Any downsides to ZDP 189?

I think that the discussion in this thread is pretty pointless. It is based on the common and naive assumption (or rather wishful thinking) that there must be THE perfect steel.

In a knife like the Caly Jr., isn't it completely irrelevant whether or not ZDP-189 has a lower Charpy value than ATS-34 or not? As long as the edge holds up (which depends a lot on what you are cutting anyway) and is not chipping out under you, the thoughness is obviously good enough. With a blade that is ground as thinly as the Caly's you are hopefully not prying anyway. No matter what kind of steel you are using, it would be trivial to break it.

And for a knife that you want much tougher, there are other steels, which are clearly optimized for a different usage....There is a reason why some steels are called "shock steels".

I think it is really necessary to evaluate a steel within the application (i.e. the type of knife, blade/edge geometry etc.) that it is used for. And even if charts and numbers give a good idea, in the end, time and user evaluation will tell, how good a steel holds up in a particular type of application.
 
Vassili, you miss in your list

OK, I want - CPM S90V, CPM 10V, CPM 9V, YSS YXR7, YSS ZDP4, YSS ZDP247, CPM M4. I am not sure is CovryX different then ZDP-189? There is also CovryY.
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CPM S125V and CPM Rex 121. Sal promissed a sprint run of the Native in S125V! I would rather have a new Manix80 in S125V (maybe as a sprint run).

Franco
 
HoB said:
In a knife like the Caly Jr., isn't it completely irrelevant whether or not ZDP-189 has a lower Charpy value than ATS-34 or not?
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For most work yes, this is only relevent if you intend to subject the blade to high shocks. It would be more important to see how they compare in terms of yield strength, tensile strength, wear resistance and corrosion resistance, and grain structure.

-Cliff
 
Hi Vassili,

I'll get right on that :D

We've got 125V in the works, we're testing 3V & M4 in powder.

I could see S90V in something? Maybe a Millie?

sal
 
It must be wonderful to snap your fingers and make fantastic knives appear. Sal do you live on Mount Olympus?
 
Sal Glesser said:
Hi Vassili,

I'll get right on that :D

We've got 125V in the works, we're testing 3V & M4 in powder.

I could see S90V in something? Maybe a Millie?

sal
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Wow!!! Woooooow!!!!!!!!

When? Where? I can not miss it!

Thanks, Vassili!!!!

Millie is great! Can you make it also whith orange G10 - SAR Millie?
 
Cliff Stamp said:
This is more dependent on the shape of the edge than its composition. I have knives made out of 1095 at 66 HRC, M2 at 65 HRC and O1 at 63.5 HRC which all sharpen trivially.

-Cliff
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Yes and no. You won't find a very thin edge/blade of ZDP in all but the smallest knives because it's too brittle at it's usualy hardness. In a medium to large Spyderco it will likely be laminated.

WYK
 
Cliff Stamp said:
No this is a myth, lots of tool steels have a much lower machinability than stainless steels, and machinability should never be an influence to you when sharpening anyway.

The carbon vs stainless general abilities that are cited usually only hold for underhardened pure carbon steels. They don't apply to harder version of the same carbon steels, and they certainly don't apply to tool steels in general.

-Cliff
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I guess I needed to be more specific. I meant simple carbon steels. No stainless is as easy to sharpen as 5160 is. ZDP189 will NOT be as easy to sharpen at their usable hardness levels of 1095/5160/1084 etc. Generally, if it isn't a relatively simple steel with mostly carbon and other trace elements, IE a significant amount of Vanadium, Moly, Tungsten, Chromium, or manganese, it is referred to generally(by knifemakers at least) as carbon steel. Once you get into higher alloyed steels like D-2, M-2, CPM etc. they are considered more tool steels or cruscible steels. Though 0-1 is considered a tool steel in name, it really isn't in the same league as M2 when we talk about sharpening. So you could call it a fallacy when it comes to tool steels, but when it comes to most non-production knifemakers, we consider the lower alloyed stuff plain old carbon steel - which is where I was coming from.

In any case you're going to have to show a little proof that m-2 and ZDP at 64-67 are as easy to sharpen as 5160 at 60 before I jump on the bandwagon.

WYK
 
It depends on what it is used for, I have some fairly large fixed blades, larger than any of Spyderco's folders and they are full hard steels, very brittle. I just don't use them for prying or impact work, they are just for cutting.

Some of Spyderco's folders like the Paramilitary are more rugged and meant for more than just cutting rope and cardboard so a steel optomized purely for cutting isn't a good choice. I would like to see Spyderco explore tool steels for some of their more rugged blades.

