Dumb Question

Not a dumb question at all. I'd like to know what it stands for, too. A quick Google search didn't turn up anything...
 
You know, that's a really good question! I'm guessing it's an acronym of a transliteration of a Japanese phrase/name, considering it's made by Hitachi (I think.)
 
ZDP-189 is an loose translation anagram of "folded metal". The 189 refers to the "effective" number of layers for a loose comparison of traditional hammer forging/folding steels. The Japanese were not content with the size of the large carbides found in high alloy stainless stainless steels. Even in the P/M steels these can approach 10 microns when the carbides aggregate to form macro-carbides and this leads to a low edge stability, ideally you want sub-micron carbides.

They also wanted to find a way to increase the wear resistance without using vanadium as that has problems with lower edge sharpness due to the very hard carbides having lower edge integrity as they require a higher counterbalance force to be cut than chromium rich carbides. They looked towards forging which is to be expected given their history of sword steels and thus was born the ZDP process, which is also called "metal ceramic technology".

Here is a shot showing the very fine carbide size and high distribution in ZDP-189 :

zdpm.gif


-Cliff
 
Yes, thank you Cliff. People bash Cliff all the time because he give his opinion, which is a highly qualified one. Even though I at times may at rare tiimes disagree with he says, I still value his informed input.

Cliff


aka the other Cliff that supports the forum.
 
No s#!$, Cliff kicks ass. Thanks again, Stiff Clamp, I still learn stuff from his posts from 1999. Good stuff -- I wish i were as curious, motivated, and as smart. oh well. Maybe i know more about single malts though ;)
 
Cliff Stamp said:
ZDP-189 is an loose translation anagram of "folded metal". The 189 refers to the "effective" number of layers for a loose comparison of traditional hammer forging/folding steels. The Japanese were not content with the size of the large carbides found in high alloy stainless stainless steels. Even in the P/M steels these can approach 10 microns when the carbides aggregate to form macro-carbides and this leads to a low edge stability, ideally you want sub-micron carbides.

They also wanted to find a way to increase the wear resistance without using vanadium as that has problems with lower edge sharpness due to the very hard carbides having lower edge integrity as they require a higher counterbalance force to be cut than chromium rich carbides. They looked towards forging which is to be expected given their history of sword steels and thus was born the ZDP process, which is also called "metal ceramic technology".

Here is a shot showing the very fine carbide size and high distribution in ZDP-189 :

zdpm.gif


-Cliff
Click to expand...

So I take it that's another "I don't know" ???:rolleyes: :D
 
The ZDP-189 is just a material designation for Hitachi Metals. In the past they have used the "Z" designation on experimental materials. For example, 15 years ago they introduced ZHD 55 which was a hot work steel. Today it is DAC 55, DAC being their standard hot work prefix. ZDP-189 has been around for over 20 years so the name is already established. If you hunt around a little you can find Hitachi's standard brochures and get a feel for how they name materials.
 
hara-kiri-yogi said:
Maybe i know more about single malts though ...
Click to expand...

There is really only one way to test that hypothesis.

To clearify the above post, read the edit which I added right after I wrote it. That is a picture of ZDP-189, comments opposing vanadium in knife steels were made by a Japanese metallurgist on the Spyderco forum, it is called ceramic metal technology, etc., however the part about forging isn't true.

There is a new forging technique being promoted for high hardness blades however which I will be evaluating shortly and it does make similar claims, able to achieve very high hardness without being brittle (same range as ZDP-189) which is what promoted the above post as I was discussing it at the time this thread.

-Cliff
 
Thanks Cliff.So what you are saying is ZDP does'nt really stand for three different words but a type of blade steel,right?
 
Thanks for the article link. Pretty impressive stuff. All I know is, when I went to sharpen my ZDP-189 Leek this morning, it took five times as long as I thought it might- and I knew it would take a while.

"To test ZDP-189, William HenryKnives sent one of its model B15 folders with the steel to an indepen-dent source. According to WHK’s Rick Thronburg, after 100 cutsthrough 1-inch manila rope and withthe edge still cutting well, testing was concluded. By comparison, hereis how some other steels performed in the same test:
•440C: 15 cuts;
•154CM: 18 cuts, and;
•D-2: 30 cuts.

“At some point in the future, wewill run the test again to see how far beyond 100 cuts ZDP can go,” Thron-burg noted. “But for now, ZDP-189 socompletely eclipsed the performanceof conventional steels, we had our an-swer.”—by BLADE® staff
 
mmarkh said:
Thanks Cliff.So what you are saying is ZDP does'nt really stand for three different words but a type of blade steel,right?
Click to expand...

Some of the steel designations like 1095 actually mean something as the numbers indicate the alloy content, that is a plain carbon steel with an average carbon percentage of 0.95%. However many of the others are just sequential. Many steel companies have their own names for the exact same steel.

Note that a lot of "scientific" names are actually made up after the fact. I watched one of my friends in the lab make up a complex defination for an technique anagram. The acutal meaning was his ex-wifes inititals which he picked because he hated the algorithm as it was very tedious and high maintenance.

Plus some numbers and letter just sound impressive, ZDP-189 certainly looks cooler than D1. Just like when you watch a late night commercial and there is a broom called XT-15. There was never a XT-1 to 14, and the letters that people rarely see like X,Z, Y etc. stand out strongly. Now yes if you ask the guy he can probably rattle off some nonsense about what it means, but odds are he is channeling P.T. Barnum.


Patapsco Mike said:
“At some point in the future, wewill run the test again to see how far beyond 100 cuts ZDP can go,” Thron-burg noted. “But for now, ZDP-189 socompletely eclipsed the performanceof conventional steels, we had our an-swer.”—[/I]by BLADE® staff
Click to expand...

They might want to try sharpening the 440C blade next time. ZDP-189 will cut more rope than 440C, but the comparison isn't as lopsided as that article presents. It is also meaningless because there is no defined stopping criteria, you don't know the details on the blades, who made them, were they all at the same edge angle and initial sharpness, etc. . David Boye and Jerry Busse have both done *thousands* of cuts on one inch hemp rope without resharpening. Busse has done them live. There are also forged blades from Zubeng which have done 10 000 hemp rope chops.

Aside from the hype, ZDP-189 does offer significant advantages to makers and users as a blade steel. ZDP-189 has a much higher maximum hardness, it heat treats just like ATS-34 which makers are very familiar with. This means it is easy to laminate and reduces issues with grindability. Feedback has been very solid on sharpness and durability in general and it easily outcuts S30V on abrasive slicing. So anyone who praise support of CATRA has to realize S30V is significantly inferior in that regard to ZDP-189. There are a bunch of interesting powder stainless steels coming out of Japan now including HSS stainless which should be interesting. Maybe Spyderco could do a sprint run in some of those as well.

-Cliff
 
The only correct answer to the question comes from Hitachi. Guess all you want, they are the only one's who know. Based on their history of literally no contact with the US market, it's a safe bet we won't ever know. Time to move on.
 
Steel companies have various ways to name the steels they invent. Don't look for mysterious ways or logical ways ! One alloy I'm familiar with was a result of a large development project where all the variations were listed on a chart .To name the chosen alloy they looked at the chart -it was at the 17th row and 22nd column - so it's called 17-22 !!!! The numbers have absolutely no relation to composition !
 
You must log in or register to reply here.
Back
Top