M390 VS ZDP-189 Rope Cutting - Informal testing

knarfeng

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In rope cutting, it's critical that there is no flex in the rope. If the rope flexes, the compressed part will be right under the edge and the compressed rope is harder to cut.

Loop a coil of hemp, pull cut through the center of the loop, then loop again and begin your pull cut along the side below the center of the loop and you'll feel the difference.

The slot in the wood would have to be very thin, which makes it easy to miss, or wide which permits rope flex.

sal

-------------------------------------------------------------

We are all teachers and we are all students.

I have a slot in my manila rope cutting test jig. I made it only a bit wider than the blades I test. Sometimes I miss when cutting and hit the side of of the slot, then have to resharpen and start the test over. "Comes with the territory."
 

Sal Glesser

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Thanx Phil.

We learned the "proper" way to make a filet knife from you. Ended up having a few arguments with the "makers" in Seki of how I wanted it done.

Crucible and Scott Devanna have been great sources for heat treat for us as well. Yes, too many steels, too little time, not enough memory. ;)

We've not been able to get much from Hitachi either, at least on ZDP. They's sell us anything else they make.

Hi Hardheart,

Testing always ends up more complicated than originally thought.

Thanx Knarfeng.

Good to know ther's others with the disease.

JNewell,

We're making 4 Mule Teams a year. We already have the next year made. I'd love to make more, but I don't think the steel-heads can afford to get more per year.

sal
 
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Hi Noctis,

CPM-S90V is among the best edge holders that we've tested, at least on CATRA. I think it's the many big vanadium carbides and the Crucible processing. S150V, then S125V, then S110V. Then ZDP and S90V are close despite their totally diffferent chemistry paths to get there. So I use them as kind of a goal.

M390 may prove to be exceptional and as you say, a good synthesis. Time and testing will tell.

We're still learning about ZDP as there is not much history in production pieces. We're planning more S90V.

I'm looking forward to releasing the M390 mule so we can get more "Real-world" testing on this new steel in a format that is similar to other pieces.

Some of the new steels from now available from Carpenter, Uddeholm, SandviK and others will be fun for steel-heads.

sal
Oh I wouldn't insinuate that M390 is superior to S90V(but that might depend on use). But isn't it true that large scale production of S90V is somewhat difficult because of the properties of the steel? At least, availability of a knife in S90V seems far and few in between. I can only speculate that there is a very good reason why some steels, despite having desirable qualities, are not in mass production.

I would think that CPM Rex 121 would make an absolutely perfect knife blade which would eat up cardboard for months and never get dull. But machining it into a blade shape would be an exercise in futility. Getting it into a production model would be a joke, and user sharpening would be frustrating as hell.

Not that I'm any less eager to get my hands on S90V, but trading some wear resistance so that you can sidestep the mentioned chipping issues doesn't seem like a bad deal:thumbup:. Plus it seems like M390 is better suited for mass production.
 
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I'm looking forward to releasing the M390 mule so we can get more "Real-world" testing on this new steel in a format that is similar to other pieces.

Some of the new steels from now available from Carpenter, Uddeholm, SandviK and others will be fun for steel-heads.

sal

That is great news indeed. Thanks!:thumbup:
 

sodak

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Well, I am still waiting for you to make this simple device - wood with partial cut to do correct testing.

But instead of discussing this particular problem, which is pretty easy to fix you starts all that drama, and I do not have answer for several years from you.

Is it too hard to make partial cut -half cut in 4x4 piece of wood?

Why do you ignoring this obvious flaw in your tests for all this years?

Thanks, Vassili.
And you wonder why most of us ignore your posts. Many of us on the forum were active in testing long before you showed up, and several in this thread probably long before you were born.

Suffice it to say, many disagree with your points, but simply don't care enough to rebut you, been there, done that.

I've enjoyed reading this thread immensely, even with your interruptions.
 
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ditto to sodak. sometimes it's really hard to remain civil with the total rudeness displayed by some formites.evenso the thread by ankerson certainly gave a ton of info :it's sad we have to endure some accompanying remarks & direct insults to good people.i guess it comes with the territory.
dennis
 

tiguy7

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Great discussion! I tend to agree that wood is a poor anvil for cutting tests. It contains silicates (which are the abrasive in Arkansas stones.). A master harness maker told me that he would not use his punches on wood because it shortened the life of them. Instead he took a 1lb. metal coffee can and filled it with Lead. When the Lead was cool and smooth, he used it for an anvil. When the Lead got roughed up, he remelted it to generate a fresh surface. I don't know much about Lead prices or safe practices, but there must be something better than wood. Polypropylene or polyethylene might be the ticket. I've gotten very good results in my kitchen with a Corian (acrylic plastic) cutting board. It is much easier on edges than wood in my experience. Keep those supersteels coming. We are the toolmaking animal, and better tools make life better.
 

nozh2002

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There is no evidence that CPM S90V is as good as ZDP-189. Crucible
failed to produce anything close to ZDP after so many attempts over
several years. A lot of promises were made - results are not as excited
as advertisements.

