New alloys; hot or hype? (advanced class)

By all means check out the products and information from Damasteel AB in Sweden.

http://www.damasteel.se/

Their powder metal pattern welded damascus steel is quite interesting. They have a great handbook available for a low price - in english - that provides a tremendous amout of informatyion about damascus technology and history, as well as another viewpoint on powder metal steel technology.

They also produce a powder metal stainless called RWL 34 which is basically ATS 34 made with powder metal technology. My friend Michael Jankowsky here in Berlin has made several knives from it and they certainly are impressive.

Damasteel sees one of the main advantages to powder metal technology as being that of greater fracture strength due to the fine grain structure. This allows for higher hardness without brittelness. - to paraphrase their book a bit.

By all means get a copy of their handbook and read it through. It makes for very interesting reading...

------------------
www.wilkins-knives.com


 
Walt, while 3V might not have the abrasion resistance of 420V it may well have much better edge holding because of the much greater toughness of the edge. This would mean that it should be significantly less likely to chip out or excessively roll than 420V.

Cobalt, why do you want a 420V, 440V laminate? Based on the info from CPM, 420V is superior to 440V in abrasion resistance, corrosion resistance and toughess.

Why is Spyderco still using 440V?

Phil, I don't know what is up with the tables on CPM's site. They don't match the data sheets that Walt sent me at all (also put out by CPM).

-Cliff
 
I'd like to echo a point hinted at by MPS. I think in order to have truly valid results, it is imperative that the tester not know what steel he is testing until after the experiment has run its course. Knife users and makers have their favorites, just as steel producers do. Deep down inside, whether I'm willing to admit it or not, I WANT my M2 AFCK to cut better than my ATS-34 AFCK. It cost more, and everyone knows M2 is the better steel, right? In light of this bias--whether M2 is ultimately better or not--does anyone trust me to hold both knives the same way, to apply identical cutting pressure, etc., while I slice up several yards of rope. Will the knife I test first have an advantage over the one I test last, after fatigue has set in? Will a knife cut more efficiently outside on a cold day than on a pleasantly warm day? Will a knife cut better or worse if Celine Dion is playing in the background, as opposed to Mariah Carey or Janis Joplin? I would try my hardest to be objective, but there are simply too many factors for me to control for. And it's going to be very difficult for me not to know with a fair degree of certainty what kind of steel is in a given production knife. (Obviously, if it's a '98 Endura, it's ATS-55). So it seems to me that the only way to get really accurate results is to have a non-interested custom knife maker (if you can find one--fat chance!) make otherwise identical knives out of a variety of different steels (several knives of each steel, preferably), mark them as to steel type according to a system unknown to the person doing the cutting, and have the cutting tests repeated by several different individuals. And then you'd probably want to have several other knifemakers make up more batches of test knives, and the process continues.

Ideally, the cutting would be done by a machine that could exactly repeat the cutting motion, pressure, etc. Does the big knife companies employ this sort of equipment?

If this kind of experimental rigor is impossible or impractical, global impressions and strong hunches are the best we can hope for.

It would not surprise me if a company like Benchmade or Spyderco actually does carry out truly scientific testing of the materials they might want to use. It's got to be a time-consuming and expensive process. You can see why I don't do much of it in my kitchen, other than peeling potatoes and scraping my thumbnail.

Of course everyone already knows all of this.

David Rock
 
David, as a general rule of thumb when doing experimental research it is of little use to use methods that are much more precise than the information you are looking for as all the extra data is of no use at all and you just wasted your time gathering it.

Now as for the bias, if you think that you will bias the testing then of course I would not trust your results. But you are far exaggerating the criteria going to precision levels that make little difference to the sought after goal.

If a knife steel wants to claim performance over another, it has to have a margin of difference that is large enough to be readily visible in real world tests. It makes no difference at all if some machine can determine that one blade has a drag coefficent .5% less than another (for example) as I would never be able to tell those two blades apart in any kind of real life work.