-Cliff
 
"I think that the discussion in this thread is pretty pointless. It is based on the common and naive assumption (or rather wishful thinking) that there must be THE perfect steel."

No it's not. It's based on me wanting to know what the downsides of ZDP are.

Now I know.

Just want to choose the best for me. And make sure a knife I'm about to buy isn't going to be replaced in a steel that I don't like more (hypothetically).
 
WYK said:
I guess I needed to be more specific. I meant simple carbon steels. No stainless is as easy to sharpen as 5160 is.
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Randall's 440B machines easier than several 5160 blades I have, this is what you are basically arguing and it doesn't hold true in general for stainless vs carbon steels. Of course this actually has no influence on sharpening anyway, or shouldn't anyway.

So you could call it a fallacy when it comes to tool steels ......
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It isn't specific to tool steels, machinability should never be a concern for sharpening, if it is then there there are serious problems with the knife, either the properties of the steel are not suitable for the scope of work, or the grind is sub-optimal.

I did some cutting with the ZDP-189 Calypso Jr. a few days ago, I blunted it down to ~1% of optimal sharpness. Yes that isn't a typo, about one percent of optimal sharpness.

The edge had little aggression and was reflecting light strongly along its entire length. It was restored to shaving sharp with 2 passes per side on the medium Sharpmaker ceramic rods.

-Cliff
 
Hi Cliff,

We're looking at CPM-3V and CPM-M4.

We've got a fixed bladed "chopper" and a folder. Both Ed Schempp designs.

Any opinions?

sal
 
Yeah, from what I read M4 is a very good steel. Sounds like it belongs in a 80mm Manix to me hint hint. I'll take two. :thumbup:
 
A manix in M-4 would be a dream come true. I'm very happy with my Benchmade M-2, so if M-4 is really a step up in all aspects, I will go crazy for that stuff!
 
You know, this is kinda funny. When S30V appeared, everyone was thrilled about it. Recently, I found that most people (me included) still preffer VG-10 over S30V. :confused: It is possible that the same thing will happen to ZDP-189.
Of course, this won't stop me from getting my (unlaminated) :D ZDP-189 Delica (because I simply feel the urge to have it) :foot:
 
Im sure if they have been using it in japan for 20 years Sal knows enough about it not to put a sub standard product on the market.....
 
Sal Glesser said:
Hi Cliff,

We're looking at CPM-3V and CPM-M4.

We've got a fixed bladed "chopper" and a folder. Both Ed Schempp designs.

Any opinions?

sal
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I love Ed's designs and 3V is my favorite blade steel. Make an Ed Schempp model with 3V and I'll have to buy a bunch of them! 1 in each car and truck in the BOB, 1 in the shed for working in the yard, 3 or 4 as spares, several as gifts ........ :D

I have a custom 3V camp knife. Total maintenance has been wiping it on my pant leg when finished chopping and putting it back in the sheath. After almost five years there are some little tiny rust spots. Here in the Seattle almost everything rusts. I'm very impressed with this steel.
 
WYK said:
You don't have to guess - Chromium and Carbon are NOT tough. They are hard and brittle. If you have a steel with more Chromium and Carbon, and nearly every other aspect is similar, it will be less strong and more brittle. All the charts I have seen for ZDP show it doesn't even have Mn(Manganese) which helps make a metal tougher, and is included in ATS-34, 154CM, 5160, M2, D-2, etc. If ZDP lacks this element, it's likely never going to be terribly tough at any usable hardness.

Does anyone have a good chart of ZDP? I only see the one on AG Russels page. It's hard to believe it only has Carbon and Chormium as it's alloying elements.


WYK
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Since Spyderco seems to be the only maker using this ZDP in large quantitiy let me toss out another interesting fact. They are also the only one that uses VG-10 in quantitiy. If you look at there steel chart from their web page it is only one of two steels using Cobalt.

Why is this? My recent set of power drills are Cobalt tipped. Must save a few pennies in manufacturing costs is my guess.


http://spyderco.com/edge-u-cation/index.php?item=3

Okay, this is a test. Look at the chart and tell me what steel type (getting lots of discussion on this thread) is not shown? Hee hee!

Is there any one particular steel that while not extremely good in edge holding or toughness can be sharpened very well so that it is impressive "out-of-the-box"? It appears to me that many folks (not KF folks) who purchase knives use this out-of-the-box sharpness as the primary measure of quality. These folks are obviously not heavy-duty users. Thoughts?
 
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