ZDP-189 is it any good?

My ZDP Delica came with an uneven grind, sharp but not at all up to the standard I've come to expect from Spyderco. It took a loooong time with a Lansky system for me to get an even 17/side bevel on it, and I still find that the knife sharpens best with a 20 microbevel from the sharpmaker. I don't know much about the qualities of different steels, but I assumed that the edge holding qualities of ZDP-189 argued for a shallower angle like 15/side, and this may be true, but I find I get the best sharpness with the 20/side microbevel. THe blade does hold its edge, but I'm not sure the hassle--for me--makes it more desirable than VG-10. I've found S30V easier to maintain. From what I've read, my experiences are unusual, though--many folks seem to love the ZDP-189.

My $.02.

Gus
 
"http://www.bladeforums.com/forums/showthread.php?t=463489&page=2"

Vassili,

What do you think about the Roman Landes' statement, particularly the points 5 and 6?

The matrix stability would be the critical factor, not the carbides grindability.
I agree with you about the ZDP Calypso jr. Even with an acute angle the edge holds on, it just needs a (tiny) secondary bevel to avoid the burr formation when cutting hard stuff like wood.

dantzk.

What is your point? Roman statement is correct to some cases. But it depends on carbide sizes and matrix properties. Now I can say that carbides are possible to sharpen because I found that CPM S90V impossible to sharpen by Spyderco White Ceramic beyond certain level - Aluminium Oxide does not make any difference for Vanadium Carbides at this size. But it make sence to do this by diamond powder. So to me this is clear indication that it is possible to sharpen carbides.

And of course anybody who work with D2 able to sharpen it to hait poping sharpness even it has huge carbides - if edge is size of this carbides then it will not be so sharp. Best example Microtech Currahi with excellent edge - even slightly better then Spyderco Military BG-42.

But this is not a case for PM steel ZDP189 - japanese steel engineers able to make high Carbon steel with finest edge on unbeatable hardness.

Thanks, Vassili.
 
What is your point? Vassili.

Vassili ,

Here's my point: i've had to sharpen a chipped in the box ZDP calypso jr.. In the same time i've read in this forum that obtain a sharp edge on a high carbide volume steel was an issue. I' ve been surprised to get easily a very good edge, better than on a thin 1075 carbon steel blade (douk-douk).
I've deduced of this experiment carbides was not the issue. Then i've read the Roman Landes' post and though have found the cause of the issue: the steel matrix. I just asked if it was your opinion.

dantzk.
 
Of course any abrasive harder than the carbides has the potential to cut it. However as the edge gets more acute and the steel gets softer with a more coarse grain then carbides will tear out rather than be cut.

-Cliff
 
Of course any abrasive harder than the carbides has the potential to cut it. However as the edge gets more acute and the steel gets softer with a more coarse grain then carbides will tear out rather than be cut. -Cliff

Don't you think that with a fine grit it's possible to sharpen carbides without tearing out the carbides? I've used a fine grit to mirror polish the edge and it seems to me it has worked. However the fact is that even with a fine grit, having thinned the edge, the blade is bity and works better by slicing than by pushcutting. After a lot of cutting on cardboard and seasoned wood sticks the edge holds on and is maintained by few passes on a fine ceramic stone.
Would the quality of the ZDP matrix explain that? Of course i 've no reference or measurement to make of my statements anything else than speculations about.

dantzk.
 
Yes, the carbides in ZDP-189 are only chromium anyway so they are the softest of the alloy carbides and there is a hard matrix so it would be expected that it would be one of the high carbide steels which would be easier to get a very sharp push cutting edge on.

-Cliff
 
Vassili ,

Here's my point: i've had to sharpen a chipped in the box ZDP calypso jr.. In the same time i've read in this forum that obtain a sharp edge on a high carbide volume steel was an issue. I' ve been surprised to get easily a very good edge, better than on a thin 1075 carbon steel blade (douk-douk).
I've deduced of this experiment carbides was not the issue. Then i've read the Roman Landes' post and though have found the cause of the issue: the steel matrix. I just asked if it was your opinion.

dantzk.

