Spyderco ZDP-189 HRC?

[Jazz]

I feel that far too many people spend far too much time worrying about blade hardness and edge holding. If a particular steel takes a good edge and holds it for a reasonable time, then it's hard enough. Learn how to sharpen a knife and exercise a little common sense in using it and your life will be far less stressful.


...just my opinion and as always,YMMV.

You have a point, but who are you talking to? A bunch of knife and steel nuts on a forum (a place to talk about these things). We're not worrying - we're curious and wondering. I'd like to know too, since I really like ZDP and find it easy to sharpen on a stone.

[can't freehand]

edit: deleted because irrelevant to main topic.

[PWork]

...just my opinion and as always,YMMV.

You have a point, but who are you talking to? A bunch of knife and steel nuts on a forum (a place to talk about these things). We're not worrying - we're curious and wondering. I'd like to know too, since I really like ZDP and find it easy to sharpen on a stone.

As I said...my opinion and I acknowledge that yours ( or anyone's) may be different.

[Cliff Stamp]

If for example Spyderco estimates 64-65 and a concerned consumers runs his/her own test and records 62 hrc then its not a "complaint", its a real defect.

A hardness test block, outside of the NIST level ones, are +/- 0.5 HRC, the equipment itself has a specific tolerance, the user also adds random error and on top of that, the steel itself will not be exactly the same in regards to hardness.

All of these add up to to create a random spread (to be specific they will RMS add up) and thus it would not be unexpected for a knife which in one exact spot is say 63 HRC could test from 65 to 61 HRC by different people testing different locations on the blade with different testers with difference calibration blocks.

If you add in the fact that not all equipment is actually calibrated, not everyone takes it fully seriously and thus might test on a non-flat, etc. - well the practical reality is that it gets even worse, meaning a larger spread.

In short, saying a knife is 63.5 HRC is like saying a knife weighs 6.015 ounces, it is likely that not all of those numbers are really meaningful.

--
As an aside, the hardness of a knife only tells you one thing, the hardness of a knife. It isn't a sign of a good heat treatment, it is a measure of quality control used on heat treatment because a specific steel ran a specific cycle will come out a specific hardness. If the hardness is off it means either the steel or the cycle was off. There are however multiple ways to hit for example 60 HRC in D2 and they produce very different physical properties (impact toughness, corrosion resistance, and wear resistance). Looking at hardness in steels would be like picking basketball players by height, not everyone 6'4" is the same level of player and not all of them are better than everyone who is a baller and only 5'10" .

[Cliff Stamp]

If it's functional ZDP-189 it will be in that 63-66 hrc range.

What, where does that come from?

First, using an argument that the hardness could tell if it is functional is itself problematic, and second ZDP-189 can be hardened up to 68/70 HRC. I just had two customs made which are in that range, though I didn't have them hardened for a hardness target, but for a micro-structure target, the hardness is a consequence, not the goal.

[Blerv]

If it's functional ZDP-189 it will be in that 63-66 hrc range.

What, where does that come from?

First, using an argument that the hardness could tell if it is functional is itself problematic, and second ZDP-189 can be hardened up to 68/70 HRC. I just had two customs made which are in that range, though I didn't have them hardened for a hardness target, but for a micro-structure target, the hardness is a consequence, not the goal.

Sorry Cliff,

"Functional" was just intended as per the average (aka normal) in Spyderco's production knife range. I can't recall seeing any under 63 hrc and also recall they Mule being around 67 or 68 when it was pulled.

I'm not saying the steel itself isn't capable of more. Especially in a specific role. Just trying to simplify things for sake of the thread.

Also, I intended the apology as a common courtesy. Not a shilly retraction of my stance :).

[Strong-Dog]

I'd love to learn that its run at 66 or 67.

Why is that? Do you have an affinity to use or collect a knife more if it's blade has, as shown above, those very meaningless hardness numbers attached to it?

[SpeedHoles]

I've only been here a short while, yet already its obvious that this forum is as shill-heavy as bladeforums, which is sad to me given that I very much admire Spyderco. I ask a simple question, try to make a neutral point and get my head bit off.

