Testing of S30V, S35VN, S90V, M390, XHP, 204P, 20CV in consistent testing conditions?

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pnsxyr

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I hope it is OK to post here even though this is more of a test request than a test...


There is so much fantastic information here, that I wanted to make a request of the people more knowledgable than me... The Spyderco Paramilitary is a really unusual knife...it has been made with almost every exotic steel on knife forums that gets significant discussion.

Correct me if I am wrong, but the PM2 has now been made with:
  • S30V
  • D2 (original)
  • S90V (both solid and composite IIRC)
  • M390
  • 204P
  • XHP
  • 20CV
  • 35VN


anything else?


Here we have a knife that is affordable, liked very much by most knife nuts, has been made with the steels that constantly get the "how does this compare to__" threads, and is made by a maker in which most users agree does an excellent job at hardening whatever steels they use. I see this as a major opportunity for testing!

I know a lot more about research than knives, but I can apply it to knives so those who know a lot more than me can roll with it if they so desire. Here, it is very difficult to order or rank something (in this case, steel) if certain design parameters are not consistent (in this case, the maker, hardening, and blade design characteristics.)

While a truly fair comparison between anything is impossible, a better comparison could be made if we had consistency in:
  • the knife (the handle/eros affect pressure/how it is held)
  • the blade shape (to stop variations from different geometries or different hardening/production styles)
  • the edge (to ensure differences in retention/deformation outcomes are not varying due to different edges)
  • the angle (something like an EP or WE would make all angles very consistent and rule out any differences from degrees)
  • the tester
  • the test mediums to be cut
  • the grading scale used to rank, order, and categorize the testing outcomes


Technically, if enough variables are kept consistent, the tester would not have to be the same and multiple people could conduct the same test in which the information they generate can be compared to tests done by someone else.

Now that a second run of 204P Paras were made, a lot of discussion seems to be happening comparing it to the M390 Para and the standard S30V and other steels. So I think now is a good time to ask of this request...



First, exactly what is being tested? What aspects of performance will be tested to make assumptions of the performance characteristics of the various steels?...what is the most important thing (or things) to look at? For example...
  1. tests that measure fine cutting ability which requires that razor edge (test determines when the razor edge is lost)
  2. tests that measure how long it takes until the edge is simply no longer useful for the set tasks?
  3. tests that measure toughness such as examining signs of fine edge chipping and other deformations? (possibly magnified)
  4. tests that measure edge retention when cutting abrasive/highly-abrasive mediums, such as cardboard with high silicone content? (presumably, this would be different from cutting other items because not all items cut are abrasive like cardboard, right?...if so, this test would presumably favor steels with characteristics more like M390 or S90V?)...if so, splitting general edge retention and edge retention that looks specifically at wear resistance may be needed?



Then, what are the actual measures of sharpness/toughness/performance? (this would determine when the test is complete.) For example...
  1. the ability to slice paper/push cut paper in a certain way or with a set amount of force?
  2. the ability to shave hair? (this seems easy, but is not very scientific as too many things can vary and we only have so much hair)
  3. the ability to cut a different medium in a certain manner (ex: a tomato without turning it into sauce)
  4. a physical weight placed on top of the blade when the blade sits on a medium and using the indentation made to represent current sharpness?
  5. when a certain visible amount of deformation has occurred to the edge?



What medium(s) are used for the testing that best represent what a knife is used for in the real world? For example...
  1. paper?
  2. cardboard?
  3. food?
  4. wire?
  5. steel?
  6. plastic/rubber/silicone material?
  7. a combination?



I think those initial questions could potentially produce the methodology for this sort of test which would keep many of the unintended variables from affecting the assessment of steel performance.


Any thoughts? If you think I am being overly anal, just say it. I just wanted to throw this out there as I have read many threads that have noted the problems in comparing steels and am curious to if something like this could potentially provide a consistent cross-comparison to make detailed and measured assumptions on general steel performance in the real world?
 
Just a clarification, the PM2 has been done in CTS-20CP, not 20CV.

Additionally, it sounds like what you are thinking of is an even more comprehensive type of testing than what Ankerson is doing over in this thread. He has tested many steels with the same method and ranked them all in two categories, fine edge and coarse edge. Many of the knives tested were PM2s or Military's or Mule Teams.
 
