A little BS from CS

Corduroy · May 21, 1999

Found this on the Cold Steel web site. Would I be out of line in suggesting that this is, um, wasn't entirely consistent with Spyderco's own test results?

"The only equal to our AUS 8A in strength and toughness was AUS 10A; however, the big breakthrough was that it exceeded AUS 8A by an honest 20% in edge holding ability, giving it a wide performance advantage over ATS-34, ATS-55 and 440V." (my italics)

Don't worry, I'm not going to run off and yell at Lynn Thompson or anything, but sometimes they just get to me...

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-Corduroy
(Why else would a bear want a pocket?)

Cliff Stamp · May 21, 1999

Corduroy it could quite possibly be true. Wear resistance is not the only factor in edge holding. While there have been claims about the high toughness of 440V, it is rated as being a lot weaker than 440C (which is similar to AUS-10A) by CPM. 440C at 56/57 RC has a 50% greater charpy value than 440V does at 55 RC.

-Cliff

Corduroy · May 22, 1999

While I obviously have a preconceived notion about the subject, I'm prepared to be shown it's incorrect. Figured I'd come to the folks I know will have the answers and who I trust to give them straight.

To be honest, in reading through Mr. Thompson's writings, I feel he is deliberately misleading, perhaps personally confused on some issues, and a braggart. But I do not see him actually lie anywhere - that's why this dubious statement caught my eye, and why I want some opinions on it.

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-Corduroy
(Why else would a bear want a pocket?)

Cliff Stamp · May 22, 1999

It is too vague to be called true or false. Its like someone saying A is better than B. Edge holding is not a precise term. It varies depending on what is being cut and how you are cutting it. AUS-10A should have better edge holding than 440V on some materials and lower on others. If you want to show how one steel is "better" just test over a narrow range of applications.

The tests that I have seen done on 440V have all had poor results. Nemo and Fred for example broke off a tip easily. I have heard of a lot of returns to PVK&T because of the same reason and of course CPM's stats do not impress me much. However a lot of knife makers/dealers claim high performance from CPM-440V even toughness (mainly due to the fine grain structure). This interested me enough to want to buy one as if it is tough enough to perform most cutting tasks its high wear resistance would be great. I was also very curious about the cutting ability and how it responded to various grits.

-Cliff

djo62 · May 21, 1999

Whew....flew into this thread like a banshee..though CS was Cust svc....lol
Danelle

jpbulli · May 21, 1999

Did they report any of the hardness measurements for the CS tests? I'm thinking they may have used different values from Spyderco when testing, which would significantly alter the charpy impact strengths, as Cliff suggested.

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JP Bullivant

Kysa · May 22, 1999

Cliff, I'd be reluctant to suggest that CPM 440V is weak and has returned "poor results." The chemistry alone of this metal does not support such a statement.

You may not be impressed by CPM's statistical results, but they are easily verifiable by other sources, viz., the Machinery's Handbook (25th ed., ISBN: 0831125756) juxtaposed to various AUS and ATS steels.

phone_archer · May 22, 1999

I don't quite get CS and their approach. Lynn Thompson seems to feel that he needs to attack other manufacturers, materials, experts in order to sell his products. CS seems to make some fine knives, but I will never buy a product from a company that uses this sort of negative self-promotion.
The more I see of all the companies in the knife world - the more I appreciate Spyderco.

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Bill
"Walk softly and carry a big folder... and a small folder... and a SAK... and a multi-tool..."

Cliff Stamp · May 25, 1999

Kysa :

Cliff, I'd be reluctant to suggest that CPM 440V is weak and has returned "poor results."

CPM 440V has a lower impact strength than 440C. It was because of this weakness that the serration pattern was changed :

http://www.bladeforums.com/ubb/Forum20/HTML/000288.html

Because of the low toughness of 440V Spyderco is now leaving it at around 55/56 RC, this means that it could actually start to roll/deform before ATS-34 at 61 RC and maybe even before AUS-8A at 57/58. So in regards to edge holding in general, the 440V might no longer be in the lead. There is more to edge holding than abrasion resistance.

You may not be impressed by CPM's statistical results, but they are easily verifiable by other sources

I was not saying that I doubted CPM but simply that the numbers that they quoted do not impress me much in regards to 440V as a knife steel, particularly in regards to heavy working knives. It would seem to be a choice more suitable for say the Calypso Jr. .