Not sure what a shill is...
But, you asked a question, made a vague stab at possible defect relating to same topic as your question... then receive an answer, ignore it, then proceed to more aggressively assume Spyderco steel is not certified and compare to Benchmade, then receive more detailed answers and read it as a to "get your head bit off"...?
And proceed to generalize this entire forum based on a very small amount of activity in this thread...

I'm pretty unbiased either way, but did not see anything as an attack on you, nor did I see your questions as neutral!

Is this because you disliked the answer?

I too have only been here a short while myself, and same with blade forum, but I have seen the same topic discussed already. Like I mentioned, with answer that was understandable and accepted.


If you really admire Spyderco like you say, why not give them a ring direct and see what the answer is? If their answer is any more likeable or agreeable than what you have read here, then just chalk it up to speaking here to members who may have already seen this question & answer and are not actual customer service representatives! That is all. Not a big deal either way, carry on.

[SpeedHoles]

Double post!

[jabba359]

Spyderco has been rocking out with ZDP-189 for about a decade now. It's seen as fairly "old hat" compared to the weird exotic alloys that sound like secret projects for the government. That doesn't deny the fact that it still is extremely impressive especially when compared to the likes of many competing models with Sanvik and lower carbon Crucible steels.

Ah Blerv, this is why I love reading your posts! :p

[can't freehand]

I've only been here a short while, yet already its obvious that this forum is as shill-heavy as bladeforums, which is sad to me given that I very much admire Spyderco. I ask a simple question, try to make a neutral point and get my head bit off.

Not sure what a shill is...
But, you asked a question, made a vague stab at possible defect relating to same topic as your question... then receive an answer, ignore it, then proceed to more aggressively assume Spyderco steel is not certified and compare to Benchmade, then receive more detailed answers and read it as a to "get your head bit off"...?
And proceed to generalize this entire forum based on a very small amount of activity in this thread...

I'm pretty unbiased either way, but did not see anything as an attack on you, nor did I see your questions as neutral!

Is this because you disliked the answer?

I too have only been here a short while myself, and same with blade forum, but I have seen the same topic discussed already. Like I mentioned, with answer that was understandable and accepted.


If you really admire Spyderco like you say, why not give them a ring direct and see what the answer is? If their answer is any more likeable or agreeable than what you have read here, then just chalk it up to speaking here to members who may have already seen this question & answer and are not actual customer service representatives! That is all. Not a big deal either way, carry on.

That's a very smug, willfully ignorant and self-serving post.

Thanks @ Cliff Stamp for clarification regarding the nature of 'hardness'.

[can't freehand]

I'd love to learn that its run at 66 or 67.

Why is that? Do you have an affinity to use or collect a knife more if it's blade has, as shown above, those very meaningless hardness numbers attached to it?

I don't think Cliff meant hardness is "meaningless", just that its variable, (very) generally speaking.

As for my previous post, I would have been pleased to learn of this high rating as I have noticed 2 things between zdp-189 and S30V and didn't know how to reconcile them. On diamond at least, they're on the same sharpening level but zdp, for me at least, is noticeably harder, brittler, and lasts longer. So I didn't know if zdp was just barely harder and what I was witnessing was the massive carbide amount, or if the hardness has a prime role in edge retention and diamond just cuts that effortlessly. Seems that its a mix of everything, as usual.

BTW, its funny how, once you veer away from the herd you immediately become a hate object, the herd then starts scrutinizing and perverting everything you ever said in an attempt to attack and destroy you by any means, the sin in this case being that I didn't shill hard enough. Guess I'm not a real forum member until I do, eh?

[chuck_roxas45]

BTW, its funny how, once you veer away from the herd you immediately become a hate object, the herd then starts scrutinizing and perverting everything you ever said in an attempt to attack and destroy you by any means, the sin in this case being that I didn't shill hard enough. Guess I'm not a real forum member until I do, eh?

That's just being paranoid. When a lot of people have different experiences from you and you state your opinion, of course they'll make themselves heard. It's not attacking you at all.

[FCM415]

Oh cut the crap. No one is out to "destroy" you. If you think otherwise then leave, and go back to bladeforums or Cliff's forum.