OK, then I will answer then it is not an issue at all at least for me. I am using only diamond benchstone and diamond powder on/ I am never has problem getting great edge on top steel, actually it is harder to has one on low grade steel, because it is tend to bend on then edge itself during sharpening - burr is way bigger.

I am talking about this for a while. I found ZDP-189 sharpens as any other steel or better.

Sorry if I misunderstand you.

Thanks, Vassili.
 
Of course any abrasive harder than the carbides has the potential to cut it. However as the edge gets more acute and the steel gets softer with a more coarse grain then carbides will tear out rather than be cut.

-Cliff

I can understand how this idea can came to mind of someone, but final stage of any scientific theory is experiment and this shows that this "theory" is not applicable in many cases. Best is D2 which can get excellent edg - I did this many times myself, as well as many here. It is not "abrasive harder than the carbides has the potential to cut it" it is actually cutting it very well all the time.

So I guess this "theory" is prooven to be wrong. If you follow main scientific practice you should admit it, otherwise we can continue to generate "theories" about this or that forever.

Thanks, Vassili.
 
Thanks guys this has helped me some. I wanted knife that would take a surgical edge and hold it longer than s30v or similiar steels. It looks like this stuff will fit the bill.
 
If you are looking for premium steel, check also SGPS - Fallkniven using it and SRS-15 G-Sakai has two models out of it.

Thanks Vassili.
 
I differ with some of the testers in this regard. Push cutting with a highly polished edge is fun. It will tell you how a given steel will perform with a given bevel, heat treat, and edge finish. So far so good. Here is where I have a problem with it. Push cutting is usefully for testing, planning wood. chisels, chippers, axes and anything that is used by pushing straight down into the material being cut. trouble is, this is not how we normally use a knife. Sure it is used for ABS style test on rope cutting. but this is just a test. With a given set of parameters. It has nothing to do with every day use. A knife is Norman used heal to tip. exactly the way we normally sharpen one. Even though small carbide firm matrix steels will hold a polished edge well, and show good results in push cuts in many different materials, many fail miserably in real use. 420, aus6 are two that come to mind. As do 440-a, and 440-c. when working in the real world, the slightest slip or slide along the cutting edge of a tough material will wipe the guilt edge right off these steels. When using a steel with larger carbides, especially when sharpened correctly for the steel, the performance can be greatly enhanced. D-2 fo instance. When sharpened on a 12300 grit diamond hone, will be hair popping sharp. It will not perform the push cut all that well on rope for very long. It will however make one hell of a hunting knife. A polished edge just slides over tallowy hide and sinew when it gets the least bit contaminated with same. A toothy edge will cut like a laser. In fact, you have to be careful not to slip and ruin the hide if you want to save it. Accidentally run the edge across a bone with aus-8 aus6 aus4 440-a, 440-b, and you had better have a sharpener handy right now! You wont have a problem with d-2 Ats-34, 154-cm. It will bite into the bone, and unless heavy side load pressure is used, remain sharp. Carbides form micro cutting teeth. When the smiths make damascus, the rave about it. Just how fantast all the micro saw teeth are. Now that all their damascus blades have gotten too expensive to use in the hunting fields, It isn't used in the advertisement so much any more. but let the subject come up when discussing stain resistant steels, All of a sudden only the push test counts. "BS" Being given big time! And for what it's worth. These are not stainless steels in the first place. They are high carbon, and in some cases high speed steels, with elements added to render them more stain resistant. Unless you simply want a knife with a shiny edge, that you can impress your friends with just how well it shaves, use a steel with larger carbides that the lower grade stainless steels. They can perform real work. Not just parlor tricks with rope, and cardboard. For what it's worth, when going to a show, especially a gun show where the majority of customers don't know all that much about knives, I apply a polished edge. The folks go nuts over the way they shave!! I even supply paper for them to play with. Push cuts look impressive, as does hair popping sharpness. These are parlor tricks my friends! If a real user, or hunter is buying a knife, I then sharpen it on a very worn 800 grit diamaon hone, or a semi worn 1200 grit diamond hone. They are dangerous sharp. They still split hair, and slice thin paper very well, but not a good push cut. The other thing they mond will is cut the hell out of the un-lucky son of a gun the buyer hands it to who just has to try shaving with it. Thats why the polish edge for show. I got tired of having people bleed on my table, and running my table cloth. That and they would some times get mad at me for having such a sharp knife one the table! Pushing is for shopping carts. Knives are for cutting and slicing. Not cleaving! Mike
 