I do not interested in Crucible steel any more. I think knife industry
has better solutions from different manufacturers. At first Carpenter.
CTS-XHP once hit the market - outperform ZDP189 right away! It was
big surprise.

M390 may be solution as well, but so far testing Ankerson did need to be
verified, because most likely curved edge on BM710 did not contact
wooden base unlike ZDP edge. Difference in performance is too big and
no one reported such an exceptional performance before - so I am a bit
skeptical, but hopeful. I guess it worse to have a look.

Still I prefer Carpenter - because it is US company, unlike Swedish
Uddeholm.

Thanks, Vassili.
 
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There is no evidence that CPM S90V is as good as ZDP-189. Crucible
failed to produce anything close to ZDP after so many attempts over
several years. A lot of promises were made - results are not as excited
as advertisements.

I do not interested in Crucible steel any more. I think knife industry
has better solutions from different manufacturers. At first Carpenter.
CTS-XHP once hit the market - outperform ZDP189 right away! It was
big surprise.


M390 may be solution as well, but so far testing Ankerson did need to be
verified, because most likely curved edge on BM710 did not contact
wooden base unlike ZDP edge. Difference in performance is too big and
no one reported such an exceptional performance before - so I am a bit
skeptical, but hopeful. I guess it worse to have a look.


Still I prefer Carpenter - because it is US company, unlike Swedish
Uddeholm.

Thanks, Vassili.
Interesting, because others could say the same about your results with CTS-XHP and Dozier D2 steel. In my own use, CTS-XHP didn't exhibit much higher edge retention than S30V. And while Dozier D2 steel could perform better than production S30V blades, I still find CPM-M4 to be better for my use(higher hardness, more toughness, higher carbide volume). Admittedly, cutting corn and cutting rope are worlds apart. Though it still doesn't make sense for a steel that has such a low carbide volume(CTS-XHP) to perform far above other high carbide steels when cutting an abrasive medium like rope.

Also, I would think it best for everyone to have their own testing methods and not force everyone else to conform to your standards. The way I see it, real world use is going to be different than cutting rope, and rope cutting specifically tests one aspect of edge retention(wear resistance). I find it valuable to have a variety of other testing methods just to get a better overall picture of how the steel performs in other areas(toughness, hardness).
 

Sal Glesser

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Hey Noctis,

I'd like to learn more about this corn cutting. Could you elaborate?

There's a good project for you Jim.

Develop a series of cuts on different materials and try to keep consistent. I'm sure the performance bent afi's could help develop the tests.

Kinda like the cutting competition, but a consistent cycle that each edge/steel would be rated on.

sal
 

Ankerson

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Hey Noctis,

I'd like to learn more about this corn cutting. Could you elaborate?

There's a good project for you Jim.

Develop a series of cuts on different materials and try to keep consistent. I'm sure the performance bent afi's could help develop the tests.

Kinda like the cutting competition, but a consistent cycle that each edge/steel would be rated on.

sal


Hi Sal,


I was already thinking about doing something like that, just have to work out what to use and get it into a workable format that could be repeatable then I got tied up in this rope cutting thing. That is Phil's fault though he suggested it to me in my cardboard cutting thread, I just finally got around to doing it. :D

I still have to finish up part 2 of this once everything gets to me, more rope, the knives etc. :)

Materials that are easy to get for testing are important. :)

Maybe a series of different materials that test the different aspects of the steels edge holding. I have some ideas, but I am still working on it. :)


Jim
 
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nozh2002

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Interesting, because others could say the same about your results with CTS-XHP and Dozier D2 steel. In my own use, CTS-XHP didn't exhibit much higher edge retention than S30V. And while Dozier D2 steel could perform better than production S30V blades, I still find CPM-M4 to be better for my use(higher hardness, more toughness, higher carbide volume). Admittedly, cutting corn and cutting rope are worlds apart. Though it still doesn't make sense for a steel that has such a low carbide volume(CTS-XHP) to perform far above other high carbide steels when cutting an abrasive medium like rope.

Also, I would think it best for everyone to have their own testing methods and not force everyone else to conform to your standards. The way I see it, real world use is going to be different than cutting rope, and rope cutting specifically tests one aspect of edge retention(wear resistance). I find it valuable to have a variety of other testing methods just to get a better overall picture of how the steel performs in other areas(toughness, hardness).

No other do not have defined testing protocol yet and did not isolate most factors.

You do not have test until you descibe what you are doing. So far you just sad you like this and don't like that because you cut some corn. This is not test results, until it is more clear what you are doing, how do you make sure that initial sharpness is same , what you use as a base. All what I asked you before.

So you are not tester - corn cutter may be, you need to make some effort to write about what are you doing. Then we may see what it is.

So far you just state thet you do not like CTS-XHP. Initially in first post you sad that it may be due to your sharpening, but now it is like fact of life. Sorry, information you provided so far is not enough to make any conclusion.