In short, if any reasonable individual (and there are scads of them who regularly post) cannot see the difference in performance (in any aspect) then for all purposes it does not exist.

-Cliff
 
Cliff, from field reports of different people, it seems that 420V is less corrosion resistant than 440V and I am not sure that 420V holds any other incredible advantages over 440V. This all remains to be seen. Usually in a Damascus two different materials are used, and I figured that these two were probably the ones I would want. I think it is rediculous to match a stainless with a high carbon non stainless steel, thus, this is my opinion. 3V may be an option, but it is not stainless. Of course you could make 420V or 440V damascus and that would be fine too. I hope I answered your question. I'm not sure if you meant why two dissimilar metals as is usually the case with damascus or as to my choice of the metals. What would you choose?
 
I should clarify the information on the Crucible data sheets.
Much of the data generated on the sheets is done by our research lab in Pittsburgh. They use standardized testing such as ASTM wear tests, charpy tests, corrosion booth, etc. to get a feel for how a material compares to the overall tool steel family. Keep in mind that not all data will translate to every application due to various reasons but it is about as close as yo can get to predicting from a lab standpoint. As was stated above, field data is worth its weight in gold.

The 3V is an interesting grade because it fits into a nitch that none of our tool steels have ever been into (high hardness, high toughness, and pretty decent wear). I have a small 3V knife now made by a well known maker. He gave it to me to try and wear out. As of yet its still cutting well.

Would it be advantageous to be able to get data sheets and other testing data off Crucibles website? That would be an easy way to get data. I can also supply Spark with data.
The question was asked if some of the new grades would be offered in knife sizes. The answer is yes. Time frame to have everything is still not official, but look for an advertisement in the knife magazines soon.
 
David Rock, Whoa!, Hey. Stop!
I cautioned against 'placing too much emphasis' on knowing what something is prior to testing it. Your kinda weird comment about why you don't feel that you, yourself could not objectively test your M2 AFCK against others was sort of what I was getting at, but I certainly don't think that all human testing is bogus or even that all humans are so biased. Quite the opposite in fact.

If you want knives that have passed machine tests, then all you have to do is buy Buck Knives. Buck has a very expensive C.A.T.R.A. machine that feeds a type of special paper to the test blades at a uniform rate that tells them that 425M should perform "similarly" to their previous alloy. So freaking what? The paper they use is not something that any normal user will ever encounter. Their expensive piece of test equipment doesn't factor in such useful things as how handle slipperiness/sharpness or discomfort interface with human perceptions of which knives cut. Nor does it compensate for the apparent field observation, that while their ti-ni coated knives may excell in the C.A.T.R.A. test, they can be difficult to sharpen if dinged or gouged.

As others have pointed out, machine data points such as Rockwell or Charpy or C.A.T.R.A. only tell one small aspect of the picture. Personally, I think there is absolutely no substitute for good objective personal testing from as many knife users as possible.

If you feel that you can't be objective, that's one thing, but I question the merits of too much single point knowledge. For instance, if one were to only ever select knives based on edge retention, then presumably we'd all be carrying thick ceramics or something and the SAK that so many of us use daily would never even be considered as a useful implement. Do you see what I'm getting at? There's far more to picking a knife than just knowing it's edge retention, or it's hardness, or it's toughness, etc.

More later,
smile.gif
smile.gif

mps
 
Phil; I regret your hard feelings about my post; I have e-mailed you in private, both explaining what I was trying to accomplish, and apologizing. I hope that you accept my apology, which I here offer publically and unconditionally.

What I was trying to do was to have people wait a short time until all the data sheets were available to eveyone. I think most people were not aware that this was imminent.
Since the data sheets are definitely soon to be posted, I think we will be ready to rock and roll before you know it.

If anyone has data on BG-42, I would appreciate them posting it.

If anyone knows who the mystery knifemaker is who made the 3V knife, let me know, as I would be interested in having one made also.

