new superstainless zdp-189 rc 67

nozh,
I already own diamond stones and diamond stroping compound. That is not my point. The point is being able to use whatever stone you have available without having to resort to diamonds. I sometimes sharpen on ceramic mugs or plates and have a preference for steels that are able to be sharpened on those materials.

With diamond paste, I have gotten every steel I've tried it on to whittle hair. But I do like to have to be forced to use diamonds in order to get a knife very sharp.

If you have a strong preference for high carbide steels that is fine. I'm not trying to change your mind. I was just stating why I do not prefer them.
 
nozh2002 said:
Well, again we jump from "Hard to sharpen" to "Edge Retention" and back one more time. We talk about EdgeRetention then change subject to HerdToSharpen and again back to EdgeRetention. What it is? Some kind of public relation trick?

You just sad "give up some long term edge retention for better initial edge retention and greater ease of sharpening" - and I replay that for ease of sharpening you do not need to give up anything, just learn how to sharpen and use right tools.

2 spyken
http://www.bladeforums.com/forums/showthread.php?t=491916

Thanks, Vassili.
Click to expand...

ease of sharpening and edge retention are tied. You sharpen because the blade has lost the edge quality you desire, so the frequency of your sharpening is determined by the edge retention (for the specific edge you apply to the steel) Who wants a hard to sharpen knife with poor edge retention, who doesn't want an easy to sharpen knife with excellent edge retention?

Now, in the tradeoffs, do you want more edge retention or more ease of sharpening? What kind of edge are you retaining? That is completely dependent on use and highly affected by other properties. Do you want to slice or pushcut, is there much impact, torquing, can you access sharpening equipment, do you need corrosion resistance, etc.

It doesn't matter what steel you use in a knife that only whittles hair and opens the mail. No steel, CPM or otherwise, is fully optimized for every task.
 
Would it be easier to sharpen a thin slip of ZDP-189 sandwiched between two pieces of softer steel in a laminated blade, than a solid ZDP-189 blade of the same size and shape?

If so, the laminated blade would have the same edge retention as the solid ZDP-189 blade, even though the laminated blade was easier to sharpen.

Win \ Win

:)
 
JoHnYKwSt said:
nozh,
I already own diamond stones and diamond stroping compound. That is not my point. The point is being able to use whatever stone you have available without having to resort to diamonds. I sometimes sharpen on ceramic mugs or plates and have a preference for steels that are able to be sharpened on those materials.

With diamond paste, I have gotten every steel I've tried it on to whittle hair. But I do like to have to be forced to use diamonds in order to get a knife very sharp.

If you have a strong preference for high carbide steels that is fine. I'm not trying to change your mind. I was just stating why I do not prefer them.
Click to expand...

OK. But you point then is not that it is harder to sharpen, but that it is harder to sharpen certain way, right? And this is different thing then - Hard to sharpen in general.

It is impossible to sharpen with ceramic but it is as easy as any other steel with diamonds. Correct? And if so we can not state that it is harder to sharpen then other steel, just skipping part that we are not talking about diamonds which as availabla as any other sharpening tool, but some people like you are do not like them.

2 hardheart

You lost my point - there is no problem with sharpening. All steel are equaly easy to sharpen with diamonds (or difference is insignificant). So there is no point to trade off non existing thing "easy to sharpen" for edge retention.

And as I already sad - best balanced solution from all points of view, which is good enough for many application is Buck steel 420HC. But I am looking for simple the best steel, not one which is good enough.

Thanks, Vassili.
 
Vassili, I don't know what you mean by public relations trick, am I advertizing for something? Like hardheart said, it is pointless to talk about ease of sharpening without talking about edge retention. It is the theory of some (including myself), that those high wear resistance steels will lose their initial high sharpness quickly, regardless of how sharp you can get it to start out with. They will of course hold an edge the longest after a certain amount of dullness.

As to ease of sharpening, whether using diamond or not, different steels sharpen different than others. It is very easy to notice when grinding down thick edges. Steels with greater wear resistance have low grindability, and take longer to grind even when using diamond. With thin edges this is less of an issue, but then the question of hardness comes in, softer steels are more likely to roll in sharpenin. However, even with thin edges steels with lower wear resistance take much less to sharpen. Phil Wilson reports that after his rope cutting test, 154CM had to be taken back to the stones, while AEB-L only needed to be stropped.
 
