Spyderco ZDP-189 HRC?

[can't freehand]

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.

[Strong-Dog]

Are you waiting to use your knife until you find out how hard the blade is? Has it chipped? Have you had to sharpen it yet?

What's the point of having a harder steel if it isn't getting used?

[can't freehand]

Are you waiting to use your knife until you find out how hard the blade is? Has it chipped? Have you had to sharpen it yet?

What's the point of having a harder steel if it isn't getting used?

Got it for Christmas. I use DMT to sharpen my knives, and it hasn't been any harder to sharpen than S30V, which I find to be trivial to sharpen on diamond. The ZDP has chipped slightly but I was using it to pry stuff, not simply cutting.

Are you able to detect the HRC of a steel just by using it?

[Strong-Dog]

Are you waiting to use your knife until you find out how hard the blade is? Has it chipped? Have you had to sharpen it yet?

What's the point of having a harder steel if it isn't getting used?

Got it for Christmas. I use DMT to sharpen my knives, and it hasn't been any harder to sharpen than S30V, which I find to be trivial to sharpen on diamond. The ZDP has chipped slightly but I was using it to pry stuff, not simply cutting.

Are you able to detect the HRC of a steel just by using it?

Not so much detect the exact HRC number, but with experience in use relative to other steels and hardnesses, then yes. To a certain extent.

[can't freehand]

Ok....so, has Spyderco ever officially stated the zdp HRC?

[Strong-Dog]

Not entirely sure. I think it's on the lower side of 62-65 however

[bh49]

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

To the best of my knowledge the only way to know how hard is the blade on your knife is to test it.
Keep in the mind that Endura is production knife and blades ate harden in batches. Any process has variation. If you take a dozen of blades from one batch, you will see some variation in hardness between blades. in addition to that will be variation from one batch to another batch. And in addition to that, there is accuracy of measurement. Most of the hardness testers are +/- 1 point. There are some with accuracy +/- .1. But they are quite expensive and require test blocks, which accurate to +/- .1. Ridiculous or not, but once I visited metrology lab of one huge international corporation. Their tester had +/-.1 accuracy, but blocks +/-.5 :confused:

[bh49]

Ok....so, has Spyderco ever officially stated the zdp HRC?

Spyderco do not officially certify hardness on any of their blades. It make sense just to avoid complains.

[can't freehand]

Ok....so, has Spyderco ever officially stated the zdp HRC?

Spyderco do not officially certify hardness on any of their blades. It make sense just to avoid complains.

I guess from a company standpoint but not for a consumer. 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.

I gotta say, I'm pretty surprised a hardcore steel company like Spyderco doesn't certify hardness. Does Benchmade experience great difficulty for their hardness ratings?

[bh49]

I guess from a company standpoint but not for a consumer. 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

This is exactly what I am talking about: there are some consumers with unreasonable expectations. Spyderco or any other company can target hardness at 64-65 or 59/60. Which doesn't mean that each blade will be in that range. Production blades are heat-treated in large batches, so there is variation in hardness in the same batch. I am Quality Assurance Manager for contract manufacturer. My company has four suppliers, who heat-treat material for us. With any of them standard range for hardness specification is four points. If we want less, than price double, triple and quadruple.
Next, I hope that you are aware that HRc reading is not most important. Heat-treater can completely mess-up micro-structure but achieve desired HRc.
IMHO when companies announcing high HRc number this is nothing more that sales trick. I hope that you read my previous post completely and realized that if you test the same blade using two different calibrated testers you can get two reading different by two points. So if Spyderco measured 64 using their tester, you can find it at 62 or 66.
I am Spyderco knives user. Currently I have 10 Spydercos in use. I have no problem with performance. Should I worry about hardness of each blade? I have calibrated hardness tester next to my office. I used it only once. Out of curiosity to see hardness on The Forum native5, mostly because people on the forum was asking.
Do not make life more complicated than it really is. If you satisfied with your Endura performance, enjoy it. If not sent it to Spyderco W&R and they will find out, if anything is wrong.

Does Benchmade experience great difficulty for their hardness ratings?

Don't you think that this is the wrong forum to ask this question? If you really interesting in this, you need to go to BM Forum.

[chuck_roxas45]

Wow, so now a blade that is around 62 rc is defective?

[Ray Allen]

The Endura ZDP-189 Jim Ankerson used in his epic test thread over on BF tested at HRC 65 per his report on page one. That at least gives one point of reference.
Best...

[bh49]

Wow, so now a blade that is around 62 rc is defective?

I missed you Chuck. Where the **** you have been? :) :) :)

[Blerv]

I guess from a company standpoint but not for a consumer. 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.

I gotta say, I'm pretty surprised a hardcore steel company like Spyderco doesn't certify hardness. Does Benchmade experience great difficulty for their hardness ratings?

What makes you think Benchmade certified HRC besides giving a general range of where it should be? The only people I've heard of that happening for are custom knifes from folks like Phil Wilson. Even those particular examples, as I understand, have ranges of hardness depending on where it is tested on the blade.

I think you are highly overestimating the average consumer. In fact, most of the most empathic knife testers who know the metallurgy are unlikely to consider something like like ZDP-189 in 62 a defect. Especially since they would need to cut up yard and yards of cardboard in a controlled test with a similar knife at 65 hrc just to tell the difference. There is a bigger variance of dyno horsepower amongst exotic sports cars and none of those would be deemed "slow".

It has almost 30 percent chromium
It has about 3 percent carbon

It's hard as heck (no matter what it HRC's at) meaning compression strength isn't the issue but if anything edge stability/embrittlement is. Especially at thin cross sections with normal people using it for normal tasks.

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.

[SpeedHoles]

Great explanation bh49.
Makes complete sense.
I have a friend who works at AAM and he has access to Rockwell tester, and I've been tempted to ask him to test a blade just to say I have for fun, but honestly it will have little, if any, impact on my actual experience (aside the fact I know very little of how it actually effects things!), beyond simply knowing a number in my head.


I think I have seen where Sal mentioned dislike for posting these numbers here for those similar reasons. Do not remember what thread it was in though.

[can't freehand]

I guess from a company standpoint but not for a consumer. 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

This is exactly what I am talking about: there are some consumers with unreasonable expectations. Spyderco or any other company can target hardness at 64-65 or 59/60. Which doesn't mean that each blade will be in that range. .

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.

[PWork]

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.

[bluntcut]

I did 3 hardness reading on my cf stretch & 1 read on dragonfly zdp189 => hrc around 63. zdp189 has ridiculously high carbide volume, good thing Spyderco lowered hardness from initial launch of 66 to ~63, otherwise the blade would be too brittle for EDC. I thinned out my stretch and sharpened my stretch around 20dps (40* inclusive), very sharp and sturdy. IMO, 66rc probably ok for kitchen knives with 10/13+dps bevels.

[kennethsime]

64. For what it's worth, all the other answers above are better than mine.

[Blerv]

Edit: deleted to avoid shill on troll mayhem