Walt
 
I think we need to becarefull when looking at certain test results or information provided by any maker that may be "legally" skewed. As an example we have probably all seen the charpy impact test results shown in one of the knife mags, which I'm sure came from the material supplier. The Charpy(and Izod) test is important and of interest when the tests are done at the same time with the same conditions. Variations in temperature can make certain steels behave better than expected, thus, not giving accurate numbers.
Crystal structure, and grain size also have an impact(no pun intended) on the Charpy test results. For example, a 20% Carbon steel can have a charpy value of 130 ft.lb.'s at 100 deg F and 80 ft.lb.'s at 0 deg. F. So, you can get a piece of high carbon forged steel that has better characteristics than some of the steels we mentioned. These results are only good when you have the whole picture, and if they are done independantly.

Also, I'm not a believer in that 420V has more corrosion resistance than 440V. With 4% less chrome, slightly more carbon and more vanadium and molybdenum, it is hard for me to believe. We shall see. The compared charpy test is similar for both, so, as of right now, the only advantage that I see to 420V is edge holding. But if 440V is more corrosion resistant, and I'm betting it is inspite of what the manufacturer says, then you get the age old question of corrosion resistance over more edge holding. If 420V is more corrosion resistant then 440V is obsolete.

Maybe we should get Sal Glesser in here, since he has worked with both and may have some input.

As for 440V/420V or similar laminates, this may be the way to get toughness and edge holding in one package. Rob, I don't understand the part about 440V core, that you mentioned one knifemaker is making. Are we talking laminate or a San Mai. If he is making a true damascus, then what is the other steel he uses. If he is using a regular carbon steel with the high chrome steel, he just created an anodic cell, which will have the Y2K self destruct problem, I'm sure.
 
Doc,

Mutual feelings of goodwill accepted and tendered in return.
Back to the scientific method and fellow members experiences,ideas,and opinions on these fine steels by cpm. Is it gonna be 420v or 440v for small blades? I'm still eyeballing 3v for large ones. Is there currently any steel that offers the fine impact resistance of 3v,combined with its superb wear resistance. ? I don't think so.
Research continues.....

Cliff, thanks for pointing out the apparently skewed bar value graphs at cpms website compared to the data sheet. The feb 1999 issue of KI had an article on cpm3v which I previously posted on. It only listed excerpts from the cpm data sheets and I am looking forward to reading them in their entirety.
Phil Wilson, the author of the article did mention the heat treat which follows:
Heat treating for this steel grade is straight forward and similar to D2:
*Austenize at 1,875 to 1,950 degreees F
*Hold for 20-45 minutes
*Ambient air or fan cool to below 125 degrees F
*Temper three times at 950-1,050 degrees F for two hours each cycle

It will be interesting to see what size stock cpm 3v will be offered in.

Stay safe and all the best, Phil <---<
 
By the way guys Stellite 6K is extremely easy to sharpen and takes a razor edge. I just did it to my Gerber/Stellite Model 525 hunter/skinner, 5.5 inch blade with no problem. It took me a few minutes to reprofile and put a razor edge with the spyderco sharpmaker coarse ceramic. No need for diamond on this stuff. I did not have to sharpen it, but wanted to see how easy it would be.
 
Cobalt; I think you bring up a good point about corrosion and wear resistance. Real world experience may be different from the lab tests. Even if they are not 'legally skewed.'

Your question about the supposed corrosion resistance superiority of CPM 420V perplexed me also. What I finally found was that CPM stated that '420V's high vanadium content favors the formation of hard vanadium carbides instead of chromium carbides for wear resistance, thus more free chromium is available to provide corrosion resistance.'

We shall see.

Phil; I have e-mailed you all the data sheets I have; I had hoped they would be posted by now. Walt

 
Cobalt, I don't understand the spec. sheets for 420V compared to 440V either. It seems like 420V is superior to 440V in every respect with regards to a knife steel. This is strange usually you lose something when you gain something else. All numbers though, no field testing. I too would like to have Sal comment on Spyderco using 440V over 420V.