There are a few people on this forum that have some good test info such as Jim Ankerson, however as far as I know his tests are used on hemp rope, and he goes through the trial once (could be wrong on this) this gives a good starting point, however I think the knowledge base could be expanded with at least 5 seperate runs (just on hemp rope) and then expanded to different materials (such as cardboard, wood, ect) Now Jim has put countless hours into his tests already so obviously we can't expect this sort of thing from one person (just imagine how long it would take to test the K390 Mule 5 times per medium)
I do think it would be very interesting to come up with a very specific set of controls for testing (using cheap easy to obtain equipment) Say the knife must be set at 30 degrees with a 800 grit finish, using a bamboo cutting board, set a starting pressure (say 3lbs to cut through a material) and once it has gone up 10lbs ( say 13lbs for example knife) the test ends, this way we can get multiple people doing multiple tests and will have a lot more data that can be compared and analyzed. Instead of having just one person's run of an M390 Para 2 to compare to one person run of a 204P Para 2, we could have have several peoples runs of an M390 Para 2, BM 581, BM 710 M390, Military in M390, ect and compare it to several peoples runs of a 204P Para 2, Southard, Microtech Whaleshark in 204P.
 
michaelm466 said:
There are a few people on this forum that have some good test info such as Jim Ankerson, however as far as I know his tests are used on hemp rope, and he goes through the trial once (could be wrong on this) this gives a good starting point, however I think the knowledge base could be expanded with at least 5 seperate runs (just on hemp rope) and then expanded to different materials (such as cardboard, wood, ect) Now Jim has put countless hours into his tests already so obviously we can't expect this sort of thing from one person (just imagine how long it would take to test the K390 Mule 5 times per medium)
I do think it would be very interesting to come up with a very specific set of controls for testing (using cheap easy to obtain equipment) Say the knife must be set at 30 degrees with a 800 grit finish, using a bamboo cutting board, set a starting pressure (say 3lbs to cut through a material) and once it has gone up 10lbs ( say 13lbs for example knife) the test ends, this way we can get multiple people doing multiple tests and will have a lot more data that can be compared and analyzed. Instead of having just one person's run of an M390 Para 2 to compare to one person run of a 204P Para 2, we could have have several peoples runs of an M390 Para 2, BM 581, BM 710 M390, Military in M390, ect and compare it to several peoples runs of a 204P Para 2, Southard, Microtech Whaleshark in 204P.
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Yes, it's a lot of work, I do more than one run to verify.

Some of the knives I have tested on Cardboard and wood along with the rope, but that's more of a performance full review.

People can use some different mediums for testing as the primary such as cardboard that's free for the most part, but very inconsistent so a large number of runs would have to be made.

I use manila rope because it's consistent for me, I get the rope from one place, a rope company and it's very clean and has been very consistent for me.

People can get as detailed or scientific as they want, but in the end they are still testing by hand so it's really only going to be so accurate no matter how many runs are made and averaged.

Just the variables between batches in the steel and the HT and tempering processes......

CATRA is where it really is and really is the best way to test for pure edge retention.

In the end in a wear resistant test the steels will follow the carbide content right down the line in order for the most part if the knives tested are similar or close enough to each other and the process is non bias.

100 runs or 200 runs won't change the order percentage wise if it's an honest non biased test, in the end it will still line up as I said.

Insanity is doing the same thing over and over and expecting a different result.... ;)
 
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pnsxyr said:
Correct me if I am wrong, but the PM2 has now been made with:
  • S30V
  • D2 (original)
  • S90V (both solid and composite IIRC)
  • M390
  • 204P
  • XHP
  • 20CP
  • 35SVN

anything else?
Click to expand...

A better platform for testing would be the Mule series, which has included most of those and many more. Other than steels that are essentially duplicates of each other from different manufacturers, the omissions would be S30V and CPM-D2 or its ingot form D2. I don't think the loss of either D2 steel would be a serious comparative loss, given the relatively small number of manufacturers that regularly offer blades in D2 or CPM-D2 .

As Jim said, he's done most of those steels and off the top of my head most have been a Mule, a Military or a Paramilitary 2, so although the consistency is not perfect, it's pretty close. The cost and time involved are prodigious.
 
