Spyderco Forums

Few steels have do many critics. Zdp-189(specifically Spyderco's Spyderco's zdp-189) seems to be a steel that is either loved or hated.

It's no M390, that's for sure.

In my experience it is not as difficult to sharpen as people claim. Not even close. This could be due to the diamond bench stones I sharpen with. The larger surface area, along with the added cutting power of diamonds, makes quick work of any steel. For me, Zdp-189 sharpens easily and takes a wonderful polish.

I've yet to see any rust on mine. Many reports of rust can be seen floating around the internet, but few have context. What caused the rust? Would other stainless blades have rusted under the same circumstances?

The brittle nature of the steel is mentioned often, but again, I've had no issues. I do have tougher steels for tougher jobs, and use the knives accordingly, so that could be why.

What are your experiences with Zdp-189? What have you experienced with edge holding, corrosion resistance, edge strength(chipping or not), and how easy or difficult it is to sharpen.

I just can give the perspective of a guy with just basic sharpening skills and "only" a basic sharpmaker (brown and white rods) plus a work sharp field sharpener and a leather strop.

Using that equipment for ME ZDP WAS too hard to sharpen. Had an Endura in that steel and sold it. Used it not long enough to really feel entitled to talk about edge holding, but just intuitively I´d say my HAP 40 Endura is not far behind concerning that, but for me a lot easier to sharpen..

I fixed a bad tip, and some chipping, while repairing a friends stretch 2 in ZDP-189. It has patina and rust pitting, but he didn’t take care of it.
I’ve also repaired chipped M4, M390, Rex 45, among plenty of other softer steel types, and I found M390 to be the most difficult. However, it was only marginally more difficult. I feel when it comes to the hardest steels (any current super steel) they’re all going to take forever unless you have some special equipment.
I feel since I did mine by hand, most of the inconsistencies in expectation vs reality(total time on the stones) can be attributed to user error.
My point is, I think because most of us use different sharpening methods/systems, and have varying levels of experience, we can’t expect to give accurate information on which steels take longer to sharpen. We have to find a way to bench test all of the steels sharpen-ability.

Sal from another thread: "ZDP is a very hard steel...Should stay sharp a long time. Don't let it get really dull before resharpening."

Personally I found it to be hard to sharpen on a sharpmaker even just for touch ups. I have yet to try it on my KME, but I have a feeling it'd be much less of a chore on that with the diamond stones and some of the "guess work" taken out of the sharpening process. Still, I think a major reprofiling job on zdp would be a loooong undertaking.

Edit: When I say "easy to sharpen", what I usually mean is more like "quick to sharpen". Maybe that's part of the issue in question here: different definitions of "easy".

Superb steel with one of the best uses on the saber ground Endura with a SE blade (C10SGRE)...unfortunately discontinued

What I like about ZDP is it is, in my experience, the only highly wear resistance steel that sharpens well on ordinary waterstones. I suspect that is one of its main reasons for existence (as it mainly seems to be used in Japanese knives). Another desirable trait (for certain applications at least) is it seems to hold a razor sharp edge for a long time, instead of degrading to a working edge relatively quickly like high vanadium steels.

I have had some light rust issues, and it’s a bit fragile, but for me its unique attributes still give it a solid place in my knife collection. I use ZDP regularly when high sharpness iand edge holding is needed.

I think when it comes to sharpening, there's 2 parts. One is grinding, which consists of resetting a bevel or grinding out edge damage (chipping/rolling), this includes apexing. The other is finishing, which consists of refining, but more importantly getting a clean durable edge.

I agree it's not hard to sharpen, because it's easy to finish.
Even though it's harder to grind than say hap40, it is easier to de-burr.
I can spend 5 minutes setting a bevel on hap40, and 15 minutes trying to get a nice clean de-burred and wire free edge (from stones only).
With ZDP, I might spent 10 minutes setting an edge, and 2 minutes getting it refined and cleaned up.
This seems to be mostly a matter of hardness, as long as it's not so hard that it just crumbles.
I find maxamet excellent in this matter.

2 experiences with it:

Plain edge Spyderco I had I let it get dull - it was a pita to get sharp. Using my Spyderco ceramic stone it took a lot of time and patience to get back to shaving sharp. Someone wanted that knife more than me so I sold it.