-Cliff
 
Re: Spyderco, About a month ago, when it was thought that CM was discontinuing 440v, someone asked Sal what they would do. He replied that they had alot of R&D money invested into production with 440v, types of grinding wheels, heat-treating and other things. They were going to keep using it, as they could not afford the same type of research for 420v at the moment. He also mentioned that they bought enough of the steel that they would probably be able to special order it even if it was discontinued.

Ed: could you send me a data sheet for CPM Rex 76?
Aaron

------------------
Why did you stab that girl?
You won't believe this, but I had too much coffee!
-Edmond by David Mamet
aaronm@cs.brandeis.edu
 
I think that the use of these super hard alloy steels may have limits in toughness. Many of the custom makers still prefer to use a 440C steel for larger utility knives instead of the harder steels like ATS or 440V, because of the toughness that 440C displays in stainless steels of course. Same goes for steels like A-2, 5160, D-2, etc. In a folder I'll try just about any new steel, but in a large fixed blade were prying may be a factor or chopping will definitely be a factor these high carbon steels just have not been tested hard yet. 3V is a different story and may hold more promise in the large knife field.
 
I have a data sheet on bg 42...got it from the guys who make it...they faxed it to me..its quite long....out in the shop...not up to copying quality...you know faxes...but the guys who make it will send it no problem. cant think of who they are at the moment....some big steel company.....

[This message has been edited by tom mayo (edited 18 March 1999).]
 
man, theres so much info on this thread it makes my head spin...but i really like what the guy from crucible said right above...the lab predicts the results but testing it is the best way to confirm them...what ive said all along....i have heard over and over that 440v is being discontinued...but the same crucible guy said in one of his first posts that this is not true...asked the guys at sheffield knife supply...they said the same..they have plenty of it.....one reason no one is using 420v yet is because its too difficult to obtain in proper sizes (unless you want to order a ton or something) and the heat treat is not being done by commercial treaters...yet...tell me if im wrong on that one....phil wilson will do it..for 40 dollars per blade!!!!!! ps..somewhere up there i saw someone say that 440v wasnt living up to its rep...let me say that i have people cleaning nearly 40 animals with 440v...and these guys do NOT sharpen their knives...they always give them back to me to do it.....that is definately in the 10 times 440c catagory.....
 
one more thing...meant to stick this all on one but my memory is toast.....especially late at night....stellite 6k has super wear resistance....but doesnt take a great edge as someone suggested above....i made a bunch of knives from it a long time ago...its relatively soft..i think around 48Rc...so the edge rolls over faily easily... especially when you grind it thin...which is what makes a knife cut well in the first place...thats why the new V steels work so well....hard as a rock...well (haha) they are like carbide (actually i guess they are) am no metalurgist....and so you can get them super thin and the edge just disappears to nothing and yet it stays there...that is one of the things i love the most about 440v... it can get ssssooooo sharp...and it stays that way....if you dont abuse it....just got some 420v....will be running some tests soon.
 
Tom your comments about the harder steels being able to take a much finer edge make a lot of sense. Also in regards to your statement about Stellite that is exactly what I would have expected from such a soft RC. Yeah I know there are hard carbides in it, but the edge itself is what rolls not the carbides they just provide good abrasion resistance which is not the only factor in edge holding. However there are multiple reports which seem to indicate that Talonite does not behave this way. It is reported to take a fine edge and hold it for a long time.

-Cliff
 
Tom, Cliff, I don't know what to tell you guys, except that I did put a razor edge on the blade and did it quick. From my understanding Carson is able to put a razor edge on the stellite knives also. And I think even Rob stated that after some practice he was able to put a razor edge on the talonite. Now, I don't know if I can get it sharper than a hard tool steel, but it is as sharp as I have seen.

Oh and Tom, I would rather roll an edge than have it so hard that it chips, which is what you will most likely get with 440V. This is why big knives aren't made of 440V, usually. Also, the slightly less sharp blade on 6K will easily outlast 440V.
 
You must log in or register to reply here.
Back
Top