You miss my point, depending on the application, the steel will not lose its cutting ability in the same manner. It doesn't matter how wear resistant a steel is if you're chipping the edge out. A friend did that with my zdp Caly on a piece of speaker wire. He's a network tech who I've given a couple CRKT AUS8 knives to. It wa a small chip, but still a chip, total loss of cutting ability in that section of the edge. A few passes at 800+ grit to restore shaving sharpness is easier/faster than recutting the whole bevel to remove nicks, no matter what your abrasives are.

You don't seem to be looking for the best steel, only the most wear resistant. You never notice the hardness numbers on the crucible charts, or actually find out what the charpy measurements are, or if they're comparing longitudinal or transverse toughness. You don't even need to harden these super high vanadium steels to get hellacious wear resistance, do you want a fully annealed blade from it? No, but then you probably want a max on the toughness while still having a martensitic transformation. Great, now you have a 54-56 Rc blade. I don't want a highly wear resistant edge that rolls and deflects, I'd spend more time straightening the edge than cutting with it. 9V might be the best example of this.
 
hardheart said:
You never notice the hardness numbers on the crucible charts, or actually find out what the charpy measurements are, or if they're comparing longitudinal or transverse toughness. You don't even need to harden these super high vanadium steels to get hellacious wear resistance, do you want a fully annealed blade from it? No, but then you probably want a max on the toughness while still having a martensitic transformation. Great, now you have a 54-56 Rc blade. I don't want a highly wear resistant edge that rolls and deflects, I'd spend more time straightening the edge than cutting with it. 9V might be the best example of this.
Click to expand...

Well, I did not notice that hardness few years ago on the Crucible chart, simple because it was not provided there and I never talk about this CPM 9V last times mostly about CPM S90V. It was surprise for me, when on new chart it was marked at 54HRC. However if we talk about CPM 10V - it can reach 63-64HRC. So your example of CPM 9V is too hypothetical - no one made knife out of it to my knowledge.

Now my excitement is based most on test results by asi who have CPM 10V knife from Phil Wilson outcut on the rope anything - 999 cuts and he stoped only because he got tiered. While the best previouce performer shows 300 (INFI) and most steel from production knives was less then 100. Of course this is not very accurate test, but this number shows clear superiority even if they are not too accurate.

I did suspect before that this steel will perform good based on that chart, but after that test I am absolutely certain that this one is excellent.

Thanks, Vassili
 
How can one steel be picked as "the best"? Doesn't what the best steel is depend on what you want to do with that particular knife. I'm not going to limit myself to just one knife. The knife I'd take in the ocean would not be the same knife I'd pick for slicing and dicing in the kitchen.
 
Gentlemen, An interesting discussion. It started out with ZDP 189 and eventually included almost all the CPM steels we use. I had some recent experience with ZDP 189 on a fishing trip to Alaska. This knife is one I made for myself, the only one I have made to date with this steel. I got a blank of laminated material via my son who lives in Japan. ZDP in the center and ATS 34 on the outside. It was 3 mm thickness and about 1 inch wide. I did a flat grind from edge thickness of about .008 to the top of the blade. The blade ended up thicker overall than what I would have preferred because if I went thinner the outside ATS34 would have been ground away. The ZDP core ended up at RC 66/67. I used the same heat treatment as I use for CPM 90V due to lack of specific heat treat information. I used this knife every day for 5 days for cutting bait, cutting line and leaders, gutting and gilling salmon and filleting halibut. It started out sharp and was sharp at the end of the trip. This was a salt water environment with several days of rain and fog mixed. At the end of each day I rinsed the knife in fresh water, dried it off and put it away in the sheath. No rust at all, not even a hint. I would have to conclude that for me, at least on this trip, the corrosion resistance was at least equal to CPM S30V and other stainless steels in the same category. Edge holding as indicated by my rope cutting tests put this blade in the same ball park as S90V at RC 60. This is all based on one blade and only one try at heat treating this steel. Sharpening is not a problem with a combination SC and India stone. I like the steel and just wish it was a little easier to obtain. It is also relatively expensive. One 12 inch bar cost $40.