I just thought of a very simple example of what I am trying to get at. Have you ever gotten a paper cut? How did it feel. I am always amazed at how many people that don't want a high polish on a blade. It isn't in vogue right now. But it isn't there for the looks. It is there to burnish the steel. To protect it. Polishing the edge does exactly the same thing. I can get a fantastic polished edge here in the shop on D-2, of just about any other large carbide steel. And no, the carbides don't tear out in the field. As I said earlier, push cutting rope is to compare different steels, and heat treats, not to mention edge thicknesses and bevels. It does nothing to show how the knife will performer in the real world, under real conditions. No one carries a electron microscope to the deer fields, much less stick it between the hide and carcase of a deer. You want a blade for edc defense? I do. Along with a good 1911! A polished edge when striking several layers of heavy clothing, and or leather , will sometimes act like the well polished bearing surface that it really is. Only speed and impact can make it cleave its way through. Where as a slightly toothy edge will bite and cut its way thru many layers without slipping by and out of the cut. Think glancing blow here. Remember the paper cut!! And this is was with a very thick, and weak edge. With no matrix to back it up. Not even comparable to the worst of blade steels. Think about it for a while. Mike
 
Cliff, Vassili,

Thanks for your replies, i 've hoped the sharpening gods had enlightened my mind and let me put "the" edge on a "nightmare steel" but no, it's not the case. At least i've got an excellent knife made in an excellent steel.

Ashtxsniper,

I can't judge of the geometry of a knife i don't own but the steels (zdp and vg10) shouldn't disappoint you.

Michael,

A cutting has two components: the slice and the push, if i well understand. I agree with you that slicing is the key. Better the slice, weaker the strenght required to push with for benefit less stress on a reduced part of the edge. If i well understand.

dantzk.
 
I also agree cutting is a combo of slicing and push/pressing and the ratio of each is different for everyone. However a pure push/pres cut isn't used much at all for most cutting tasks and a edge with some bite works better than fully polished. At least for me that is true. I think if most of my cutting was a push/press cut a hard thin chisel would be what I'd carry rather than a knife. :)
 
I must say that the Burgundy Caly. Jr. that I had, was one wicked sharp knife!! Get yourself a Spyderco in ZDP-189. I think that I am in the minority, regarding the chipping.
 
Just to through something else into the ring here, I seem to remember from my woodworking that the use of a plane, normally a push cut, works better at times when used at an angle. It becomes more of a shearing cut and the effective blade angle is decreased.

Two cents worth,
Richard
 
It is not theory, it is measured fact supported by fundamental physical laws.

-Cliff

No it is not. Just read my posts I wrote about it.

This kind of answer is quite symptomatic. I do not really think that you may impress me with this silly statement.

Thanks, Vassili.
 
Yes it is, because you don't understand the statement nor the physics doesn't change it. if you really can't understand the physics then here is a simple demonstration. Take an apple and place it on a table, now without holding onto the apple try to slice it in half parallel to the table with a knife. You will note that even though the knife is much harder than the apple that it will push the apple off the table rather than cut it. Only when the apple is held in place will the knife cut it.

I had described push cutting shaving with D2 edges almost 10 years ago. This however does not contend the results I noted in the above. If you really want to understand the issue then read the article I wrote on edge stability and further the references I provided, including the published materials one. Calling them silly is just absurd and shows a complete ignorance of what is being said and actual scientific method.

-Cliff
 
Yes it is, because you don't understand the statement nor the physics doesn't change it.

-Cliff

I perfectly understand statement and it is about "I am scientist here and I will not talk to you". I gave you examples and proves and you answering me - "it is measured fact supported by fundamental physical laws". This is B.S.!

It is answer from scientist so high so he is not bother to talk to this simple non scientific people. It is like you already achive highest level of scientific holiness of and know the truth so no need to bother with facts.

I will not waste my time on you. Sorry.

Thanks, Vassili.
 
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