Is ZDP 189 a stainless steel or not?

[lonerider1013]

So question about zdp 189. Is it a stainless steel or will it rust (i.e. non stainless)?

[The Meat man]

ZDP is a stainless steel, but stainless steels can rust. They're not corrosion "proof" (H-1 and LC200N are notable exceptions to this), they're simply more corrosion "resistant".

For more information about ZDP-189 in particular, here is a fairly recent thread on the topic:


//forum.spyderco.com/viewtopic.php?t=81440

[lonerider1013]

Thanks!

[The Deacon]

FWIW, my personal experience is at odds with the majority of those in that thread. I've found my ZDP-189 Spydercos to be the least stain resistant of any of my stainless steel Spydercos and I have Spydercos in AUS-6, AUS-8, AUS-10, GIN-1 (aka G-2), ATS-34, ATS-55, MBS-26, VG-10, 440A, 440C, CPM S30V, CPM S35V, CTS-XHP, and CTS-BD1.

[vivi]

Yes.

[Basetta70]

It has a big content of chrome but it's not as stainless as foe example 440A.
My delica zdp has started a pitting process due to food cutting and carry it in pocket.

[Sjucaveman]

Mine got surface rust spots after being in a sweaty pocket 8 hours.

[Doc Dan]

It is a "stainless" steel, but it is not rust proof like H1. ZDP-189 has a good amount of chromium, but it has so much more carbon than a normal steel that it has enough free of the chromium to allow corrosion, if you are not careful. (I hope I explained that well enough).

[dreadpirate]

I am more concerned with how brittle the steel may be. I saw a You Tube of a guy who has a Stretch in ZDP189 and he used it to cut 75 ohm coax and the wire core took out a nice V shaped chunk off of the edge. Of course if you don't do anything stupid with your knife then I guess it's not a problem; but that video was painful to watch.

EDIT Here it is; and it was RG6 cable the guy was cutting:

https://youtu.be/a0Cq1BlRab0

[dreadpirate]

Wow - and then the guy did a follow up vid where he took the chip out of his Stretch and made multiple cuts of RG6 cable with no issues what so ever. He's sold on ZDP-189. Hmm - maybe an Endura or Delica ZDP-189 knife may be in my future. :)

[sal]

Hey Paul,

What is the average humidity where you are?

I'm finding that bet ween rust and no rust has more to do with humidity that I previously thought.

sal

[Pelagic]

Lots of chromium carbide, not enough free chromium in the matrix. Zdp is an extremely high carbon steel. It can rust. But I'm pretty sure it's classified as stainless.

[bearfacedkiller]

Is “almost stainless” a category? Folks like to call D2 “semi-stainless” and I think ZDP falls into an ambiguous category as well.

It is easy to maintain but under certain conditions it can stain, rust and even pit easy enough.

[JD Spydo]

According to one of my Metallurgy textbooks any steel alloy with over 1% Carbon and 12% Chromium is categorized as a "stainless steel' But when it comes to corrosion resistance I've had a couple of disappointments with my ZDP-189 blades. I can tell you all up front that ZDP-189 is not very resistant to food acids. I've also had a couple of disappointments using it in Salt Water environments.

But technically ZDP-189 is a stainless steel from what the textbooks say. But it's not the only stainless I've had that has questionable properties concerning corrosion resistance. I've also experienced a couple of minor problems with MBS-26 as well.

I still like ZDP-189 because of the "scalpel sharp" edge you can obtain with it. But do be advised that it's only for plain edges because Spyderco themselves will tell you that it didn't do so well with Spyderedges.

[bearfacedkiller]

According to one of my Metallurgy textbooks any steel alloy with over 1% Carbon and 12% Chromium is categorized as a "stainless steel'

True, but that same textbook may tell you that with 3% carbon content that ZDP isn't actually a steel.

[PayneTrain]

I'd say it's definitely stainLESS. Better than D2 or even Cruwear, though not quite as good as more traditional stainless steels like S30V or 440C or whatnot. I've never rusted my Stretch (OG dark green FRN), but as one of my favorite culinary folders, it has taken on this super subtle, what I'd call a "ghost patina" that really isn't always apparent. I love it. And I love the edge performance too. A really awesome, classic steel. May it never die!