M2HS vs ZDP-189

tenman

tenman

Joined
Jun 17, 2006
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This may have been discussed, but thought I'd throw it out there anyway. I recently aquired a couple of Benchmades with M2 steel, and am highly impressed with the edge this stuff will take. I have zero experience with ZDP189, but it is my understanding that it will take an incredible edge as well. I know the two are totally different types (tool steel vs stainless, etc) and are intrinsically different, but for sheer edge taking ability does ZDP189 have the same potential as M2? How does M2HS stack up against the current crop of supersteels in general?

Opinions welcomed:)

chris
 
Whoa now. ZDP-189 is far from being as tough as M2.
Here’s a chart from Hitachi, the makers of ZDP-189.
YSS.gif

As you can see, ZDP-189 isn’t even as tough as 440C. M2 is closer to D-2 and S30V in toughness (a little better actually). ZDP-189 also has a fine grain structure, and because of it’s hardness you can sharpen it at much lower angles than just about any other steel out there, making it a potentially extremely sharp steel.
 
i think its the other way around. zdp has 3%carbon, often more carbon means more brittle. personally i think its kinda hard to break hss (when machining) its fairly tough imo. but zpd i really wouldnt know it just a guess
 
It is not fare to compare ZDP vs M2. To compete M2 Japanese knifmakers have SRS15 or YXR7 as you may see from this picture. ZDP is more like BG42, but better.

Thanks, Vassili.
 
Ok I had it backwards. ZDP isnt as tough but it does hold an edge better than most heat treats of M2. Seems fit for most non-choppers.
 
The main benefit of M2 is that it offers a very high edge stability given its wear resistance. Thus it is designed to work best when ran very hard in very acute profiles. Benchmade however doesn't temper it optimally as a cutting tool but more as a utility tool thus it often gets praise for toughness when compared to stainless steels. A comparison of the two would be very dependent on the edge profiles due to issues of edge stability.

-Cliff
 
Okay, what steels other than SRS15 or YXR7 can meet the M2 as tempered by Benchmade, but at the higher hardness level of 65HRc?

Any that would lend themselves to mass production at an affordable cost to the user (approx. same price as M2's street price)?
 
hss such as m2 (6% w )or t1(18% ) are expensive in industrial cutting use ,but is compaing cheap in knife making beause a knife costs about usd 40-100,only use little portion of steel for the blade .
for stainless steel with hss hardness (about 64 ) are expensive such as yxr7 ,supergold powder steel or zdp189.those steel are mainly made by japanese .

as an enduser or collect ,those steels knives are wothy to collect or practical use .the most useful but cheap one is u2 of fallkniven while expensive &tough one are rockstead which is extrmely expensive .
one of rockstead straight knife,''hunter'' or ''sin '' is sold about usd 1500,its size similar to fallkniven s1.
 
Has anybody here ever seen or used one of these "rockstead" YXR7 "Worlds toughest knives"? These are big claims and some custom makers have made knives out of every possible steel you can think of, including HSS like T1, etc.

Of course it would be fun to play with one and I sure wouldn't turn one down. Joe.
 
A lot of people make such claims, according to Cold Steel they are the "world's strongest, sharpest knives", Reeve has the most "optimal materals/performance", etc. . With Rockstead, as with most makers, they are defining terms from the steels which they have used and not all steels, thus YXR7 is tough compared to ZDP-189. Interesting grind though :

http://www.rockstead.jp/en/rockstead_2.html

Does that look familiar to anyone?

-Cliff
 
I think you really have to look at this a bit more closely than just comparing steels. In principle, I think it is not unreasonable to compare M2 and ZDP-189 even though one is a stainless steel and the other one is not, one is a powder steel and the other is not.

Both steels can be run very hard, meaning that retain edge stability at high hardness, and both contain large amounts of carbides, even though ZDP-189 certainly more than M2 and both are very wear resistant. At high hardnesses neither are overly tough.

But the problem is, really, that other than with custom makers you will not find a company that runs them at comparable hardnesses and it is really not very sensible to compare M2 @60 Rc with ZDP-189 @ 65 Rc. Finally, the grind needs to be optimized for a given steel. One of the reasons that the Caly Jr. got such raving reviews was because they got pretty much everything right on this one. They (Spyderco) selected a small, high performance cutter gave it a steel that isn't that tough but has high edgestability and gave it a very thin profile (sub 0.020" edge thickness) that fit well with the type of knife and the steel selected and what you get is a slicer that is pretty much unsurpassed among production knives. If you compare that against a hard use knife with a very oblique geometry in M2 (this is meant in general, not in particular to the 710, even though the 710 is a much more rugged piece than the Caly Jr) it won't tell you anything about the steel.
 