Only person I've ever seen use the term "shill" in a forum is Cliff, there you have something in common. I'm sure you two will hit it off.

If you read Speedhole's post smugly, then you would think it was smug. See how that works?

[FCM415]

That's just being paranoid. When a lot of people have different experiences from you and you state your opinion, of course they'll make themselves heard. It's not attacking you at all.

Welp, his mind is set....Too late. Even your post, he'll take in negatively. It's downhill from here.

[chuck_roxas45]

That's just being paranoid. When a lot of people have different experiences from you and you state your opinion, of course they'll make themselves heard. It's not attacking you at all.

Welp, his mind is set....Too late. Even your post, he'll take in negatively. It's downhill from here.

Good, I love train wrecks. :D

[can't freehand]

If you read Speedhole's post smugly, then you would think it was smug. See how that works?

I literally LOL'ed

[Cliff Stamp]

Not sure what a shill is...

It is when someone has an intentional bais towards promotion but pretends to be unbiased. It is easy to see in threads like these because criticism is responded to very different than praise. Criticism can be condemned while praise is accepted even if the praise has no justification or the justification is obviously invalid. Now to be frank, everyone tends to do that for the things they like, the term shill only tends to be used when it becomes really overt as in criticism sets off personal responses almost instantly.

If you really admire Spyderco like you say, why not give them a ring direct and see what the answer is?

Not everyone lives in the US, not everyone is comfortable talking on the phone, some people also just like to chat about knives and make such topics to discuss the issue generally.

[Cliff Stamp]

I don't think Cliff meant hardness is "meaningless", just that its variable, (very) generally speaking.

Like any measurement it has a meaning, you just need care in understanding that meaning.

For example in general it is true that wear resistance can influence edge retention, but there are actually many different materials tests for wear resistance, there are two fairly large different types of wear (adhesive vs abrasive), and even the various tests will give different results based on the parameters used. Therefore even if you know specifically that one knife scored 5.4 and another 3.2 on a specific wear test, using a specific load, sliding distance, etc. - well it isn't at all obvious that :

-if a different wear test was used that difference would be similar
-if even the parameters were changed in that test the difference would be similar

and thus it really isn't obvious that you could conclude that one steel has better edge retention than another.

As a general rule, it is pretty easy to take a measurement, it is harder to do it really well, it is very hard to figure out from that measurement what some property which depends on something which that measurement is only measuring weakly/indirectly. Imagine for example you have to pick someone for a basketball team and the only thing you can use to evaluate them is their height. Now it should be obvious that you can't really know who is the best basketball players looking at a sheet of 100 names and heights, but height is better than nothing so you choose based on that vs random.

Similar if you are looking for two 1095 knives for example and you want one for skinning and one for chopping wood then it would not be unreasonable to pick out of a hundred knives on paper with no other information than hardness, one at 68 HRC and the other at 56 HRC. Ideally you would want the HT cycle, or even better the material properties - but if all you have is hardness, it is better than random.

As for my previous post, I would have been pleased to learn of this high rating as I have noticed 2 things between zdp-189 and S30V and didn't know how to reconcile them. On diamond at least, they're on the same sharpening level but zdp, for me at least, is noticeably harder, brittler, and lasts longer. So I didn't know if zdp was just barely harder and what I was witnessing was the massive carbide amount, or if the hardness has a prime role in edge retention and diamond just cuts that effortlessly. Seems that its a mix of everything, as usual.

That is an interesting question, how much of it is hardness vs carbide volume, here is the influence of hardness :



Carbide volume is much harder to do as I would need knives with similar micro-structure aside from carbide volume unless I had a large enough sample for a multi-variate comparison.

I would estimate that you are fairly close to correct when that you say you are seeing both, and equal influence is a decent first approximation.

[Ankerson]

I own an Endura in ZDP-189 and was wondering what the actual HRC for Spyderco's ZDP-189 really is.

I've googled the topic and have found claims of the ZDP's HRC being anywhere from 65 to 62, and I haven't found a claim yet that is referenced.

So, do we really know how hard it is? I'd love to learn that its run at 66 or 67.

I have one that tested 65 HRC.

So I would guess it's in the 64-65 range.