topside was directed at Cliff, not you.

I just don't understand how you, or anyone else can put up with the crap he mixes in with his VERY HIGH level of knowledge.

Eat S**T AND Die, Mother f'r, is what the acronym stands, for, and again, is directed at Cliff. He and others may be dispassionate about this arena, but I am not.

Best Regards,

STeven Garsson

 

[STR]

I really need to take my wife's advice and start wearing my glasses again. My eyes are just terrible these days. Looks like a maginfying lens in in order I guess. Gettin' old sucks!

Now I see what you said. Dah!.

Even still I feel I'm relieved but Cliff isn't one I'd say I see slither much. If anything he will beat a dead horse until its a rotting corpse around here. Not that I am innocent of that myself.

STR

 

[Sal Glesser]

I really need to take my wife's advice and start wearing my glasses again. My eyes are just terrible these days. Looks like a maginfying lens in in order I guess. Gettin' old sucks!

STR

We call that being "Chronologically gifted"

sal

 

[Kohai999]

Even still I feel I'm relieved but Cliff isn't one I'd say I see slither much. If anything he will beat a dead horse until its a rotting corpse around here. Not that I am innocent of that myself.

STR

He directly avoids challenges. He turns words around.
He is dismissive by his very bearing, and arrogant as hell(THAT I am guilty of!)

For instance-Cliff says to dismiss salespeople as sources of knowledge.

That is myopic.....have seen excellent salespeople who happened to be scientists, but not many scientists who happened to be excellent salespeople.

Ed Severson who was a Crucible would be an example of a good salesperson.

Bob Egnath was more of an artist than a scientist, but he was a HELL of a great salesperson.

I don't ever start out wanting to make threads on General into personal attacks, but I will when it has to be like that, and it always strikes me funny, when you get into a fight, and those that follow the "higher moral" ground look like deer in the headlights when you bust 'em in the lip. In other words, well equipped to think, not so well equipped to survive in a hostile world.

Best Regards,

STeven Garsson

 

[M Wadel]

hey sal i just got a crazy thought, how about a "mora" type blade but in a folder (ie scandigrind)? as soon as my grinder is done i will make folding moras just for fun but still. do you think it would work (commercially i mean)?

 

[STR]

Thanks Sal. I'll remember that for reference. I've been calling my spare tire my symbol of success so that little quip of yours is good too.


Cliff, now I'm puzzled by something else I just picked up. You said earlier that the steel saw its demise last time and that this can be proven historically and then last post point out that this steel has been used in cutlery for a very long time which sounds like it never stopped being used at all. Which is it?

Also, heat treating it to 59 vs 63 or 64 Rc means a lot usually with steel in one key area which is increased brittleness the harder you make it which in my mind anyway, is highly relevant. Also relevant is the loss in corrosion resistance at the higher hardness which as I understand it is part of the reason Sandvik recommended it be where it is being used by Kershaw. Correct me if I'm wrong Thomas. From Sandvik's web site regarding the steel. "Good corrosion resistance is achieved with a chromium content of 11-12 %. This is obtained by a heat treatment that leaves about 15 % of retained austenite after quenching and deep freezing

Although brittleness is not something I have seen with this 13C26 steel in either of my Kershaws to date I have not handled any harder than the EKA or Kershaw knives is running it either. (actually my EKA knife is 12C27 and not 13C26)

Who has experience with it at the harder Rc to compare it for how well it would hold up and/or how brittle it may or may not end up at say 63Rc if it were made 'thin'? Also, who can comment on corrosion resistance changes at the higher Rc and tempering difference. cryo differences and how that will affect the overall performance of the steel in a mass produced knife?

STR

 

[kel_aa]

...I'm puzzled by something else I just picked up. You said earlier that the steel saw its demise last time and that this can be proven historically and then last post point out that this steel has been used in cutlery for a very long time which sounds like it never stopped being used at all. Which is it?

I think the discussion points out that it died in popularity/reputation in the North American market, while being continously used in the European market.

Also, heat treating it to 59 vs 63 or 64 Rc means a lot usually with steel in one key area which is increased brittleness the harder you make it which in my mind anyway, is highly relevant.

I'm sure it is relevant, but that would depend on the overall objective. I don't recall you complainting of brittleness in the ZDP189 Caly Jr and Delica designs. I doubt you use those knives the same as you would one of "beater" 420HC. I don't see the point being made that a 13C26 blade at >60 should make a nice "beater", but instead as a very sharp cutter provided the correct geometry. The higher hardness makes the material stronger, so toughness aside it should be less prone to deformation/damage.

Also relevant is the loss in corrosion resistance at the higher hardness...

My understanding is that you austentize the blade at a high temperature to dissolve an desired amount of carbon and chromium. The dissolved chrom gives the corrosion resistance by froming a passive chromium oxide layer at the surface of the steel, the carbon the martsentic hardness. When you quench it and temper it you don't want to precipitate out much of the chromium again in the form of carbides. Since it comes from the dissolved chromium, corrosion resistance wil suffer, as well as other properties. So by keeping out the carbides, you can achieve hardness and corrosion resistance.

 

[Larrin]

Thanks Sal. I'll remember that for reference. I've been calling my spare tire my symbol of success so that little quip of yours is good too.


Cliff, now I'm puzzled by something else I just picked up. You said earlier that the steel saw its demise last time and that this can be proven historically and then last post point out that this steel has been used in cutlery for a very long time which sounds like it never stopped being used at all. Which is it?

Also, heat treating it to 59 vs 63 or 64 Rc means a lot usually with steel in one key area which is increased brittleness the harder you make it which in my mind anyway, is highly relevant. Also relevant is the loss in corrosion resistance at the higher hardness which as I understand it is part of the reason Sandvik recommended it be where it is being used by Kershaw. Correct me if I'm wrong Thomas. From Sandvik's web site regarding the steel. "Good corrosion resistance is achieved with a chromium content of 11-12 %. This is obtained by a heat treatment that leaves about 15 % of retained austenite after quenching and deep freezing

Although brittleness is not something I have seen with this 13C26 steel in either of my Kershaws to date I have not handled any harder than the EKA or Kershaw knives is running it either. (actually my EKA knife is 12C27 and not 13C26)

Who has experience with it at the harder Rc to compare it for how well it would hold up and/or how brittle it may or may not end up at say 63Rc if it were made 'thin'? Also, who can comment on corrosion resistance changes at the higher Rc and tempering difference. cryo differences and how that will affect the overall performance of the steel in a mass produced knife?

STR

Higher austenitizing temperatures bring higher carbon and higher chromium in solution, so you would actually expect to have greater corrosion resistance. 63 Rc is probably too hard for AEB-L, because like I said before, it gets 63-64 Rc as quenched, so you'd need like a 250F temper to get that hardness. 62 Rc is probably pushing it in the first place. I want to do some tests for toughness up at that hardness (62) against a couple heat treatments at 60 Rc, but that's not going to be for a while.