Fully serrated Delica I have chipped. Not bad, but it looks like some serrations have extra serrations. To be fair I was using the knife to sideways torque/cut open plastic packing strips. Use to do the same with my VG-10 serrated rescue to no ill effect so I thought all would be fine. Knife still cuts fine so it has become my beater Delica.

ZDP-189 in my humble opinion is a great steel I’d like to see more off particularly in a practical fixed blade akin to Sprig, Waterway, Junction ..

I find it easy and very satisfying to sharpen with SiC hones on a guided system and being relatively hard it doesn’t hold a burr, and the inevitable burrs formed through sharpening are easily cut away cleanly. That said I can see that use of excessive (?) pressure with coarse abrasives can actually fracture the edge as you sharpen.

Light pressure, clean, sharp 1000grit SiC and plenty of Windex leave me a silly sharp edge and a couple of ultralight passes either side on stiff leather and chrome oxide has left me with edges that whittle free hanging hair.

Having heard the steel is “brittle” I’ve not pushed it too hard, but in every day use in a folder I find it holds it’s initial sharpness exceptionally well and haven’t experienced chipping or any corrosion even though we live a kilometre from the ocean and I work on a Naval Base. :)

in my use it was nearly impossible to sharpen past "barely sharp enough" with water stones, but using diamond abrasives it isn't bad at all.

I agree that it holds a fine/polished edge longer than other "Super" steels, though, not all that much better than the M390-ish steels.

my experience with edge damage is mixed: I inadvertantly cut down hard on an aluminum cylinder head with my D'fly, causing zero damage, not even any dulling, there was enough force behind it to cut into the aluminum a few tenths of a millimeter. The flip side to that was knocking the tip of my Delica lightly on the edge of a diamond plate and having the point snap off like it was glass, in fairness to ZDP, I *had* re-profiled that edge to about 12dps...

Both knives have hinted at surface rust on occasion, but they're still much more resistant than any HC steel. FYI, I don't tend to have rust issues... if a blade gets wet or gunky, I'll clean and at least wipe it dry as soon as I'm able to.

I'm a ZDP fan. ZDP Dragonfly is on my all time top 5 list, and likely to stay there. I feel like it's been obscured by the latest "super steel of the month" lately, but I have no complaints about it and a lot of love for it.

I love the steel.

Most of the reasons for that have already been mentioned, but in brief-

Sharpens well on alumina based waterstones, not just diamonds and SiC.

Keeps a fine razor edge better than the high vanadium PM stainlesses, in my experience.

Polishes really nicely, which aids a bit in corrosion resistance as well as being aesthetically pleasing.

Regarding corrosion resistance and toughness, it's 'good enough' for my purposes.

In terms of rust, it seems to take a kind of misty orange surface oxidisation which wipes away. I've only ever had it happen once, when I was carrying my Dragonfly in waistband, cycling and sweating all day in Aussie summer heat. Also, you need to wipe and rinse when using it on acidic foodstuffs like oranges.

Hitachi knew what they were doing when they developed it. I get the impression it was probably intended for high end knives and more advanced users, than just the average person on the street. That is, some ability with benchstone sharpening, and basic maintenance, and cutting technique was probably taken for granted in it's end line users.

Also, bear in mind, they are strict about who gets to heat treat it, so we are always getting a high quality, benchmark heat treat. I would conjecture the process involves some kind of deep cryo aging.

For those who have had trouble with it, I recommend getting a coarse benchstone (doesn't have to be an expensive one) and thin out the edge area, just holding the spine a couple of coin thicknesses above the stone. Just as you are reaching the apex with your bevel, go to the Sharpmaker and put a 15 or 20 dps edge on it. It will be very easy to resharpen, because the contact area is drastically decreased. The diamond/CBN rods will help, of course.

Cambertree wrote: ↑

Tue Sep 10, 2019 9:51 pm

I love the steel.

Most of the reasons for that have already been mentioned, but in brief-

Sharpens well on alumina based waterstones, not just diamonds and SiC.

Keeps a fine razor edge better than the high vanadium PM stainlesses, in my experience.

.......

For those who have had trouble with it, I recommend getting a coarse benchstone (doesn't have to be an expensive one) and thin out the edge area, just holding the spine a couple of coin thicknesses above the stone. Just as you are reaching the apex with your bevel, go to the Sharpmaker and put a 15 or 20 dps edge on it. It will be very easy to resharpen, because the contact area is drastically decreased. The diamond/CBN rods will help, of course.

Folks, listening to you all makes me admire and respect your sharpening skills and -knowledge, and I mean that honestly.

