Cowry-X question for Sal

rdangerer

rdangerer

Joined
May 26, 2000
Messages
1,922
Sal,

I'm seeing Cowry-X creeping into a few production knives now, mostly Japanese, but also Fallkniven (who probably have theirs built in Japan given VG-10 useage).

You had mentioned, in a thread from waaay back, that Spyderco's testing had found that ZDP-189 had done pretty well in some of your testing.
http://www.bladeforums.com/forums/showthread.php?s=&threadid=120692&highlight=zdp189

And ZDP-189 and Cowry-X are, arguably, somewhat similar, in that they both are made from powder metallurgy process, and both contain a supersaturated 3% carbon and 20% chrome.

Question: In your CATRA testing of Cowry-X and ZDP-189, did you vary hardness of your mules and arrive at some CATRA-derived idea of what the optimum hardness for these steels?

I ask, as some of the Cowry-X that is showing up is run quite hard, Rc64 and Rc67 (!) have been quoted, and while it's in a San Mai sandwich, that still strikes me as too hard to retain enough toughness to survive the silica in CATRA.

Could you comment on the premium you'd have to charge to make one of your products available in either steel, Cowry-X (or Cowry-Y), ZDP-189, just out of curiosity?
 
You guys ask some tough questions. We do not have much data on Cowry and ZDP-189. The pieces that we tested in edge retention were knives, not mules. We didn't make they, they were purchased as complete knives.

The materials are highly prized by Japanese custom makers. Like custom makers all over the world, they ususally are more sensitive to and have a greater interest in new things to play with, so we always pay attention.

ZDP-189 is made by Hitachi. Information is more difficult to obtain. We list specs in our steel charts but this info is IMO, not complete. I think there is more stuff in it, but Hitachi has made some great steels and their metalurgical skill is exceptional, so my questions are somewhat insignificant. They have very exacting heat treating requirements and only a few heat treaters in Japan are authorized to heat treat ZDP-189. I imagine that Hitachi has provided special instruction and meticulous controls.

The knives that we tested in edge retention placed it with S90V. Very impressive. It was in fact Rc-65. Also impressive and no chipping was experienced.

Cowry testing was done with a small knife (too small to be a mule) but we also got impressive edge retention results. No Rc testing was done (a very special custom from a special maker and I didn't want to put marks in the blade). I don't know who makes Cowry or too much about it. We're on a quest for info at this time. We might be able to gather more info.

We're trying to create a piece in ZDP-189, haven't nailed down model, materials or lock style.

Try to remember that the number of people acutally interested in and can afford these "super exotics" are but a few. I would like to make small amounts of knives using these steels, but the quantity required for production is always a question. They are not likely to make any money, but seem to have more value in serving a few "specialized humans", they give us more data and creditability.

sal
 
Thank you. From you saying that ZDP-189 has edge retention like s90V I'm guessing it is slightly better than S30V in that respect. I would ask you how it compares toughness wise, but you seem to want to test these steels more before commenting further. Thanks again Sal.
-Kevin
 
This ZDP-189 by composition looks like stainless bulat (C 2%, Cr 18-20%):
http://ckdforums.com/showthread.php?threadid=15747
May be Hitachy use same trick with special cooling/hardening process? So it is not homogenious as usual steel and has some carbon/chrome microstructure.
Does it looks grained (but this pattern may be visible only after etching)?
Thanks, Vassili.
 
No problemo... that's the least I could do, Sal.

...and I'm always asking myself, "Self... what's the least I can do". ;)


Sidebar:

Fallkniven indicates Cowry-X has this composition:
The edge comprises a powder steel with the following extreme content: C 3%, Cr 20%, Mo 1%, V 0.3% and iron to 100%. Its hardness is no less than 64 HRC!
Click to expand...
http://www.fallkniven.com/nothern/us-nl5.htm

On-line currency calculator indicates that one US Dollar is worth about 8.3644 Swedish Kroner (SEK) right now.

Fallknives lists the retail price of the VG-10 san mai version of the NL5 knife at ==> SEK 2250 = USD $268.99

The Cowry-X model of the NL5 is==> SEK 11,200 = USD $1339.00

So, yeah, the Cowry-X san mai damascus makes this a bit pricey for a production knife (!!!).

:eek: :rolleyes:
 
Regarding Cowry steels, I received the following information from Daido Steel America a few months ago when I made an inquiry:

Here is the information you requested on Cowry-X and Cowry-Y powdered high speed steel alloys developed for knives by Daido Steel. These materials have a very fine and uniform microstructure, distortion due to heat treatment is small and good mirror surfaces can be achieved.

Chemical compositions and hardness are:


Steel C Cr Mo V HRC
COWRY-X 3 20 1 0.3 63-67
COWRY-Y 1.2 14 3 1 61-64

Hope this helps.

Rick
 
You must log in or register to reply here.
Back
Top