JNewell said:
A better platform for testing would be the Mule series, which has included most of those and many more. Other than steels that are essentially duplicates of each other from different manufacturers, the omissions would be S30V and CPM-D2 or its ingot form D2. I don't think the loss of either D2 steel would be a serious comparative loss, given the relatively small number of manufacturers that regularly offer blades in D2 or CPM-D2 .

As Jim said, he's done most of those steels and off the top of my head most have been a Mule, a Military or a Paramilitary 2, so although the consistency is not perfect, it's pretty close. The cost and time involved are prodigious.
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The problem with a lot of the testing are people own perceptions of how things should be or how they perceive they should be based on their own experience or from what they heard or read someplace.

There are so many variables it's crazy.... :D
 
Do you find that the test results change using different mediums? I wouldn't think so but if it did I would assume minor differences? I surely could see the results changing using different edge angles? Or, maybe not?
 
sirupatespecial said:
Do you find that the test results change using different mediums? I wouldn't think so but if it did I would assume minor differences? I surely could see the results changing using different edge angles? Or, maybe not?
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If it's abrasive medium in a wear resistant test then the results should be the same percentage wise as long as the knives are very close.

Have to keep it as close to apples to apples as possible.

Well if you take the edge angles down to the point of failure then yeah things would change, that is thin the edge out enough that it weakens it.

But that changes the parameters of the test so it's no longer is about wear resistance.

That's called changing the lab to fit what the tester wants the outcome to be.

Like a Scientist has a theory... OK...

Now they have to prove it so they keep changing the variables until that happens... That's if the outcome doesn't match the theory they are trying to prove.

Theory proven..... Then they publish the findings with exact parameters so the lab can be repeated by other Scientists and then there is a bunch of back patting etc, maybe even a grant.

However change the variables again and the results will also change.... This happens a lot also and the reason for a lot of so called facts to be reversed years later.

Theory disproved.


One has to outline what they are testing for from the beginning and have all the details out in the open before hand.
 
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sirupatespecial said:
Do you find that the test results change using different mediums? I wouldn't think so but if it did I would assume minor differences? I surely could see the results changing using different edge angles? Or, maybe not?
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The results will change based on geometry and what you're cutting. If you need to maintain a high sharpness edge then you don't want a low sharpness "working" edge. Take slicing fish flesh for example. Ever hear sushi chefs arguing that s110v offers better performance than a simple carbon steel? It doesn't for that type of cutting because you want thin edges at high sharpness for that. Performance at a given task is what we need to look at, not only basing performance claims off of rope cutting. So if you don't cut rope or rope like materials why would you choose a steel based on that criteria? It's something to think about when looking at testing.
 
Fanglekai said:
The results will change based on geometry and what you're cutting. If you need to maintain a high sharpness edge then you don't want a low sharpness "working" edge. Take slicing fish flesh for example. Ever hear sushi chefs arguing that s110v offers better performance than a simple carbon steel? It doesn't for that type of cutting because you want thin edges at high sharpness for that. Performance at a given task is what we need to look at, not only basing performance claims off of rope cutting. So if you don't cut rope or rope like materials why would you choose a steel based on that criteria? It's something to think about when looking at testing.
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Sushi Chef's use what they use due to tradition and what has been used for a very long time, and they use traditional Japanese model knives.

Nothing wrong with that either as what they use works so there is no real reason to change unless they want to try something different, I have seen some ZDP-189 and VG-10 Sushi knives.

Most I have seen are either Blue or White Steel.... Not exactly cheap either especially the Blue Steel knives.

Hard to argue with tradition really when what they are using still works the same way it always has.

The Japanese are in general very traditional and very proud of that tradition.
 
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If someone wanted to fund the research I am sure I could expand on what I have already done.

But we aren't talking about a few bucks here.... ;)

I would have to have the test knives made, not really an issue at all really, likely 2 knives in each steel all the same.

But it all costs money, time and materials.

Would send the test knives to CATRA and follow up with rope cutting.
 
Ankerson said:
If someone wanted to fund the research I am sure I could expand on what I have already done.

But we aren't talking about a few bucks here.... ;)
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The OP mentioned 8 different models of Para2- just to buy 2 of each of those would probably run about $5k total.