-Cliff

Sal Glesser · May 29, 1999

Cliff - Do you currently own and use a blade made from CPM-440V? Perhaps that might help you understand the "experience" of the steel in the best manner. One can read all sorts of "road reports" about anything, but "reading about" and "experiencing" often times makes the difference and answers the questions.

In addition, I know that Spyderco is continually "tweaking" and learning about this material. I would guess others do like wise. Todays test improves tomorrows product. Fred's "tip breaking" caused us to re-evalutate and change the Rc. I have also heard many positive comments on this forum regarding 440V. Do you feel that these opinions are without suffieient knowledge or experience?

We began working with this steel several years ago because we "believed" it would be "better" for our performance needs. I have personally been pleased with the performance of the steel. Our edge testing results concur. Many ELU haved mentioned positive things. Could it be that perhaps it might possibly be a "duck".
sal

Cliff Stamp · May 31, 1999

Sal :

I have also heard many positive comments on this forum regarding 440V. Do you feel that these opinions are without suffieient knowledge or experience?

No. But I have also read many positive comments about AUS-8A, ATS-34, GIN-1 etc. I can't recall a series of tests comparing CPM-440V and another decent stainless steel directly. If they are out there please post the link. My main critism of it is from CPM specs its impact toughness is quite low. At 56 RC its only 60% of what 440C is. And also regarding what R. J. Martin has said, even though you get wear resistance, once you start going to low RC the compressability drops so the edge will roll faster.

I will be evaluating 440V once my Military arrives. It was sent back from your warrenty dept. last week so I should have it next week.

-Cliff

[This message has been edited by Cliff Stamp (edited 31 May 1999).]

Sal Glesser · May 31, 1999

Cliff - sorry, I can see where my post might have seemed overly assertive. I am certainly interested in your opinions. That is how we progress. It was the numbers that first caught my attention, but the refinements necessary over the past few years to "appreciate" this steel have been frustrating.

Impact toughness may be less than 440C, but edge retention is 3 - 4 times greater. We also learned that 440C has an inheirant problem with secondary carbides chipping out on a very thin edge. Always one is choosing between a list of compromises. But the real proof is always in the pudding.
sal

Sal Glesser · May 31, 1999

Getting back to Corduroy's original question. Cliff is correct in that everything is best at something. Apples to apples is the first question (but we all make that error, don't we?). AUS-10 (10A)Should provide 20% additional edge retension ove3r AUS-8 (8A). AUS-10M will do even better (in edge retention). Corrosion resistance goes out the window though.

Our ICP (Initial Cutting Performance) on 440V is higher than AUS-8, indicating that 440V will get sharper than 8A. Microphotography shows 440V to have a finer grain structure than 8A. Lynn may be testing for something else. As Cliff mentioned in another thread, there are many variations of test possible, trying to determine the results of diffeent questions. (straight load vs side load, toughness vs impact strength, etc,)

Even if it were just a wild claim, wouldn't you just classify that type of marketing for what it is. All products cannot possible be the "best", yet many make that claim.
sal

scorpio · Jun 1, 1999

cliff,
as i recall there was a test being done by one of the knife magazines just few months ago.
it was a fix blade knife by a custom knife maker who made the knife in 3 steels.
ats-34,bg-42,and cpm-440v, as i recall the cpm came up the best and the bg-42 a close second, the both proformed better than the ats-34 by a respectible margin.
i'm sorry i don't recall the magazine but it was for sure one of the two..blade or tactical knives.

Cliff Stamp · Jun 1, 1999

Sal :

Impact toughness may be less than 440C, but edge retention is 3 - 4 times greater.

This depends on what you are cutting. Edge retention is not just wear resistance, impact toughness can be a factor as well.

We also learned that 440C has an inheirant problem with secondary carbides chipping out on a very thin edge.

Very true, I don't like the 440 series for exactly this reason. The steel Buck uses has the same problem.

wouldn't you just classify that type of marketing for what it is

Yes, that is why I stated that it is too vague to argue about.

Microphotography shows 440V to have a finer grain structure than 8A.

Which would mean that it would take a better push cutting edge, but not one for slicing.

-Cliff