On the other hand, when reading threads like this, I sometimes wonder if any regular average knife Joe can really sharpen a super-ish steel knife at all... ?!
I mean, look: In the context of this forum I for example really know almost nothing about steels and sharpening (that is just a simple fact, and it does not bother me), but in my "real world" I still am the guy who CAN (at least) sharpen knives. On a sharpmaker with its fixed angles, but also somewhat ok-ish freehand now (with the rods placed on the sharpmaker base).

Still, reading your and many other posts on other threads: All t burr forming stuff, which steel responds better to what abrasive or method better, reprofile-and-specific-micro-bevel-stuff and so on and so on are for the most part far above my level.

Now, for example the sharpmaker is said to be designedso that anybody can get any knife to VERY sharp (just watch the instructional dvd) - of course without all that knowledge and skillset you have - how is this possible? I am NOT sarcastic here, just a bit confused... :confused:

Hey Wartstein, my friend:

I always like reading your posts, and let me just say that with your earnest and open minded approach to knowledge seeking, it’s only a matter of time before you’ll be sittin’ whittlin’ hair with a REX121 blade with the grizzled forumite edge junkies. :D

But seriously, we’re all students here, mate.

I’d say don’t get too hung up on technical nomenclature - there’s many ways to get a stubborn steel razor sharp.

In terms of the Sharpmaker, it’s a superb, versatile tool for maintaining edges, but you’re going to need some patience if you want to do serious thinning out or reprofiling on the higher carbide, higher Rockwell hardness steels.

If you have the time and patience it can certainly be done, but investing in a good coarse benchstone will just make the process a whole lot easier.

I personally use the Japanese Atoma series of stones for removing material on my initial resharpening of new knives. Then I refine with the Venev bonded diamond stones from Gritomatic, and finish on a variety of different stones I’ve accumulated over the years.

If you’re set on just using the Sharpmaker, you should start with either the the diamond or CBN rods and use a constant up and down motion, as opposed to doing distinct singular passes.

Be careful you don’t run the tip off the rods.

A good loupe is your best friend. I think I recall you already have one?

If not, I use and recommend the bombproof 10x Belomo with Zeiss glass.

A few of the forum old hands have detailed the technique, but I’ll just reference Surfingringo’s excellent how-to:

https://youtu.be/DI8lTj-F8gA

Apart from that, my only other advice is to maybe pass up one or two knife purchases and buy stones instead. Then it’s just practice, practice, practice and you’ll be there in no time. :)

This obviously applies to ZDP-189 just as it does to any steel which may be giving difficulties in sharpening.

I am a big fan of ZDP.

How would zdp be as my first supersteel? Still practicing on my sharpening technique, but from what everyone has said, it responds well to most abrasives, unlike the vanadium carbide heavy stuff?

I've had a ZDP-189 Delica for three years, with no chipping or corrosion issues. I found it challenging to sharpen when all I had was a Sharpmeaker. I bought a KME system earlier this year and was easily able to put an extremely sharp edge on it. I sharpened it on the KME three months ago and it has become my default EDC. I give it a few passes on a strop when I think about it, but its edge holding ability is astounding me.

GarageBoy wrote: ↑

Wed Sep 11, 2019 8:26 am

How would zdp be as my first supersteel? Still practicing on my sharpening technique, but from what everyone has said, it responds well to most abrasives, unlike the vanadium carbide heavy stuff?

I’m inclined to think ZDP-189 will be a good introduction to “Super Steels”. It truly isn’t as hard to sharpen/grind as some may suggest and can’t really be compared to high carbide steels like S90V or S110V, which for a better word don’t particularly like being sharpened/ground. :)

Lots of the brittle reports are likely related to burrs.

It will definitely chip before it rolls in my experience.

Reprofiling just takes the right stones.

I've had it rust in my pocket.

Rust is the most disputed attribute of steel, and for good reasons. We're limited to personal experience. I grew up on the coast, and despite working on the water I now live in the country, where an immaculate 1970 chevelle may be parked outside rust-free. I've seen both extremes and I'll say corrosion resistance completely depends on your environment and specific uses, not to mention yourself (sweat - some people's sweat can rusty cruwear easily). If anything (disregarding H1 and LC200N), this is the attribute everyone needs to continuously keep an open mind about. Rest assured, you're situation is unique. No matter where you live, who you are, what season it is, or how you use your knife.