I've been thinking about angles and testing and so forth. It would be great if we could come up with a material better to use than cardboard, and some other material to use for testing sharpness, but I haven't had any good ideas on that. It also seems that if you pick a steel and you pick a type of material to cut, you could then pick the optimum angle for that combination. So maybe testing should be at the optimum angle too. If that gives a certain steel an advantage then so be it. A person that is attuned to the benefits of their steel might be willing to sharpen it at its optimum angle for their use in order to get the best performance out of it. And I think it would be interesting to see what the optimum angles would be. But that is a whole new series of tests for each steel, or multiple series to determine what the optimum angles are for different types of materials. It's almost becoming an impossible task.

I did some quick and dirty testing with my new Spyderco Gayle Bradley folder yesterday. I had a lot of cardboard boxes to be sliced up for the trash so I use the GB. After cutting somewhere between 80 and 100 linear foot of cut, it became fairly dull. Not a very scientific test but just this amount of cutting with one knife was a lot of work for me. I wouldn't want to do it with 16 knives at different angles, then do it again with other materials.
 
Personally, I don't cut a lot of cardboard, but I get the feeling that a lot of people do, so I'm not sure it isn't as good a real-world test medium as anything else? Probably more common than rope. This is just thinking out loud, not arguing. I do wonder how much cardboard varies from source to source - whether some of it has more cr@p in it that dulls blades than other types of cardboard.
 
bdmicarta said:
The OP mentioned 8 different models of Para2- just to buy 2 of each of those would probably run about $5k total.


I've been thinking about angles and testing and so forth. It would be great if we could come up with a material better to use than cardboard, and some other material to use for testing sharpness, but I haven't had any good ideas on that. It also seems that if you pick a steel and you pick a type of material to cut, you could then pick the optimum angle for that combination. So maybe testing should be at the optimum angle too. If that gives a certain steel an advantage then so be it. A person that is attuned to the benefits of their steel might be willing to sharpen it at its optimum angle for their use in order to get the best performance out of it. And I think it would be interesting to see what the optimum angles would be. But that is a whole new series of tests for each steel, or multiple series to determine what the optimum angles are for different types of materials. It's almost becoming an impossible task.

I did some quick and dirty testing with my new Spyderco Gayle Bradley folder yesterday. I had a lot of cardboard boxes to be sliced up for the trash so I use the GB. After cutting somewhere between 80 and 100 linear foot of cut, it became fairly dull. Not a very scientific test but just this amount of cutting with one knife was a lot of work for me. I wouldn't want to do it with 16 knives at different angles, then do it again with other materials.
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That's why I was talking about getting exact knives made in the different steels, 2 of each steel and sending them to CATRA for testing.

Then follow up with the rope cutting after that, multiple runs.

The reason why I mentioned funding, the one who funded it all would own the data and the knives in the end obviously.
 
JNewell said:
BTW, I really hope you're wrong about that $5k figure. :eek:
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S30V
D2 (original)
S90V solid
S90V composite
M390
204P
XHP
20CV
35VN

I haven't kept up with the values all that much and I was doing a quick counting in my head, (and BTW I realize now that it is NINE knives total)
There is 1 that is $100+, two that are +/- $200, 5 that are going to be $250-300 each, and the last one that is easily $500+. That is roughly $2250-2500, and remember that he said he wanted two of each.

It would be cheaper to buy the Mules and do it that way. It might be hard to find a custom maker to make them any cheaper than the mules, and it might be hard to find one maker that is completely up on the heat treatment for this wide range of steels.
 
You may be right. That's scary if it's true, though. Both of the S90V versions would be in the $500-600 range, though, so 2x of each would be $2200 or more right there, so, yeah, you could easily be right. That's crazy. You might even be low... :rolleyes: :eek:
 
The problem with the Mules are they aren't all the same thickness behind the edge and stock thickness.

Also some aren't at optimal hardness either..

Another reason for the customs, all would be at optimal hardness and CYRO Tempered.

Plus the blades really should be 4" ideally and all the same stock thickness and same thickness behind the edge @ .015" and within .002".

That would make things much more accurate for CATRA and the rope cutting also.

Expensive, yep...

Time consuming, yep....

I would figure a year as a conservative estimate time line wise....

And that's with complete funding...

Figure 15 Steels, 2 knives each..... More if the person funding it would want more tested.



I figure I did 40 steels that are posted in my testing thread. :)
 
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