Thanks, Vassili.
 

nozh2002

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Hi Sal,


I was already thinking about doing something like that, just have to work out what to use and get it into a workable format that could be repeatable then I got tied up in this rope cutting thing. That is Phil's fault though he suggested it to me in my cardboard cutting thread, I just finally got around to doing it. :D

I still have to finish up part 2 of this once everything gets to me. :)

Materials that are easy to get for testing are important. :)

Maybe a series of different materials that test the different aspects of the steels edge holding. I have some ideas, but I am still working on it. :)


Jim

Be careful you may ends up with permanently damaged wrist. Amount of work you are doing is not healthy already.

Thanks, Vassili.
 

Ankerson

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Be careful you may ends up with permanently damaged wrist. Amount of work you are doing is not healthy already.

Thanks, Vassili.

Oh I know believe me. :D

I take breaks every 100 cuts or so, get up and walk around, drink some coffee, stuff like that. :)
 
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I think Sal's idea of developing different segments of testing with different cutting medium is a very good idea. And since you're already cutting on Wood now, it would be logical to keep it the same way.

While I do not agree most of Vassili's comments or research, I think a Corian or Plastic cutting board will suffice as a decent cutting backboard. It certainly will be of my choice when I do any testing.

Sal, I really appreciate you being here. It's almost of an authoritative presence amongst this discussion. I also cannot wait for Spyderco's future released. Thank you very much for contributing to the knife world
 

nozh2002

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Oh I know believe me. :D

I take breaks every 100 cuts or so, get up and walk around, drink some coffee, stuff like that. :)

I wrap my wrist tight to help keep bones in place - like boxers do. But it is too late for me and I need few weeks to rest between tests.

Thanks, Vassili.

P.S. And Sal does not publish CATRA results so we have to do this by hands...
 

Ankerson

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I wrap my wrist tight to help keep bones in place - like boxers do. But it is too late for me and I need few weeks to rest between tests.

Thanks, Vassili.

P.S. And Sal does not publish CATRA results so we have to do this by hands...

Sal really can't publish them from what he had stated before. :(

I will be doing more steels cutting rope also. :D
 
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I just thought of this, Jim

Wouldn't it be a good idea to test non Super-steels as well just to grab an idea how much better some steels could do better? I'm thinking of normal 420, 440 series steels:D
 
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Hey Noctis,

I'd like to learn more about this corn cutting. Could you elaborate?

There's a good project for you Jim.

Develop a series of cuts on different materials and try to keep consistent. I'm sure the performance bent afi's could help develop the tests.

Kinda like the cutting competition, but a consistent cycle that each edge/steel would be rated on.

sal
Well, I work in a produce department of a grocery store, and one of my tasks include trimming unnecessary parts of corn so that it looks more appealing, is easier to stack, and doesn't leave a mess all over the floor(customers will often husk the corn and leave a mess if you don't clean it beforehand).

The parts I remove are the stalk, some of the leaves, and the hair. I typically hold my knife with the blade facing towards me and push the stalk of the corn towards the blade with my right thumb while simultaneously twisting the corn with my left hand. Sometimes it isn't necessary to twist the corn with thinner blades like my Spyderco Endura FFG or my Spyderco Gayle Bradley which can push cut the stalk, but thicker blades like my ZT 0301 and BM 755 MPR will need that extra twist. For the most part, the tip won't see much use with this type of cutting, and it can be done with a blade shorter than 3 inches.

During the process you can somewhat tell when the blade is getting dull because you can't take off all the hair with one forward slice, but the real test is on slicing paper. For me, if it can't slice paper without tearing it, the knife no longer has a working edge.

I think the main causes of a dull edge with this kind of use is edge rolling and abrasion. Steels with less than 60 Rc(S30V) tends to roll, while steels with little to no wear resistant carbides(CTS-XHP) will be worn away by the silicates in the stalk and leftover dirt. Micro-chipping only seems to occur in especially brittle steels like ZDP-189.
No other do not have defined testing protocol yet and did not isolate most factors.

You do not have test until you descibe what you are doing. So far you just sad you like this and don't like that because you cut some corn. This is not test results, until it is more clear what you are doing, how do you make sure that initial sharpness is same , what you use as a base. All what I asked you before.

So you are not tester - corn cutter may be, you need to make some effort to write about what are you doing. Then we may see what it is.

So far you just state thet you do not like CTS-XHP. Initially in first post you sad that it may be due to your sharpening, but now it is like fact of life. Sorry, information you provided so far is not enough to make any conclusion.

Thanks, Vassili.
Like Ankerson, it's mostly informal. And rather than call it testing, I call it real world use. I used my knife on the job, and I get the feeling my boss wouldn't allow me to take a video and post it on YouTube.

I'm not trying to say that CTS-XHP is bad, just that it isn't the choice for corn. For most other kitchen uses(carrots, tomatoes, lettuce, celery) I'm sure it would do excellent. Besides which, the data and Carpenter made no mention of the steel being wear resistant.
 

nozh2002

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Sal really can't publish them from what he had stated before. :(

I will be doing more steels cutting rope also. :D

Sure he can! Different sources publish results time to time here and there. Just recently some were published disclosing average results for CPM S30V vs super performing CPM S60V. Why Sal can not? Same as I can publish my results and same as you can publish yours.

I am not buying it!

Thanks, Vassili.
 
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