HoB said:
One of the reasons that the Caly Jr. got such raving reviews was because they got pretty much everything right on this one. They (Spyderco) selected a small, high performance cutter gave it a steel that isn't that tough but has high edgestability and gave it a very thin profile (sub 0.020" edge thickness) that fit well with the type of knife and the steel selected and what you get is a slicer that is pretty much unsurpassed among production knives.
Click to expand...

Exactly right, the steel and knife were near ideal for each other. That is such a critical point which is constantly misunderstood. There are not high performance steels, there are however combination of steel+heat treatment+geometry which are high performance. If any of that combination isn't optomized considering the others then the performance can be scuttled. I think it is also reasonable to compare the steels since there are knives of similar promotion in each.

-Cliff
 
All,
Intersting and informative responses, and they are appreciated. Based on what I am reading, for the typical end-user cutting normal, everday stuff (cardboard, rope, etc) both M2 and ZDP189 can take fairly narrow edge profiles yet maintain blade and edge integrity; I also take it that zdp can indeed take a screaming sharp edge that is comparable to M2HS and hold it reasonably well. One thing I have noticed about M2- though it is a tough steel it really sharpens nicely with very little burr to mess with. I am also gaining a better understanding of what it means to match/maximize edge profile angle with the steel's capabilities in relation to what you will expect out of it on a routine, daily basis.

Exactly right, the steel and knife were near ideal for each other. That is such a critical point which is constantly misunderstood. There are not high performance steels, there are however combination of steel+heat treatment+geometry which are high performance. If any of that combination isn't optomized considering the others then the performance can be scuttled. I think it is also reasonable to compare the steels since there are knives of similar promotion in each.
Click to expand...

I really like this concept, it is kind of analagous to sports cars- you cant just cram a hi-po engine into just any automobile frame and expect 'high performance'. It takes the entire package to make it work efficiently and correctly. This is where, as HoB pointed out with the Caly Jr., all aspects of the knife such as blade length, shape, and handle come into play.

Hypothetical: if a Caly Jr. were made using M2HS, would the performance be similar to the same knife in ZDP?

The more I visit this forum, the more I learn.

thanks,
chris
 
tenman said:
I really like this concept, it is kind of analagous to sports cars- you cant just cram a hi-po engine into just any automobile frame and expect 'high performance'.
Click to expand...

Yes and the "high performance" parts are specific to the type of the car. It is the same with knives, not only do all the parts have to work well together but they have to suit the demands on the knife.

Hypothetical: if a Caly Jr. were made using M2HS, would the performance be similar to the same knife in ZDP?
Click to expand...

According to the work of Landes, I would expect M2 to be superior in terms of edge stability, long term slicing I would expect ZDP-189 to dominate due to the extreme carbide fraction and both are of similar hardness. I have been meaning to do some work myself looking at his ideas as I have steels in both types, 1095, O1, M2 all hardened for maximal edge stability. I have intended to do it for some time as the same basic ideas were noted by Johnston some years ago. Landes however studied the subject in extreme detail measuring the edge stability of steels to great precision under controlled conditions.

-Cliff
 
Cliff Stamp said:
Originally Posted by Cliff Stamp

http://www.rockstead.jp/en/rockstead_2.html

Does that look familiar to anyone?
Click to expand...

Dog of War said:
Sure does - Busse zero edge.
Click to expand...

Well this is handreds years old Japanese HAMAGURI-HA - translated from Japanese shell-like cross-section. Katanas with this grind in ancient times usually show best results in brutal TEMESHIGIRI...

And Busse also recently invented AK-47...

Thanks, Vassili.
 
The grind is convex on one side with a secondary flat bevel on the other side towards the edge, I thought a katana had a symmetric convex profile?

-Cliff
 
Cliff Stamp said:
The grind is convex on one side with a secondary flat bevel on the other side towards the edge, I thought a katana had a symmetric convex profile?

-Cliff
Click to expand...
Yes, this profile is for champion katanas used for TEMESHIGIRI contests.

Thanks, Vassili.
 
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