I am a little surprised at the discussion on CPM 9V for knife blade material. 9V has the advantage of high toughness for some applications (non knife blades) but has a very low obtainable hardness. This low hardness means low strength and a thin edge would roll long before the wear resistance offered by the high vanadium carbide percentage would give it any advantage. CPM 10V heat treated to say RC 60 would also offer good toughness but would have enough strength to keep the edge up there for the carbides to wear. I have not tried this since CPM 10V at RC 63/64 offers such great edge holding.

Some one called CPM S30 an entry level steel. Not sure why one would come to that conclusion. CPM S30V has been beat up pretty bad here and other places but my experience with it has been great. Reasonable toughness at a high hardness (60/61). Good corrosion resistance. A notch above ATS34/154Cm in edge holding in my experience and testing.
The one CPM steel that is showing the most promise for me right now is CPM 154. It does not have enough vanadium to offer a significant amount of VC but it does have about 4% Moly. The combination of chrome and moly somehow makes for a better than expected edge holding and toughness. I have been experimenting with tempering at 950 F and get 62 RC. There does not seem to be a significant loss in either toughness and corrosion resistance.

Anyhow a few observations for what it is worth.. PHIL
 
Phil Wilson said:
Some one called CPM S30 an entry level steel. Not sure why one would come to that conclusion. CPM S30V has been beat up pretty bad here and other places but my experience with it has been great. Reasonable toughness at a high hardness (60/61). Good corrosion resistance. A notch above ATS34/154Cm in edge holding in my experience and testing.
The one CPM steel that is showing the most promise for me right now is CPM 154. It does not have enough vanadium to offer a significant amount of VC but it does have about 4% Moly. The combination of chrome and moly somehow makes for a better than expected edge holding and toughness. I have been experimenting with tempering at 950 F and get 62 RC. There does not seem to be a significant loss in either toughness and corrosion resistance.

Anyhow a few observations for what it is worth.. PHIL
Click to expand...
Phil, I would be interested in any testing you do using the upper temper on CPm-154.
 
Phil Wilson said:
Some one called CPM S30 an entry level steel. Not sure why one would come to that conclusion. CPM S30V has been beat up pretty bad here and other places but my experience with it has been great. Reasonable toughness at a high hardness (60/61). Good corrosion resistance.
Click to expand...

Hi Phil, that one was me who call it "entry level powder metallurgy steel". Which is perfectly in tact with what you just mentioned.

Thanks, Vassili.
 
nozh2002 said:
Hi Phil, that one was me who call it "entry level powder metallurgy steel". Which is perfectly in tact with what you just mentioned.

Thanks, Vassili.
Click to expand...

Just have to be careful with the wording..... CPM S30V is a top choice for many of the high end production and custom knives. So calling it "entry level" can be taken the wrong way.
 
Bkultra said:
Just have to be careful with the wording..... CPM S30V is a top choice for many of the high end production and custom knives. So calling it "entry level" can be taken the wrong way.
Click to expand...

I rather like to see CPM S90V and CPM 10V as a top choice for many high end production and custom knives, as it was intended by Crucible initially I think. CPM S30V was designed as an entry level, a top level is CPM S90V and CPM 10V and this choice is not best, for high end ... IMHO.

Thanks, Vassili.
 
Vassili, I guess I see what you mean. Both CPM 90V and 10V as you say were developed by Crucible. I think CPM 10V was the first one. These were invented for plastic die steels. Plastic has fillers that can be very abrasive so these steels can save a lot of money for long production runs. Both have been adapted for blade steels by some custom guys and just a few production knives. S30v was developed with one of the targets as a knife blade steel. It is much easier to work with than both 10V and 90V. Mostly due to the lower heat treat temperture and higher workabilty. This is history and will not be news to most of you. PHIL
 
Most people would not be able to sharpen a S90V blade, and forget about being able to sharpen it out in the field. S30V was a compromise, it gives A2 class toughness and almost S90V class wear resistance. Don't get me wrong every steel has a place but S90V is very hard to work and would not be practical for many field work knives (due to the inability to sharpen it easily).

*Note* I have a few knives made of S90V and I absolutely love them :thumbup:
 
There are different steels for different applications. There is no steel that is directly better in ever category over S30V, so I don't see how it can be an entry level steel. Wear resistance is not the most important feature in a knife steel.
 
2 Phil,

Yes, CPM S30V will outperforms many not PM steels, but as I undertand was introduced by demand from knife manufacturers to lover wear resistance and make it more machinable. I have no problem with this at all - in result PM steel technology is more awailable for customers then before. With wear resistance lowered it gain some toughness slightly over CPM S90V and have other benefits...

But what I do not like is that PR campainn that CPM S30V is just super and best for me as a customer, and CPM S90V is just bad, because it is impossible to sharpens and brittle etc - all this marketing noise, which completely mislead and which only cover that knife manufacturers do not want to do too much to deliver best solution to customers.

And in result American metallurgist were moved aside when Japanese came with ZDP189. Like US just not able to make good steel, while in reality it is American knife-manufacturers refuse to work with American steel, because it is just too good!

Bkultra said:
Most people would not be able to sharpen a S90V blade, and forget about being able to sharpen it out in the field. S30V was a compromise, it gives A2 class toughness and almost S90V class wear resistance. Don't get me wrong every steel has a place but S90V is very hard to work and would not be practical for many field work knives (due to the inability to sharpen it easily).

*Note* I have a few knives made of S90V and I absolutely love them :thumbup:
Click to expand...

I talk already a lot about sharpening "issue" which to my understanding does not exist at all. With modern sharpening there is no difference is it CPM S90V or INFI or 420HC.

Inability to sharpen any steel is just not true! And I proved this many times already.

Thanks, Vassili.
 
nozh2002 said:
Inability to sharpen any steel is just not true! And I proved this many times already.
Click to expand...

So you are saying all steels are the same when it comes to sharping????? If you mean with the right gear, skill, and time... Notice I pointed out that I was referring to what the average user would be able to do. I also pointed out that in the field one would not be able to bust out their "super modern sharp master 5000".

Another thing: S30V is significantly tougher then S90V. S90V is stronger, this is a given... typically when toughness goes up strength goes down and visa versa. Like I said every steel has its own place and applications. Each has pros/cons. BUT S30V is in no way "entry level". Why would a majority of custom knife makers use it on their highest end knives if this was the case?
 
I have the Kershaw Mini-Cyclone in ZDP-189 and found I worked way too hard trying
to tune up the edge on ceramics, I ended up buying the DMT diamond stones and
used the coarse and fine and then the ultra fine ceramic and a strop and now the
blade is what I'd call amazingly sharp, as others have made mention, if it isn't sharp
you are not finished sharpening it yet, but, there is the possibility that you are also
not holding a consistent angle, so I'd give fair warning to practice on a knife you are
not as fond of first before addressing a more expensive one.
This knife will easily do what I call tree top trimming of the hair, where you need not
bring it near the skin in order to cut the hair off, also of course it will make curlicues
or fuzzy sticks of a length of hair as well, nice shots Vassili !

So, if you have some 'new' tuff stuff in your folder, you would do well to not give up
but give the diamonds a try and a word of caution, do not press as hard as you would
on regular stones, moderate pressure does the trick...

G2

edited to add, what to look for when sharpening, I hold the knife up towards the light with
the blade angled so the bevels catch the light and you should see a very smooth even flat area
of the bevel, if when you tilt the blade and see additional reflections, other bevels, it means you
need to keep working on it, similar to the magic marker trick some people do, to see if you are really
getting down to the final edge. I just look for the light, follow it along the edge to the point and it
should be nice even plane of the bevel down to the very edge. I'll try to get a shot of that, tough to do!

didn't get a good shot of the edge, as it's more that you 'follow' it along the edge in the light, but did
take a strand of hair, luckily it keeps falling out! lol, it's a bit grey so it's not as cleanly seen as the other
shots above but you'll get the idea, took the one and made several slices against it with the mini-cyclone

IMG_1359.jpg


G2
 
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